Source: UNIVERSITY OF GEORGIA submitted to NRP
DEVELOPMENT OF PEANUT LINES WITH SUPERIOR PEST RESISTANCE USING WILD SPECIES AND MARKER-ASSISTED BREEDING
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1015669
Grant No.
2018-67013-28139
Cumulative Award Amt.
$445,226.00
Proposal No.
2017-07760
Multistate No.
(N/A)
Project Start Date
May 1, 2018
Project End Date
Apr 30, 2022
Grant Year
2018
Program Code
[A1141]- Plant Health and Production and Plant Products: Plant Breeding for Agricultural Production
Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
CTR APPLIED GEN TECH - COLLEGE
Non Technical Summary
Peanut is a nutritious legume, widely grown in countries of tropical and sub-tropical climate. The U.S. is the fourth largest producer, and over 85% of the production is used in edible products, such as roasted peanuts, peanut butter and peanut candy; the remainder is crushed to extract oil. On average, each American consumes more than 6 pounds of peanut products each year, worth more than $2 billion at the retail level. The peanut crop in the U.S., however, is plagued by pests, such as leaf diseases caused by fungi and root diseases caused by worms. These pests decrease or impede productivity, and, because no natural resistances are found in peanut, crops need many chemical applications each season. This makes peanut production costly and environmentally unfriendly. New ways to make peanut resistant are needed, so costs are reduced, and less harmful agrochemicals are used.In this project, we will make use of peanut wild relatives, which are plants that occur naturally in South America. In the 60's, 70's and 80's, hundreds of populations were collected from the wild and deposited in the USDA seed bank. Several studies show that these species carry resistance to pests and diseases that affect the peanut crop. However, because their genetic characteristics make them difficult to cross with peanut, they have mostly not been used for agricultural improvement. So, they are an invaluable almost untapped source of resistance to the peanut crop and, therefore, revenue to the peanut industry. Here we are doing systematic analyses of these species, selecting the ones with the most valuable traits (disease/pest resistances), making them compatible with peanut, crossing them with high producing, but susceptible elite lines and making successive selections. The goal is to combine the good agronomical traits of the elite peanut lines with the high resistance of the wild species. This process will be aided by DNA-based markers, which makes plant selection more efficient. The use of wild species has been a game changer for other crop species, and we expect the same for peanut.
Animal Health Component
30%
Research Effort Categories
Basic
20%
Applied
30%
Developmental
50%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20118301081100%
Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1830 - Peanut;

Field Of Science
1081 - Breeding;
Goals / Objectives
Peanut is an expensive, high agrochemical input crop. The main goal of this project is to make a major impact on peanut cultivation in the U.S. by reducing farmers' agrochemicals costs for control of pests and diseases and increase production. We propose to accomplish this via the introgression of high value chromosomal segments from wild species that confer strong pest and disease resistances into peanut using crossing schemes aided by genome information and genotyping. We also aim to create publically available strategic resources (hybrids, populations, markers) to facilitate the introduction of new wild genes into peanut breeding programs over the longer term, beyond the completion of this project.The project has one main goal, divided in three objectives (short-, medium, and long-term), with different milestones that can be accomplished within the time frame of this project.Objective 1 - short-term - Using introgression lines, transfer the three well-defined chromosome segments of the wild species A. cardenasii (that confer resistance to LLS and rust) into U.S. elite high oleic peanut cultivars and breeding lines. This will generate advanced agronomically-adapted, resistant lines.Objective 2 - medium-term - Introgress chromosome segments of peanut wild relative A. stenosperma (that confer resistance against Late Leaf Spot, LLS and Root Knot Nematode, RKN) from newly synthesized allotetraploids. This will generate genetically characterized, resistant pre-breeding lines that predominantly have the genetic background of cultivated peanut.Objective 3 - long-term - In order to create a resource of wild genes for peanut breeders and for the general scientific community, we will produce new peanut-compatible induced allotetraploids using wild diploid species that confer resistance to various other pests and diseases and widen the genetic base of peanut.
Project Methods
For all goals, obtaining lines with high levels of resistance to LLS and RKN will indicate success. We will use molecular markers (e.g. Affy Axiom SNP array, KASP markers) to confirm hybrid plants and introgression segments in ensuring backcross generations. In addition, we will phenotype plants for the target traits and, where feasible, use trait-associated markers to confirm the presence and transmission of desired traits. Advanced populations will be analysed in the field for agronomically important traits, such as seed number, plant architecture and multiple resistances. Germplasm will be shared with those that request materials. Publications will be used to disseminate data and many data sets (e.g. mapping and phenotyping data) will be shared via the USDA-ARS supported peanut genomics portal peanutbase.org.The measure of success for each objective will be as follows:Objective 1 (short-term): number of advanced (BC1F4-F5) agronomically adapted A. cardenasii-containing lines; their level of resistance to LLS, productivity and plant architecture as compared to the recurrent peanut parent.Objective 2 (medium-term): number of genetically characterized BC3 A. stenosperma-containing lines that predominantly have the genetic background of cultivated peanut; their level of resistance to Late Leaf Spot and Root-knot nematode. Evaluation will be done in greenhouse and in the field.Objective 3 (long-term): new peanut-compatible, induced allotetraploids, with resistance to Late Leaf Spot and Root-knot nematode. Evaluations will be done in greenhouse to assess the transmission of resistances and levels of resistance.

Progress 05/01/18 to 04/30/22

Outputs
Target Audience:During this project, three main audiences were targeted and reached by our efforts: Research scientists and breeders - a number of joint activities to facilitate discussions were conducted in UGA Athens and partners' labs. Discussions centered on use of new sources of disease resistance from wild species in combination with DNA markers, phenotyping and genetic analysis, breeding priorities, release strategies. Students -mentoring of students focused on experimental design, critical thinking, and practical skills. Students in both the Athens and Tifton campuses were involved. Industry - several meetings were had with members of the peanut industry (ie. Shellers, manufacturers and growers). There has been interest in adopting lines for use in field with little or no use of pesticides; interest from shellers on pod size/shape; interest from manufacturers on quality traits that wild species can bring to the table. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided opportunity for the training of graduate and undergraduate students. Six UGA undergraduate students have done laboratory and greenhouse activities related to the objectives of the project, as student workers. Two MS students developed their thesis on the activities of Objective 1 (Samuelle Lamon and Kate Costello). Samuele is now doing a PhD under D Bertioli's supervision. Two PhD students developed her thesis on activities of Objective 2 (Carolina Ballen and Chandler Levinson). They all had senior author papers and were co-authors on various other publications. One MS and six other PhD students were also involved in the activities of this project: Alexi Dong, Maricel Gonzales, Wendy Tsai and Namrata Marjahan (S Bertioli, UGA, Athens campus), Emile Barnes and Dan Matusinek (D Bertioli). The students had the chance to attend the following conferences: 51st, 52nd, 53rdand 54thAnnual Meetings of the American Peanut Research and Education Society (several students); Advances in Arachis through Genomics and Biotechnology AAGB Nov 12-16, 2018. Saly Senegal (C Ballen), AAGB China (C Levinson);21stAnnual Meeting of the National Association of Plant BreedersChina (C Levinson) UC Davis Plant Science Symposium. Davis, CA., 2018 (C Ballen). CROPS Huntsville, AL (C Ballen, S Lamon, N Marjaran). Annual Meeting of the Georgia Association of Plant Pathologist (M Gonzales, K Costello and W Tsai) and Pest Management Council of the Philippines Annual Meeting 2019 (M Gonzales), Annual Meeting of the Georgia Association of Plant Pathologist (M Gonzales and W Tsai, A Dong), Plant Health 2020 Online (M Gonzales),Plant and Animal Genome(C Ballen and S Lamon). Laboratory and department seminars are regularly given by the students. How have the results been disseminated to communities of interest?The information obtained in this project was disseminated in various communications: 65 poster and oral presentations in different conferences and seven different countries (USA, Uganda, Philippines, France, Canada, China and Senegal). We estimate that over 4,500 people were reached by these presentations. The conferences were attended by a range of audiences, including graduate and undergraduate students, peanut extensionists, peanut research scientists, legume research scientists, university professors, members of the peanut industry, stakeholders and governing bodies. Seven germplasms were released in 2021, and six are in the process of being released in 2022. Their seeds are deposited in public repositories and are available to any breeder or researcher. Additionally, 17 manuscripts were published in refereed journals, two are under review and two have been accepted for publication. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1 At the start of this project, we had hybrids between the wild derived peanut cultivar TifNV-High O/L (high yielding, RKN resistance) and IAC 322 (resistant to LLS). KASP markers for the segments were designed and tested. Real hybrids were selected using these markers and hybrid seed grown to produce F2s. Progeny with all three segments were used in backcrosses.BC2F3families were planted ontrials underfungicide sprayed, and non-sprayed, showing highresistance to LLS. Pyramiding LLS + ELS +RKN LLS resistance segments were transferred to the cultivar Bailey, themost grown in NC.CrossesBailey x IAC321 (322 sister line) generated 31BC1lines.Hybrids were crossed with Bailey and withTifNV-High O/L.Hybrids had slower lesion development and reduced sporulation rate to both ELS and LLS than the parents. Some lines were sent to Haiti, where fields have high and consistent rust pressure and were more resistant to rust and LLS than the locally grown cultivars. Advanced lines have excellent plant, pod and seed configuration. Objective 2 This work started with an F2population derived from Runner-886 and BatSten. 14 advanced lines have been field tested and seven produced more than elite cultivars. Genetic map and QTL identification.Two large-effect QTL for all three measurements of resistance to RKN were detected at the bottom of LG A02 and A09. 22 KASP markers were developed to detect the introgressed segment areassociated with nematode resistance. Four superior F2lines were selected based on better vigor, greater biomass, good agronomic traits, LLS and RKN resistance; and presence of A02 and A09 QTLs. BC1lines were confirmed using KASP markers linked to the segments on LG A02 and A09 and were backcrossed, producing 10 BC2s. Creation of advanced lines The BC2s were selected and genotyped using the 'SNP array v.02, evaluated for plant architecture, seed size and resistance to LLS and RKN. AllA. hypogaeacultivars were susceptible, but the BatSten1 and most BC2linesassayed were resistant.Twenty-one BC2lines were backcrossed with peanut.BC3F3segregating lines from sixBC3F1families were evaluated for RKN resistance to further validate A02 and A09 QTLs. 84BC3F2lineswere selected basedon high cultivar genome recovery and superior field performance of theBC3F2generation. Two hundred and forty-nine BC3F2lines were field evaluated for agronomic traits in the absence of nematode pressure or disease control, architecture, total pod weight, 100-seed weight, pod constriction, pod reticulation, % of double pods; and for field resistance to leaf spots and TSWV. Over 80 lines had very high productivity, with pods of similar configuration and seeds of comparable size, and comparable yield to elite cultivars. Lines were evaluated in Tifton, GA with moderate levels of RKN pressure (Fig 2.5). Greenhouse tests confirmed the nematode resistance in a selection of the best performing lines (BC3F3). With these results, the initial aim of incorporating two new sources of RKN into elite peanut genetic background is complete. Objective 3 Allotetraploid production During all four years, new crosses were made to create diploid hybrids using wild Arachis accessions; existing diploid hybrids were treated with colchicine to duplicate genome; new allotetraploids were obtained. Hybridity of diploids was confirmed by pollen staining or using SNP markers developed here. Genome duplication is confirmed by pollen staining and /or chromosome count. Pods of allotetraploids are single seeded and seeds are small, compared to cultivated peanut. In total, 21 new allotetraploids and eight new diploid hybrids were obtained. Development of markers distinguish A- and B/K-genomes were designed to span the entire genome andcan be used to confirm diploid hybridity. distinguish cultivated and wild peanut. Testing for diseases-IpaDur3, IpaCor2,ValSten1and MagSten2 were field tested showing immunity to leafspots and partial resistance to TSWV.Several allotetraploids were also confirmed to be resistant to ELS, LLS, rust, and one (ValSten1)had partial resistance to stem rot, as observed under greenhouse or in vitro assays. Crosses with peanut -IpaDur3, IpaCor2, ValSten1, MagDio1, IpaCor2, MagSten2, MagSten3 andMagCar1were crossed with peanut elite lines. Over 3000 backcrossed lines have been created. Germplasm release -Five allotetraploids were released as germplasm and seeds were deposited in the National Plant Germplasm System. In 2022, six are being released. Keyoutcomes objective 1(1) development of DNA markers to detectA. cardenasii-derived chromosome segments that confer LLS resistance and their use to introgress these segments into elite peanut lines (2)Development of BC5advanced high oleic lines with combined resistance to LLS, ELS and RKN(3)Release of two advanced lines highly resistant to LLS. objective 2.(1) identification of 2 new sources of resistance to RKN (2) development of markers within these segments (3) Development of lines with high resistance to RKN, ELS, LLS, high yield, good seed and pod configuration. objective3. (1) production of 30 new diploid hybrids, 21 tetraploidized. (2) production of over 3000 families of BC1to BC4introgressed lines. Several allotetraploids and advanced lines were resistant to LLS and moderately resistant to TSWV under field conditions. In vitro, there was resistance to LLS, ELS, rust, RKN and white mold. (3) development of markers that distinguish A from B/K genomes; and distinguish all wild from all cultivated peanut (4) 5allotetraploids released as germplasm. These materials are available to all breeders and the scientific community and can serve as foundation for breeding programs in years to come. This will broaden the genetic basis of the peanut crop and increase the overall resistance and resilience of new cultivars. All objectives were accomplished with success.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Barnes, E.C., Leal-Bertioli, S.C.M. & Bertioli, D.J. 2022. The Construction of a Chromosome Segment Substitution Line Population for the Systematic Introduction of Wild Alleles from Arachis batizocoi and Arachis stenosperma into Cultivated Peanut.  54th Annual Meeting of the American Peanut Research and Education Society. July 12-14, Dallas TX, USA. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Bertioli DJ. 2022. Beyond the Peanut Genome.  54th Annual Meeting of the American Peanut Research and Education Society. July 12-14, Dallas TX, USA. (Invited Oral presentation - opening session)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2022 Citation: Dong AK, Hopkins M, Leal-Bertioli, SCM, Bertioli, DJ. 2022 Identifying resistance to early leaf spot (Passalora arachidicola) in nascent allotetraploids cross-compatible with cultivated peanut - Annual Plant Health Meeting of the American Phytopathological Society. August 6-10, Pittsburgh PA. (Poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonzales, MC, Kemerait, R, Culbreath, A, Bertioli, DJ, Leal-Bertioli, SCM. Pyramiding Resistance to Early and Late Leaf Spot in Peanut with Alleles from the Wild Species Arachis cardenasii. 2022 American Pythopathological Society- Southern Division Meeting. March 7-10, 2022, in person. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonzales, MC, Kemerait, R, Culbreath, A, Bertioli, DJ, Leal-Bertioli, SCM. Pyramiding Alleles from the Wild Species Arachis cardenasii Improves Resistance to Early and Late leafspot. May 23-25, 2022, in person. Georgia Association of Plant Pathologists 2022. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Gonzales, MC, Kemerait, R, Culbreath, A, Andres, A, Dunne, J, Bertioli, DJ, Leal-Bertioli, SCM. 2022. Pyramiding Alleles from the Wild Crop Relative Arachis cardenasii Increases Resistance to Early and Late Leaf Spot in Peanut.  54th Annual Meeting of the American Peanut Research and Education Society. July 12-14. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Hopkins MS, Leverett J, Leal-Bertioli S, Araujo ACG, Bertioli D. 2022. Development and characterization of interspecific peanut hybrids for the enhancement of genetic diversity within cultivated peanut and deposition into germplasm banks. 54th Annual Meeting of the American Peanut Research and Education Society. July 12-14, Dallas TX, USA. (Poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Lamon S, Dos Santos JF, De Godoy IJ, Moretzsohn MDC, Leal-Bertioli S, Bertioli DJ. 2022. Estimation of Double Reduction in Segmental Allotetraploid Peanut - Plant and Animal Genome XXIX; 2022 January 8-12; online. (Poster)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Lamon S, Leal-Bertioli S, Bertioli DJ. 2022 Reinventing Peanut: Origin, Evolution and Domestication of [Arachis ipa�nsis x Arachis duranensis]4x neopolyploids - CROPS; 2022 June 13-16; Huntsville, AL. (Poster
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Lamon S. Leal-Bertioli, S.C.M. & Bertioli, D.J. 2022. Reinventing Peanut: Origin, Evolution and Domestication of [[Arachis ipa�nsis x Arachis duranensis]4x neopolyploids neopolyploids. 54th Annual Meeting of the American Peanut Research and Education Society. July 12-14, Dallas TX, USA. (Poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Lamon S, J Santos JF, Godoy IJ, Custodio AR, Moretzsohn MC, Leal-Bertioli S. Bertioli DJ. 2022. Estimation of double reduction in segmental allotetraploid peanut.  54th Annual Meeting of the American Peanut Research and Education Society. July 12-14. Dallas TX, USA (Poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Leal-Bertioli SCM. 2022. Addressing the limitations of peanut resistance due to narrow genetic diversity.  54th Annual Meeting of the American Peanut Research and Education Society. July 12-14. Dallas TX, USA (Invited Oral Presentation, Sustainability Symposium)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2022 Citation: Gonzales, MC, Kemerait, R, Culbreath, A, Bertioli, DJ, Leal-Bertioli, SCM. Evaluation of Leaf Spot Resistance in Peanut with Alleles from the Wild Species Arachis cardenasii. Plant Health 2022, The American Phytopathological Society. August 6-10, 2022, in person. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Maharjan N, Ballen-Taborda, C, Hopkins M, Bertioli, DJ, Leal-Bertioli, SCM. 2022. Discovering wild introgressions affecting pod constriction in peanut. - 4th Annual Crops Conference. June 13-16. Poster Presentation
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Matusinec D, Costello KM, de Blas FJ, Leal-Bertioli SCM, Bertioli DJ. Helping wild Arachis taxonomy and introgression using SNP markers  54th Annual Meeting of the American Peanut Research and Education Society. July 9-11, virtual. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Tsai, Y-C, Chu, Y., Ozias-Akins, P., Brenneman, T., Bertioli, DJ., and Leal-Bertioli, SCM. 2022. Using wild peanut to improve stem rot resistance in cultivated peanut resistance identification in allotetraploid peanuts.  Annual meeting of the 67th Annual Conference on Soilborne Plant Pathogens. Mar. 23-24, virtual. (Oral presentation)
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Ball�n-Taborda C, Chu Y, Ozias-Akins P, Holbrook CC, Timper P, Jackson SA, Bertioli DJ, Leal-Bertioli SCM. 2022. Development and genetic characterization of peanut advanced backcross lines that incorporate root-knot nematode resistance from Arachis stenosperma. Frontiers in Plant Science doi: 10.3389/fpls.2021.785358.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Holbrook CC, P. Ozias-Akins, Y. Chu, S. Lamon, D.J. Bertioli, S.C.M. Leal-Bertioli, A.K. Culbreath, and I.J. Godoy. 2022. Registration of TifGP-3 and TifGP-4 peanut germplasm lines. J. Plant Registrations. 16:120-123.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Gonzales M, Kemerait Jr. R, Bertioli D, Leal-Bertioli S. 2022. Wild-derived neotetraploids show strong resistance to peanut Early and Late Leaf Spots. Plant Disease. Jun 24. doi: 10.1094/PDIS-03-22-0721-RE. Epub ahead of print.
  • Type: Journal Articles Status: Accepted Year Published: 2022 Citation: Godoy IJ, Santos, JF, Moretzsohn, MC, Moraes, ARA, Michelotto, MD, Bolonhezi, D, Nakayama, FT, Freitas, RS, Bertioli DJ, Leal-Bertioli SCM. 2022. IAC SEMPRE VERDE: a wild-derived peanut cultivar highly resistant to foliar diseases. Crop Breeding and Applied Biotechnology. In press.
  • Type: Theses/Dissertations Status: Published Year Published: 2022 Citation: Costello, Kathleen. 2022. A new source of peanut rust (Puccinia arachidis) resistance from wild peanut species Arachis batizocoi. MS degree. Department of Plant Pathology. UGA.


Progress 05/01/20 to 04/30/21

Outputs
Target Audience:In this third year, two main audiences were targeted and reached by our efforts: Research scientists and breeders - a number of joint activities to facilitate discussions were conducted in UGA Athens and partners' labs. Discussions centered on use of new sources of disease resistance from wild species in combination with DNA markers, phenotyping and genetic analysis. Students -mentoring of students focused on experimental design, critical thinking, and practical skills. Students in both the Athens and Tifton campuses were involved. The information obtained in the third year of this project was disseminated in various communications: seven posters and oral presentations in two different domestic conferences. The conferences were attended by a diverse audience, including graduate and undergraduate students, peanut farmers, extensionists, research scientists, legume research scientists, university professors, members of the peanut industry, stakeholders and governing bodies.Thirteen manuscripts are in different stages of publication in refereed scientificjournals. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project is providing opportunity for the training of graduate and undergraduate students. One PhD student has finalized her theses successfully, Chandler Maddox, from the University of Georgia, and had senior author publications. Now, Samuele Lamon is a PhD student at UGA and Carolina Ballen is a post-doctoral associate. Three other PhD and one Master studentare also involved in the activities of this project: Emile Barnes, Maricel Gonzales, Wendy Tsai (PhD) and Kate Costello (MS). The students attended the following conferences: Annual Meeting of the Georgia Association of Plant Pathologist (M Gonzales and W Tsai) (in person), 52th Annual Meeting of the American Peanut Research and Education Society (M Gonzales, W Tsai, C Ballen, C Maddox), 22nd Annual Meeting of the National Association of Plant Breeders (C Levinson) and Plant Health 2020 Online (M Gonzales). Laboratory and department seminars are regularly given by the students. How have the results been disseminated to communities of interest?The information obtained here was disseminated in various communications: two posters and five oral presentations in different domestic conferences. Due to travel and gathering restrictions, all conferences were done virtually. Mostly, the conferences were attended by graduate and undergraduate students, extensionists, research scientists, legume research scientists, university professors, members of the peanut industry, stakeholders and governing bodies. Additionally, six manuscripts were published in refereed journals, four are under review and three have been accepted for publication. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? IMPACT Peanut is an expensive, high agrochemical input crop. Over 150 dollars are spent per acre each year to control pests and diseases. Our main goal is to make a major impact on peanut cultivation in the U.S. by reducing farmers' agrochemicals costs and increasing production. This will provide reduction of up to 20% of production costs. The use of wild relatives has been a game changer for other crop species, and we expect the same for peanut. We are on our way to accomplish this by crossing high yielding cultivars with lines that contain high value segments of wild relatives confering strong resistances aided by advanced tools based on DNA sequence information. Over 2500 crosses were made, new hybrids produced, new peanut-compatible allotetraploids were obtained, over 1000 breeding lines containing resistance to RKN, and LLS resistance were obtained. Although not in the objectives, strong resistance to TSWV was also observed in lines developed this year. A/B genome specific markers were developed. Allotetraploids and advanced breeding lines were tested for LLS, ELS, rust and TSWV and were released as germplasm. Seeds were depositedwith the USDA PGRCU (Griffin, GA) and the NLGRP (Fort Collins, CO) for distribution.These strategic resources will facilitate the introduction of new wild genes into peanut breeding programs within this project and beyond. Objective 1 In the third year, BC1and BC2selections fromhybrids between the the advancedA. cardenasiicontainingline IAC 322 and the recurrent parent peanut cultivar TifNV-High O/L were testedin replicated yield trails under fungicide sprayed and non-sprayed conditions. Leaf spot ratings confirmed that these selections have excellent resistance to late leaf spot, confirming in vitro bioassays. Two lines (TifGP-3 and TifGP-4)had yields higher than check cultivarsand were jointly released as germplasm (Holbrook et al., 2021). TheLLS resistance segments are also being transferred to the cultivar Bailey. Bailey has moderate resistance to ELS, from a differentA. cardenasiisegment. CrossesBailey x IAC321 (322 sister line) generated 31BC1lines. In vitro assays suggests that the incorporation segments from IAC321 increase resistance to LLS whilst maintaining resistance to ELS on Bailey. Key outcomes: Development, testing and genotyping of BC3advanced lines with high levels of resistance to LLS tested in vitro and in the field. Development of BC2lines with combined resistance to LLS and ELS.Release of two advanced lines. Objective 2 In the third year, we continued advancing and testing populations withA. stenospermasegments that confer resistance to RKN. This was the first year thatA. stenosperma-derived lines were evaluated for agronomical traits in the field. Production of a BC3populationTwenty-one BC2lines were backcrossed with peanutto produce a BC3population.This population was genotyped using the'Axiom_Arachis v02' SNP array. Individuals had between 1.1%and 19.1% wild alleles. Confirmation of segment effect on nematode development and reproductionBC3F3segregating lines from sixBC3F1families were evaluated for RKN resistance to further validate A02 and A09 QTLs. 84BC3F3lineswere selected basedon high cultivar genome recovery (89.1% - 95.9%) and superior field performance of theBC3F2generation.To analyze the effect of the segments,lines were grouped according to segments they carried. Bioassays were done as described in Ballen et al. (2019). Linesharboring smallA02 or large A02 only were completely resistant to RKN, not supporting development (galls) or reproduction (eggs). Lines with small A09 and both small A02+ small A09 presented nematodedevelopmentbut not reproduction. Lines with small A09 presented galling and egg production comparable to susceptible controls. We conclude that either segment on chromosome 2 or the large on chromosome 9 is sufficient to confer complete resistance. Field trial of BC3F2lines -In 2020, 249 BC3F2lines were evaluated in Midville, GA for agronomic traits in the absence of nematode pressure or disease control. Four representatives (sister lines) of each family were planted side by side on two squares of 6-by-6 feet, and evaluated for: architecture, total pod weight, 100-seed weight, pod constriction, pod reticulation, % of double pods; and for field resistance to leaf spots and TSWV. There was low incidence of leaf diseases, but high TSWV pressure. There was segregation in 27 families, where one or more sister lines were resistant and one or more completely susceptible to TSWV. This result was unexpected and grants further evaluation. These plants are being genotyped this year. Progeny will be evaluated in 2021. Most BC3F2lines produced seed of similar size and higher seed weight than the recurrent parents. Greenhouse and In vitro evaluations -Segregation for leaf spot incidence, architecture, branching and extra leaveswas noticed in greenhouse. 38 lines exhibitedleaf spot incidencebut 61 did not.Around half had the cultivatedprostratearchitecture phenotype, some withupright growth habitand few dwarfs. Most lines had normal peanut branching.Single marker correlation between these traits and genotyping profile revealed candidate genome regions. Chromosomes A06 and B02 are candidate regions for Late leaf spot resistance. Key outcomes: confirmation of effect of individual segments on RKN resistance; production and evaluation BC3F3lines, revealing lines with resistance to TSWV, high vigor and peanut desired traits; identification of candidate regions for resistance to LLS. Objective 3 In the third year,we continued producing new combinations of hybrids, treating hybrids with colchicine to obtain peanut-compatible allotetraploids, and advanced crosses with cultivated peanut for wild allele introgression. Making primary hybrids -seven potential primary diploid hybrids were created. Out of those, six were confirmed using KASP primers: A. valida PI 666102 x A. microsperma Grif 15116 A. magna V13752 x A.hoehnei V9140 A. magna V13752 x A. hoehnei V9094 A. magna PI599184 x A. kuhlmanni PI 476108 A. ipaensis K30076 x A. duranensis V14167 A. batizocoi K9484 x A. kempff-mercadoi PI 468330 A. batizocoi PI 468325 x A kempff-mercadoi PI 468330 Onenew allotetraploid was created: A. ipaensisK30076x A. aff. helodes Grif 7526 Five hybrids being colchicine treated: A. batizocoi K9484 x A. kempff-mercadoi PI 468334 A. cruziana Grif 14257 x A. simpsonii Grif 14534 A. magna V13752 x A. hoehnei PI 666086 A. valida PI 666103 x A. microsperma Grif 15116 A. cruziana PI 476003 x A. simpsonii Grif 14534 Diploid hybrids A. ipaensis K30079 x A. diogoi V10602and A. batizocoi 9484 x A. diogoi V10602 were discarded as theywere recalcitrant to chromosome doubling. Crosses with peanut MagDio1, MagSten2 andMagCar1crosses with peanut are underway. IpaDur3, IpaCor2 andValSten1were backcrossed with peanut. Seeds of 190 BC1F1families were planted for generation advancement. Development of 105 KASP markers for quick testing hybrids detection-markers distinguishing A- and B/K-genomes were designed to span the entire genome. This improves on previous time consuming methods Genotyping analyses of IpaSten1 showed that wrong accessions were used, therefore this allotetraploid was discarded. Keyoutcomes:production of six diploid hybrids, one allotetraploid, two allotetraploids were crossed with peanut, backcrosses, generating over 1000 families of peanut with wild alleles.Specific A/B to rapidly confirm hybridity. Release of five allotetraploids as germplasm.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: MCC Chavarro, DJ Bertioli2 S Tallury, CE Simpson, GJ Seijo, MC Moretzsohn, JFM Valls, HT Stalker, and SCM Leal-Bertioli. Arachis genus in-depth characterization for conservation and peanut breeding. APRES 2020  52nd Annual Meeting of the American Peanut Research and Education Society. July 9-11, virtual. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: C Ballen-Taborda, Y Chu, P Ozias-Akins, P Timper, CC Holbrook, SA Jackson, DJ Bertioli, SCM Leal-Bertioli, Nematode resistance from Arachis stenosperma incorporated into elite peanut. APRES 2020  52nd Annual Meeting of the American Peanut Research and Education Society. July 9-11, virtual. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: D Bertioli, C Ball�n-Taborda, K Costello, Y Chu, CC Holbrook, P Ozias-Akins, P Timper, S C M Leal-Bertioli. Arachis stenosperma, new sources of nematode, rust and leaf spot resistance incorporated into peanut elite lines. APRES 2020  52nd Annual Meeting of the American Peanut Research and Education Society. July 9-11, virtual. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: CC Holbrook, P Ozias-Akins, Y Chu, S, Botton, D Bertioli, S C M Leal-Bertioli, and AK Culbreath. Precision Breeding Using Molecular Genetic Tools to Develop Disease Resistant Peanut Cultivars APRES 2020  52nd Annual Meeting of the American Peanut Research and Education Society. July 9-11, virtual. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Y-C Tsai, CC Holbrook, S Leal-Bertioli. Towards Reliable Greenhouse Methods for Evaluating Peanut White Mold. APRES 2020  52nd Annual Meeting of the American Peanut Research and Education Society. July 9-11, virtual. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: SCM Leal-Bertioli, Dongying Gao, Carolina T Ballen, David J Bertioli. Peanut on the wild side introgression of disease resistance from wild relatives. APS Plant Health 2020. virtual Y-C Tsai, T Brenneman, and S Leal-Bertioli. Towards reliable greenhouse Methods for Evaluating Peanut White Mold. APS Plant Health 2020. Virtual.
  • Type: Journal Articles Status: Under Review Year Published: 2021 Citation: Levinson CM, Bertioli DJ, Chu Y, Hopkins M, Leal-Bertioli SCM, Stalker HT, Ozias-Akins P. 2021. Development and applications of KASP markers distinguishing A- and B/K-genomes of Arachis.
  • Type: Journal Articles Status: Submitted Year Published: 2021 Citation: Leal-Bertioli SCM, Nascimento EFMB, Chavarro CF, Cust�dio AR, Hopkins MS, Moretzsohn MC, Bertioli DJ, Araujo ACG. 2021. Spontaneous generation of diversity in Arachis neopolyploids (A. ipa�nsis x A. duranensis)4x replays the early stages of peanut evolution. G3 Genes|Genomes|Genetics.
  • Type: Conference Papers and Presentations Status: Under Review Year Published: 2021 Citation: Chu Y, Stalker HT, Marasigan K, Levinson CM, Gao D, Bertioli DJ, Leal-Bertioli SCM, Holbrook CC, Jackson SA, Ozias-Akins P 2021. Registration of three peanut allotetraploid interspecific hybrids resistant to leaf spot diseases. J. Plant Registrations.
  • Type: Conference Papers and Presentations Status: Under Review Year Published: 2021 Citation: Holbrook CC, P. Ozias-Akins, Y. Chu, S. Lamon, D.J. Bertioli, S.C.M. Leal-Bertioli, A.K. Culbreath, and I.J. Godoy. 2021. Registration of TifGP-3 and TifGP-4 peanut germplasm lines. J. Plant Registrations.
  • Type: Journal Articles Status: Accepted Year Published: 2021 Citation: Bertioli DJ, J Clevenger, IJ Godoy, H T Stalker, S Wood, J F Santos, C Ball�n-Taborda, B L Abernathy, V Azevedo, J Campbell, C Chavarro, Y Chu, A D Farmer, D Fonceka, D Gao, J Grimwood, N Halpin, W Korani, M D Michelotto, P Ozias-Akins, J Vaughn, C Youngblood, MC Moretzsohn, GC Wright, SA Jackson, S B Cannon, BE Scheffler, Leal-Bertioli SCM. 2021. Legacy genetics of Arachis cardenasii in the peanut crop shows the profound benefits of international seed exchange
  • Type: Journal Articles Status: Accepted Year Published: 2021 Citation: Levinson CM, C. M. Levinson, Chu YY. Chu, X. Luo X; H. Stalker HTT. Stalker, D. Gao D, Holbrook CC, Ozias-Akins P. 2021. C. C. Holbrook, P. Ozias-Akins (2021) Morphological and reproductive characterization of nascent allotetraploids cross-compatible with cultivated peanut (Arachis hypogaea) Genetic Resources and Crop Evolution.
  • Type: Journal Articles Status: Accepted Year Published: 2021 Citation: Bertioli DJ, Gao D, Ballen-Taborda C, Chu Y, Ozias-Akins P, Jackson SA, Holbrook CC & Leal-Bertioli SCM. 2021. Registration of GA-BatSten1 and GA-MagSten1, two induced allotetraploids derived from peanut wild relatives with superior resistance to leaf spots, rust and root-knot nematode. Journal of Plant Registrations.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Chu Y, Bertioli D, Levinson CM, Stalker HT, Holbrook CC, Ozias-Akins P. 2021. Homoeologous recombination is recurrent in the nascent synthetic allotetraploid A. ipa�nsis x A. correntina4x and its derivatives. G3 Genes|Genomes|Genetics DOI: 10.1093/g3journal/jkab066
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Gao D, Araujo, ACG, Nascimento, EFMB, Chavarro, MC, Xia H, Jackson, SA, Bertioli DJ, Leal-Bertioli SCM. 2021. ValSten: a new wild species derived allotetraploid for increasing genetic diversity of the peanut crop. Genetic Resources and Crop Evolution. doi.org/10.1007/s10722-020-01076-2.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Ball�n?Taborda C, Chu Y, Ozias?Akins P, Timper P, Jackson SA, Bertioli DJ and Leal?Bertioli SCM. 2021. Validation of resistance to root?knot nematode incorporated in peanut from the wild relative Arachis stenosperma. Agronomy Journal. https://doi.org/10.1002/agj2.20654
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Levinson CMC. M. Levinson, K. M. Marasigan KM, Chu Y Y. Chu, Stalker HTH. T. Stalker, C. C. Holbrook CC, X. Ni X, W.P. Williams WP. &, P. Ozias-Akins P. 2020. Resistance to fall armyworm (Lepidoptera: Nicotuidae) feeding identified in nascent allotetraploids cross-compatible to cultivated peanut (Arachis hypogaea L.). Peanut Science. 47:123-134
  • Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Lamon S, Chu Y, Guimaraes LA, Bertioli DJ, Leal-Bertioli SCM, Santos JF, Godoy IJ, Culbreath AK, Holbrook CC & Ozias-Akins P. 2020. Characterization of peanut lines with interspecific introgressions conferring Late Leaf Spot resistance. Crop Science. 2020, 1-15. DOI: 10.1002/csc2.20414.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Suassuna T, Suassuna N, Martins K, Matos R, Heuert J, Bertioli D, Leal-Bertioli S & Moretzsohn M. 2020. Broadening the variability for peanut breeding with a wild species-derived induced allotetraploid. Agronomy. 10, 1917; doi:10.3390/agronomy10121917
  • Type: Theses/Dissertations Status: Published Year Published: 2021 Citation: Levinson, Chandler. 2021. Characterization of allotetraploids cross compatible to cultivated peanut (Arachis hypogaea L.) PhD Degree. University of Georgia.


Progress 05/01/19 to 04/30/20

Outputs
Target Audience:In this second year, two main audiences were targeted and reached by our efforts: Research scientists and breeders - a number of joint activities to facilitate discussions were conducted in UGA Athens and partners' labs. Discussions centered on use of new sources of disease resistance from wild species in combination with DNA markers, phenotyping and genetic analysis. Students -mentoring of students focused on experimental design, critical thinking, and practical skills. Students in both in the Athens and in the Tifton campus were involved. The information obtained in this second year of project was disseminated in various communications: six posters and 14 oral presentations in eight different conferences and three different countries (USA, China and Philipines). Two manuscripts were published in refereed journals. The conferences were attended by a diverse audience, including graduate and undergraduate students, peanut farmers, extensionists, research scientists, legume research scientists, university professors, members of the peanut industry, stakeholders and governing bodies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project is providing opportunity for the training of graduate and undergraduate students. Two UGA undergraduate students have finalized their theses successfully, obtaining a master's degree (Samuele Lamon) and a PhD (Carolina Ballen) from the University of Georgia, and had senior author publications. Now, Samuele Lamon is a PhD student at UGA and Carolina Ballen is a pos-doctoral associate. Three other PhD students are also involved in the activities of this project: Chandler Maddox Levinson (UGA, Tifton campus), Maricel Gonzales and Wendy Tsai (UGA, Athens campus). The students attended the following conferences: 51thAnnual Meeting of the American Peanut Research and Education Society (Auburn AL), (C Ballen, C Levinson and M Gonzales); Advances in Arachis through Genomics and Biotechnology, China (C Levinston);21stAnnual Meeting of the National Association of Plant Breeders(C Levinson),Annual Meeting of the Georgia Association of Plant Pathologist (M Gonzales and W Tsai) and Pest Management Council of the Philippines Annual Meeting 2019 (M Gonzales). Laboratory and department seminars are regularly given by the students. How have the results been disseminated to communities of interest?The information obtained in this second year of project was disseminated in various communications: six posters and 14 oral presentations in eight different conferences and three different countries (USA, China and Philippines). The conferences were attended by a range of audiences, including graduate and undergraduate students, peanut farmers, extensionists, research scientists, legume research scientists, university professors, members of the peanut industry, stakeholders and governing bodies. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1- Using introgression lines, transfer the three well-defined chromosome segments of the wild speciesA. cardenasiiinto U.S. elite high oleic peanut cultivars and breeding lines. At the start of this project, we had produced hybrids between the peanut cultivar TifNV-High O/L and the advanced line IAC 322.In the first year we (1) produced KASP markers for marker-assisted selection (2) produced BC1F2sseeds with segments with resistance to LLS. 2019/2020 -Twelve 12 BC1breeding lines withA. cardenasiisegmentsLG02A, LG02B and LG03 onTifNV-High O/L backgroundwere tested under fungicide sprayed, and non-sprayed conditions.Over 1,200 BC2F2seeds of these lines were genotyped and selected for the presence of the three segments. About 200 selected BC2F2individuals were advanced to the BC2F2:3generation.The BC2F3families were planted in 2019.Replicated yield trials were conducted underfungicide sprayed, and non-sprayed conditions.Leaf spot ratings confirmed that these selections have excellent resistance to late leaf spot. Three of these selections also had yield that was numerically higher that the check cultivars (Georgia-06G and TifNV-High O/L).Field selections for TSWV resistance and agronomic traits were also made and the best 30 lines were sent to the winter nursery for seed increase.This will allow for replicated yield trials in 2020. It is anticipated that breeding lines with strong leaf spot resistance will emerge from these materials. TheA. cardenasii-derived segments that confer resistance to LLS are also being transferred to the cultivar Bailey. Bailey is mostly grown in NC and has moderate resistance to ELS, derived from a different introgressed segments ofA. cardenasii. Pyramiding all segments has the potential to generate a cultivar that has stronger resistances to both leaf spots. Crosses were made betweenBailey and IAC321 (a sister line of 322). Hybrids were confirmed using KASP markers all segments. Hybrids were crossed with Bailey and withTifNV-High O/L. The key outcomes of this objective are: The development of DNA markers to detectA. cardenasii-derived chromosome segments that confer leaf spot resistance and their use to introgress these segments into elite peanut genetic backgrounds for the SE of the USA. Objective 2- Introgress chromosome segments of peanut wild relativeA. stenospermafrom newly synthesized allotetraploids. In the first year of this project, we constructed a genetic map, identified QTLs linked to nematode resistance and crossed selected F2segregants with A. hypogaea. The key outcomes of this objective in the first year were: (1) Construction of genetic map and identification of two major QTL linked to RKN resistance; (2) development of markers linked toA. stenosperma-derived RKN resistance; (3) production of BC1lines containing both segments for RKN-resistance. Main achievements in the second year: -Creation of BC2 lines Four superior F2lines were selected based onbetter vigor, greaterbiomass, good agronomic traits, LLS and RKN resistance; and presence of A02 and A09 QTLs. F2:3progeny homozygous for the QTL regions, and with validated resistance to RKN, were used as initial donor parents for backcrosses into TifGP-2, 5-646-10 and 13-1014 all elite butRKN-susceptible lines. True BC1lines were confirmed using KASP markers linked to the segments on LG A02 and A09and were backcrossed, producing 10 BC2s. - Confirming Nematode marker associations The BC2s were selected and genotyped using the 'Axiom_Arachis' 47K high-density SNP array v.02(Clevenger et al. 2018; Korani et al. 2019). They were also evaluated for plant architecture, seed size and resistance to LLS and RKN. As expected, allA. hypogaeacultivars were susceptible, along with a singleBC2F1;M.arenariawas able to complete the life cycle to produce eggs. In contrast, the resistant wild species, BatSten1 and most BC2linesassayed had very low numbers of eggs and galls. In general, these materialsexhibited high levels of resistance to RKN. Selected BC2lines were backcrossed withA. hypogaea We used two new synthetic allotetraploids containing the RKN resistantA. stenosperma, IpaSten1 and ValSten1 to produce BC1F2populations with cultivated peanut breeding lines as females. The female parents harbor the LG A09 nematode resistance fromA. cardenassii(introgressed more than two decades ago). In order to pyramid the multiple sources of nematode resistance, these BC1F2populations that were planted in Rigdon farm, The University of Georgia, Tifton, GA this year will be genotyped and selected using KASP markers for nematode resistance spanning the QTL regions on LG A02 and A09 from both sources. The key outcomes of this objective are: The identification of two new sources of resistance to root knot nematode: chromosome segments fromA. stenosperma. The development of DNA markers, within these segments, for use in Marker Assisted Selection and the incorporation of these chromosome segments, to BC2generation, into elite peanut genetic backgrounds adapted to cultivation in the SE of the USA. Objective 3- Produce new peanut-compatible induced allotetraploids using wild diploid species that confer resistance to various other pests and diseases to widen the genetic base of peanut. In the first year,seven new diploid hybrids one new allotetraploid derived from wild relatives of peanuts with multiple resistances were obtained. This work continued in the second year. Making new primary hybrids In the second year, seven potential primary diploid hybrids were created: A. valida PI 666103 x A. microsperma Grif 15116 A. cruziana Grif 14257 x A. simpsonii Grif 14534 A. magna K30092 X A. cardenasiX 10017 A. magna K30092 x A. diogoi V10602 A. magna K30097 x A. diogoi V10602 A. magna V13752 x A. hoehnei PI 666086 A. batizocoi K9484 x A. kempff-mercadoi PI 468334 These potential hybrids will be confirmed by genotyping. Although COVID delayed this, we anticipate results soon. Hybrids will be treated with colchicine for genome doubling and fertility recovery. Making new allotetraploids Ten new synthetic allotetraploid were created in the second year: A. valida PI468154 x A. stenosperma V10309 (ValSten1) A. magna K30097 x A. duranensis V14167 (MagDur1) A. magna K30097 x A. stenosperma V10309 (MagSten1) A. ipaensis K30079 xA. duranensis V30060 (IpaDur3) A. ipaensis K30079 x A. correntina 9530 (IpaCor2) A. magna K30092 x A. stenosperma410 (MagSten2) A. magna K30092 x A. diogoi V10602 (MagDio1) A. magna 30092 x A. cardenasii 10017 (MagCar1) A. ipaensis K30079 xA. stenosperma V10309(IpaSten1) A. ipaensis K30079 xA. stenosperma410 (IpaSten2) The diploid hybrids A. ipaensis K30079 x A. diogoi V10602and A. batizocoi 9484 x A. diogoi V10602were found to be completely recalcitrant to chromosome doubling. So, we discontinued work with these hybrids. IpaDur3, IpaCor2,ValSten1and MagSten2 were tested for field resistance to TSWV and leaf spots in a replicated study, showing immunity to leafspots and partial resistance to TSWV. IpaDur3, IpaCor2,ValSten1 and MagSten1were crossed with peanut lines. Seeds of 190 BC1F1families were planted for generation advancement.As for IpaSten1, MagSten2 andMagCar1, crosses with cultivated peanut are being made this year to initiate the introgression of beneficial wild alleles. The keyoutcomes in this objective are the production of seven new diploid hybrids, 10 new allotetraploids, over 1,000 families of allotetraploids crossed with peanut.Several allotetraploids were confirmed to be resistant to LLS, and resistance to TSWV was observed.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Holbrook, C.C., Y. Chu, S. Lamon, A.K. Culbreath, D. Bertioli, S.C.M. Bertioli, I.J. Godoy, and P. Ozias-Akins. 2019. Marker assisted breeding to develop peanut cultivars with resistance to late leaf spot. Advances in Arachis through Genomics and Biotechnology Conference, Jinan, China. http://f.scievent.com/aagb2019/aagb2019_program_book_and_abstract.pdf (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Holbrook, C.C., Y. Chu, S. Lamon, A.K. Culbreath, D. Bertioli, S.C.M. Bertioli, I. Godoy, and P. Ozias-Akins. 2019. Using marker assisted selection to develop peanut cultivars with resistance to late leaf spot. Proc ASA/CSSA annual meeting. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Gonzales M, R. Kemerait Jr. A. Culbreath. D.J. Bertioli, S.C.M. Leal-Bertioli. Wild-derived resistance to early and late leaf spot caused by Passalora arachidicola and Nothopassalora personata in peanut. APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (poster presentation)
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Gonzales M, Robert Kemerait Jr., Albert Culbreath, Marin T. Brewer, David J. Bertioli and Soraya C.M. Leal-Bertioli. Response of wild peanut relatives and synthetic allotetraploids to early and late leaf spot. Pest Management Council of the Philippines Annual Meeting 2019 (oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Holbrook CC, S. Lamon, Y. Chu, P. Ozias-Akins, A.K. Culbreath, D. Bertioli, S. C. M. Leal-Bertioli, & I Godoy. 2019. Field evaluation of peanut lines with introgressions conferring resistance to late leaf spot. APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Leal-Bertioli SCM . 2019. Genomics and wild crop relatives for peanut improvement. Southern Peanut Growers Conference July 18?20, 2019 Edgewater Beach & Golf Resort Panama City Beach, Florida. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Holbrook, C.C., P. Ozias-Akins, Y. Chu, S. Botton, D. Bertioli, S.C.M. Leal-Bertioli, and A.K. Culbreath. 2020. Precision breeding using molecular genetic tools to develop disease resistant peanut cultivars. Proc. ASA/CSSA/SSA Annual Meeting. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Leal-Bertioli SCM, H.T. Stalker, I.J. Godoy, J.F. Santos, C.C. Holbrook, P. Ozias-Akins, Y. Chu, G. Wright, J. Clevenger, M.C. Moretzsohn &D.J. Bertioli. 2019. The worldwide influence of the wild species, A. cardenasii, on the peanut crop. APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Leal-Bertioli SCM, Stalker T, Holbrook C, Jackson S, Ozias-Akins P & Bertioli DJ. 2019. Unlocking novel wild alleles in cultivated peanut to increase disease resistance and productivity". 21st Annual Meeting of the National Association of Plant Breeders. Callaway, GA. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Levinson C., Chu Y, Ni X, Ozias-Akins P. 2019. Evaluation of wild peanut (A. ipa�nsis x A. correntina) synthetic tetraploid-derived materials to fall armyworm. 21st Annual Meeting of the National Association of Plant Breeders. Callaway, GA. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Levinson CM, Chu Y, Ozias-Akins, P. 2019. Evaluation of A. ipa�nsis x A. correntina wild-peanut derived materials for resistance to fall armyworm. Advances in Arachis through Genomics and Biotechnology Conference, Jinan, China. http://f.scievent.com/aagb2019/aagb2019_program_book_and_abstract.pdf (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Levinson CM, Y. Chu, P. Ozias-Akins and C. C. Holbrook. Harnessing the wild side of peanuts: morphological and reproductive characterization of wild peanut relative-derived synthetic tetraploids. APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Stalker HT, Leal-Bertioli SCM & Bertioli DJ. 2019. Solving the Leaf Spot Problem in Peanut. Advances in Arachis through Genomics and Biotechnology Conference, Jinan, China. http://f.scievent.com/aagb2019/aagb2019_program_book_and_abstract.pdf (Oral presentation)
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Lamon, Samuele. 2019. Genotypic and Phenotypic Characterization of Peanut Lines with Interspecific Introgressions Conferring Late Leaf Spot Resistance. Masters degree. University of Georgia.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Ball�n-Taborda C, Chu Y, Ozias-Akins P, Timper P, Holbrook CC, Jackson SA, Bertioli DJ & Leal-Bertioli SCM. 2019. A new source of root-knot nematode resistance from Arachis stenosperma incorporated into allotetraploid peanut (Arachis hypogaea). Scientific Reports. 9:17702. https://doi.org/10.1038/s41598-019-54183-1
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Lamon, S., Y. Chu, L.A. Guimaraes, D.J. Bertioli, S.C.M. Leal-Bertioli, J.F. Santo, I.J. Godoy, A.K. Culbreath, C.C. Holbrook, and P. Ozias-Akins. 2020. Characterization of peanut lines with introgressions conferring late leaf spot resistance. Crop Sci. in press
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Ball�n-Taborda, Ana Carolina. 2019. Exploration of Arachis stenosperma as a source of nematode resistance for peanut. PhD Degree. University of Georgia.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ball�n-Taborda C, Y. Chu, P. Ozias-Akins, P. Timper, C.C. Holbrook, S.A. Jackson, D.J. Bertioli, S.C.M. Leal- Bertioli. A new source of root-knot nematode resistance from Arachis stenosperma incorporated into allotetraploid peanut (Arachis hypogaea). APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ball�n-Taborda, C.., et al. (2019). Genotypic characterization of peanut advanced backcrossed lines (BC3F1) that incorporate root-knot nematode resistance from A. stenosperma. APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Bertioli D, Gonzales M, Abernathy B, Jackson SA, Clevenger J, Leal-Bertioli SCM. 2019. The peculiar genetics of peanut - breeding with a segmental allotetraploid. 21st Annual Meeting of the National Association of Plant Breeders (NAPB). Callaway, GA. (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Chavarro C, Shin JH, Kim KD, Abernathy B, Bertioli DJ & Leal-Bertioli SCM. 2019. Differential expression of the transposons elements (TEs) based on mRNA and small RNA in the peanut genome after hybridization and tetraploidization. CROPS meeting. Huntsville, AL. (poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Chu, Y., Bertioli, D., Jackson, S., & Ozias-Akins, P. 2019. Segmental subgenome exchange is captured in the nascent synthetic allotetraploid [A. ipaensis x A. correntina]4x and its derivatives. Advances in Arachis through Genomics and Biotechnology Conference, Jinan, China. http://f.scievent.com/aagb2019/aagb2019_program_book_and_abstract.pdf (Oral presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Gao DY, C. Ball�n-Taborda, H. Xia, S. C. M Leal-Bertioli, D.J. Bertioli, S. Jackson, E. Bellard, A. C. G. Araujo, Y. Chu, P. Ozias-Akins. Development of new synthetic tetraploid wild peanuts. APRES 2019 - 51th Annual Meeting of the American Peanut Research and Education Society. July 9-11, 2019. The Hotel at Auburn University & Dixon Conference Center- Auburn, AL. (poster presentation)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Gonzales M, David Bertioli, Albert Culbreath, Robert Kemerait Jr., Marin Brewer and Soraya Leal-Bertioli. Sources of Resistance to Peanut Late Leaf Spot caused by Nothopassalora personata. Annual Meeting of the Georgia Association of Plant Pathologist (GAPP). 2019. (poster presentation)


Progress 05/01/18 to 04/30/19

Outputs
Target Audience:In this first year, two main audiences were targeted and reached by our efforts: Research scientists and breeders - a number of joint activities to facilitate discussions were conducted in UGA Athens and partners' labs. Discussions centered on use of new sources of disease resistance from wild species in combination with DNA markers, phenotyping and genetic analysis. Students - mentoring to students focused on experimental design, critical thinking, and practical skills. Students in both in the Athens and in the Tifton campus were involved. Moreover, results obtained in this first year of project were disseminated in various communications: three poster and seven oral presentations in seven different conferences and four different countries (USA, France, Canada and Senegal). We estimate that over 1,500 people were reached by these presentations. Conference attendees were diverse and included graduate and undergraduate students, peanut extensionists, peanut research scientists, legume research scientists, university professors, members of the peanut industry and governing bodies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project is providing opportunity for the training of graduate and undergraduate students. Two UGA undergraduate students have been doing laboratory and greenhouse activities related to the objectives of the project, as student workers. An MS student from Italy has developed his thesis on the activities of Objective 1 (Samuelle Lamon), under the supervision of Drs. Peggy Ozias-Akins and Scott Jackson. A PhD student from Colombia is developing her thesis on activitiesof Objective 2 (Carolina Ballen), under the supervision of Drs. Scott Jackson, Soraya Leal-Bertioli and David Bertioli. The students had the chance to attend the following conferences: 50thAnnual Meeting of the American Peanut Research and Education Society. July 10-12, 2018. Doubletree Hotel Williamsburg Williamsburg, VA (C Ballen and S Lamon); Advances in Arachis through Genomics and Biotechnology. Nov 12-16, 2018. Saly Senegal (C Ballen); UC Davis Plant Science Symposium. Davis, CA., 2018 (C Ballen). Huntsville, AL (C Ballen). Laboratory and department seminars were also given by the students.Professional Grant Development Workshop. Georgia Institute of Technology, Atlanta, GA. 2018 (C Ballen). How have the results been disseminated to communities of interest?The information obtained in this first year of project was disseminated in various communications: three poster and seven oral presentations in seven different conferences and four different countries (USA, France, Canada and Senegal). We estimate that over 1,500 people were reached by these presentations. The conferences were attended by a range of audiences, including graduate and undergraduate students, peanut extensionists, peanut research scientists, legume research scientists, university professors, members of the peanut industry and governing bodies. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? IMPACT Peanut is an expensive, high agrochemical input crop. Over 150 dollars are spent per acre each year to control pests and diseases. The main goal of this project is to make a major impact on peanut cultivation in the U.S. by reducing farmers' agrochemicals costs and increase production. We started to accomplish this by combining high yielding cultivars with peanut lines that contain high value segments of wild relatives that confer strong pest and disease resistances using crossing schemes aided by advanced tools based on DNA sequence information. Over 1000 crosses were made, new hybrids produced, new wild-derived, peanut-compatible allotetraploids were obtained, over 200 resistance-containing breeding lines and 21 specific markers for RKN resistance obtained. These strategic resources will facilitate the introduction of new wild genes into peanut breeding programs within this project and beyond. The decreased use of agrochemicals on the peanut crop will provide reduction to up to 20% of production costs. The use of wild relatives has been a game changer for other crop species, and we expect the same for peanut. The information obtained here was disseminated in various communications: 3 poster and 7 oral presentations in 7 different conferences and 4 different countries (USA, France, Canada and Senegal). We estimate that over 1,500 people were reached by these presentations. They include graduate and undergraduate students, extensionists, peanut and legume research scientists, university professors, members of the industry and governing bodies. ACCOMPLISHMENTS Objective 1- Using introgression lines, transfer the three well-defined chromosome segments of the wild speciesA. cardenasii(that confer resistance to LLS and rust) into U.S. elite high oleic peanut cultivars and breeding lines. At the start of this project, we had produced hybrids between the peanut cultivar TifNV-High O/L (female) and the advanced line IAC 322 (male). TifNV-High O/L is a high yielding cultivar that contains a segment of the wild relative A. cardenasii that confers root-nematode resistance but moderately susceptible to LLS. IAC 322 has chromosomal segments in LG02 and LG03 that confer resistance to LLS. KASP markers for the segments were designed and tested. Real hybrids were selected using these markers and hybrid seed grown to produce F2s. Seed of these progenies were chipped (a portion of a cotyledon was excised), DNA was extracted from the chips and used for genotyping with KASP markers. Six F2 progeny containing all three segments were selected and used as males in crosses with TifNV-High O/L. Putative BC1 seeds were planted and tested with KASP markers. BC1F2s seeds were harvested and, in the fall, plants will be evaluated for resistance to LLS in vitro. The key outcomes of this objective are (1) design, production and test of KASP markers linked to three introgressed segments, that can be used for marker-assisted selection (2) production of BC1F2s seeds with segments that confer resistance to LLS. Objective 2- Introgress chromosome segments of peanut wild relativeA. stenosperma(that confer resistance against Late Leaf Spot, LLS and Root Knot Nematode, RKN) from newly synthesized allotetraploids. An F2 population derived from a cross between peanut Runner-886 and (A. batizocoi x A. stenosperma)4x (called here RBS) had been previously produced, genotyped and phenotyped for RKN over three years. Construction of genetic map and identification of QTL Map construction - The RBS F2 population was genotyped using the 60k Affy-chip version 1. 1587 polymorphic SNP markers were identified, 911 assigned to A-subgenome (A. stenosperma-specific markers) and 676 to B/K-subgenome (A. batizocoi-specific markers). The physical positions of the A-genome and B-genome markers were determined according to the position of their homologues in the A. duranensis and A. ipaensis pseudomolecules, respectively (www.peanutbase.org). After removing low-quality and unlinked markers, 1499 SNP markers were ordered into 20 linkage groups that ranged from 100.7 cM (LG A05) to 359.5 cM (LG A02), spanning 3984.9 cM and an average marker density of 2.85 cM. Identification of QTL - Resistance to RKN was evaluated on the F2 population over three years. The following traits for RKN resistance were evaluated: EGR (eggs/gram of root), RF (reproductive factor), and GI (galling index). Two large-effect QTL for all three measurements of resistance to RKN were detected at the bottom of LG A02 and A09. QTL on LG A02 contributed to a percentage reduction up to 98.2% and QTL on A09 reduced the nematode development up to 91.6%. Two bioassays were performed for Late leaf spot, measuring incubation period, number of lesions per leaf area and percentage of diseased leaf area. However, mapping of these traits did not reveal any consistent QTL. In the second year, a more advanced progeny will be assayed. Development of KASP markers linked with resistance to RNK KASP primers were designed for use in KASP endpoint genotyping (LGC Biosearch technologies), with the web-based program BatchPrimer3 (http://probes.pw.usda.gov/batchprimer3/). 41 assays were designed for the region across the resistance segments and R-gene clusters, 22 of them were suitable to distinguish the introgressed segment from A. stenosperma from the background of A. hypogaea and are associated with nematode resistance. Cross of selected F2 segregants with A. hypogaea The F2s that were most resistant, produced more seed and were more vigorous were selected to be crossed with A. hypogaea. They were called RBS-F2-7, RBS-F2-13, RBS-F2-34 and RBS-F2-73 These lines were crossed with TifGP-2 (RKN-susceptible runner-type peanut and is a near isogenic sister line of the RKN-resistant 'Tifguard', good yield and grade and normal oleic content) and 5-646-10 (a Florida-07 x Tifguard derived breeding line susceptible to root knot nematode, with good yield and grade, and high O/L content. 1802 crosses were made over the period of 42 days. Real backcrossed lines were detected using RKN resistance-linked markers, using seed chip. With this method of early detection, the seeds are tested prior to germination, false positives can be discarded, leading to saving time, space and labor. The key outcomes are: (1) Construction of genetic map and identification of two major QTL linked to RKN resistance; (2) development of markers linked to A. stenosperma-derived RKN resistance; (3) production of BC1 lines containing both segments for RKN-resistance. Objective 3- Produce new peanut-compatible induced allotetraploids using wild diploid species that confer resistance to various other pests and diseases to widen the genetic base of peanut. In the first year of this project, new crosses were made to create diploid hybrids; existing diploid hybrids were treated with colchicine as an attempt to duplicate the genome; and new allotetraploids were obtained. Seven new diploid hybrids were obtained and hybridity confirmed by pollen staining. A. valida PI468154 x A. stenosperma V10309 A. magna K30097 x A. duranensis V14167 A. magna K30097 x A. stenosperma V10309 A. ipaensis x A. aff. helodes Grif 7526. Existing diploid hybrids were treated with colchicine. Because of past lack of success in obtaining tetraploids, colchicine concentration was increased from 0.2 to 0.5%. The diploid hybrids are: A. magna K30092 x A. diogoi V10602 A. ipaensis K30079 x A. diogoi V10602 A. batizocoi 9484 x A. diogoi V10602 A. magna 30092 x A. cardenasii 10017 Over 390 cuttings were treated, 3 pegs emerged and 1 seedling of the hybrid A. magna K30092 x A. diogoi V10602 (MagDio) was found. The key outcomes in this objective are the production of new diploid hybrids and one new allotetraploid derived from wild relatives of peanuts with multiple resistances.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: BALL�N-TABORDA, C., Y. CHU, P. OZIAS-AKINS, P. TIMPER, C.C. HOLBROOK, S.A. JACKSON, D.J. BERTIOLI & S. LEAL-BERTIOLI. 2018. Mapping of resistance to root-knot nematode (RKN) from the wild species A. stenosperma and introgression into peanut Arachis hypogaea. UC Davis Plant Science Symposium. Davis, CA., 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: BALL�N-TABORDA, C., Y. CHU, S.A. JACKSON, P. OZIAS-AKINS, P. TIMPER, C.C. HOLBROOK, D.J. BERTIOLI & S. LEAL-BERTIOLI. 2018. Mapping of root-knot nematode resistance from the wild species A. stenosperma and introgression into peanut A. hypogaea. Plant and Animal Genome. San Diego, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: BALL�N-TABORDA, C., Y. CHU, P. OZIAS-AKINS, P. TIMPER, C.C. HOLBROOK, S.A. JACKSON, D.J. BERTIOLI & S. LEAL-BERTIOLI. 2018. Evaluation of Root-knot nematode (RKN) resistance from the peanut wild relative Arachis stenosperma incorporated in allotetraploid backcrossed lines. 10th AAGB International conference: Advances in Arachis through Genomics and Biotechnology. Saly, Senegal.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: LEAL-BERTIOLI S.C.M., H.T. STALKER, I.J. GODOY, J.F. SANTOS, C.C. HOLBROOK, P. OZIAS-AKINS, Y. CHU, J. CLEVENGER, G WRIGHT, M.C. MORETZSOHN, S.A. JACKSON & D.J. BERTIOLI. 2018. A detective tale: the worldwide influence of the wild species A. cardenasii on the peanut crop revealed through the lens of genome analyses. 50th Annual Meeting of the American Peanut Research and Education Society. July 10-12, 2018. Doubletree Hotel Williamsburg Williamsburg, VA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: LEAL-BERTIOLI S.C.M., M.C. MORETZSOHN, D. Gao, C. Ballen, Y Chu, P Ozias-Akins, T Stalker, CC Holbrook, S Jackson, D Bertioli. 2018. Peanut on the wild side  surprises of introgression with wild relatives. National Association of Plant Breeders 2018 Annual Meeting. University of Guelph Guelph, Ontario, Canada August 7-10, 2018
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: LEAL-BERTIOLI. S.C.M. 2019. The impact of genomics and wild crop relatives on peanut breeding: a new era in pursuit of food security. International Conference on Legume Genetics and Genomics. May 13-17, 2019. Dijon, France.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Y. CHU, B. M. CHANDLER, P. OZIAS-AKINS, H. T. STALKER, S. C. M. LEAL-BERTIOLI, D. BERTIOLI. 2018. Development of newly synthesized amphidiploids and their genome composition. 50th Annual Meeting of the American Peanut Research and Education Society. July 10-12, 2018. Doubletree Hotel Williamsburg Williamsburg, VA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: S. LAMON, D. BERTIOLI, S. C. M. LEAL-BERTIOLI, C.C. HOLBROOK, L. A. GUIMARAES, Y. CHU and P. OZIAS-AKINS. 2018. Genotypic and phenotypic characterization of peanut lines with interspecific introgressions conferring late leaf spot resistance. 50th Annual Meeting of the American Peanut Research and Education Society. July 10-12, 2018. Doubletree Hotel Williamsburg Williamsburg, VA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: S.C.M. LEAL-BERTIOLI, H.T. STALKER, I.J. GODOY, J.F. SANTOS, C.C. HOLBROOK, P. OZIAS-AKINS, Y. CHU, J. CLEVENGER, G WRIGHT, M.C. MORETZSOHN, S.A. JACKSON & D.J. BERTIOLI. 2018. A detective tale: the worldwide influence of the wild species A. cardenasii on the peanut crop revealed through the lens of genome analyses. 50th Annual Meeting of the American Peanut Research and Education Society. July 10-12, 2018. Doubletree Hotel Williamsburg Williamsburg, VA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: S.C.M. LEAL-BERTIOLI, H.T. STALKER, I.J. GODOY, J.F. SANTOS, C.C. HOLBROOK, P. OZIAS-AKINS, Y. CHU, J. CLEVENGER, G. WRIGHT, P. JANILA, M.C. MORETZSOHN, S.A. JACKSON and D.J. BERTIOLI. 2018. The impact of wild species in peanut breeding: old stories and future prospects. Advances in Arachis through Genomics and Biotechnology. Nov 12-16, 2018. Saly Senegal
  • Type: Other Status: Other Year Published: 2018 Citation: BALL�N-TABORDA, C. When close species get together: Homeologous chromosome exchange in the allopolyploid, peanut. Research seminar at the Institute of Plant Breeding, Genetics and Genomics. The University of Georgia. Athens, GA. 2018.