Source: AUBURN UNIVERSITY submitted to
BREEDING COTTON FOR IMPROVED YIELD, FIBER QUALITY, AND PEST RESISTANCE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1006317
Grant No.
(N/A)
Project No.
ALA012-1-15004
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Apr 4, 2015
Project End Date
Mar 31, 2020
Grant Year
(N/A)
Project Director
Koebernick, JE, CL.
Recipient Organization
AUBURN UNIVERSITY
108 M. WHITE SMITH HALL
AUBURN,AL 36849
Performing Department
College of Agriculture
Non Technical Summary
Breeding cultivars and germplasms of cotton with higher yield and better resistance to pests is an environmentally friendly way of improving production with little cost to the producer. We propose to use standard breeding protocols to improve yield, fiber quality, and pest resistance in upland cotton. Crosses will be made among adapted parents and resistance sources, with selection for improved traits taking place in succeeding generations. Experimental genotypes will be tested for yield and fiber samples will be analyzed for fiber length, fiber strength, fiber uniformity and other traits identified as affecting processing and the quality of the finished product. We further propose to incorporate genes for resistance to reniform nematode in these populations and lines, as reniform nematode is a major pathogen affecting cotton production in Alabama. Populations segregating for this trait will be subjected to greenhouse evaluation for nematode reproduction, and performance in fields infested with reniform nematode will be evaluated.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20117101081100%
Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1710 - Upland cotton;

Field Of Science
1081 - Breeding;
Goals / Objectives
1. Determine the impact of genes for reniform nematode resistance in upland cotton, specifically with regard to their effectiveness in reducing yield losses in a field situation, and their associated effects on other important agronomic traits in cotton, specifically fiber properties.2. Develop and release improved cotton germplasm with superior field performance, fiber properties, and resistance to reniform nematode.
Project Methods
Standard conventional breeding methods will be used, together with selection for molecular markers associated with traits of interest. Crosses will be made between elite adapted experimental lines and cultivars and germplasm lines with various sources of resistance to reniform nematode. Progenies will be self-pollinated and advanced to the F2, F3 or F4 generation using the bulk method. Progeny-rows of plants in various generations will be evaluated agronomic traits and also evaluated in preliminary yield trials in at least one location. Plants and progenies will be evaluated for resistance to reniform nematode using standard nematode reproduction indices and also evaluated for molecular markers associated with resistance to reniform nematode. Fiber analysis, yield and nematode reaction will be evaluated using field trials, and lines superior for yield, fiber quality and reniform nematode resistance will be selected and tested in advanced trials the next year using similar methods. Lines with the best performance will be tested in advanced trials for a second year, and also evaluated in the Regional Breeders Testing Network (RBTN). Lines that continue to show good performance will continue to be tested in the RBTN and entered into the Alabama Cotton Variety Test. The best lines will be released as germplasm to be utilized by industry and the greater cotton community.

Progress 04/04/15 to 03/31/20

Outputs
Target Audience:The projectfocuseson the Alabama cotton growers and stakeholders. Each year the grower makes the decision of which cultivar to plant which is critical to their success. This work has been in collaboration with the cultivar testing personnel at Auburn and strives to determine grower and stakeholder needs. In addition, advanced breeding lines have been grown in other cotton growing regions to determine suitablility for breeding in those states. Ultimately, knowledge gained will directly impact the grower as anyimproved cultivars will be picked up by private industry. Secondary focus targets other researchers and breeders at other institutions they they may benefit and expand on the results of this work. Changes/Problems:David Weaver retired and I, Jenny Koebernick, started in 2016. At that time, research priorities shifted as the renifom nematode objectives were being addressed by other institutions. In 2019, research shifted to work primarily on Cotton Leafroll Dwarf Virus as it had major impact on the cotton producers of Alabama. What opportunities for training and professional development has the project provided?The project has graduated three masters' students, Gulsah kaplan, Carly Moore and Brianna Heilsnis and one PhD, Hayden Moye. In addition, there have been two postdocs. The project has allowed special topics to be taken from 3 undergraduate students, Courtney Garrett, Elizabeth Farrer and Kimberly Waggoner and multiple others have worked within the lab. For the PI, training and professional development, the project has supported countless presentations, trips to other institutions to learn from senior cotton breeders and participation in conferences. I have been the co-chair and chair for the Beltwide Cotton conference and the ASA community session (Cotton and other fibers) in 2019 and 2020. I am currently the associate editor of journal of plant registration. I have also served on numerous communities which has increased my contacts and increased my knowledge on the inner workings of academia and grant writing. In addition, I submitted aPVP for the department for AU Victory which wasgood experience on handling intellectual property. How have the results been disseminated to communities of interest?These projects have been presented each year at the Beltwide Cotton Conference and at the International Cotton Genome Initiative in Edinburgh, Scotland in 2018. The projects are published in Crop Science, Plant Disease, and Journal of Economic Entomology. In addition, I am a co-author on Alabama extension bulletins for the cotton virus CLRDV. Presentations were made each year to the Alabama Cotton commission and for the Alabama Farmers Federation Association. 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:In 2015, the evaluation for the Renbarb2 QTL as a gene for resistance to reniform nematode was completed. In a reniform nematode infested fields, 20 experimental recombinant inbred lines with the Renbarb2 QTL yielded 240 kg ha-1 more than 20 susceptible lines, a yield increase of 29% more than susceptible lines. However, in a nematode-free field lines with the Renbarb2 QTL yielded 10% less than lines without the QTL, so there is still a significant yield drag associated with the gene. Effects on fiber quality were minimal, but resistant lines with the QTL had 0.5 mm shorter fiber on average. We are continuing to develop lines with introgressed genes from the BARBREN-713 source of resistance, as well as lines from the M713 series of germplasm releases. Composite breeding lines were developed by self-pollinating at each generation in the greenhouse and a field study was conducted to evaluate the resistant lines coupled with nematicide use. This project was two years, 2107-2019, and the results showed that the resistance was strong but when coupled with a nematicide yields were improved. This suggest other sources of resistance are needed in order to eliminate the need for nematicides. As of 2020, commercial cultivars are available to the grower, this material is a direct outcome of the USDA-ARS and Auburn played a significant role in providing testing for the genotypic response as the state has high populations of reniform nematode. Target spot, caused by Corynespora cassiicola, has recently become a problematic disease in cotton (Gossypium hirsutum L.) in the southeastern U.S. While this pathogen affects other economically important crops, relatively little is known about C. cassiicola on cotton, especially with regards to conditions conducive for disease development and sources of genetic resistance. Therefore, in order to screen genotypes more efficiently for resistance, a greenhouse protocol is needed. Optimum temperature and conducive leaf wetness duration were determined in growth chamber trials. Temperature range for disease onset as well as greatest lesion counts occurred between 20 and 28°C. Generally, with ≥ 24 h leaf wetness at these temperatures, disease onset was noted 1 day after inoculation. A mist irrigation system was used to maintain long periods of leaf wetness in the greenhouse. In greenhouse trials, inoculation of cotyledons with 4 × 104 spores/ml allowed differentiation of five selected genotypes with disease reactions that reflected their field rankings. This protocol will be useful for evaluating cotton breeding lines for resistance to target spot. During September 2017, cotton plants at the Plant Breeding Unit (PBU) in Tallassee, Alabama exhibited virus symptoms (distorted new growth, discoloration, and stunting). This cotton had previously been infested with aphids (Aphis gossypii) the virus was initially identified as the 'atypical' form of Cotton leafroll dwarf virus (CLRDV) (genus Polerovirus, family Luteoviridae) It is generally regarded as the second most damaging virus disease to commercial cotton, second to Cotton leaf curl virus. Breeding efforts were initiated to screen for immunity to the virus. In 2019, 821 diverse cotton varieties were screened and 6% tested negative for the virus. A leaf disc assay was developed and all the lines that tested negative in the field could be infected with the virus. The experiment was repeated in 2020 and the we are waiting on test results. Objective 2: There are a number of advanced populations in the pipeline with moderate resistance and good fiber quality. Crosses were made in 2018in order to improve yield and agronomic on this material. Advanced material will be evaluated in 2021 for both agronomic and reniform resistance in the Regional Breeders Testing Network. If these traits are present, then release may occur as early as 2024.

Publications

  • Type: Book Chapters Status: Awaiting Publication Year Published: 2021 Citation: Patel, J., Lubbers, E., Chee, P. and J.C. Koebernick. 2020. Genetics and Genomics of Cottonseed Oil In: Tombuloglu, H. (ed) Oil Crop Genomics. Springer, New York, NY
  • Type: Journal Articles Status: Accepted Year Published: 2021 Citation: Koebernick, J.C., Ahl, J., and Weaver, D. 2021. Merging of plant breeding and pathology: A history of cotton breeding at Auburn. J. of Cotton Science.
  • Type: Journal Articles Status: Accepted Year Published: 2021 Citation: Moore, C., Sharma, N., Koebernick, J., and Bowen, K. 2020. Establishing a greenhouse protocol for evaluating resistance to Corynespora cassiicola in cotton. Plant Disease. Accepted
  • Type: Journal Articles Status: Under Review Year Published: 2021 Citation: McLaughlin, A., Heilsnis, B., Koebernick, J., Conner, K., and Jacobson, A. 2020. First Report of Tomato yellow leaf curl virus infecting Upland Cotton (Gossypium hirsutum) in Alabama, USA. Plant Disease.
  • Type: Journal Articles Status: Published Year Published: 2020 Citation: Thiessen, L., Schappe, T., Zaccaron, M., Conner, K., Koebernick, J. and Jacobson, A. 2020. First Report of Cotton Leafroll Dwarf Virus Affecting Cotton in North Carolina. Plant Disease.
  • Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Koebernick, J.C., Kaplan, G., Lawrence, K., Brown, S. and Sikkens, R. 2020. Response to nematicide by cotton genotypes varying in reniform nematode resistance. Crop Science.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: TRANSMISSION OF COTTON LEAFROLL DWARF VIRUS BY APHIS GOSSYPII Kassie Connor Brianna Heilsnis Jenny Koebernick Alana L. Jacobson Auburn University Auburn, AL
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: A Front Row Seat to Three Great Advancement in U.S. Cotton in the Past 25 Years Steve Brown, Jenny Koebernick ASA meeting 2020
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Effect of High Night Temperature on Soybean: Is There Cultivar Variation to High Night Temperatures?Tianchu Shu, Auburn University, Auburn, AL, Alvaro Sanz, Department of Crop, Soil, and Environmental Science, Auburn University, Auburn, AL, Jenny D Koebernick, 256 Funchess Hall, Auburn University, Auburn, AL and Charles Y. Chen, Auburn University, Auburn University, Auburn, AL ASA meeting 2020
  • Type: Theses/Dissertations Status: Accepted Year Published: 2020 Citation: Transmission and Host Plant Resistance of Cotton leafroll dwarf virus (CLRDV) in the Southeastern United States Brianna J Heilsnis
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Wang, H., D. B. Weaver, R. Sikkens, K. Lawrence, and R. Li. 2015. Performance screening results from Barbren-713 derived lines. p. 360  361. In S. Boyd and M. Huffman (ed). Proc. Beltwide Cotton Conf. San Antonio, TX.
  • Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: Madan Mohan Chapala. 2015. Exotic Germplasm Introgression Effects on Agronomic Traits and Fiber Properties of Upland Cotton. Ph. D. Dissertation, Auburn University.
  • Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: Wang, Huawei. 2015. Yield, Resistance and Fiber Quality Performance of Reniform Nematode resistant QTL Renbarb2 in BARBREN-713 Derived Upland Cotton Lines. M. S. Thesis, Auburn University.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Stallings, A. M, K. S. Balkcom, C. W. Wood, E. A. Guertal and D. B. Weaver. 2016. Nitrogen mineralization from AU Golden sunn hemp residue. J. Plant Nutrition 39: DOI:10.1080/01904167.2016.1193613
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Ogles, C.Z., E.A. Guertal, and D.B. Weaver. 2016. Edamame cultivar evaluation in central Alabama. Agron. J. 108: 2371- 2378.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Sikkens, R. B, D. B. Weaver, K. S. Lawrence and B. L. Nichols. 2016. Three years of field performance results of reniform nematode resistant germplasm lines. p. XXX-XXX. In S. Boyd and M. Huffman (ed). Proc. Beltwide Cotton Conf. New Orleans, LA.
  • Type: Journal Articles Status: Under Review Year Published: 2021 Citation: Investigating the Vector Competency of Aphis gossypii and Bemisia tabaci MEAM1 to Transmit Cotton leafroll dwarf virus. 2021. Brianna Heilsnis, Jenny Koebernick, Alana Jacobson, and Kassie Conner. Journal of economic entomology.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Hu, Hongtao, A. M. Rashotte, N. K. Singh, D. B. Weaver, L. Goertzen, S. R. Singh, and R. D. Locy. 2015. The complexity of posttranscriptional small RNA regulatory networks revealed by in silico analysis of Gossypium arboreum L. leaf, flower and boll small regulatory RNAs. PLoS ONE 10(6): e0127468. doi:10.1371/journal.pone.0127468
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Li, Ruijuan, A. M. Rashotte, N. K. Singh, K. S. Lawrence, D. B. Weaver, and R. D. Locy. 2015. Transcriptome analysis of cotton (Gossypium hirsutum L.) genotypes that are susceptible, resistant, and hypersensitive to reniform nematode (Rotylenchulus reniformis). PLoS ONE 11/2015; 10(11):e0143261. DOI:10.1371/journal.pone.0143261
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Chen, J., D. B. Weaver, N. Xiang, and K. S. Lawrence. 2016. Inoculum level effect of Corynespora cassiicola on evaluation of cotton resistance in a controlled environment. p. XXX-XXX. In S. Boyd and M. Huffman (ed). Proc. Beltwide Cotton Conf. New Orleans, LA.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Koebernick, Constable, Liu and Stiller. 2019. Parental selection strategy for improving fibre strength and maintaining lint yield in cotton. Industrial Crops 129: 585-593
  • Type: Theses/Dissertations Status: Published Year Published: 2020 Citation: Screening for target spot (Corynespora cassiicola) resistance in cotton (Gossypium hirsutum L.). Carly Moore. Auburn University
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Birdsfoot Trefoil (Lotus corniculatus) Cultivars Adaption Concerning Drought and Heat Tolerance Enabling the Expansion of Geographic Adaptation to include Alabama Along with Disease Resistance to Fungi and Nematodes as well as Herbicide Injury. Hugh Moye. Auburn University
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: INVESTIGATING RENIFORM NEMATODE RESISTANT GENOTYPES IN COMBINATION WITH VELUM TOTAL IN COTTON GOSSYPIUM HIRSUTUM L. Gulsah Kaplan. Auburn University
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Testing and validating alleles (or QTLs) conferring resistance to reniform nematode, Rotylenchulus reniformis, from M713 Ren4 in a different genetic background


Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The stake holders for this project are Alabama soybean and cotton growers. The target audience are consumers of cotton clothing, textile mills, cotton gins, beef cattle farmers and cotton producers. This project also encompasses training next generation breeders and scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Beltwide Cotton Conference- New Orleans, LA- Presented ALFA organizational meeting- Montgomery, AL- Presented Soybean Breeders Workshop- St Louis, MO United Soybean Board- Annual Board Meeting- Dallas, TX Southern Southeastern Regional Cotton Commission Meeting- Amelia Island, GA- Presented (Invited) Georgia Annual Plant Pathology Meeting- Savannah, Ga Alabama Crop Management Annual Meeting- Perdido Key, Fl- Presented (Invited) Alabama Crop Improvement Annual Meeting- Auburn, Al Auburn Short Row Course- Auburn, AL National Association of Plant Breeders Annual Meeting- Callaway Gardens, GA (invited) Southern Soybean Disease Workshop- Pensacola, FL Crops Meeting at Hudson Alpha- Huntsville, AL Cotton Incorporated Breeders Tour- College Station, TX (Invited) RCRS Meeting- Birmingham, AL (Invited) Presented to the undersecretary of Agriculture (Invited) Genetics and Genomics for improved cultivar Team meeting 2020 Beltwide Planning Meeting- Austin, TX Meeting with Alan Ford of Global Ag Contacts and prime genetics for testing cultivars in Greece. Material Transfer agreement with Bayer to breed round-up ready trait. Promotion and Tenure information session Search committee for cotton agronomist, blueberry breeder, variety testing and plant genomics position at Hudson Alpha Organized CLRDV meetings at Pensacola and Auburn University Spectrum IQ informational tutorial Met with industry reps for cotton clrdv trial Participated in the genetics and genomics for improved cultivars team Early Career working group at NAPB Wrote article on AU-NPRL 17 for NAPB newsletter Interviewed by Southeast Farm Press and Cotton Growing magazine for CLRDV Ethical Conduct and Research Training for USDA CPPM grant How have the results been disseminated to communities of interest?The manuscript is in preparation and will be submitted this year. What do you plan to do during the next reporting period to accomplish the goals?The plan is to release germplasm that is distinct, uniform and stable for the renifrom resistant breeding lines.

Impacts
What was accomplished under these goals? An agronomic study was completed to determine the use of reniform resistant cultivars and their interaction with nematicides. The results demonstrate that the resistant cultivars did not warrant the exclusion of the nematicide at this time. Resistance levels need to be increased with in the available germplasm.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Koebernick, Constable, Liu and Stiller. 2019. Parental selection strategy for improving fibre strength and maintaining lint yield in cotton. Industrial Crops 129: 585-593


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:This project targets cotton and soybean stakeholders for the growers, Alabama Farmers Federation, United Soybean Board and Cotton Incorporated. The efforts are directed at generating knowledge for improved cotton and soybean production using the available commercial cultivars combined with the best management practices. The project primarily focuses on germplasm enhancement and cultivar improvement. Classes are taught in plant breeding and advanced crop production each year. Undergraduate research projects as well as graduate projects for both MS and PHD fall under this project. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has allowed professional training in a molecular lab learning techniques for SSR marker analysis. It has allowed travel to USDA-ARS in Starkville, MS, to visit with the scientist at the pulse of this issue. This knowledge was invaluable for understanding the genetic mechanism and deciphering our own results. How have the results been disseminated to communities of interest?This project was presented at the Beltwide Cotton Conference in 2018 and a publication will be submitted in spring of 2019. What do you plan to do during the next reporting period to accomplish the goals?This next cycle will work on breeding for agronomic traits and generating pure breeding material for the sister lines with nematode resistance. A publication on the management study will be submitted and work will gravitate to other pests in the state.

Impacts
What was accomplished under these goals? The 2nd year of a nematode by management field study was completed under heavy renifrom nematode pressure. The information generated demonstrated that the current level of resistance is not high enough to reduce the need for nematicides. There are two QTL's that contribute the most to the known resistance from the line GB 713. The sister lines that were developed under this project do indeed have the markers related to these QTLs. Our lines have high field performance, good fiber properties with decent resistance to reniform nematode.

Publications


    Progress 10/01/16 to 09/30/17

    Outputs
    Target Audience:Breeding new cotton cultivars and improving germplasm with higher yield and disease resistance is an environmentally friendly way of improving cotton production. We propose to use standard breeding protocols to improve yield, fiber quality, and pest resistance in upland cotton. Crosses will be made among adapted parents and resistance sources, with selection for improved traits taking place in succeeding generations. Breeding lines will be tested for yield and fiber samples will be analyzed for fiber length, fiber strength, fiber uniformity and other traits identified as affecting processing and the quality of the finished product. We further propose to incorporate genes for resistance to reniform nematode in these populations and lines, as reniform nematode is a major pathogen affecting cotton production in Alabama. Populations segregating for this trait will be subjected to greenhouse evaluation for nematode reproduction, and performance in fields infested with reniform nematode will be evaluated. Changes/Problems:There has been the addition of Target spot and Fusarium wilt resistance breeding in the program. These are two prevalent diseases in the state and management strategies are becoming more limited. Resistant cul;tivars are highly desirable. What opportunities for training and professional development has the project provided?There are three graduate students on the project ranging from nematode resistance to yield and quality improvement.Several graduate and undergraduate students have worked on this project. One Ph.D. student graduated in August 2015 and conducted field research on the impact of exotic germplasm introgression on cotton yield and fiber quality. One M.S. student graduated in December 2015 and conducted field and laboratory research on the impact of the Renbarb2 QTL on yield and fiber properties. Also a 3 + 2 student from China Agricultural University conducted greenhouse work associated with the target spot inoculum and evaluation research as part of her undergraduate thesis at CAU. Currently a Turksih student is working on population 194 and its response to the nematocide Velum Total. How have the results been disseminated to communities of interest?This research was presented at the Beltwide Cotton Conference in 2016 and 2018. The Alabama Cotton Comission helps fund this project and every year stakeholders see the value and progress of the program. What do you plan to do during the next reporting period to accomplish the goals?We will continue to work on introgression of genes for resistance to reniform nematode into adapted cotton germplasm, and evaluate the impact of various resistance genes on other traits in cotton. Populations in various stages of development will be planted and evaluated as a part of the cultivar development efforts. Crosses will be made among elite cotton lines to create populations for further evaluation. Work will continue on development of evaluation methods for resistance to targe spot.

    Impacts
    What was accomplished under these goals? A population 194 was created by crossing resistant lines into an elite conventional cultivar in 2013. In 2017, the yield potential of these lines does not lag behind yields obtained with established commercial cultivars.Fiber quality of lines in population 194 is comparable with the quality of existing cultivars. All the tested cotton varieties showed signs of nematode damage (perhaps at different thresholds), exist our population. However, the extent of the damage/yield losses is most definitively influenced by resistance/tolerance levels within the plants, as well as by a multitude of external factors (climate, soil characteristics, soil humidity, soil fertility, environment, etc.).? Superior lines have been identified for yield and fiber quality, which will be incorporated into the core breeding program and retested next year.

    Publications


      Progress 10/01/15 to 09/30/16

      Outputs
      Target Audience:Target audience is professionals in the area of plant breeding and genetics. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training and experience has been provided to undergraduate students and also to my replacement. How have the results been disseminated to communities of interest?We have communicated our results via refereed journal articles and at research conferences. What do you plan to do during the next reporting period to accomplish the goals?Since I retired in 2016, I do to plan to pursue any of the stated goals. That will be up to my successor.

      Impacts
      What was accomplished under these goals? Field experiments were conducted in both reniform-infested field and reniform-free fields using a variety of sources of resistance to reniform nematode in advanced generation breeding lines. One major problem that was identified is that resistance does not seem to be stable for some reason. We continued our work on breeding improved types of cotton genotypes, with several lines being identified for future testing. The project is being handed over to a new researcher this year.

      Publications

      • Type: Journal Articles Status: Published Year Published: 2016 Citation: Stallings, A. M, K. S. Balkcom, C. W. Wood, E. A. Guertal and D. B. Weaver. 2016. Nitrogen mineralization from AU Golden sunn hemp residue. J. Plant Nutrition 39: DOI:10.1080/01904167.2016.1193613
      • Type: Journal Articles Status: Published Year Published: 2016 Citation: Ogles, C.Z., E.A. Guertal, and D.B. Weaver. 2016. Edamame cultivar evaluation in central Alabama. Agron. J. 108: 2371-2378.
      • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Sikkens, R. B, D. B. Weaver, K. S. Lawrence and B. L. Nichols. 2016. Three years of field performance results of reniform nematode resistant germplasm lines. p. XXX-XXX. In S. Boyd and M. Huffman (ed). Proc. Beltwide Cotton Conf. New Orleans, LA.
      • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Chen, J., D. B. Weaver, N. Xiang, and K. S. Lawrence. 2016. Inoculum level effect of Corynespora cassiicola on evaluation of cotton resistance in a controlled environment. p. XXX-XXX. In S. Boyd and M. Huffman (ed). Proc. Beltwide Cotton Conf. New Orleans, LA.


      Progress 04/04/15 to 09/30/15

      Outputs
      Target Audience:Scientists, extension personnel, crop consultants, producers Changes/Problems:I plan to retire sometime in 2016. A search for a replacement for my position is already underway. I anticipate the transition to be very smooth. What opportunities for training and professional development has the project provided?Several graduate and undergraduate students have worked on this project. One Ph.D. student graduated in August and conducted field research on the impact of exotic germplasm introgression on cotton yield and fiber quality. One M.S. student graduated in December and conducted field and laboratory research on the impact of the Renbarb2QTL on yield and fiber properties. Also a 3 + 2 student from China Agricultural University conducted greenhouse work associated with the target spot inoculum and evaluation research as part of her undergraduate thesis at CAU. How have the results been disseminated to communities of interest?Research results have been published, or will be published in refereed journals as well as a dissertation and a thesis. Some of the research has been presented to the cotton producers of Alabama. More wasdisseminated at the Beltwide Cotton Conferences in January. What do you plan to do during the next reporting period to accomplish the goals?We will continue to work on introgression of genes for resistance to reniform nematode into adapted cotton germplasm, and evaluate the impact of various resistance genes on other traits in cotton. Lines that are more advanced will be field-evaluated in 2016. Populations in various stages of development will be planted and evaluated as a part of the cultivar development efforts. Crosses will be made among elite cotton lines to create populations for further evaluation. Work will continue on development of evaluation methods for resistance to targe spot.

      Impacts
      What was accomplished under these goals? Continuous cotton breeding has been conducted at Auburn University since 2001. In 2015 cultivar development efforts have been put temporarily on hold, as personnel changes precluded the large-scale field-testing requirements. Other efforts continued, with the final year of evaluation of the Renbarb2 QTL as a gene for resistance to reniform nematode. In a reniform nematode infested fields, 20 experimental recombinant inbred lines with the Renbarb2 QTL yielded 240 kg ha-1 more than 20 susceptible lines, a yield increase of 29% more than susceptible lines. However in a nematode-free field lines with the Renbarb2 QTL yielded 10% less than lines without the QTL, so there is still a significant yield drag associated with the gene. Effects on fiber quality were minimal, but resistant lines with the QTL had 0.5 mm shorter fiber on average. We are continuing to develop lines with introgressed genes from the BARBREN-713 source of resistance, as well as lines from the M713 series of germplasm releases. These are now at the F2:4 stage and are being greenhouse evaluated for resistance to reniform. Field testing will follow. We have also continued to work on methods of evaluating cotton genotypes for resistance to target spot (caused by Corynespora cassiicola). Greenhouse testing of inoculum level revealed that concentrations of 1 ×103 and 1 ×104 conidia ml-1 were better at discriminating among genotypes of known field reaction than higher inoculum levels. We have also continued to participate in the Regional Breeders Testing Network in 2015, evaluating 23 elite breeding lines against 5 adapted cultivars.

      Publications

      • Type: Book Chapters Status: Published Year Published: 2015 Citation: Weaver, D. B. 2015. Cotton nematodes. p. 547  570. In D. Fang (ed.) Cotton. American Society of Agronomy Monograph. Madison, WI.
      • Type: Journal Articles Status: Published Year Published: 2015 Citation: Hu, Hongtao, A. M. Rashotte, N. K. Singh, D. B. Weaver, L. Goertzen, S. R. Singh, and R. D. Locy. 2015. The complexity of posttranscriptional small RNA regulatory networks revealed by in silico analysis of Gossypium arboreum L. leaf, flower and boll small regulatory RNAs. PLoS ONE 10(6): e0127468. doi:10.1371/journal.pone.0127468
      • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Wang, H., D. B. Weaver, R. Sikkens, K. Lawrence, and R. Li. 2015. Performance screening results from Barbren-713 derived lines. p. 360  361. In S. Boyd and M. Huffman (ed). Proc. Beltwide Cotton Conf. San Antonio, TX.
      • Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: Madan Mohan Chapala. 2015. Exotic Germplasm Introgression Effects on Agronomic Traits and Fiber Properties of Upland Cotton. Ph. D. Dissertation, Auburn University.
      • Type: Theses/Dissertations Status: Published Year Published: 2015 Citation: Wang, Huawei. 2015. Yield, Resistance and Fiber Quality Performance of Reniform Nematode resistant QTL Renbarb2 in BARBREN-713 Derived Upland Cotton Lines. M. S. Thesis, Auburn University.
      • Type: Journal Articles Status: Published Year Published: 2015 Citation: Li, Ruijuan, A. M. Rashotte, N. K. Singh, K. S. Lawrence, D. B. Weaver, and R. D. Locy. 2015. Transcriptome analysis of cotton (Gossypium hirsutum L.) genotypes that are susceptible, resistant, and hypersensitive to reniform nematode (Rotylenchulus reniformis). PLoS ONE 11/2015; 10(11):e0143261. DOI:10.1371/journal.pone.0143261