BREEDING ONION AND WATERMELON FOR HIGHER YIELD AND ENHANCED TOLERANCE TO BIOTIC AND ABIOTIC STRESSES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1014064
• Project Start Date: Sep 21, 2017
• Project End Date: Aug 20, 2022
• Program Code: [(N/A)]- (N/A)

Recipient Organization
TEXAS A&M UNIVERSITY
750 AGRONOMY RD STE 2701
COLLEGE STATION,TX 77843-0001

Performing Department
Uvalde-TAMU Agr Res & Ext Cntr

Non Technical Summary
Onion (Allium cepa) is a high value vegetable crop in Texas. The share of spring onion production from Texas is more than 30 percent of all U.S. spring onion production, with a value of $83 million in 2013 (USDA NASS, 2015). However, the production declined in 2014 due to cooler wet conditions around harvest time, which increased pests and diseases, and reduced storability. Thrips (Thrips tabaci and Frankliniella fusca) is a major pest of onion and it is the main vector of Iris yellow spot virus (Tospovirus, IYSV). Other important diseases of onions are pink root (Phoma terrestris), powdery mildew (Leveillula taurica), botrytis leaf blight (Botrytis squamosal), stemphylium leaf blight (Stemphylium vesicarium), purple blotch (Alternaria porri), Fusarium basal rot (Fusarium oxysporum f. sp. Cepae, FBR), and slippery skin (Pseudomonas gladioli pv. alliicola). Host resistance has been one of the most effective approaches for managing pests and diseases. Our onion breeding program will emphasize breeding for host resistance for biotic stresses. Onion takes two years to complete a crossing cycle and consequently takes longer for cultivar development. Genetic gain per year can be increased by reducing the number of years it takes to develop a cultivar.With the use of double haploid, homozygosity will be reached in one cycle which utlimatelyreduces the cultivar development period.The effectiveness of DH for hybrid cultivar development will be explored to shorten the breeding cycle.Texas is one of the largest watermelon (Citrullus lanatus) producing states in the U.S. In 2014, watermelon was planted on 0.1 million acres with a total production of 3.1 billion pounds, with Texas ranking first with 0.52 billion pounds (USDA NASS, 2015). In addition to water (>90%), watermelons are known for their content of vitamins, lycopene, anti-oxidants, and amino acids.Fusarium wilt, gummy stem blight, and anthracnose are importance diseases of watermelon in the U.S. The project will use genomic selection tool for host resistance breeding.Genomic selection (GS) is a breeding tool where all molecular markers are fit into a model to predict breeding values for lines with an expectation that the genomic prediction model will increase genetic gains and decrease the breeding cycle. The GS will allow lines to be selected by genotyping before phenotypic evaluation. Markers across the whole genome will be used to select for lines as parents, to make crossing decisions, to enrich populations, and to select for lines for cultivar development. The GS will be carried out in the Texas A&M onion and watermelon breeding programs to shorten the breeding cycle and develop cultivars having higher yield, better end-use quality, and biotic and abiotic tolerance.

Animal Health Component

90%

Research Effort Categories

Basic

10%

Applied

90%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
201	1451	1081	100%

Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1451 - Onion, garlic, leek, shallot;

Field Of Science
1081 - Breeding;

Keywords

onion

watermelon

double haploid

genomic selection

Goals / Objectives
The overall goal of the program is to develop adapted and commercially viable onion and watermelon cultivars by identifying, incorporating, and pyramiding diverse types of resistance into elite genotypes. Our specific objectives for both crops are to: 1) evaluate watermelon germplasm for yield, end-use quality, and biotic and abiotic stress tolerance in Texas; 2) develop and release commercially viable high yielding, better end-use quality, and biotic and abiotic stress tolerance cultivars via GS; and 3) map disease and insect resistance genes/QTL and identify and develop diagnostic molecular markers for MAS.

Project Methods
Germplasm will be evaluated in the field with periodic checks for moving mean analysis in the first year. Genotypes showing better phenotypic characteristics will be advanced for crossing in the second year. There will be selfing from each selected genotype or fertile x fertile crosses will be made from the selected genotypes. In the third year, S1 or F1 progeny will be evaluated with appropriate checks in un-replicated trials at two locations using an augmented design. The best S1 progeny rows or the best F1 populations will be selected for selfing for the fourth year. The S2 or F2 population will be evaluated with appropriate checks in un-replicated trials at two locations in the fifth year. The selected progeny rows from S2 or F2 will be open pollinated in the sixth year. The genotypes will be evaluated in the observation nurseries with appropriate checks in a randomized complete block design at three locations. The best performing genotypes will be open pollinated in the eighth year. Early variety testing and advanced variety testing will be done with appropriate checks in a randomized complete block design in the ninth and eleventh year, respectively, before releasing a cultivar in the twelfth year. DH populations will be generated in the fourth year and subsequently evaluated in the Early Variety Trial (EVT) nursery; hence, the onion breeding cycle might be completed in eighth year.Male sterile A lines also will be developed. Germplasm will be evaluated with periodic checks for moving mean analysis in the first year. The best performing genotypes will be selfed or test crossed with male sterile lines to identify B lines. Once the B-lines are identified, they will be backcrossed with the appropriate male sterile line for four times to obtain A line pair of B line. It will take twelve years to obtain the A lines. Recently, Kim et al. (2015) reported molecular markers associated with fertility restorer gene. These molecular markers will be tested on Texas A&M onion germplasm to identify lines with recessive fertility restorer gene i.e. to identify B line. The best performing B lines will be crossed with male sterile line to generate A line. The use of molecular marker associated with fertility restorer gene will increase breeding efficient by avoiding the need for test crossing. The method of seed-to-seed generation in a year will be applied to develop A-line hence saving four years. These A -line pair of B -line will be used for onion hybrid cultivar development.For GS, training populations, germplasm and advanced lines, will be evaluated at three locations (College Station, Uvalde, and Weslaco) for watermelon at Texas. Data on yield, end-use quality, and biotic and abiotic stress traits will be collected. The training populations will be genotyped (genotyping-by-sequencing, GBS) at Texas AgriLife Genomics and Bioinformatics Center at College Station, TX. A genomic model will be developed using "rrBLUP" package in R software. Five elite parents will be selected and a partial diallel cross will be made to generate 10 F2 populations. The GS model will be validated on 10 F2 populations (50 lines in each population). Genomic prediction model will be used for estimating breeding values of lines. The possible parental crosses will be predicted using "PopVar" package in R software. Based on genomic prediction model, lines will be selected for cultivar development both in early (F2) and later generations (F3 and higher).

Progress 10/01/19 to 09/30/20

Outputs
Target Audience: Texas Winter Garden vegetable growers,Texas Department of Agriculture representatives and vegetable industry representatives were informed about the results of onions research at two South Texas Onion Committee meetings. High throughput phenotyping research outputs were shared with university faculty, USDA researchers, students, growers, and industry representative at the annual 2020 Americal Society of Horticultural Sciences conference. Researchers from Texas A&M, Texas Winter Garden vegetable growers andvegetable industry representativewere updated on onions and watermelon breeding research at the Annual Vegetable Working Group Meeting, College Station, TX. Onions and watermelon breeding results were shared with Texas A&M faculty, students and researchers via Plant Breeding Circle meeting. Changes/Problems:Due to COVID-19, a limited onion crossing and seed production was done in 2019-20 season. Watermelon nursery was delayed planted in July 2020 (normal planting is in May). Watermelon performance was poor due to a combination of factors - late planting and high biotic stresses (white fly and charcoal rot disease). What opportunities for training and professional development has the project provided?The project provided training and professional development for one Research Technician, one graduate student and two undergraduate students. Subas and Manzeal participated at Team Planning and hands-on bacterial isolation and inoculation Workshop under 'Stop the Rot' USDA NIFA SCRI project #2019-51181-30013 at University of Georgia, Athens, GA, 3-4 February 2020. Subas organized and participated at 'High throughput phenotyping for germplasm selection and cultivar breeding in vegetable crops' workshop at the annual American Society for Horticultural Sciences (ASHS) conference. Subas and Bed Prakash attended online workshop on CRISPR organized at TAMU.Nathalia Figueroa-Silva, an undergraduate from Sul Ross State University, and Mark Hernandez, an undergraduate from South West Texas Junior College, were trained on research field layout, planting, data collection, and post-harvest handling of vegetable crops to support vegetable breeding program at Uvalde.? How have the results been disseminated to communities of interest?Subas organized workshop titled 'High throughput phenotyping for germplasm selection and cultivar breeding in vegetable crops' at the annual 2020 ASHS conference. He gave presentation on 'Phenotyping for Disease Resistance Screening in Crops'. He also participated at South Texas Onion Committee meetings where he had interaction with representatives from growers, USDA, and industry. He also attended W3008 multistate project meeting. He also gave presentation of vegetable research outcomes to researchers, extension personnel and students at Plant Breeding Circle meeting organized by Soil and Crop Science Department at TAMU. Hesummarized and presented onion and watermelon research results to researchers at Annual Vegetable Working Group meeting at College Station, TX in January 2020. What do you plan to do during the next reporting period to accomplish the goals?The program has been conducting research on mapping anthracnose race 1 QTL in watermelon. Preliminary analysis had found one resistant QTL on chromosome 8. The program is testing more markers to identify diagnostics markers for the QTL. The diagnostic markers will be published and could be used for marker-assisted selection in the watermelon breeding programs (both public and private). The program had phenotyped four mapping populations for anthracnose race 2. The program has planned to genotype (GBS) on one population and validate the markers on the remaining three populations. The program will continue to evaluate Texas A&M onion and watermelon germplasm and breeding populations in 2020-21 season. Crosses will be made on selected lines to develop breeding populations. We will develop mapping populations to identify QTL for Stemphylium leaf blight.

Impacts
What was accomplished under these goals? A study was conducted to understand genotype x environment (GXE) interaction in watermelon in the southern region of TX. Twenty diploid genotypes were evaluated for total yield, total fruit count, total soluble solids, rind thickness, fruit length, fruit diameter and fruit weight traits at two locations, Uvalde and Weslaco TX, for two years, 2018 and 2019. The ANOVA results showed that genotypes did not significantly differ across locations and years. 'Crimson Diamond' was the highest yielder followed by 'Sunshade' and the breeding line TAM 2. Path analysis on fruit traits showed that a positive direct effect of 0.89 and 0.85 for total fruit count on yield and fruit diameter on yield, respectively. A negative indirect effect was observed between total fruit count and fruit weight (-0.20), total fruit count and fruit diameter (-0.13), and total fruit count and fruit length (-0.22). A negative indirect effect was observed between fruit weight and total fruit count (−0.44). The results inferred selecting for optimum total fruit count and fruit weight for yield. Anthracnose is one of the important diseases in watermelon. A study on inoculum concentration was conducted to understand the optimum inoculum for the seedling resistance screening. Five levels of inoculums - 25,000, 50,000, 100,000, 200,000 and 500,000 spores per mL - were tested on six levels of genotypes (Muchas Shandia, Charleston Gray, Black Diamond, H19 Little Leaf, Marketer and PI189225). The disease rating was scored after 5 days after inoculation (dpi) to 14 dpi. The results showed that 100,000 spores per mL was optimum for seedling resistance screening for anthracnose. The program developed 262 F1, 23 BC1, 146 generation advancement (F2, F3, F4) in the nethouse at Uvalde in FY 20. About 257 entries were planted in the field at Uvalde and will be evaluated for agronomic traits in the Fall 2020. About 955 lines were also planted seed were increased in the field at Uvalde. Thirteen recurrent selection populations, 41 F1 and 388 TAM breeding lines of onions were evaluated at Uvalde, TX in 2019-20 season. Three F1 and four TAM breeding lines had bulb maturity (April 15, 2020) at par with early cultivar check 'Vulcana'. Sixty two TAM germplasm showed bulb firmness higher or at par with commercial checks 'Francesca', 'Red Coach', 'Gabriella', 'Copperhead', and 'Cal 214 Imperial'. The program developed 131 new populations (104 F1 and 27 recurrent selection) were developed in 2019-20 season.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Bhatta, B.P. and S. Malla. 2020. Improving Horticultural Crops via CRISPR/Cas9: Current Successes and Prospects. Plants. 9(10): 1360.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Correa, E., S. Malla, K.M. Crosby, and C.A. Avila. 2020. Evaluation of Genotypes and Association of Traits in Watermelon Across Two Southern Texas Locations. Horticulturae. 6(4):67
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Carpenter, N.R., E. Wright, S. Malla, L. Singh, D. Van Sanford, A. Clark, S. Harrison, J.P. Murphy, J. Costa, S. Chao, G.L. Brown?Guedira, N. McMaster, D.G. Schmale III, C.A. Griffey, and N. Rawat. 2020. Identification and validation of Fusarium head blight resistance QTL in the US soft red winter wheat cultivar Jamestown. Crop Sci. 60(6):2919-2930.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Griffey, C., S. Malla, W. Brooks, J. Seago, A. Christopher, W.E. Thomason, R.M. Pitman, R. Markham, M.E. Vaughn, D.W. Dunaway, M. Beahm, C.L. Barrack, E. Rucker, H. Behl, T. Hardiman, B. Beahm, P. Browning, D. Schmale III, N. McMaster, J.T. Custis, S. Gulick, S.B. Ashburn, N. Joneds Jr., B.-K. Baik, H. Bockelman, D. Marshall, M. Fountain, G. Brown-Guedira, C. Cowger, S. Cambron, J. Kolmer, Y. Jin, X. Chen, K. Garland-Campbell, and E. Sparry. 2020. Registration of Hilliard Wheat. J. Plant Reg. 14(3):406-417.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Meier, N. A., S. Malla, J.C. Oakes, J.P. Murphy, B.-K. Baik, S. Chao and C.A. Griffey. 2020. Registration of Soft Red Winter Wheat VA11DH-P46xTrib-28, VA11DH-P46xTrib-99, and VA11DH-P46xTrib-103 Germplasm Lines with Exceptional Milling and Cookie Baking Performance. J. Plant Reg. 14(3):450-456.

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

Outputs
Target Audience: Texas Winter Garden vegetable growers, researchers, extension personnel,and vegetable industry representatives were informed about the results of onion and watermelon germplasm evaluations at Farmer's Field Day at Uvalde, TX. Researchers from Texas A&M were updated on onion and watermelon breeding status efforts at the Annual Vegetable Working Group Meeting, College Station, TX. Texas growers and industry were updated on watermelon breeding program at the Texas Watermelon Association Convention. Changes/Problems:In collaboration with Dr. Kimberly Cochran - Plant Pathologist, we were able to narrow down seedling foliar disease in watermelon to a germplasm (Klondike Black Seeded). Earlier testing for bacterial fruit blotch was negative. Subas is in touch with Dr. Carolee T. Bull (Penn State Univ)to test if the causal agent for the disease isPseudomonas syringae. What opportunities for training and professional development has the project provided?The project provided training and professional development for a research technician and three graduate students.Subas provided Texas status report at W3008 Multistate Onion Project meeting. Edgar Correa, Bed Prakash Bhatta and Roshan Paudel, graduate students, were trained on DNA extraction from leaf samples, artificial disease screening for germplasm, evaluation and selection of germplasm in the field, data collection, harvesting and post-harvest handling of vegetable crops. Manzeal Khanal, research technician, was trained on artificial disease screening for germplasm, crossing, data management, and data analysis. Subas, Manzeal, Edgar, Bed Prakash and Roshan visited watermelon growers' field to learn farming practices and scout diseases and insects at Dilley, TX and Brownfield, TX. How have the results been disseminated to communities of interest?Texas A&M AgriLife Research and Extension Center conducted Farmers Field Day in May 2019. Texas Winter Garden vegetable farmers, vegetable packers, researchers and extension personnel participated in the Field Day. Subas gave an oral presentation on results from onion, whereas Edgar gave an oral presentation on watermelon research. Subas presented findings for multilocation field trial in onion at W3008 multistate project meeting. Subas summarized and presented onion and watermelon research results to researchers at Annual Vegetable Working Group meeting at College Station, TX in December 2018. What do you plan to do during the next reporting period to accomplish the goals?The program is genotyping Charleston/New Hempshire Midget population to map anthracnose race1 gene locus in watermelon. The population was phenotyped by Dr. Wehner's group. The program had phenotyped four F2 populations (PI 189225/New Hampshire Midget, Perola/PI 189225, Sugarlee/PI 271778, and Verona/PI 189225) for anthracnose race 2 resistance. We plan to map and validate gene/QTL for race1 and race2 in 2020. The program will continue to evaluate about 350 additional Texas A&M onion germplasm in 2019-20 season. Data on leaf number, plant height, bulb diameter, bulb height, bulb weight, yield, diseases, insects, pyruvate and sugar will be taken from the field nursery in 2019-2020 season. About 100 lines selected in 2018-19 season will be evaluated for seed production traits. Crosses will be made on selected lines to develop breeding populations. We will develop mapping populations to identify QTL for Stemphylium leaf blight. We optimized DH technique in onion and developed few DH lines in 2019-20 season. We will put emphasis on generating DH lines as inbred parental lines for hybrid breeding program.

Impacts
What was accomplished under these goals? Goals: 1)Evaluate watermelon and onion germplasm for yield, end-use quality, and biotic and abiotic stress tolerance in Texas One-hundred diploid watermelon germplasm were evaluated for yield, quality and disease tolerance/resistance atUvalde, TX. Foliar bacterial disease (<15% disease incidence) was observed at seedling stage in the field. Texas A&M Plant Disease Diagnostic Lab reportedPseudomonassp. as a causal agent. As weather turned into dry and hot weather after seedling stage, bacterial disease did not progress. Though whitefly was observed in vegetable crops during watermelon growing season in Uvalde, less than 2% of the crop showed viral infection. Germplasm Wm-21 produced the highest total yield (101.6 t ha-1) followed by Big Crimson (100.8 t ha-1) and Nunhems #840 (100.0 t ha-1). TAM Expt #AM WM6 had the highest brix (11.60Bx) followed by TAM Expt # AM2 Yellow (11.50Bx), Crimson Sweet (11.50Bx) and Hebei China (11.50Bx). Texas A&M Plant Disease Diagnostic Lab detected Tobacco Mosaic Virus, alternaria leaf spot, cercospora leaf spot, thrips, spider mites and Cucumber Mosaic Virus on diseased leaf samples from Overton, TX. Pink root rot (Phoma terrestris) has been an important disease in onion.About three hundredonion lines, including cultivars as checks, were evaluated in the pink root screening nursery at Uvalde, TX during 2018-2019 season. Data on diseases, yield and other agronomic traits were recorded. The disease was recorded on a percentage of root infection where 0% = immune and 100% = highly susceptible. Germplasm showed variation for pink root rot (5% to 85%). Ten germplasm (TAM Expt #: 33015, 40026, 40027, 40060, 40061, 40066, 40067, 90519, 92007 and 92021) had the pink root severity of 5% indicating that the germplasm have resistance against the disease. TAM Expt #40055 had the highest yield of 40.9 t ha-1, followed by 'Don Victor' (38.3 t ha-1) and 'Althea" (35.4 t ha-1). 2) Develop and release commercially viable high yielding, better end-use quality, and biotic and abiotic stress tolerance cultivars via GS A total of 136 diploid F1 were evaluated for yield, quality and other agronomic traits at Uvalde, TX. A total of 43 F1 had brix value at or above 100Bx. The F1 progeny from Au-Sweet Scarlet/TAM Expt #AM WM6 had the highest brix (11.80Bx), whereas the F1 progeny from Long Crimson/Crimson Diamond produced the highest yield (59.6 t ha-1). Selected F1 progenies are being advanced to develop training and validation populations for genomic selection study. 3) Map disease and insect resistance genes/QTL and identify and develop diagnostic molecular markers for MAS In collaboration with Dr. Todd Wehner (North Carolina State University, NC), the program is genotyping (genotype-by-sequencing) Charleston/New Hampshire Midget to map anthracnose race1 gene in watermelon. Genetic study on PI 189225 X New Hampshire Midget F2mapping population showed that a single gene governed resistance for anthracnose race 2 in watermelon.We will utilize the mapping populations to map and validate QTL for anthracnose race1 and race2.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Liu, L., M. D. Barnett, C. A. Griffey, S. Malla, W. S. Brooks, J. E. Seago, K. Kirby, W. E. Thomason, E. G. Rucker, H. D. Behl, R. M. Pitman, D. W. Dunaway, M. E. Vaughn, J. T. Custis, B. Seabourn, R. Chen, M. Fountain, D. Marshall, R. A. Graybosch, L. A. Divis, L. E. Hansen, C. Cowger, S. Cambron, Y. Jin, B. R. Beahm, T. H. Hardiman, C. J. Lin, D. F. Mennel and D. L. Mennel. (2019). Registration of LCS Compass Wheat. J. Plant Reg. 13:50-57.

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

Outputs
Target Audience:- Undergraduate students at South West Texas Junior College, Uvalde, TX learned how breeding research methods are used and conducted in the vegetable breeding program. - Texas Winter Garden vegetable growers and vegetable packers were informed about the results of onion germplasm evaluations at Farmer's Field Day at Uvalde, TX. - Researchers across the U.S. were updated on Texas A&M watermelon breeding program and germplasm evaluation in onion. - Researchers from Texas A&M were updated on onion and watermelon breeding status efforts at the Annual Vegetable Working Group Meeting, College Station, TX. - Texas growers and industry were updated on watermelon breeding program at the Texas Watermelon Association Convention. Changes/Problems:Viruses (SLCV, Cucumber mosaic virus, Tobacco mosaic virus) were major problems in watermelon seed production in the nethouse. Seedling mortality in the greenhouse has been another major problem in watermelon. The seedling disease symptom was similar to the disease symptom caused by bacterial fruit blotch. We tested diseased leaf samples for bacterial fruit blotch using Agdia immunostrips kit. Samples tested negative for bacterial fruit blotch. The program in collaboration with plant pathologist will continue to work on identifying the causal agent for seedling mortality in the greenhouse. Due to high mortality of seedlings and viruses in the nethouse, we were not able to produce enough seed to conduct multilocation trial for USDA watermelon germplasm in 2018. ? What opportunities for training and professional development has the project provided?The project provided training and professional development for one Research Technician, four graduate students and two undergraduate students. Diwas Silwal joined the program as a graduate student (Ph.D.) in January 2018, whereas Bed Prakash Bhatta and Roshan Paudel joined the program as graduate students (Ph.D.) in August 2018. Subas, Edgar and Diwas participated and gave an oral presentation, two posters presentation, and a poster presentation, respectively at Southern Region American Society for Horticultural Sciences (ASHS) conference. Subas attended and presented an oral at ASHS conference. Subas also gave a presentation on vegetable breeding program at Texas Watermelon Association Convention. Edgar attended and presented a poster at Cucurbitaceae 2018 meeting. Subas provided Texas status report at W3008 Multistate Onion Project meeting. Nathan Olivarez, an undergraduate from South West Texas Junior College, was trained on research field layout, planting, data collection, crossing, harvesting and post-harvest handling of vegetable crops to support vegetable breeding program at Uvalde. Amanda Penney, an undergraduate from South West Texas Junior College, was trained on plant disease identification, insect identification, fungal culture, disease screening and genotyping to support vegetable breeding research at Uvalde. ? How have the results been disseminated to communities of interest?At Southern Region ASHS conference in February 2018, oral and poster presentations were made to disseminate the results for onion and watermelon research. Texas A&M AgriLife Research and Extension Center conducted Farmers Field Day in May 2017. Texas Winter Garden vegetable farmers, vegetable packers, researchers and extension personnel participated in the Field Day. Subas gave an oral presentation on results from onion and watermelon research and guided tour to the onion research field. In August 2018, Subas presented an oral titled "Short Day Onion Germplasm Evaluation in Southern Texas" at ASHS conference. In November 2018, Edgar presented multilocation watermelon research findings at Cucurbitaceae 2018 meeting, whereas Subas presented findings for multilocation field trial in onion at W3008 multistate project meeting. Subas summarized and presented onion and watermelon research results to researchers at Annual Vegetable Working Group meeting at College Station, TX in December 2018. What do you plan to do during the next reporting period to accomplish the goals?The program optimized artificial anthracnose screening protocol in the BSL1 greenhouse. Mapping populations for anthracnose race1 and race2 were developed at North Carolina State University and Texas A&M AgriLife Research in 2018. The vegetable breeding program will map and validate gene/QTL for race1 and race2 in 2019. The program will continue to evaluate about 350 additional Texas A&M onion germplasm in 2018-19 season. Data on leaf number, plant height, bulb diameter, bulb height, bulb weight, yield, diseases, insects, pyruvate and sugar will be taken from the field nursery in 2018-2019 season. About 100 bulbs selected in 2017-2018 season will be evaluated for seed production traits. Crosses will be made on selected lines to develop breeding populations. We will develop mapping populations to identify QTL for Stemphylium leaf blight. We optimized DH technique in onion and developed few DH lines in 2017-18 season. We will put emphasis on generating DH lines as inbred parental lines for hybrid breeding program.

Impacts
What was accomplished under these goals? 1) Evaluate watermelon germplasm for yield, end-use quality, and biotic and abiotic stress tolerance in Texas; Thirty-nine watermelon germplasm were evaluated for yield, quality and disease tolerance/resistance at three locations at Texas (Weslaco, Uvalde and College Station). Whitefly was observed in vegetable crops during watermelon growing season in Uvalde. Late in the season, watermelon plants showed stunted and deformed growth, whereas leaves were small, thickened, mottling and distorted. Upon testing at USDA-ARS, South Carolina, the plant samples were positive for Squash Leaf Curl Virus disease (SLCV). Whitefly is a vector for SLCV. A better management practice for whitefly and identification of SLCV tolerant germplasm is needed for higher crop productivity. An analysis of variance showed significant interaction (P < 0.05) between genotype and environment for total yield, sugar content, rind thickness, fruit number, and firmness. Texas A&M experimental (TAM Expt)#4 and 'Chubby Gray' were superior germplasm in Uvalde, whereas 'Crimson Diamond' was superior germplasm in College Station and Weslaco. 'Charleston Gray' and 'Chubby Gray' were stable germplasm. One hundred thirty-seven onion lines, including cultivars as checks, were evaluated at Uvalde, TX during 2017-2018 season. Data on diseases, yield and other agronomic traits were recorded. Pink root rot (Phoma terrestris) was an important disease observed during the season. The disease was recorded on a percentage of root infection where 0% = immune and 100% = highly susceptible. Germplasm showed variation for pink root rot (15% to 60%). Yellow H6 showed the least pink root rot (15%), followed by TAM Expt #50084 (17.5%) and TAM Expt #50014 (17.5%). TAM Expt #31028 had the highest yield of 69.6 t ha-1, followed by 'Vulkana' (67.7 t ha-1) and 'Sweet Sunrise' (65.7 t ha-1). 2) Develop and release commercially viable high yielding, better end-use quality, and biotic and abiotic stress tolerance cultivars via GS; The program acquired additional 134 watermelon germplasm from USDA repository in 2018. More than 150 crosses were made to develop breeding populations. The program evaluated about 37 early generation population for yield, quality and disease tolerance in the field. A high surge of whitefly population was observed during July. Stunted growth, mottling and distorted leaves were observed on plant in the field. Leaf samples were sent to USDA-ARS, SC to test for virus. Leaf samples were tested positive for SLCV. The program has about 200 USDA germplasm which will evaluated for SLCV resistance and whitefly tolerance in 2019. Fusarium oxysporum f. sp. niveum race2 was obtained from Dr. Cecilia McGregor (University of Georgia, GA) and stored at AgriLife Research Center, Uvalde. All watermelon germplasm will be screened for anthracnose race1 and race2 as well as Fusarium race2 in the greenhouse at Uvalde in 2019. 3) Map disease and insect resistance genes/QTL and identify and develop diagnostic molecular markers for MAS. Dr. Todd Wehner (North Carolina State University, NC) has developed anthracnose race1 and race2 resistance mapping populations. We also developed mapping populations for anthracnose race 2. We will utilize the mapping populations to map and validate QTL for anthracnose race1 and race2.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Carpenter, N.R., C.A. Griffey, L. Rosso, S. Malla, S. Chao, and G.L. Brown-Guedira. 2018. Mapping Lr18: A leaf rust resistance gene widely deployed in soft red winter wheat. J Plant Dis Biomark 1(1):4-10.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Correa, E., S. Malla, M. Khanal, C. Avila and K. Crosby. 2018. Evaluation of Watermelon Germplasm in Texas, a Genotype-By-Environment Study on Yield and Path Analysis on Associated Traits. Cucurbitaceae 2018, Davis, CA. 12-16 Nov. 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Silwal, D., S. Malla, and M. Khanal. 2018. Short Day Onion (Allium cepa) Germplasm Evaluation for Agronomic and Disease Tolerance in South Texas. Southern Region American Society for Horticultural Science Meeting, Jacksonville, FL. 2-4 Feb. 2018
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Malla, S., E. Correa, M. Khanal, C. Avila, and K. Crosby. Watermelon Breeding at Texas A&M. 53rd Annual Convention -Texas Watermelon Association, McAllen, TX. 8-10 Nov. 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Malla, S., E. Correa, M. Khanal, C. Avila, and K. Crosby. Watermelon Breeding at Texas A&M: A Molecular Approach. Southern Region American Society of Horticultural Science, Jacksonville, FL. 2-4 Feb. 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Malla, S., M. Khanal, D. Silwal, J. Jifon, B. Patil, K. Crosby, and E. Correa. Short Day Onion Germplasm Evaluation in Southern Texas. American Society for Horticultural Science, Washington, D.C. 31 July ⿿ 3 Aug. 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Malla, S., J. Jifon, I. Badillo and K. Crosby. Onion report ⿿ Texas. W3008 Onion Multistate Project, Kennewick, WA. 13 Nov. 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Correa, E., S. Malla, M. Khanal, C. Avila, and K. Crosby. 2018. Watermelon Germplasm Evaluation for Yield and its Components in South Texas. Southern Region American Society for Horticultural Science Meeting, Jacksonville, FL. 2-4 Feb. 2018.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Correa, E., S. Malla, M. Khanal, C. Avila, and K. Crosby. 2018. Application of Genomic Selection on Anthracnose in Texas A&M⿿s Watermelon Breeding Program. Southern Region American Society for Horticultural Science Meeting, Jacksonville, FL. 2-4 Feb. 2018.

Progress 09/21/17 to 09/30/17

Outputs
Target Audience: Undergraduate students at South West Texas Junior College, Uvalde, TX learned how breeding research methods are used and conducted in the vegetable breeding program. Texas Winter Garden vegetable growers and vegetable packers were informed about the results of onion germplasm evaluations at Farmer's Field Day at Uvalde, TX. International researchers under Cochran Fellowship were educated in molecular breeding through discussions and presentation of a seminar titled "QTL Mapping and Genomic Selection for Cultivar Development". Researchers from Texas A&M were updated on onion and watermelon breeding status efforts at the Annual Vegetable Working Group Meeting, College Station, TX. Changes/Problems:A total of 57 watermelon germplasm was obtained from USDA repository in 2017. Due to low number of seed availability and high mortality of seedlings due to bacterial infection, we could not evaluate the germplasm for yield, quality and diseases in the field in 2017. We obtained a second batch of seeds from the USDA repository and we are increasing seed for the germplasm in fall 2017. We propose to evaluate 57 USDA germplasm in the field in the summer 2018. What opportunities for training and professional development has the project provided?The project provided training and professional development for one Research Technician, one graduate student and two undergraduate students. Subas Malla visited Havey Lab (Dr. Michael Havey, USDA-ARS and University of Madison, WI) to learn genetics and breeding research in onion. Subas Malla and Manzeal Khanal visited Onion Breeding Program at University of New Mexico, NM and Watermelon Breeding Program at North Carolina State University, NC to learn the latest breeding research in onion and watermelon at the respective universities. Edgar Correa joined the program as a graduate student (MS) in August 2017. He was trained on statistical analysis of field data. Selena Ramirez, an undergraduate from South West Texas Junior College, was trained on field data collection, crossing and genotyping to support vegetable breeding program at Uvalde. Amanda Penney, an undergraduate from South West Texas Junior College, was trained on plant disease identification, insect identification, fungal culture, disease screening and genotyping to support vegetable breeding research at Uvalde. How have the results been disseminated to communities of interest?To provide understanding of vegetable breeding program, Subas delivered an oral presentation to undergraduate students at South West Texas Junior College, Uvalde, TX in March 2017. Texas A&M AgriLife Research and Extension Center conducted Farmers Field Day in May 2017. Texas Winter Garden vegetable farmers, vegetable packers, researchers and extension personnel participated in the Field Day. Subas gave oral presentation on results from onion research and guided tour to the onion research field. In June 2017, Subas presented an oral titled "QTL Mapping and Genomic Selection for Cultivar Development" to international scholars participated under Cochran Fellowship. Subas summarized and presented onion and watermelon research results to researchers at Annual Vegetable Working Group meeting at College Station, TX in October 2017. What do you plan to do during the next reporting period to accomplish the goals?Although anthracnose disease was not observed in the field in the summer 2017, we received anthracnose race1 and race2 cultures from Dr. Anthony Keinath (Clemson University, SC). Vegetable breeding lab was upgraded into biosafety level 1 plant pathology lab to maintain and multiply out of state anthracnose races. Artificial inoculation of the races to screen watermelon germplasm will be carried out in the greenhouse at Uvalde in the spring 2018. Watermelon germplasm received from USDA repository will be evaluated in the field in the summer 2018. Lines selected as parents will be utilized to develop validation population for genomic selection study. Genomic selection model will be developed for yield and quality traits from first year's field data. Later, genomic selection model will be developed for anthracnose resistance after screening germplasm in the greenhouse. Texas A&M onion germplasm will be evaluated in the field for the second year phenotyping. Crosses will be made for lines selected during 2017-2018 season. We will develop mapping populations to identify QTL for Stemphylium leaf blight. We will put emphasis on generating DH lines as inbred parental lines for hybrid breeding program. We will standardize DH technique in onion and develop DH lines.

Impacts
What was accomplished under these goals? Goal 1: a) Thirty-five Texas A&M watermelon germplasm were evaluated for yield, quality and disease tolerance/resistance at three locations at Texas (Weslaco, Uvalde and College Station). High incidence and severity of downy mildew was observed at College Station. The diseases were recorded on a scale of 0 to 9 where 0 = immune and 9 = highly susceptible. The disease severity ranged from 1 to 5. PI 244019 had the least disease to downy mildew at College Station, TX. Due to dry crop season at Weslaco and Uvalde in 2017, no major disease was observed. Line AM WM #1 Sel 2 produced the highest yield (37375 kg ha-1) at Weslaco, TX, whereas line AM2 Yellow produced the highest yield (75637 kg ha-1) at Uvalde, TX. ZWRM50 and Crimson Sweet had the highest 0Brix of 10.23% at Weslaco, TX. AU-Sugar Scarlet had the highest 0Brix (10.94%) at Uvalde, TX. b) One hundred fifty-one onion lines, including cultivars as checks, were evaluated at Uvalde, TX during 2016-2017 season. Data on diseases, yield and other agronomic traits were recorded. Stemphylium leaf blight (Stemphylium vesicarium) and pink root rot (Phoma terrestris) were important diseases observed during the season. The diseases were recorded on a scale of 0 to 9 where 0 = immune and 9 = highly susceptible. Germplasm showed variation for Stemphylium leaf blight (2.5 to 8.0) and pink root rot (1.0 to 8.0). Chinese germplasm showed the lowest Stemphylium leaf blight (2.5), whereas Texas A&M expt. lines 34155, 50034 and 50045 had the least pink root rot (1.0). Carta Blanca had the highest per bulb weight (566.9 g) followed by Texas A&M expt. lines 50023 (498.7 g) and 31074A (496.9 g). Goal 2: A total of fifty-two Texas A&M watermelon germplasm was evaluated for yield, quality and anthracnose (Colletotrichum orbiculate) disease at three locations at Texas (Weslaco, Uvalde and College Station). Additional 57 lines from USDA repository having variation for yield, diseases and quality traits were selected for evaluation in the summer of 2017. However, we could not evaluate USDA lines due to high mortality of seedling caused by bacterial disease. Since watermelon growing season was drier this year, anthracnose disease was not observed under the natural field condition. Germplasm were evaluated for yield and quality parameters at three locations and some lines were selected as parents to develop validation populations for genomic selection study. Anthracnose race1 and race2 fungal culture plates were received from Dr. Anthony Keinath (Clemson University, SC) and stored at AgriLife Research Center, Uvalde. All watermelon germplasm will be screened for anthracnose race1 and race2 in the greenhouse at Uvalde in the spring 2018. Goal 3: Dr. Cecilia McGregor (University of Georgia, GA) has developed mapping populations from twelve watermelon parents. We received twelve parents to screen for anthracnose resistance. We will screen parents for anthracnose race1 and race2 resistance in the greenhouse at Uvalde in the spring 2018. We will then utilize mapping population to identify anthracnose resistance QTL. We evaluated onion germplasm for Stemphylium leaf bight resistance and identified onion lines showing resistance to the disease. We are planning to develop mapping populations to identify Stemphylium leaf blight resistance QTL in onion in 2018.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Carpenter, N.R., C.A. Griffey, S. Malla, M. Barnett, D. Marshall, M.O. Fountain, J.P. Murphy, E. Milus, J. Johnson, J. Buck, S. Chao, G.L. Brown-Guedira, and E. Wright. (2017). Identification of Quantitative Resistance to Puccina striiformis and Puccina triticina in the Soft Red Winter Wheat Cultivar Jamestown, Crop Sci. 57(6):2991-3001.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Meier, N., N. Carpenter, S. Malla, C. Griffey, and B. Baik. 2017. Identification of Quantitative Trait Loci for Improved Flour Milling and Baking Traits to Facilitate Marker Assisted Selection in Soft Red Winter Wheat. In: Proceedings of the Plant and Animal Genome XXV (abstract), San Diego, CA, January, 2017.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Raman, R., X. Dong, S. Murray, W. Rooney, S. Malla. 2017. Characterization of drought tolerance traits in corn and sorghum: a phenotypical approach, ASA-CSSA-SSSA Annual Meeting (abstract), Tampa, FL, October, 2017.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Raman, R., X. Dong, S. Murray, W. Rooney, S. Malla. 2017. Water-Use Efficiency of Selected Corn and Sorghum Genotypes in Southwest Texas, The 29th Annual Conference of Texas Plant Protection Association (abstract), Bryan, TX, December, 2017.