Seed size has a major impact on fall seedling vigor in the cover crop hairy vetch (Vicia villosa Roth.)

Authors: Tilhou, Neal; Kucek, Lisa; MOORE, VIRGINIA - Cornell University; HANSON, SOLVEIG - Cornell University; REBERG-HORTON, CHRIS - North Carolina State University; RYAN, MATTHEW - Cornell University; EHLKE, NANCY - University Of Minnesota; BARTOW, AMY - Natural Resources Conservation Service (NRCS, USDA); CARR, BRANDON - Natural Resources Conservation Service (NRCS, USDA); DOUGLAS, JOEL - Natural Resources Conservation Service (NRCS, USDA); ENGLERT, JOHN - Natural Resources Conservation Service (NRCS, USDA); CRAWFORD, JAMIE - Cornell University; CRAWFORD, RYAN - Cornell University; ALI, SHAHJAHAN - Oak Ridge Institute For Science And Education (ORISE); BHAMIDIMARRI, SURESH - Dlf North America; Mirsky, Steven; MONTEROS, MARIA - Bayer Crop Sciences, Germany; Hayes, Ryan; Riday, Heathcliffe

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2024
Publication Date: 12/15/2024
Citation: Tilhou, N.W., Kucek, L.K., Moore, V., Hanson, S., Reberg-Horton, C., Ryan, M.R., Ehlke, N., Bartow, A., Carr, B., Douglas, J., Englert, J., Crawford, J., Crawford, R., Ali, S., Bhamidimarri, S., Mirsky, S.B., Monteros, M.J., Hayes, R.J., Riday, H. 2024. Seed size has a major impact on fall seedling vigor in the cover crop hairy vetch (Vicia villosa Roth.). Crop Science. 65(1). Article e21439. https://doi.org/10.1002/csc2.21439.
DOI: https://doi.org/10.1002/csc2.21439

Interpretive Summary: Cover crops can be planted between cash crops to reduce environmental harms such as erosion and nutrient leaching. Germination and establishment of new plants (seedlings) is challenging in fall established cover crops. Hairy vetch (Vicia villosa) is an aggressive legume which can produce nitrogen and supress weeds. Farmers prioritize greater vetch seedling vigor and selection for increased seed size could meet this need. This study found that seed size in a large experiment (>10,000 parent-progeny pairs) was strongly related to fall vigor across multiple growing environments. This study indicates that seed size is a major component of seedling vigor in the cover crop hairy vetch.

Technical Abstract: Seedling vigor is a critical trait for successful cover crop varieties. Selection for seed size can impact fall seedling vigor in the cover crop hairy vetch (Vicia villosa Roth). Fall vigor and seed size measurements from 1,239 plants and fall vigor measurements from 13,923 progeny across 25 different growing environments, were used to calculate narrow sense heritabilities, and identify relationships between variance components of fall vigor and seed size. Tandardized parent-progeny heritabilities were estimated across multiple years and environments and used to determine the impact of seed size on offspring fall vigor. A genome-wide association study for seed size (n=853, m=1,010,403, two environments) to explore genetic determinants associated with this trait. Seed size was influenced by parent genetics and parent growing environments, and had a significant impact on the fall vigor of the offspring. The narrow sense heritability of seed size was greater than visual fall vigor scores (0.580 and 0.111, respectively), and was less influenced by genotype-by-environment variance. Finally, parental seed size had a strong and consistent genetic correlation to offspring fall vigor relative to direct parental measurements of fall vigor (standardized parent-progeny heritability 0.17 for parent seed size-progeny fall vigor compared to nearly zero for parent fall vigor- offspring fall vigor). The genome-wide association study did not find significant loci controlling seed size. The strong correlation between seed size and fall vigor highlights an important consideration for growers since larger seed size may increase fall vigor, thus impacting the profitability for producers.