Efforts to Domesticate Hairy Vetch (Vicia villosa Roth): Eliminating Hard Seed and Pod Shatter

Authors: Kissing Kucek, Lisa; Riday, Heathcliffe; Burke, Allen; EAGEN, SARAH - North Carolina State University; EHKLE, NANCY - University Of Minnesota; KROGMAN, S - Noble Research Institute; Mirsky, Steven; REBERG-HORTON, C - North Carolina State University; RYAN, MATT - Cornell University; TRAMMEL, MIKE - Noble Research Institute; WAYMAN, SANDRA - Cornell University; WIERING, NICK - University Of Minnesota

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/11/2020
Publication Date: 1/11/2020
Citation: Kucek, L.K., Riday, H., Burke, A.N., Eagen, S.S., Ehkle, N., Krogman, S., Mirsky, S.B., Reberg-Horton, C., Ryan, M.R., Trammel, M., Wayman, S., Wiering, N.P. 2020. Efforts to Domesticate Hairy Vetch (Vicia villosa Roth): Eliminating Hard Seed and Pod Shatter. Plant and Animal Genome Conference. 1/11/2020.

Interpretive Summary: Hairy vetch provides many benefits: supplying fertilizer to crops, reducing soil erosion, and improving water quality. Seeds of hairy vetch, however, do not readily sprout and easily shatter out of the pod. This causes hairy vetch to become a weed problem for farms. The tendency of vetch seeds to shatter also makes seed expensive, which discourages more farmers from using this conservation crop. We screened over 1600 hairy vetch lines to find those that readily sprouted and stayed intact in the pod. Although the majority of lines shattered and did not sprout, some lines were identified with the traits of interest. Lines that did not shatter, however, also tended to have low seed yield, which is undesirable.

Technical Abstract: Hairy vetch, Vicia villosa (Roth), is a common cover crop that supplies nitrogen and improves water quality. Seed dormancy and pod dehiscence reduces seed yield and makes the species a weed. Thousands of years ago, domestication efforts eliminated hard seed and shatter in many agricultural crops. We report on a domestication effort to reduce hard seed and pod dehiscence in hairy vetch. Among seven locations and three years in the United States, we screened over 1600 genotypes for seed dormancy, pod dehiscence, and force required to cause dehiscence. Genotypes exhibited a complete range of variation in the traits of interest, from 0 to 100% seed dormancy and pod shatter. Despite left-skewed distributions of both traits, outlier genotypes were identified with soft seed and low dehiscence. As seed dormancy and pod shatter were controlled by a small number of genes in related species, heritability was expected to be high. However, heritability of seed dormancy and pod shatter was moderate in hairy vetch, at h2=0.3 and 0.2, respectively. Weather conditions during plant growth, maturity timing, post-harvest handling, and time between harvest and sample screening all influenced seed dormancy and pod shatter. Such influences likely reduced heritability, clouding the typically simple genetic mechanisms behind these traits. A correlation between seed yield and pod dehiscence (r=0.124, p=0.0052) presented a tradeoff and additional challenge for selection.