Leveraging legume genomic resources to identify genes associated with non-seed shattering in hairy vetch (vicia villosa roth)

Authors: HERNANDEZ, TIM - Noble Research Institute; ALARCON, YANINA - Noble Research Institute; Kissing Kucek, Lisa; KROM, NICK - Noble Research Institute; MONTES, CHRISTY - Noble Research Institute; SHAHJAHAN, ALI - Noble Research Institute; Riday, Heathcliffe; MONTEROS, MARIA - Noble Research Institute

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/11/2020
Publication Date: 1/11/2020
Citation: Hernandez, T.D., Alarcon, Y., Kucek, L.K., Krom, N.D., Montes, C., Shahjahan, A., Riday, H., Monteros, M.J. 2020. Leveraging legume genomic resources to identify genes associated with non-seed shattering in hairy vetch (vicia villosa roth). 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, 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 475 hairy vetch lines to find genes associated with pod shatter. Lines that did and did not shatter were found to have different genetic regulation mechanisms. These mechanisms can be incorporated in breeding programs to select low shatter lines. Such lines can help improve the sustainability of agriculture.

Technical Abstract: Hairy vetch (Vicia villosa Roth) is a versatile annual legume with utility as both a forage and cover crop. It has the capacity for biological nitrogen fixation, serves as a ground cover to protect from soil erosion and improves soil structure. Seed shattering is the natural ability of plants to disperse seed and continue with the next generation. However, seed shattering is undesirable in agricultural systems as it presents challenges for seed harvest that leads to seed yield losses. Selection against seed shattering has been successful as part of the domestication process, but non-seed shattering is still a target of improvement in hairy vetch and other legume breeding programs. The objective of this project is to identify genetic components associated with non-seed shattering in hairy vetch leveraging existing resources in legumes and complemented with association studies with genotypes contrasting for seed shattering in the field. Genotyping-by-sequencing (GBS) enabled characterization of sequence variants in hairy vetch accessions with a range of seed shattering phenotypes. Molecular pathways and regulatory elements involved in pod dehiscence including transcription factors catalogued in other species served as templates to capture sequence variants in hairy vetch. Additional exploration of differential gene expression in common vetch resulted in additional gene targets to complement the genome-wide SNP discovery efforts to explain the genetic variation in the seed shattering phenotype. Deployment of comparative genomics approaches combined with transcriptome mining and genome-wide SNP discovery efforts can facilitate understanding of the genetic mechanisms underlying non-seed shattering in hairy vetch. The genomic tools developed can serve to launch future genome-wide association studies and fine mapping to inform selection decisions in breeding programs aimed at developing cultivars with seed retention capabilities.