AUTHOR=Tilhou Neal , Kucek Lisa Kissing , Carr Brandon , Marion Annie , Douglas Joel , Englert John , Ali Shahjahan , Raasch John , Bhamidimarri Suresh , Mirsky Steven Brian , Monteros Maria J. , Krogman Sarah , Hayes Ryan , Azevedo Mark , Riday Heathcliffe 

TITLE=Genome-wide association mapping in hairy vetch (Vicia villosa) discovers a large effect locus controlling seed dormancy

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1282187

DOI=10.3389/fpls.2023.1282187

ISSN=1664-462X

ABSTRACT=<p>Hairy vetch (<italic>Vicia villosa</italic> Roth), a winter-hardy annual legume, is a promising cover crop. To fully leverage its potential, seed production and field performance of <italic>V. villosa</italic> must be improved to facilitate producer adoption. Two classic domestication traits, seed dormancy (hard seed) and dehiscence (pod shatter), are selection targets in an ongoing breeding program. This study reports a genome-wide association study of 1,019 <italic>V. villosa</italic> individuals evaluated at two sites (Knox City, Texas and Corvallis, Oregon) for the proportion of dormant seed, visual pod dehiscence scores, and two dehiscence surrogate measures (force to dehiscence and pod spiraling score). Trait performance varied between sites, but reliability (related to heritability) across sites was strong (dormant seed proportion: 0.68; dehiscence score: 0.61; spiraling score: 0.42; force to dehiscence: 0.41). A major locus controlling seed dormancy was found (<italic>q</italic>-value: 1.29 × 10<sup>−5</sup>; chromosome 1: position: 63611165), which can be used by breeding programs to rapidly reduce dormancy in breeding populations. No significant dehiscence score QTL was found, primarily due to the high dehiscence rates in Corvallis, Oregon. Since Oregon is a potentially major <italic>V. villosa</italic> seed production region, further dehiscence resistance screening is necessary</p>