Research Technician Boyce Thompson Institute Ithaca, New York
Body of Abstract: Cowpea (Vigna unguiculata) is an important crop in dry-land agriculture and a source of protein for many subsistence farmers. Cowpeas exhibit high levels of drought tolerance, but genetic constituents underlying drought stress resilience are yet to be identified. We developed a cost-efficient, non-destructive phenotyping protocol to monitor cowpea’s growth rate, evapotranspiration and photosynthetic efficacy and screened the UCR Minicore cowpea diversity panel. Through Genome Wide Association Study, we identified nine genetic loci associated with drought tolerance. As cowpea plants are difficult to transform, we pursued validation of identified loci through screening T-DNA insertion mutants in Arabidopsis homologoues. Out of 41 screened Arabidopsis mutants, 11 mutants showed larger rosette size under non-stress and drought stress conditions, including mutants of WRKY70, 1,8-cineole synthase, CAAX amino terminal protease, and xyloglucan hydrolase 16. Our results not only indicate a function of these genes under drought stress resilience, but also provide a low-cost and high-accuracy platform to screen large germplasm and identify genes involved in environmental resilience.