Exploration of global faba bean germplasm for agronomic and nitrogen fixation traits

Abstract

The growing regional and global interests in legume crops for cover cropping and sustainable agriculture has provided new opportunities for growers to incorporate faba bean (Vicia faba L.) into their production systems. Much of faba bean's potential, especially in the western United States, is rooted in its high N fixation potential compared with other cultivated legumes. However, faba bean production is currently hindered by existing markets, regional agronomic extension guides, and availability of regionally adapted cultivars. This experiment began the effort to bridge one of the three gaps by evaluating 63 regionally and globally derived plant materials for agronomic and N fixation traits in four environments in California's Central Valley. The experiment observed significant (P ≤.05) genotype × environment interactions for all faba bean N and agronomic except % of N derived from the atmosphere, harvest index, and 100-seed weight. Further, we found opportunities to leverage global germplasm to increase or decrease the 100-seed weight and days to flowering in locally adapted plant materials. Finally, this experiment identified trait-trait-associations that provide both opportunities and challenges to improving screening efficiencies (e.g., link between N yield and 100-seed weight in Chico2019 [r = 0.57; P ≤.001] and in Fresno2020 [r = 0.51; P ≤.001]). This work sets a framework for regional faba bean cultivar development work in the western United States.