Domesticating Vigna Stipulacea: A Potential Legume Crop With Broad Resistance to Biotic Stresses

Abstract

Though crossing wild relatives to modern cultivars is a usual means to introduce alleles of stress tolerance, an alternative is <i>de novo</i> domesticating wild species that are already tolerant to various kinds of stresses. As a test case, we chose <i>Vigna stipulacea</i> Kuntze, which has fast growth, short vegetative stage, and broad resistance to pests and diseases. We developed an ethyl methanesulfonate-mutagenized population and obtained three mutants with reduced seed dormancy and one with reduced pod shattering. We crossed one of the mutants of less seed dormancy to the wild type and confirmed that the phenotype was inherited in a Mendelian manner. <i>De novo</i> assembly of <i>V. stipulacea</i> genome, and the following resequencing of the F2 progenies successfully identified a Single Nucleotide Polymorphism (SNP) associated with seed dormancy. By crossing and pyramiding the mutant phenotypes, we will be able to turn <i>V. stipulacea</i> into a crop which is yet primitive but can be cultivated without pesticides.