The plant journal
The plant journal
RESOURCE
A multi-parent advanced generation inter-cross population for genetic analysis and improvement of cowpea (Vigna unguiculata L. Walp.)
SUMMARY
SUMMARY
Multi-parent advanced generation inter-cross populations are an emerging type of resource for dissecting the genetic structure of traits and improving breeding populations. We developed a multi-parent advanced generation inter-cross population for cowpea (Vigna unguiculata L. Walp.) from eight founder parents. These founders were genetically diverse and carried many abiotic and biotic stress resistance, seed quality and agronomic traits relevant to cowpea improvement in the United States and sub-Saharan Africa, where cowpea is vitally important in the human diet and local economies. The eight parents were inter-crossed using structured matings to ensure that the population would have balanced representation from each parent, followed by single-seed descent, resulting in three hundred five recombinant inbred lines each carrying a mosaic of genome blocks contributed by all founders. This was confirmed by single nucleotide polymorphism genotyping with the Illumina Cowpea Consortium Array. These lines were on average ninety-nine point seven four percent homozygous but also diverse in agronomic traits across environments. Quantitative trait loci were identified for several parental traits. Loci with major effects on photoperiod sensitivity and seed size were also verified by biparental genetic mapping. The recombination events were concentrated in telomeric regions. Due to its broad genetic base, this cowpea multi-parent advanced generation inter-cross population promises breakthroughs in genetic gain, quantitative trait locus and gene discovery, enhancement of breeding populations and, for some lines, direct releases as new varieties.