Identification of superior haplotypes for seed protein content in pigeonpea (Cajanus cajan L.)

Pigeonpea (Cajanus cajan L.) is an important source of quality dietary protein for over a billion people worldwide. The seeds of pigeonpea contain approximately 20–22% digestible protein, which makes it a valuable source of nutrition. Despite this, there has been little attention paid to enhancing the seed protein content (SPC) through genetic means. Recently, high-protein germplasm lines have been discovered in the secondary gene pool, which presents an opportunity to breed for high-protein cultivars. To accelerate the breeding process, genomics-assisted breeding (GAB) can be utilized. In this context, this study identified the superior haplotypes for the genes that control SPC in pigeonpea. Whole-genome re-sequencing (WGRS) data from 344 pigeonpea genotypes were analyzed to identify the superior haplotypes for 57 SPC governing genes. A total of 231 haplotypes in 43 candidate genes were identified, and haplo-pheno analysis was performed to provide superior haplotypes for 10 genes. The identification of superior haplotypes and genotypes will greatly facilitate the development of protein-rich pigeonpea seeds through the application of haplotype-based breeding (HBB).