Understanding Trait Architectures to Accelerate Pigeonpea (Cajanus Cajan) Improvement

Although pigeonpea ( Cajanus cajan ), a pivotal grain legume crop of semiarid tropics, has immense biological and socioeconomic significance, genetic improvement in this crop compared to other field crops, such as legumes like soybean or chickpea, in particular, has lagged. Understanding the complex architecture of traits with economic values, viz., abiotic stress tolerance, disease resistance, nutritional enrichment, and yield enhancement, recent advances made in omics technologies bring tremendous promise to speed up pigeonpea breeding. In combination with their interactions with breeding and multi-omics, contributing to the clarification of trait architecture, this chapter addresses general physiological and agronomic processes, as well as the importance of genomics tools for pigeonpea traits’ improvement. Additionally, crop wild relatives (CWRs) are among the principal genetic resource materials for breeding programs to enhance and dissect beneficial traits of pigeonpea. Moreover, the incorporation of multi-omics studies contributes to a comprehensive understanding of molecular mechanisms and gene networks that underpin trait expression. Very generalized and commonly used genomics technologies like genome-wide association study (GWAS), quantitative trait loci (QTL) mapping, and genomic selection (GS) are used to search for genes and potential biomarkers that can be used for breeding purposes, also with the aid of newly evolved biotechnological tools and integrative platforms. In an era of climate change and increasing global food demands, this chapter discusses omics-assisted breeding strategies in conjunction with state-of-the-art computational approaches that can play a significant role in fast-tracking genetic gains in pigeonpea, and contribute to enhanced pigeonpea production and cultivational sustainability.