Advances in genomics and molecular breeding for legume improvement

Abstract

Grain legumes are a key source for human nutrition and animal feed in the world. Also, these crops are important to support sustainable, low-input, and diverse farming systems. Efforts to improve legume crop yields have delivered modest outcomes. Increasing the productivity of these crops in an increasingly challenging environment with dwindling natural resources such as land and water demands the immediate incorporation of breakthrough technologies in crop breeding programs. A variety of genomic technologies in combination with modern breeding designs are now in place to optimize strategies for accelerated legume crop improvement. The current genomic arsenal of these grain legume crops includes reference genome assemblies and resequenced genomes, high-density molecular markers and genome maps, and a variety of genes/QTLs controlling agriculturally important traits. Innovative breeding techniques such as genomic selection and speed breeding that significantly reduce the breeding cycle time have been optimized in legume crops to improve breeding outcomes. The continuous decline in sequencing costs has paved the way for adopting sequence-based breeding to improve the breeding populations and varietal development. In this chapter, we highlight the recent genomic advances made in three major semiarid tropic (SAT) grain legume crops, that is, chickpea, pigeonpea, and groundnut. We follow with a discussion on how these technological advances have been translated into molecular breeding products in these crops. The chapter also explores opportunities to adopt modern breeding techniques to hasten the rate of genetic gains in these crops.