Advances in "omics" approaches to tackle drought stress in grain legumes

Grain legumes being affordable sources of proteins, vitamins and essential micronutrients are key to human nutrition worldwide. However, frequent drought episodes present serious threat to grain legume production worldwide. Advances in legume omics in concert with evolving phenotyping and breeding techniques hold great promise to improve drought response of these crops. These resources could underpin prebreeding efforts to expedite discovery and deployment of novel drought tolerance traits into elite backgrounds. Fast-track transfer of traits that confer drought tolerance using marker technologies has been demonstrated in grain legumes like chickpea. However, complex genetic architecture of drought tolerance demands embracing more efficient tools like genomic selection (GS) for accelerated trait improvement. Recent studies on GS for addressing complex traits like drought tolerance have yielded encouraging results in these crops. Recently, speed breeding (SB) protocols have also been optimized for the improvement of long-day/day-neutral grain legumes. Efficacy of SB protocols with regard to complex traits awaits further evidences though. There remains immense scope for integrating SB with GS and gene editing to deliver drought-tolerant cultivars.