Root Traits: A Key for Breeding Climate‐Smart Wheat (Triticum aestivum)

Abstract

Climate change poses a serious threat to global food security by introducing uncertainty in production condition including water availability to growing crops. Technological intervention like improved crop adaptation and higher yield potential through breeding are immediately needed to ensure better availability of food to still growing low‐ and middle‐income societies like South Asia. Root traits, such as root system architecture, root biomass, root angle, xylem diameter, root hairs, root length and root hydraulics, are crucial for plant adaptation to variable environments, but they are often overlooked in the most of crop improvement programme because of difficulty in scoring these traits. Water banking by optimization hydraulic efficiency of vascular system through reduced root density and reduced xylem diameter can play important role for adaptation for reduced water availability. The challenges of nondestructive screening in the segregating generation hampers the genetic progress Recent advances in high‐throughput phenotyping facilities and identification of molecular markers has made the selection in breeding population feasible. This review explores how root morphology and anatomy influence water and nutrient uptake and how high‐throughput phenotyping and genotyping can facilitate the identification of root traits associated with climate resilience. As outcome of the study, we propose an ideal wheat ideotype with deep roots, narrow root angles and low axial hydraulic conductance combined with high xylem hydraulic safety in pursuit of climate‐smart wheat crops thriving under decreasing water availability throughout the growing season. In this review, we have also discussed the root‐related quantitative trait loci/genes in wheat and its related species to facilitate comparative genomic analyses and their subsequent integration in the breeding programme. The review thus highlights the potential importance of optimization of metaxylem vessel size, root biomass, root length, roots hairs and understanding soil microbiota and its interaction with different root phenes in designing the better wheat ideotypes, which can offer the potential solution to climate change in the future.