Comprehensive phenotyping of SKUAST-K released rice varieties reveals significant role of root traits in drought resilience

The North Western Himalayan region, particularly the Kashmir valley, harbors a rich diversity of rice landraces, yet systematic studies on climate resilience are lacking. The present study was aimed at investigating the root traits and their interplay with shoot morphological and physiological traits under drought stress using seven indica and three japonica rice varieties released by SKUAST-Kashmir and their possible role in adaptive capacity to different environments. Significant variability was observed in root and shoot traits across the varieties. Root traits exhibited a wide phenotypic range, including rooting depth, fresh and dry weight, diameter, length, volume, surface area, and length density. Associations between root and shoot traits were identified, with notable correlations such as shoot weight with root shoot ratio, shoot length with root dry weight, diameter, and surface area, and tiller number with various root traits. Additionally, physiological traits like canopy temperature depression showed significant correlations with root depth and surface area. Principal component analysis (PCA) analysis grouped japonica type varieties together with a notable outlier, Chenab, due to its superior root traits among indica varieties. These findings emphasize the substantial contribution of root traits to productivity and advocate for their integration into varietal development processes. In view of the increasing evidences in crop plants about their role of root traits in defining plant productivity and reproductive fitness, study of root traits could provide valuable insights into the patterns of crop adaptation to diverse areas and growing environments.