Physiological and morphological evaluation of MABB derived lines under drought stress in bread wheat (Triticum aestivum L. em. Thell.)

The present study was conducted to assess the performance of advanced lines developed through marker assisted backcross breeding (MABB) program for different morphological and physiological traits under drought stress. A popular widely grown but drought susceptible Indian bread wheat variety, HD2733 was improved by transferring QTLs linked to traits like chlorophyll content, canopy temperature, normalized difference vegetation index (NDVI) and grain yield under drought stress, from a known drought tolerant variety, HI1500. The backcross derived lines were phenotyped at BC2F3 and BC1F4 generation and a significant difference (at P<0.05) was observed for traits such as NDVI, chlorophyll content, thousand kernel weight and grain yield/plot at phenotypic level. Few backcross derived lines showed enhancement over recipient parent for morpho-physiological traits as well as yield under drought stress. Distinctness, uniformity and stability (DUS) characters in selected backcross derived lines were similar to the recipient parent indicating higher recovery of the recipient parent genome. We selected 20 lines in BC2F3 and 9 lines in BC1F4 (with average yield of 265.39gm/plot) on the basis of their superior performance against parental genotypes HD2733 (242.31gm/plot) and HI1500 (253.74gm/plot). Among the 29 lines, five lines were identified to be superior during assessment in multi-location yield trials.