Variability of root and agro-morphological traits, and grain yield of elite spring wheat lines developed for high temperature tolerance

A set of fifty bread wheat genotypes that comprised of 49 high temperature tolerant lines from CIMMYT and a local check Gautam were evaluated for root, early vigor and agro-morphological traits at the research farm of Agriculture and Forestry University, Rampur during the winter season 2016/2017 under late sown condition to facilitate screening for post anthesis heat stress. The experiment was laid out following Alpha Lattice design with two replications. Significant differences were observed in the field experiment for number of roots, root length of field (assessed at Zadok's growth stage 12), days to booting, heading, flowering, flag leaf senescence and maturity among the studied genotypes. Similarly, significant differences were observed for plant height, grains per spike, thousand grain weight, grain yield, biomass yield, harvest index, canopy temperature depression 10 days after flowering (CTD-2), SPAD reading immediately after flowering (SPAD-1), 10 days after flowering (SPAD-2) and 20 days after flowering (SPAD-3), flag leaf area and number of tiller per square meter. The mean root length was 8.24 cm. The mean grain yield was 3.23 ton ha-1. 15HTWYT-41 had the highest yield 4.35 ton ha-1 followed by 15HTWYT-38, 15HTWYT-30 and 15HTWYT-42 while genotype Gautam had 2.83 ton ha-1. Thirty seven genotypes out-numbered local check Gautam in terms of yield. Biomass yield, number of grain per spike and CTD-2 were found to be the major traits. Correlation analysis revealed significant positive correlation between grain with flag leaf area, plant height, number of grain per spike, biomass yield, harvest index, thousand kernel eight, SPAD-1, SPAD-2. Days to booting, days to heading and days to flowering showed negative significant correlation with the grain yield. From the overall analysis, genotypes 15HTWYT-41, 15HTWYT-38 15HTWYT-30 15HTWYT-42 performed superior to the check Gautam.