Assessment of genetic diversity for heat tolerance in advanced breeding lines of bread wheat (Triticum aestivum L. em.Thell.)

Abstract

Food security and public health are becoming major concerns for the global leaders due to climate change. The uneven distribution of rainfall and temperature has increased the global food demand with quality food. The current study was carried out for analysis of genetic diversity among 64 bread wheat genotypes for heat tolerance based on 21 morpho-physiological traits. The sixty four genotypes were grouped into five different clusters. Maximum number of genotypes was in cluster V (17) with lowest intra cluster distance (3.866) followed by cluster II (15), I (14), III and IV (each having 9 genotypes). Genotypes of cluster IV and I were more genetically diverse due to maximum inter cluster distance between them (8.873). The cluster II was designated as “highly tolerant” while cluster I and V as “moderately tolerant” and “highly sensitive” respectively, to heat stress on the basis of comparison of cluster mean values for yield and its major contributing traits like, peduncle length, flag leaf length, grain filling duration and so on. By collating their mean performance, the genotypes P-13348, P-13676, P-13820 and P- 14114 were found to be more heat tolerant in cluster II. Similarly, genotypes P-13808, P-13638 and P-14050 were found more moderately tolerant among cluster I genotypes and genotypes P-14106, P-14112 and P-14121 were most sensitive among the cluster V genotypes to terminal heat stress.