Cluster Analysis of Wheat (Triticum aestivum L.) Genotypes Based Upon Response to Terminal Heat Stress

Abstract

High temperature stress adversely affects plant physiological processes; limiting plant growth and reducing grain yield. Heat stress is often encountered due to late sowing of wheat in winter. Fifty wheat genotypes were studied for days to maturity, thousand kernel weight, grain filling duration, grain filling rate, and SPAD reading in alpha lattice design at Agriculture and Forestry University at Rampur, Chitwan, Nepal with the objective to identify superior heat stress tolerant varieties after clustering them based on their response to heat stress. All the genotypes were clustered using reduction in thousand kernel weight, heat susceptibility index for thousand kernel weight, heat susceptibility index for grain filling duration, area under SPAD retreat curve, maturity duration under normal condition, maturity duration at late sown condition, grain filling rate under normal condition and grain filling rate at late sown condition as variables and dendogram was prepared. UPGMA revealed that these genotypes formed five distinct clusters. The resistant genotypes and susceptible genotypes formed different clusters. The member of cluster 3 was found to be tolerant to terminal heat stress where as members of cluster 2 were found most susceptible to terminal heat stress. From this study genotype BAJ #1/SUP152 was found most tolerant to terminal heat stress. The genotypes belonging to superior cluster could be considered very useful in developing heat tolerant variety and other breeding activities.

Rising Atmospheric Temperature Impact on Wheat and Thermotolerance Strategies

“…Cell membrane stability [50,51,188,189] Proline content [131,[190][191][192] Heat susceptibility index for grain yield [25,[193][194][195][196] Chlorophyll content [76,131,188,189,197,198] Photosynthesis [48,106,107,117,199]…”

Genetic Divergence in Micronutrient Rich wheat– A Tool to Identify Diverse Parents

“…Crossing of genotypes from these groups can increase the micronutrient concentration by combining the diverse genes controlling different morphological traits into single plant. Such recommendations in wheat breeding has been advocated by different researchers in past by [7,8,9,10]. Genotype HP-44, HP-49, HP-13 and HP-14 lying in different clusters can be ideal candidate lines for utilization in hybridization with adapted varieties namely, HD-3086, RSP-561 and JAUW -683 provided they have high zinc and iron content.…”

Effects of salinity stress on proline content and expression ofΔ1-pyrroline-5-carboxylate synthaseandvacuolar-type H+subunit Egenes in wheat

“…According to the results of the bi-plot analysis in this study, Mihan and Shirudi cultivars were recognized as the most sensitive and Backcross and Roshan as the most resistant bread wheat cultivars under moderate and high salinity levels, respectively. Cluster analysis was also performed to classify cultivars in different groups (Calin´ski and Harabasz, 1974; Poudel et al ., 2017; Bazzaz et al ., 2019). Based on the cluster analysis, Mihan and Shirudi, as the sensitive cultivars, as well as the Backcross and Roshan, as the tolerant ones, were grouped into a separated group under moderate and high salinity levels (online Supplementary Figs S5 and S6).…”