Vegetos

Abstract

High temperature stress limits wheat production worldwide. Several studies reflect that genotypic variability exists for thermo-tolerance in wheat. In this study, genotypic varia-bility for thermo-tolerance was dissected at mo-lecular level. We accessed 20 selected bread wheat genotypes (10 thermo-tolerant and 10 thermo-sensitive) for genetic diversity analysis using random amplified polymorphic DNA (RAPD) and inter simple sequence repeats (ISSR) markers. In RAPD analysis, a total of 126 alleles were detected using 18 primers, among which 76 alleles (60.3%) were polymorphic. In ISSR analy-sis, using a total of 11 ISSR primers, 95 am-plified bands were obtained of which 46 (48.4%) were polymorphic. The average num-ber of polymorphic bands was higher in case of RAPDs (4.22) as compared to that in ISSRs (4.18). The clustering dendrogram generated by ISSR based similarity matrix, segregated thermo-tolerant and thermo-sensitive genotypes better than the RAPD based clustering dendrogram. One of ISSR primers (ISSR-41) amplified a ≈2800 bp band which was able to distinguish all the thermo-tolerant and sensitive genotypes except one. This marker identified in the study may po-tentially be used in marker assisted selection to develop thermo-tolerant wheat varieties.