Mapping of QTLs for frost tolerance and heading time using SSR markers in bread wheat

Abstract

Selection for complex genetic traits, such as frost tolerance, can be simplified in plant breeding programs when linked markers were detected. The use of microsatellite markers for tagging and mapping important genes or QTLs is a goal in wheat genetic projects. In this study, 200 microsatellite markers were studied and after parental assay, 41 polymorphic SSR markers were used for genotyping of 280 F2 individual plants derived from F1 generation of wheat cross (Norstar× Zagros). The progeny of individual F2 plants were used as F2:3 families for the assessment of LT50 and heading time. Single marker analysis revealed that seven markers with total of 27% of phenotypic variance determination linked to LT50 and five markers linked to the heading time. Two markers that were located on 2B and 5A chromosomes affected both LT50 and heading time significantly. It was assumed, therefore, that some closely linked QTLs or QTLs with pleiotropic effects govern both traits simultaneously, as the LT50 of F2:3 families were significantly correlated with the heading time of F2:3 families, Thus, it is concluded that later heading time is associated with the higher level of frost tolerance in wheat.