earticle

영어

Low temperature tolerance (LT) is an important agronomic trait in winter wheat that determines the plants ability to cope with below freezing temperatures. To identify genomic regions, which determine the level of LT tolerance in hexaploid wheat, F2:3 and F2:4 populations produced from crossing between winter type tolerant parent Mirnovoskaya 808(LT50 =-20 oC) and spring type, susceptible parent, Pishtaz (LT50 =-7 oC) were analyzed. The levels of LT tolerance for these populations were evaluated using artificial freeze test LT50, the temperature at which 50%of plants were killed by LT stresses. The molecular analyses were assessed using 170 SSR primer pairs and 22 AFLP primer combinations. The result of phenotypic analysis showed continuous distribution of trait values (LT50 =-3 to -23 oC) which is in agreement with the distribution of trait expected for a polygenic and quantitatively inherited trait. The relationship between LT tolerance ( LT50) and genotypic data was analyzed using single marker analysis, interval mapping and composite interval mapping methods. Three detected QTLs for spring parent, Pishtaz, with partial dominant effects and three detected QTLs of winter parent, Mirnovoskaya 808, with over dominant effects. Because the detected QTLs located on the 5B and 7D chromosomes and other ones which were linked to AFLP markers were inherited in both parents; therefore theses results do confirm the effectiveness of both parents for this characteristic.