Thermotolerance-related QTL Mapping of Spring Wheat at Filling Stage

BAI Haibo; Lü Xuelian; HUI Jian; ZHU Yongxing; SHA Xinling; KANG Xuebing; DONG Jianli; LI Shuhua

doi:10.15933/j.cnki.1004-3268.2018.12.002

Abstract：In order to find out thermotolerance-related genes of spring wheat at filling stage, recombinant inbred lines(RILs) constructed by Ningchun No.4×Ningchun No.27 were used as material, the chlorophyll content, relative water content, grain weight per spike and thousand-kernel weight were determined under three heat stress and normal temperature conditions, the number and chromosome distribution of thermotolerance-related QTLs were analyzed using mixed-model based composite interval mapping method.The results showed that the parent Ningchun No.4 had higher heat tolerance than Ningchun No.27, and the RILs exhibited transgressive segregation.Most QTLs which controlled heat tolerance traits at filling stage were located on chromosomes 2A, 2B, 3A, 4B, 4D, 5D, 6A, 6D and 7B.Thirteen, eight, fourteen, ten QTLs which controlled chlorophyll content, relative water content, grain weight per spike, thousandkernel weight respectively were detected under three heat stress conditions.A total of 33 additive QTLs were located on all chromosomes except 1A, 1B, 4A and 7A, the phenotypic contribution rate of QTLs reached 5.16％—61.13％.Qtkw-2B.2 and Qtkw-3D.2 had greater contribution rate, Qtkw-2B.2 and Qtkw-7B.1 had greater additive effect.The genetic effect of QTLs which controlled chlorophyll content, relative water content, grain weight per spike mainly was additive effect.Most QTLs were specific under single temperature treatment, indicating that these traits were affected by a certain temperature.