小麦重组自交系(RILs)群体碳同位素分辨率的QTL分析

QTL Analysis on Carbon Isotope Discrimination of Wheat RILs

为了探知小麦水分利用效率(WUE)碳同位素分辨率(Δ)的遗传机理,以小麦重组自交系(RILs)群体为材料,在不同水分条件下研究Δ的遗传规律,并进行QTL定位。结果表明:(1)RILs群体的Δ值呈正态分布,Δ属于数量性状遗传。(2)共检测到11个主效QTL,主要位于2B、3B、7B、1D和3D染色体上,表型贡献率在10.83%~46.87%之间,有9个加性QTL(A-QTL)与环境发生互作,互作贡献率在1.02%~3.15%之间。(3)检测到5对影响Δ的上位QTL(AA-QTL),其中3对AA-QTL与环境发生互作,互作贡献率在0.86%~2.01%之间。(4)加性效应及贡献率大于上位性效应及贡献率,A-QTL与环境互作贡献率大于AA-QTL与环境互作贡献率,表明RILs群体中Δ遗传变异主要受加性效应影响,控制Δ的主效基因作用较大,受水分环境影响较小。

In order to understand the genetic mechanism of carbon isotope discrimination （Δ） and water use efficiency（WUE） in wheat, we used recombinant inbred lines （RILs） of wheat to study the genetic basis of Δ under different water treatments, based on QTL mapping and environment-specific assistive effect analy- sis. The results show that： （1） Δ value in the RILs population showed a normal distribution, indicating that Δ is a quantitative trait. （2） We detected 11 major-effect Δ QTLs in 2B, 3B, 7B, 1D, 3D and analyzed their phenotypic variation rate between 10.83%- 46.87%, 9 additive N environment interactions QTLs and analyzed their phenotypic variation rate between 1.02%--3. 15% were detected. （3） We detected 5 pairs of epistatic QTLs which include 3 pairs of epistatic QTLs and their interactions rate between 0. 86% --2.01%. （4） Additive effect and contribution rate were larger than epistatic effect and contribution rate, A-QTL and A-QTL X environment contribution rate were larger than AA-QTL X environment contribution rate. The results indicated that the genetic variation of Δ in the RILs population was mainly affected by additive effect QTLs, the major-gene-controlled Δ has a greater effect than the water environment.