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玉米(Zea mays)出籽率作为典型的数量性状,受微效多基因控制,且易受环境因素影响,因而在育种实践中限制了对其进行遗传改良的能力。为挖掘不同环境条件下稳定遗传的控制玉米出籽率性状的QTL,同时分析QTL与环境的互作效应。本研究以许178×K12衍生的150个重组自交系(recombinant inbred lines,RIL)群体为实验材料,通过2年3点的田间实验,分别利用单环境分析、多环境联合分析和上位性分析方法,对玉米籽粒出籽率性状的表型数据和最佳线性无偏估计值(best linear unbiased prediction,BLUP)值进行QTL分析。采用出籽率表型值进行单环境分析,共检测到13个QTL位点,分布在第1,3,5,6,7,8和9染色体上,单个QTL可解释6.74%~22.18%的表型变异;利用最佳线性无偏估计值BLUP值进行QTL分析,共定位到4个位点,且均在单环境中被检测到。多环境联合分析检测到8个QTL位点,加性效应贡献率范围0.78%~2.31%,互作贡献率范围为0.21%~1.96%;上位性分析共检测到15对加性×加性互作位点,分布在所有染色体上。本研究通过多环境对玉米出籽率进行QTL定位,共筛选出4个能够稳定遗传出籽率性状的的染色体区域即Bin1.06~1.07,Bin6.01~6.02,Bin8.07和Bin9.03~9.05。同时发现,出籽率性状与环境存在着复杂的互作效应,上位性效应也是影响玉米出籽率性状的重要遗传基础。本研究结果将为今后种质资源的改良以及分子标记辅助育种(marker assisted selection,MAS)提供理论指导。
The seed yield of Zea mays, as a typical quantitative trait, is controlled by the microscopic polygene and is susceptible to environmental factors, thus limiting its ability to be genetically modified in breeding practice. In order to explore the QTL for controlling the seed-yield rate trait of maize in different environmental conditions, the interaction between QTL and environment was analyzed. In this study, 150 recombinant inbred lines (RIL) populations derived from 178 × K12 were used as experimental materials. By 2-year and 3-point field experiments, single-environment analysis, multi-environment analysis and epistasis analysis Method, QTL analysis was performed on phenotypic data and best linear unbiased prediction (BLUP) values of seed-yield traits in maize. A single environmental analysis based on the phenotypic values of seed-yield showed that 13 QTLs were detected on chromosomes 1, 3, 5, 6, 7, 8 and 9, and single QTL explained 6.74% -22.18% Phenotypic variation; QTL analysis using the best linear unbiased estimate of BLUP value co-localized to 4 loci and were all detected in a single environment. Multiple QTL analysis detected 8 QTLs, with the contribution rate of additive effect ranging from 0.78% to 2.31% and the contribution rate of interaction ranging from 0.21% to 1.96%. Epistasis analysis detected a total of 15 pairs of additive × additive As a locus, distributed in all chromosomes. In this study, the QTL mapping of maize seed yield was conducted in a multi-environment, and four chromosome regions that could stably inherit the seed-yield traits were Bin1.06 ~ 1.07, Bin6.01 ~ 6.02, Bin8.07 and Bin9.03 ~ 9.05. At the same time, it is found that there is a complex interaction effect between the trait yield rate and the environment, and the epistatic effect is also an important genetic basis that affects the trait yield of maize. The results of this study will provide theoretical guidance for future improvement of germplasm resources and marker assisted selection (MAS).