控制小麦穗颈长数量性状位点的遗传鉴定

为了解控制小麦穗颈长的遗传位点,以西藏半野生小麦Q1028与郑麦9023(ZM9023)杂交后所构建的重组自交系(RIL)群体为材料,于2011、2012、2013和2014年分别在四川农业大学温江试验田种植,对其穗颈长进行遗传分析。结果表明,群体内穗颈长呈正态分布,符合数量遗传的特点。在四年环境中,总共检测到4个控制穗颈长的QTL位点,分布于3A、5A和6B染色体上,贡献率为7.55%~11.44%。位于6B染色上wPt-669607~wPt-5480标记之间的QTL位点在三年环境中被稳定检测到。同时,四年环境下穗颈长与株高都呈显著正相关(P0.01),而仅在一年环境中与穗长呈显著正相关(P0.01),与小穗数、穗粒数、穗粒重、千粒重、粒长和粒宽无显著相关性(P0.05)。本研究鉴定的QTL为分子标记辅助选育穗茎长度适中的小麦品系及其进一步的精细定位奠定了基础。

Genetic Identification of QTL for Neck Length of Spike in Wheat

Neck length of spike(NLS,also known as panicle exertion) of wheat is regarded as an important indicator for ideal plant type in breeding programs. Compared to that in rice,the genetic base of NLS in wheat has been poorly studied. In this study,aiming at detecting QTL for NLS,a recombinant inbred line population derived from a cross between Tibetan semi-wild wheat Q1028 and Zhengmai 9023 were grown in Wenjiang,Sichuan in 2011,2012,2013 and 2015. The results showed that NLS of the recombinant inbred line population is normally distributed. Totally,four QTLs for NLS were detected on chromosome 3A,5A and 6B,with explained phenotypic variance ranging from 7.55% to 11.44% . Interestingly,the QTL located between wPt-669607 and wPt-5480 on 6B was detected across three growing seasons. In addition,correlation analysis indicated that NLS was significantly and positively related to plant height in four growing seasons(P<0.01). The significant and positive correlation(P<0.01) between NLS and spike length was detected in one growing season only. No significant correlation(P>0.05) between NLS and each of spikelet number per spike,grain number per spike,grain weight per spike,1 000-grain weight,grain length,and grain width(GW) was detected. Taken together,the identification of these QTLs laid the foundation of screening genotypes with proper length of NLS by molecular marker assisted selection and fine mapping of NLS controlled alleles.