基于MAGIC群体的水稻抽穗期和产量相关性状全基因组关联分析

【目的】挖掘水稻抽穗期和产量相关性状新基因,并筛选携带有利等位基因的优良株系,为分子标记辅助育种提供新基因和优异种质。【方法】以多亲本重组自交系群体MAGIC-Hei群体为材料,分别于2017和2018年连续两年种植于湖南长沙开展抽穗期和产量性状表型调查,基于基因分型(genotyping by sequencing,GBS)技术进行全基因组关联分析发掘影响水稻抽穗期、单株有效穗数、每穗粒数、结实率、千粒重和单株产量性状QTL。【结果】在两个环境下共计检测到26个控制抽穗期和产量相关性状的QTL,分布于除第10染色体外的其他染色体上。其中,11个位点为新位点,1个新位点(qNTP9)在两年均被检测到,该位点受环境影响较小,可用于进一步的精细定位和基因克隆。根据抽穗期和产量性状表型数据,结合SNP基因型筛选到5个携带有利等位基因的优良株系,可用于将来的水稻高产育种。【结论】本研究发掘一批新的水稻抽穗期和产量相关性状QTL位点,可有效加速水稻遗传研究和高产育种进程。

Genome-wide Association Analysis of Rice Heading Date and Yield-related Traits Based on MAGIC Population

【Objective】The objective of the study is to identify new genes related to heading date and yield related traits in rice,and to screen the elite rice lines carrying favorable alleles,therefore providing new genes and excellent germplasm for molecular marker-assisted(MAS)breeding.【Method】The multi-parent generation inter-crosses(MAGIC)population MAGIC-Hei was planted in 2017 and 2018 in Changsha,Hunan Province.Genome-wide association analysis was performed to detect the quantitative trait loci associated with heading date,number of tillers per plant,grain number per panicle,seed setting rate,1000-grain weight and grain yield per plant based on genotyping by sequencing(GBS).【Results】Totally,26 QTLs that control heading date and yield related traits were identified on all the chromosomes except chromosome 10 in the two years.Of these,11 are new and qNTP9,associated with the number of effective panicles,was detected in the two years.qNTP9 was less affected by environment and could be used for further fine mapping and gene cloning.Based on the phenotypic and the SNP genotypes five elite lines carrying favorable alleles were selected,which could be used for future high-yielding rice breeding.【Conclusion】The loci associated with heading date and yield related traits could be used for rice breeding.