新疆冬小麦品种资源主要产量性状全基因组关联分析

Genome-Wide Association Analysis of Yield Traits in Xinjiang Winter Wheat Germplasm

【目的】高产是小麦育种的永恒主题,利用全基因组关联分析发掘控制小麦产量性状的QTL区段及优异基因,为小麦分子标记辅助选择育种提供理论依据和标记信息。【方法】以新疆本地188个冬小麦品种资源为材料,利用小麦55K SNP芯片进行全基因组扫描,通过对6个不同环境下的株高、穗长、小穗数、可育小穗数、穗粒数、千粒重、粒长、粒宽、籽粒长/宽比9个产量相关性状进行表型鉴定,利用6个环境下各性状数据及最佳线性无偏预测(BLUP)数据,基于混合线性模型(MLM)对表型和基因型进行全基因组关联分析。【结果】经主成分分析,将188个材料分为地方品种和育成品种2个亚群;利用6个环境下各性状数据,9个性状共检测到1309个显著性SNP标记,其中,每个显著性SNP位点可解释7.259%—70.792%的表型变异。利用BLUP数据,9个性状共检测到66个显著性位点,同时与2个性状关联的共有SNP位点有5个,贡献率波动范围为8.498%—21.877%。将同时与2个性状或2个以上环境关联到的重复位点作为稳定的显著性关联位点,9个性状共检测到38个稳定关联位点,包括株高重复位点5个,穗长重复位点10个,小穗数重复位点10个,结实小穗数重复位点6个,穗粒数重复位点6个,千粒重重复位点1个,可解释9.10%—23.81%的表型变异。将这38个位点与已发布小麦基因组位点比对,仅找到3个与本研究关联重复位点位置相近、且有注释基因功能的基因,分别是:2A染色体上与株高关联位点AX-108794050距离相近的TraesCS2A01G448800,与转录因子bHLH71的代谢合成有关;1A染色体上与穗长关联位点AX-110689765距离相近的TraesCS2A01G448800,与蛋白质编码有关;4B染色体上与千粒重关联位点AX-110399975距离相近的TraesCS4B01G031100,与编码丝氨酸/苏氨酸蛋白激酶SD1-8有关,参与对细胞增殖与分化的调控。【结论】检测到38个与小麦产量性状关联的QTL位点,关联的优良等位基因具有降低株高、增加穗长、小穗数、可育小穗数、穗粒数和千粒重的作用。

【Objective】To discover new high yield genes in wheat by association analysis,which can provide technical supports for the innovation and genetic improvement of high yield germplasm resources in wheat.【Method】Totally 188 bread wheat cultivars in Xinjiang were genotyped using the wheat 55K genotyping assay.GWAS was carried out to identify the signifcant single nucleotide polymorphisms(SNPs)which were associated with 9 wheat yield traits in 6 environments.The MLM algorithm in TASSEL5.0 was used to analyze the nine traits related to wheat yield traits.【Result】Totally 1309 SNPs explained 7.259%-70.792%of the phenotypic variation.38 SNP loci were identifed,which were significantly correlated with 5 plant height weight SNP loci,10 spike length weight SNP loci,10 spikelet number SNP loci,6 fertile spikelet number SNP loci,6 spike grain number SNP loci,and 1 thousand grain weight SNP loci.These loci can explain 9.10%-23.81%of phenotypic variations.Comparing these 38 loci with the published wheat genome loci,only 3 functional genes were found,which annotated with gene function.There genes are:TraesCS2A01G448800 on chromosome 2A,which is close to the plant height associated site AX-108794050 and is related to the metabolic synthesis of transcription factor bHLH71;TraesCS2A01G448800,located on chromosome 1A at a distance similar to the spike length associated site AX-110689765,is related to protein coding;TraesCS4B01G031100,located on the 4B chromosome at a distance similar to the 1000 grain weight associated site AX-110399975,is associated with the encoding serine/threonine protein kinase SD1-8 and is involved in regulating cell proliferation and differentiation.【Conclusion】38 QTL loci associated with wheat yield traits were detected.After verification,it was found that the associated excellent alleles have the effect of reducing plant height,increasing spike length,spikelet number,fertile spikelet number,grain number per spike,and thousand grain weight.