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穗粒数是小麦产量构成的重要因子,研究小麦穗粒数及其相关性状的变化规律与遗传机制对于高产育种具有指导意义。以198份河南种植或审定的小麦品种(系)为材料,在4个环境下鉴定穗粒数相关性状表现,选用660K SNP芯片检测材料的基因型并进行全基因组关联分析。发现穗粒数存在着广泛的变异,穗粒数、穗长、总小穗数、可育小穗数和不育小穗数的广义遗传力分别为77.43%、87.54%、85.45%、79.70%和68.08%,2002年以前、2003-2008年、2009-2014年和2015年以来育成品种的平均穗粒数分别为35.71个、36.85个、37.40个和37.98个,随着育种时期的推进总小穗数和可育小穗数也表现出逐渐提高的趋势。共发现41个和穗粒数等性状相关联的位点,分布在除了1D、3A、3D、4B和4D的16条染色体上,单个关联位点的表型变异贡献率(R2)范围为6.19%~20.83%,其中10个位点至少在2个环境中稳定表达。对关联位点进一步分析发掘了多个与穗粒数性状相关的优异等位变异,如7A上AX-109368219(A)能增加穗粒数1.86粒,2A上AX-111674224(C)能提高总小穗数0.96个,2D上AX-111582877(G)能提高可育小穗数0.73个。研究揭示近五十年河南小麦穗粒数性状的动态变化及其规律,获得了多个和穗粒数等性状关联位点及等位变异,为小麦产量性状的遗传改良及分子设计育种提供了技术支持和基因资源。
The number of grains per spike is an important factor in the yield formation of wheat. It is instructive to study the law of variation of grain number per spike and its related traits and genetic mechanism for high-yielding breeding. A total of 198 wheat cultivars (lines) planted or validated in Henan Province were used to identify the traits related to grain per spike in four environments. The 660K SNP was used to detect the genotypes of the cultivars and the genome-wide association analysis. The general heritability of the number of spikelets per panicle was 77.43%, 87.54%, 85.45% and 79.70% respectively. The number of spikelets, spike length, total spikelets, And 68.08% respectively. The average number of cultivars per hectare of cultivars from 2003 to 2008, from 2009 to 2014 and from 2015 to 2015 was 35.71, 36.85, 37.40 and 37.98, respectively. As the breeding period progressed, The number of spikes and the number of fertile spikes also showed a gradual increase. A total of 41 loci associated with traits such as grain number per spike were found in 16 chromosomes except for 1D, 3A, 3D, 4B and 4D. The phenotypic variation contribution rate (R2) of individual association sites ranged from 6.19 % ~ 20.83%, of which 10 loci stably expressed in at least two environments. Further analysis of the association sites revealed a number of excellent allelic variations associated with grain number traits, such as AX-109368219 (A) on 7A increased the number of grains per panicle by 1.86, AX-111674224 (C) at 2A increased total The number of spikelets was 0.96, AX-111582877 (G) on 2D could increase the number of fertile spikelets by 0.73. The research revealed the dynamic changes and their regularities of the spike grain number traits in Henan wheat in the recent 50 years and obtained the correlation sites and allelic variations of traits such as grain number per spike and seed number, providing the genetic improvement and molecular design breeding of wheat yield traits Technical support and genetic resources.