The inference of genome ancestry and the estimation of molecular relatedness are of great importance for breeding efficiency and association studies. Seventy SSR loci, evenly distributed in 10 chromosomes, were assaye...The inference of genome ancestry and the estimation of molecular relatedness are of great importance for breeding efficiency and association studies. Seventy SSR loci, evenly distributed in 10 chromosomes, were assayed for polymorphism among 187 commonly used maize （Zea mays L.） inbreds which represent the genetic diversity in China. The identified 290 alleles served as raw data for estimating population structure using the coalescent linked loci, based on the ADMIXTURE model. Population number, K, has been inferred to be between five and seven. Specifying five subpopulations （K = 5） led to a distinct decrease and specifying K to be greater than six resulted in only minimal increases in the likelihood value. Therefore, population number, K, has been inferred into six subpopulations, which are PA, BSSS （includes Reid）, PB, Lan （Lancaster Sure Crop）, LRC （Luda Reb Cob, a Chinese landrace, and its derivatives）, and SPT （Si-ping-tou, a Chinese landrace and its derivatives）. The Kullback-Leibler distance of pairwise subpopulation was also inferred as n × p （187 ×6） Q matrices, which gave a detailed percentage of genetic composition of six subpopulations and molecular relatedness of each line. The genome-wide linkage disequilibrium （LD） indicated that the asso- ciation studies in QTLs and/or candidate genes might avoid nonfunctional and spurious associations, as most of the LD blocks were broken among diverse germplasm. The defined population structure has given us a clear genetic structure of these lines for breeding practice and established a good basis for association analysis.展开更多
采取混合取样策略,利用荧光SSR技术对来源于我国7个省(自治区)的90份糯玉米地方品种和6个标准测验种自交系基因组的31个简单序列重复(SSR)位点进行了分析。在90个糯玉米地方品种中,共检测出216个等位变异,每个位点检测出2～12个,平均6.9...采取混合取样策略,利用荧光SSR技术对来源于我国7个省(自治区)的90份糯玉米地方品种和6个标准测验种自交系基因组的31个简单序列重复(SSR)位点进行了分析。在90个糯玉米地方品种中,共检测出216个等位变异,每个位点检测出2～12个,平均6.97个,多态性信息量(PIC,polymorphic information content)为0.67,标记指数(MI,marker index)为4.92。可初步将90份糯玉米地方品种划为3个类群,其中,广西和贵州的糯玉米地方品种的遗传多样性相对更丰富。展开更多
文摘The inference of genome ancestry and the estimation of molecular relatedness are of great importance for breeding efficiency and association studies. Seventy SSR loci, evenly distributed in 10 chromosomes, were assayed for polymorphism among 187 commonly used maize （Zea mays L.） inbreds which represent the genetic diversity in China. The identified 290 alleles served as raw data for estimating population structure using the coalescent linked loci, based on the ADMIXTURE model. Population number, K, has been inferred to be between five and seven. Specifying five subpopulations （K = 5） led to a distinct decrease and specifying K to be greater than six resulted in only minimal increases in the likelihood value. Therefore, population number, K, has been inferred into six subpopulations, which are PA, BSSS （includes Reid）, PB, Lan （Lancaster Sure Crop）, LRC （Luda Reb Cob, a Chinese landrace, and its derivatives）, and SPT （Si-ping-tou, a Chinese landrace and its derivatives）. The Kullback-Leibler distance of pairwise subpopulation was also inferred as n × p （187 ×6） Q matrices, which gave a detailed percentage of genetic composition of six subpopulations and molecular relatedness of each line. The genome-wide linkage disequilibrium （LD） indicated that the asso- ciation studies in QTLs and/or candidate genes might avoid nonfunctional and spurious associations, as most of the LD blocks were broken among diverse germplasm. The defined population structure has given us a clear genetic structure of these lines for breeding practice and established a good basis for association analysis.
文摘采取混合取样策略,利用荧光SSR技术对来源于我国7个省(自治区)的90份糯玉米地方品种和6个标准测验种自交系基因组的31个简单序列重复(SSR)位点进行了分析。在90个糯玉米地方品种中,共检测出216个等位变异,每个位点检测出2～12个,平均6.97个,多态性信息量(PIC,polymorphic information content)为0.67,标记指数(MI,marker index)为4.92。可初步将90份糯玉米地方品种划为3个类群,其中,广西和贵州的糯玉米地方品种的遗传多样性相对更丰富。
