CAJ | 학술논문

为提高育种效率以及开展重要QTL和关键基因关联性分析研究,以187份生产上重要玉米白交系为材料,以70个均匀分布于全基因组简单重复序列(SSR)基因座鉴定出的290个等位基因多态性为分析数据,采用联合连锁位点与混合模型分析,推测这些自交系的基因组血缘构成以及分子亲缘关系,并分析了全基因连锁不平衡.当亚群数目K=5时,导致似然值P明显下降,亚群数据K＞6时,似然值P没有明显上升,表明群体结构的亚群数K最佳推测为6.六个亚群分别为PA、BSSS(含Reid)、PB、兰卡斯特(Lancaster)、旅大红骨(旅大红骨及其衍生系)、四平头(唐四平头及其衍生系).亚群间的Kullback-Leibler距离自0.13至1.06不等,平均为0.599,各亚群间区分度较好.全基因组连锁不平衡(LD)分析表明:与四平头种质类群内相比,遗传基础宽泛种质的基因组内存在LD"区块"(LDblock)少且小,对重要QTLs与基因的关联性分析可以避免假阳性.本研究群体结构与基因组构成分析数据为这些材料育种应用与改良提供了重要信息,也为基于这些材料的关联性分析奠定了分析基础.
위제고육충효솔이급개전중요QTL화관건기인관련성분석연구,이187빈생산상중요옥미백교계위재료,이70개균균분포우전기인조간단중복서렬(SSR)기인좌감정출적290개등위기인다태성위분석수거,채용연합련쇄위점여혼합모형분석,추측저사자교계적기인조혈연구성이급분자친연관계,병분석료전기인련쇄불평형.당아군수목K=5시,도치사연치P명현하강,아군수거K＞6시,사연치P몰유명현상승,표명군체결구적아군수K최가추측위6.륙개아군분별위PA、BSSS(함Reid)、PB、란잡사특(Lancaster)、려대홍골(려대홍골급기연생계)、사평두(당사평두급기연생계).아군간적Kullback-Leibler거리자0.13지1.06불등,평균위0.599,각아군간구분도교호.전기인조련쇄불평형(LD)분석표명:여사평두충질류군내상비,유전기출관범충질적기인조내존재LD"구괴"(LDblock)소차소,대중요QTLs여기인적관련성분석가이피면가양성.본연구군체결구여기인조구성분석수거위저사재료육충응용여개량제공료중요신식,야위기우저사재료적관련성분석전정료분석기출.
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 association 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.