尾叶桉木材密度和生长性状的微卫星关联分析

Association Analysis of Wood Density and Growth Traits for Microsatellite Locus in Eucalyptus urophylla

本研究以尾叶桉育种群体的两个试验(T77和T164)为对象,借助微卫星技术挖掘与尾叶桉木材密度和生长性状关联的标记。经过筛选的83个微卫星标记用于样本关联分析,其中中性标记用于计算个体间的亲缘关系系数矩阵。基于群体最佳分类数时的K值对应的个体成员系数组成个体间亲缘关系的Q矩阵。分别用一般线性模型(GLM)算法和混合线性模型(MLM)算法进行标记木材密度和性状的关联分析。基于p<0.05的显著水平,在群体T164和T77中分别找到17个和19个与尾叶桉木材密度和生长性状关联的位点,两个群体中与木材密度关联的位点均多于生长性状,且关联位点的表型变异率普遍较高。位点Embra100与木材密度的关联达到了极显著水平(p<0.001)。位点EUCeSSR261同时在两个关联群体中都检测到,且其与木材密度的关联达到了显著水平(p<0.01)。本研究结果将为尾叶桉木材和生长性状的分子标记辅助选择提供有力的标记信息,为其快速改良提供理论储备。

In this study, two trials（T77 and T164） of breeding population of Eucalyptus urophylla were used for association analysis between wood density and growth traits by means of microsatellite loci technology. 83 microsatellite locus were screened out for sample association analysis, in which the neutral locus were used to calculate the kinship matrix among all individuals. The population structure Q matrix was created by membership coefficient（Q） of each individual when the optimal K value was estimated by structure analysis. The tool of general linear model（GLM） and mixed linear model（MLM） were used for association analysis between wood density and growth traits in E. urophylla. At a significant level of p〈0.05, 17 and 19 microsatellite loci associated with wood density and growth traits of E. urophylla were detected in population T164 and T77 respectively. Microsatellite loci associated with wood density were more than growth traits that detected in both populations, and most of the association loci had higher phenotypic variation. The locus Embra100 was associated with wood density at extremely significant level（p〈0.001）. The most noteworthy locus was EUCeSSR261, which was associated with wood density at a significant level of p〈0.01, and it was detected in both two populations with different ages. All the findings of the study could provide resources for marker assisted selection in the improvement of wood properties and growth and theoretical basis for the rapid improvement of the interested properties in E. urophylla.