赤皮青冈天然群体的果实表型性状变异分析

Variation analysis of fruit phenotypic traits in naturalpopulations of Cyclobalanopsis gilva

[目的]通过比较12个国内赤皮青冈天然群体的果实表型性状,探索果实表型性状在群体间和群体内的变异规律,为赤皮青冈良种选育和苗木繁育提供依据。[方法]采集了福建、湖南和贵州等地12个赤皮青冈天然群体的优良单株果实,测定果纵径、果横径和鲜果百粒重等果实表型性状,计算果形指数并建立数据库,估算果实表型性状在群体间和群体内的方差分量及表型分化系数,并进行聚类分析和相关分析。[结果]赤皮青冈果纵径、果横径、果形指数和鲜果百粒重的平均变异系数分别为9.39%、9.03%、10.66%和16.44%,变幅分别为6.37%~13.11%、5.67%~15.31%、6.81%~18.01%和4.76%~31.88%。不同天然群体的变异丰富度有较大差异,鲜果百粒重的变异系数最大、多样性最为丰富。果纵径、果横径、果形指数和鲜果百粒重在群体间和群体内个体间的差异均达极显著水平,群体间的方差分量百分比分别为58.46%、55.52%、66.26%和84.56%,群体内个体间的方差分量百分比在15.44%~44.48%之间。以不同欧氏距离进行分类,可以将赤皮青冈的11个群体明显地分为6类、4类或3类,群体的分类与地理位置的关联性不大。相关分析表明,果形指数与年均气温、果形指数与纬度及果纵径与纬度的负相关关系达显著水平,其余相关性均未达到显著水平。[结论]赤皮青冈的果纵径、果横径、果形指数和鲜果百粒重等表型性状在不同天然群体间差异较大、群体内个体间差异较小,群体间变异是表型变异的主要部分。本试验样本和表型性状数据较少,还须对全分布区的赤皮青冈群体和更多表型性状数据进行调查与分析,以进一步探索赤皮青冈天然群体的变异规律。

[Purpose]To provide information of superior variety selection and seedling breeding of Cyclobalanopsis gilva,the variation laws of fruit phenotypic traits among and within populations were studied,according to analysis of fruit phenotypic traits of 12 domestic natural populations of C.gilva.[Method]Fruits of C.gilva superior trees from 12 natural populations were collected in Fujian,Hunan and Guizhou Provinces to measure fruit phenotypic traits including fruit longitudinal diameter,fruit transverse diameter,weight of 100 fresh fruits,calculate fruit shape index and establish phenotypic traits database.The variance components of fruit phenotypic traits among and within populations and phenotypic differentiation coefficients were evaluated,and clustering and correlation analysis were conducted.[Result]The average variation coefficients of fruit longitudinal diameter,fruit transverse diameter,fruit shape index and weight of 100 fresh fruits were 9.39%,9.03%,10.66%and 16.44%respectively,and the amplitudes of variation were 6.37%to 13.11%,5.67%to 15.31%,6.81%to 18.01%and 4.76%to 31.88%respectively.Variation of phenotypic traits differed among populations,and the variation coefficient of weight of 100 fresh fruits was the highest,demonstrating the richest diversity.Fruit longitudinal diameter,fruit transverse diameter,fruit shape index and weight of 100 fresh fruits showed significant differences among and within populations,with the percentage of variance component among populations being 58.46%,55.52%,66.26%and 84.56%respectively,and the one within populations being from 15.44%to 44.48%.The 11 populations of C.gilva could be clearly divided into 6,4,or 3 categories by using different Euclidean distance thresholds,and there were little correlations between population classification and geographical location.Relevant analysis showed that significant negative correlations were observed only between fruit shape index and annual temperature or latitude,between fruit longitudinal diameter and latitude.[Conclusion]The variations of fruit longitudinal diameter,fruit transverse diameter,fruit shape index and weight of 100 fresh fruits were relatively large among populations but small within populations,thereby proving variation among populations was the main part of phenotypic variation.The samples and phenotype data are limited in this experiment,and more phenotype data from the entire distribution area of C.gilva populations would be collected and analyzed to further explore the variation patterns of C.gilva natural populations.