白桦核心种质初步构建

以白桦240个家系的胸径、树高、材积和纤维素含量数据为依据,采用不同的抽样比率(5%,10%和15%)、2种距离计算方法(马氏距离和欧氏距离)、8种系统聚类方法(最短距离法、最长距离法、中间距离法、重心法、类平均法、加权配对算术平均法、可变法和离差平方和法)和3种抽样方法(随机取样法、优先取样法和偏离度取样法)构建白桦初级核心种质资源,并利用均值差异百分率、方差差异百分率、极差符合率和变异系数变化率评价不同方法构建的核心种质.结果表明:采用10%的抽样比例、马氏距离、最短距离系统聚类法和优先取样法构建的包括24个家系的白桦初级核心种质最能代表原有的种质群体.

Preliminary Construction of Core Collection of Betula platyphylla Germplasm

Based on four quantitative traits, height, diameter, volume and cellulose content of 240 families of Betula platyphylla, primary core collections were constructed using different sampling proportion(5% ,10% and 15%) , two distances (Mahalanobis distance and Euclidean distance) calculi, eight hierarchical cluster methods (Single linkage, Complete linkage, Median method, Centroid method, Unweighted pair-group method using arithmetic averages, Weighted pair-group average, flexible method and Ward' s method) and three sampling strategies ( random sampling, preferred sampling and deviation sampling). The genetic variation of the quantitative traits among these primary core collections was compared by evaluating the mean difference percentage (MD), variance difference percentage (VD), coincidence rate of range (CR) and changeable rate of coefficient of variation (VR) of the traits. The results showed that the primary core collection was constructed with 10% sampling percent, Mahalanobis distance, preferred sampling strategy, and single linkage clustering method, and it was composed of 24 families of Betula platyphylla and the best representative of total germplasm.