米老排不同种源的表型性状变异分析

Phenotypic trait variation for different provenances of Mytilaria laosensis

以8个米老排Mytilaria laosensis地理种源为研究对象,采用巢式方差分析、变异系数分析、多重比较、相关性分析和聚类分析(UPGMA)等多种分析方法,对7个表型性状(叶片长、叶片宽、叶长宽比、叶形、树干通直度、树皮颜色和树皮形状)进行研究,探讨米老排种源间和种源内的表型变异规律。结果表明:米老排各表型性状在种源间和种源内均存在较丰富的变异,种源内变异(18.08%)大于种源间变异(5.68%),种源间平均表型分化系数为35.10%。在7个表型性状中,树皮颜色的变异系数值最大(21.16%),叶长宽比的最小(11.26%);在不同种源之间,广西德保种源性状变异平均变异系数值最大(18.41%),广西龙州种源最小(16.10%)。米老排的树皮颜色随纬度增加而由深向浅变异,叶片则随纬度增加叶面积越大。8个米老排种源可划分为3个种源分布区,即东部的广东封开种源区,中部的广西上思和防城种源区,西部的广西德保、靖西、凭祥和龙州种源区。米老排表型性状的变异主要来源于种源内家系间,而且主要是因纬度变化而导致变异。

To probe the variation in phenotypic traits among and within provenances of Mytilaria laosensis Lecomte,seven phenotypic traits （leaf length, leaf width, ratio of leaf length to leaf width, leaf shape, degree of trunk straightness, color, and shape of bark） of eightprovenances were tested,using nested analysis of variance, coefficient of variation （CV）, multiple comparison, correlation analysis, and cluster analysis （UPGMA） to ana-lyze the results.Results showed significant differences in phenotypic traits among and within provenances （P =0.05）. Variation was greater within provenance （18.08%） than among provenances （5.68% ） , withthe mean phenotypic differentiation coefficient among provenances being 35.1%. For the seven phenotypic traits, the CV of bark color was largest （21.16%） and the ratio of leaf length to leaf width was smallest （11.26%）; among different provenances, the average CV for all traits revealed that Guangei Debao Provenance was the largest （18.41%） and Guangei Longzhou Provenance was smallest （16.10%）. The bark color of M . laosensis with in-creasing latitudesvariedfrom deep to shallow, and leaves had greater leaf area with increasing latitudes. The eight provenances could be divided into three source distribution areas including Guangdong Fengkai Prove-nance in the eastern part, Guangei Fangcheng and Guangei Shangsi Provenances in the central area, and Guangei Debao, Guangei Jingei, Guangei Longzhou, and Guangei Pingeiang Provenances in the western section. This suggested that the main source of phenotypic variation in M . laosensis was from pedigrees within prove-nances, and the main variation was caused by the change in latitude. [Ch, 1 fig. 6 tab. 30 ref.]