基于针叶性状云南松天然群体表型分化研究

Study on the Phenotypic Differentiation of Needle Traits Among Populations of Pinus yunnanensis

在云南松主要分布区内,采集不同区域的18个天然群体540株单株的针叶,通过对各单株的10束针叶7个性状进行测定分析。结果表明:不同表型性状在各群体间和群体内单株间均存在极显著差异,表明变异存在的广泛性;不同性状的变异规律有所差异,大多数性状的变异主要来自于群体内,表型分化系数低于50%;基于各性状两两群体间的表型分化均很低,甚至没有分化。不同表型性状对揭示群体间的遗传距离关系贡献不同,综合多个性状能反映群体间的遗传关系。经各性状遗传距离与地理距离、生态距离间的相关检测,由地理距离、生态距离等引起针叶性状变异的趋势不明显,但由生态距离引起的作用大于地理距离的作用,表明地理、气候和土壤因子对云南松群体间的分化有一定的影响作用。经聚类分析,各群体的聚类并不完全按地理分布进行聚类。

In this study, seven traits of ten bundle needles of each trees collected from 18 populations of Pinus yunnanensis in main distribution regions were measured. The results showed that there were significant differences both among populations and within populations in each needle trait, which suggested that there existed wide and a- bundant genetic variation in P. yunnanensis populations. There were different variation tendency of each needle trait among populations. The phenotypic variation was more abundant within population than among populations. The co- efficients of variation （CV） were lower than 50%. There were weak phenotypic differentiation or no phenotypic dif- ferentiation for each pair-wise population based on individual needle trait. Different needle traits revealed the genetic relationship among populations in varying degrees. The complex of the measured needle traits could reflect the genetic relationship among populations. The test on geographical and ecological distance with relations of genetic distance of each trait indicated that was no obvious effect of isolation by distance （IBD） and isolation of ecology （IBE） in needle trait, but the effect of IBE was more obvious than IBD. The phenotypic differentiation among pop- ulations may be influenced by the complex of the geographical, climatic and soil factors. Cluster analysis indicated that each popolation was not clustered entirely based on geographical distribution.