濒危植物多辐溲疏柠檬酸脱氢酶同工酶分化的数量分析

NUMERICAL ANALYSES OF CITRIC ACID DEHYDROGENASE ISOZYME DIFFERENTIATION IN THE NDANGERED SPECIES DEUTZIA MULTIRADIATA

运用电泳分析技术研究了特产四川省南川县金佛山处于濒危状态的多辐溲疏（ＤｅｕｔｚｉａｍｕｌｔｉｒａｄｉａｔａＷ．Ｔ．ｗａｎｇ）不同生境的５个小居群的５０个个体叶片柠檬酸脱氢酶同工酶，并对谱带位置进行了编码，然后采用Ｒｏｇｅｒｓ－Ｔａｎｉｍｏｔｏ、Ｋｕｌｅｚｙｎｓｋｉ、Ｃｚｅｋａｎｏｗｓｋｉ及Ｊａｃｃａｒｄ结合系数上的ＵＰＧＭＡＴ和ＷＰＧＭＡ法对其个体及居群水平酶谱带位置上的变异式样进行了聚类分析．结果表明，不论是在个体水平或是在居群水平上，柠檬酸脱氢酶同工酶都表现出较大的变异性，因此仅凭一份或数份样品的同工酶谱来代表该种的谱带作为分类标准是极其主观的．此外，柠檬酸脱氢酶同工酶有居群间分化的趋势，来源于不同小居群的个体在谱带位置上表现一定的趋异性，显示出酶谱带位置与小居群生长的微生境有一定的相关性，部分小居群具有某些特有的酶谱带，这与其分布特性和生殖特征有关．该种呈岛屿状的小居群散布于非常狭窄的区域，小居群体间的空间隔离限制了居群间个体的相互基因交流．在漫长的进化过程中那些适应新的小生境的遗传变异体得以保存下来，致使小居群间在酶谱带位置上愈来愈呈现出明显的趋异性，而微生境只不过对该种居群间那些适应该微生境的遗传?

The Citric acid dehydrogenase( CDH)in leaves of 5 0 plants from 5 small populations with differ-ent altitudes and habitats of the endangered species Deutzia multiradiata, endemic to Mt.Jinfo ofNanchuan,China. Was studies with sreat care according to the eletrophoretic technique. The bandsof CDH are scored to construct the two-state data matrix which is calculated by Rogers-Tanimoto,Kulezynski,Czekanowski and Jaccard association coefficients with UPGMA and WPGMA respectivelyfor the anal yses of that isozymic differentiat ion among individuals and populations of Deutzia multiradia-ta. The result reveals the there are vivid variabilities on the CDH bands not only among individuals butalso among populations,even rich among the individuals wthin the same population,which indicatesthat we cannot choose the CDH bands of one or geveral individuals to kepresent the studieds pecicswhen its taxonomy and interspecific affinities were interprated. The CDH bands show diffe rentiationsto some extent among diferent populations and individuals from the same micro-population are more orless clustered,while individuals from the different micro-populations show certain dlssimilarities inisozyme bands,Dis clear that the CDH bands of a given nucro-population are somewhat correlatedwith the habitat from which it was colllected,Certain micro-populations pcasess some unique CDHbands,which can be explained by the distribution pettern and reproductive features of the species,Itdistributes as scattered micro-populations which are isolated each other spatially. Such spatial isolationlargely inhabites the gene exchange among individuls from diferent micro-populations and those adapt-ed genetic variations to these micro-habitas are selected and remained in the evolutionary process,which makes the genetic divergence among micro- populations becomming more obvious. The micro-habitats here only play the role in selecting that habitat.The remarkable hybridizations among individu-als of the same population lead to more easily gene exchange and can enrich the genetic heterogeneitywhthin the same population, which can be regarded as the genetic variation resource that will be benifi-cial for the survivorship of the endangered species as D. multiradiata.