栗疫病菌群体的遗传结构

采用聚丙烯酸胺凝胶电泳方法，从栗疫病菌Cryphonectriaparasitica的18种酶体系中筛选到9种分辨率高的同工酶。对同工酶的检测结果表明，在中国的北京、辽宁、江西、福建及意大利、美国、日本共7个群体的115个栗疫病菌菌株中，多酚氧化酶（PPO）、过氧化物酶（POX）、细胞色素氧化酶（CCO）、乙醇脱氢酶（ADH）、超氧化物歧化酶（SOD）为单态性；α-酯酶（α－EST）、β-酯酶（β-EST）、苹果酸脱氢酶（MDH）、苹果酸酶（ME）为多态性，分别具有10、7、3、3种电泳表现型。通过9种同工酶的凝胶电泳分析，对栗疫病菌的群体结构进行了比较。中国地区4个群体间的遗传相似性较大，与美国、意大利、日本群体间的相似性较小；美国、意大利群体间的遗传相似性较大，且它们与日本群体间的相似性大于与中国各群体间的相似性，这一结果表明美国的栗疫苗可能是从日本传人的。病菌群体的遗传变异率为of60，其中83．1％由群体内的变异引起，16．9％由群体间的差异引起。群体间的基因流动值为246。

COMPARISON OF POPULATION STRUCTURES OF CRYPHONECTRIA PARASITICA

Nine well--resolved isozymes were chosen from eighteen ones of Cryphonectria parasitica by polyacrylamide gel electrophoresis. Among these detected nine isozymes of 115 isolates from 7 populations, viz. Beijing, Liaoning, Jiangxi,Fujian, Italy, USA, and Japan, polyphenol oxidase, peroxidase, cytochrome oxidase,alcohol dehydrogenase and superoxide dismutase were monomorphic, but α-esterase,β-esterase, malate dehydrogenase and malic enzyme were polymorphic, and had 10, 7,3, 3 electrophoretic phenotypes, separately. The population sattur of Cryphonectria paraitica was analyzed using the isozymes gel electrophoresis. Genetic similarity analysis showed that four populations in China were more similar to each other, than to populations in italy and the US; American and italian populations were similar to each other, and more similar to Japanese than to Chinese. TIs result suggested that the pathogen might be introduced into the US from Japan. The genetic diversity of the total population was 0.160, with 83.1% attributable to diversity within populations,and 16.9% among populations. The gene flow estimate between populations was 2.46.