日本囊对虾人工诱变子一代遗传变异的RAPD分析

Genetic Diversity Analysis on the First Generation of Radiation-induced Marsupenaeus japonicus by RAPD

以性腺成熟的日本囊对虾（Marsupenaeus japonicus）作为亲代，进行不同剂量的^60Co-γ射线照射．采用RAPD技术对诱变子一代的无节幼体基因组DNA多态性进行了检测．从20个随机寡核苷酸引物共检测177个位点，其中多态位点152个，占85．9％．单个引物获得的标记为6～12个，平均8．85个，分子量在150～2500bp之间．遗传相似系数用Nei的计算方法进行计算。遗传距离则用Lynch的计算方法进行计算．实验数据表明：诱变子代与正常对照组相比，遗传多样性水平较高，诱变产生了较为显著的变异．研究结果证实：在对虾大规模养殖，种质质量严重退化的情况下，人工诱变能够促进基因组更加广泛的变异，为新品种的选育打下坚实的基础；同时证明RAPD技术在检测遗传差异方面具有较高的灵敏度和分辨率．

Matured kuruma prawn, Marsupenaeus japonicus, were divided into four different groups and irradiated by ^60Co-γ rays at different doses before spawning. Random amplified polymorphic DNA （RAPD） method was employed to detect the genetic variation within or between all these groups. Amplification with 20 random primers produced 177 distinctive and reproducible fingerprints. These fingerprints acquired by single primer ranged from 6 to 12 were 8.85 on average and varying in length from 150～2 500 bp, 152 of which were polymorphic and the proportion of polymorphic loci was 85.9%. The genetic similarity coefficient was calculated by Nei＇s matching coefficient method with designed computer program, and the correspondingly average genetic distance （D） was also calculated by Lynch＇s method to evaluate genetic structure. All these calculated data had indicated high genetic variations within radiation - induced populations. Our research had proved that irradiation might cause so extensive variance in genome that might be the basis of further work of breeding. Furthermore, data ate presented with regard to RAPD technique that had comparatively high sensitivity for genetic variations assessment at molecular level.