玉米自交系48-2和R08辐照后代M_3株系遗传变异的SSR分析

SSR MARKER ANALYSIS ON GENETIC VARIATION OF M_3 FROM MAIZE INBRED LINES 48-2 AND R08 AFTER IRRADIATION INDUCEMENT

为研究玉米自交系辐射诱变后代的性状遗传变异规律,促进突变体的高效选择和利用,本研究用3种剂量梯度的60Coγ射线对玉米自交系48-2和R08的种子进行辐射诱变处理,用32个多态性SSR分子标记对48-2和R08及其辐射诱变后代M3株系等103份材料进行了遗传变异分析。结果表明:48-2和R08 M3株系位点多态信息量(PIC)变化范围分别为0.307～0.948和0.108～0.955,平均值分别为0.762和0.701;基因型多样性(H’)变化范围分别为0.552～2.830和0.254～3.309,平均值分别为1.830和1.777。49份48-2 M3株系与未辐射处理对照(M673)的平均遗传相似系数为0.8194,而52份R08 M3株系与未辐射处理对照(M487)的平均遗传相似系数为0.8373。对遗传相似系数进行聚类分析,将自交系48-2和R08及其101份M3株系分别划分成了7个和5个类群,表明辐射诱变后产生了较大的遗传变异。在育种实践中,根据育种目标结合各类群突变株系主要性状的遗传变异特点和规律,加强对突变系的选择和利用,可提高玉米辐射诱变育种的效率。

Analyzing the biological effects and the genetic variations of maize mutagenic progenies is important to facilitate effective selections and utilization of the mutants.In this study,the genetic variation of 103 mutagenic progenies of M3 lines of inbred lines 48-2 and R08 with60Co γ-rays inducement were evaluated with SSR molecular markers.The results indicated that,the amplitude of polymorphism information content（PIC） of the 48-2 and R08 M3 lines ranged 0.307~0.948 and 0.108~0.955,with an average of 0.762 and 0.701,respectively.The amplitude of genetic diversity indexes（H＇） ranged 0.552~2.830 and 0.254~3.309,with an average of 1.830 and 1.777,respectively.The average value of genetic similarity coefficient of the 49 M3 lines of 48-2 with its check（M673） was 0.8194.However,the average value of genetic similarity coefficient of the M3 lines of R08 with its check（M487） was 0.8373.Based on the genetic similarity coefficient,inbred lines 48-2,R08 and their 101 M3 lines were clustered in 7 and 5 populations respectively.This phenomenon indicated that massive genetic variation could appear in progenies due to irradiation.The strengthen of selection and utilization of mutants based on the breeding objectives and in accordance with the feature and regularity on genetic variations of main characteristics of mutant lines in various populations could be enhanced in breeding program,to some extent,which can increase the breeding efficiency of irradiation induced mutation in maize.