榆耳回交菌株遗传多样性

Genetic diversity of backcross strains of Gloeostereum incarnatum

本研究以优势性状互补的早熟型榆耳菌株GiC和高产型榆耳菌株GiD的单核菌株杂交获得杂交菌株126-15,再以126-15的单核菌株分别与GiC、GiD的单核菌株进行回交构建回交群体。通过SSR分子标记结合农艺性状分析榆耳回交群体的遗传多样性。SSR引物多态性分析表明29对SSR分子标记共检测到269个等位基因位点,多态性信息含量(PIC)为0.8025±0.0907,多态性较丰富;SSR分子标记聚类将67个菌株在相似系数为0.9656处分为7个类群,其中第Ⅰ类群仅包含2个轮回亲本GiC、GiD及其杂交菌株126-15,第Ⅱ、第Ⅲ和第Ⅴ类群共包含了21个轮回亲本为GiC的回交菌株,第Ⅳ、第Ⅵ类群共包含了25个轮回亲本为GiD的回交菌株,其余菌株聚为第Ⅶ类群。基于农艺性状的聚类分析将67个菌株分为7类,其中仅有第Ⅱ类群包含的7个回交菌株生育期最短,仅有第Ⅵ类群包含的5个回交菌株为中早熟高产的菌株。两种聚类结果均表明回交群体具有一定的遗传多样性。7个农艺性状的变异范围在7.9%–20.5%之间,产量的变异系数最大,轮回亲本为GiC时回交菌株中有34.3%的菌株产量表现超亲遗传,轮回亲本为GiD时回交菌株的生育期表现超亲遗传;有6个农艺性状间的相关系数达到显著或极显著水平。研究结果可以为榆耳种质资源多样性利用、品种鉴定及回交选育提供参考。

The hybrid strain 126-15 was obtained by crossing the monoploid strains of early-maturing strain GiC and high-yielding strain GiD of Gloeostereum incarnatum with complementary advantages.The backcross population was constructed by backcrossing the monoploid strain of 126-15 with the monoploid strains of GiC and GiD.The genetic diversity of the G.incarnatum backcross population was analyzed by SSR molecular markers combined with agronomic traits.SSR primer polymorphism analysis showed that 269 allele loci were detected from 29 pairs of SSR molecular markers,and the polymorphism information content(PIC)was 0.8025±0.0907,indicating relatively rich polymorphism.Cluster analysis of SSR molecular markers divided 67 strains into 7 groups at a similarity coefficient of 0.9656.Among them,groupⅠonly contained two recurrent parents GiC and GiD,and their hybrid strain 126-15.GroupsⅡ,Ⅲ,andⅤcontained 21 backcross strains with GiC as the recurrent parent,and groupsⅣandⅥcontained 25 backcross strains with GiD as the recurrent parent.The remaining strains were clustered into groupⅦ.Cluster analysis based on agronomic traits divided 67 strains into 7 categories,of which only 7 backcross strains in groupⅡhad the shortest growth period,and only 5 backcross strains in groupⅥwere early-maturing and high-yielding strains.Both clustering results indicated that the backcross population had certain genetic diversity.The variation range of 7 agronomic traits was between 7.9%and 20.5%,and the coefficient of variation of yield was the largest.When the recurrent parent was GiC,34.3%of the backcross strains showed over-parent heterosis in yield.When the recurrent parent was GiD,the backcross strains showed over-parent heterosis in growth period.The correlation coefficients between 6 agronomic traits reached significant or extremely significant levels.The research results provide references for the utilization of G.incarnatum germplasm resource diversity,variety identification,and backcross breeding.