9个果蔗品种(系)遗传多样性分析及DNA指纹图谱构建

【目的】对9个果蔗品种(系)进行遗传多样性分析并构建其DNA指纹图谱,为果蔗品种鉴定和分子育种等提供理论依据。【方法】利用21个SSR分子标记和毛细管电泳技术对来自4个省份的9个果蔗品种(系)进行遗传多样性分析,应用NTSYS-pc 2.11计算供试材料间遗传相似系数,并运用UPGMA法进行聚类分析,同时构建其DNA指纹图谱。【结果】21对SSR引物共扩增出204条带,多态性比例为75.99%,每对引物可扩增出4~31条带,平均为9.71条。其中,17对引物含有9个果蔗品种(系)的44个特征位点,仅有5对引物鉴别能力最强,单个引物即可将其完全区分开。选择多态性高、鉴别力强且含有品种(系)特征位点的3对引物(SMC36BUQ、SMC597CS和SMC851MS)构建了9份果蔗品种(系)基于44个位点的DNA指纹图谱。9份果蔗材料的遗传相似系数为0.62~0.90,平均为0.77。UPGMA聚类结果显示,9个果蔗材料可分为三大类群,且与材料来源地无直接关系。【结论】9个果蔗品种(系)间的遗传基础差异较小,亲缘关系较近,遗传多样性并不丰富,在育种中应加大果蔗亲本遗传背景的差异,提高其遗传多样性。

Genetic diversity analysis of nine chewing cane varieties(lines) and construction of their DNA fingerprints

Objective]In order to provide theoretical basis for variety identification and parental selection during su-garcane breeding process,the present study was conducted to analyze genetic diversity of nine chewing cane varieties(lines) and construct their DNA fingerprints. Method]Combining twenty-one SSR molecular markers with capillary electrophore-sis technique,genetic diversities of nine chewing cane varieties(lines) from four provinces were analyzed,and genetic simi-larity coefficient between tested materials was calculated using NTSYS-pc 2.11. Then nine chewing cane varieties (lines) were clustered for analysis using UPGMA,and their DNA fingerprints were constructed. Result]Results showed that,a to-tal of 204 bands were amplified from nine chewing cane varieties(lines) using twenty-one pairs of SSR primers,with poly-morphic rate of 75.99%. So every pair of SSR primers could amplify 4-31 bands,with an average of 9.71 bands. Seventeen pairs of primer contained 44 cultivar-specific loci of nine chewing cane varieties(lines). Only five pairs of primers had the strongest ability to discriminate nine chewing cane varieties ( lines ) , and each pair of primer was able to discriminate each chewing cane varieties(lines). However,only three pairs of primers(SMC36BUQ,SMC597CS and SMC851MS),which were characterized by high polymorphism and discriminability and contained cultivar-specific loci,were chosen to con-struct DNA fingerprints of nine chewing cane varieties ( lines ) . Furethermore , genetic similarity coefficients among nine chewing cane varieties(lines) varied from 0.62 to 0.90,with an average of 0.77. UPGMA clustering result showed that,nine chewing cane materials were clustered into three groups,this result was not related to origins of materials. Conclusion]There are little differences in genetic basis,close genetic relationship and poor genetic diversity among nine chewing cane varieties(lines),so genetic background of parents should be increased in breeding process of new varieties.