沙田柚多倍体遗传差异的SSR分析

应用21对柑橘SSR引物对7份有沙田柚血缘的不同倍性材料进行了基因组的遗传差异分析。平均每对引物扩增出3个等位基因,每对引物可检测到的等位基因数目为2～5个不等,多态性带纹为62.5%。NTSYS软件进行相似系数计算,7份材料的相似性系数为0.763～0.892。UPGMA法聚类分析,在相似性系数为0.83处可划分为3类,即3株天然四倍体为第Ⅰ类;2株人工同源四倍体与1株天然三倍体为第Ⅱ类;二倍体母株为第Ⅲ类。天然三倍体与二倍体的遗传相似性较四倍体与二倍体的遗传相似性更高。4对引物(CAT01,TAA33,AG14 and TC26)可以区分天然四倍体与人工同源四倍体。与亲本二倍体母本相比,所试三倍体和四倍体均发生了DNA水平变异,表现为带纹缺失同时又增加了新的带纹。这些多倍体试材可为培育无核三倍体柑橘提供丰富变异的亲本材料。

Genetic diversity of polyploids of Shatianyou pomelo by SSR markers

A total of 7 induced or natural polyploid samples of Shatianyou pomelo(Citrus grandis var.Shatianyou Osbeck.) were used as material for studying their genetic diversity by using SSR markers with 21 pairs of primers.Two to five alleles with a mean value of 3 alleles per locus were detected and polymorphic bands accounted for 62.5%.Coefficients were 0.763 to 0.892 by Unweighted pair-group method(UPGMA).It can be partitioned with 3 types at coefficient of 0.83 as follow: Ⅰ: natural tetraploids,Ⅱ: induced tetraploids and natural triploid,Ⅲ: the diploid.The genetic similarity between natural triploid and the diploid was higher than that between tetraploid(especially natural autotetraploid)and the diploid.Natural and artifi-cial tetraploids could be distinguished by four pairs of primers(CAT01,TAA33,AG14 and TC26).According to the results of SSR bands,there was DNA variation of natural triploid,natural and induced tetraploids of Shatianyou that had new bands and bands deleted with corresponding diploid.These polyploids may be abundant variation parents for seedless citrus breeding.