花椰菜转录组SSR位点分析及其分子标记开发

Analysis of SSR loci in transcriptome and development of molecular markers in Brassica oleracea L.var.botrytis L.

【目的】开发适合花椰菜的SSR分子标记,为花椰菜品种遗传关系鉴定、遗传图谱绘制等提供候选标记。【方法】以24份花椰菜材料为研究对象,通过MISA软件对其转录组SSR位点信息进行分析,设计SSR引物,对这些引物进行PCR扩增,开发高多态性花椰菜的SSR分子标记;利用差异条带对不同花椰菜材料的亲缘关系进行分析。【结果】从转录组数据中得到66 450条Unigene基因,包含10 715个SSR位点,发生频率为12.09%,平均分布距离为5.9kb。SSR位点中优势类型为二核苷酸重复基序,出现频率占总SSR的51.16%;其次是三核苷酸,占总SSR的47.37%。重复序列基序共49种,其中出现频率较高的重复基序主要为AG/CT、GA/TC和AAG/CTT。有1 164个长度≥20bp的SSR位点,获得具有潜在高多态性的SSR引物6 119对。随机设计的40对引物中有31对引物能进行有效扩增,其中有17对引物在24份花椰菜品种中表现出多态性。UPGMA分析显示,在遗传距离为0.625时,17对多态性引物可将24份花椰菜分为3类。【结论】开发的花椰菜SSR标记类型丰富,出现频率高,具有较高的可用性。

【Objective】SSR molecular markers were developed for genetic diversity analysis and genetic mapping construction in cauliflower.【Method】In this study,24 cauliflower materials were used to analyze SSR loci of transcription group by MISA software.SSR primers were designed and amplified by PCR to develop SSR markers of highly polymorphic cauliflower.The genetic relationships of different cauliflower materials were analyzed by using different bands.【Result】A total of 66 450 Unigenes were obtained from transcriptional data and then 10 715 simple sequence repeats(SSR)loci were identified with occurring frequency of 12.09%and mean distribution distance of 5.9 kb.Dinucleotide repeat was the main type of SSR loci(51.16%),followed by trinucleotide repeat motif(47.37%).Forty-nine repeat motifs were identified,and the most abundant motifs were AG/CT,GA/TC and AAG/CTT.There were 1 164 SSR loci with length larger than 20 bp.A total of 6 119 pairs of SSR primers with the potential to produce polymorphism were designed and 31 primers were randomly selected for PCR amplification using 24 loofah materials,of which 17 primers showed polymorphism.According to the UPGMA analysis,24 plants were divided into 3 groups at the genetic distance of 0.625.【Conclusion】The large amount of SSR markers obtained can be widely used.