摘要
[Objective] The aim was to identify genetic variation in Citrus sinensis （sweet orange） germplasm from Hunan Province according to the Start Codon Targeted （SCoT） Polymorphism. [Method] The reaction system for SCoT amplification from sweet orange was first optimized, and then the SCoT fragments were amplified from 24 sweet orange cultivars collected in Hunan Province and sequenced for genetic variation analysis. [Result] The optimum reaction system for SCoT markers amplification was 2.0 μl containing 80 ng of template DNA, 0.3 mmol/L dNTPs, 0.2 μmol/L primer, 1.6 mmol/L Mg2＋, 1.6 U of Taq DNA polymerase and 10×PCR buffer. By using this reaction system, the PCR products from the sweet orange cultivars produced clear and reproducible bands at 100-2 000 bp through electrophoresis. The SCoT fragments of the 24 sweet orange cultivars were 1 090-1 091 bp, with the homology of 99.84% and nucleotide deletion and substitution. After being sequenced, the SCoT polymorphisms could distinguish 12 sweet orange cultivars. In addition, the BLAST result showed that part of the SCoT fragments coding region shared high homology with ribosomal protein S3 N superfamily. [Conclusion] This study will provide a theoretical basis for breeding sweet orange cultivars.
[目的]根据SCoT多态性对湖南甜橙变异类型进行鉴定和分析。[方法]首先对SCoT反应体系进行优化,并筛选合适的引物,然后对24份试材进行SCoT标记,获得的目的片段克隆测序,通过测序结果探讨其遗传变异。[结果]甜橙SCoT标记的20μl优化反应体系为:DNA模板80ng,Mg2+1.6mmol/L,dNTPs0.3mmol/L,引物0.2μmol/L,TaqDNA聚合酶用量1.6U,扩增产物在100～2000bp,扩增条带明亮清晰,反应体系具有良好的稳定性和可重复性。24份试材的测序片段的大小为1090-1091bp,一致性达到99.84%,存在单碱基缺失与替换;利用单碱基变异可以区分其中的12个甜橙变异株系和‘安江香柚’。[结论]本研究将为甜橙的育种工作提供科学的理论依据。
基金
Supported by National Key Technology Research and Development Program(2006BAD01A1702)~~
