核桃EST-SSR标记的开发

从GenBank数据库上公布的5025条核桃（Juglans regia）EST序列中，用SSRHunter软件搜索到485条EST序列中含有540个SSR，SSR出现频率为10.75%，SSR-ESTs检出率为9.7%。利用检出的SSR-ESTs序列设计SSR引物43对，对6个核桃样品、1个黑核桃（J. nigra）样品和1个核桃楸（J. mandshurica）样品进行了PCR扩增，其中40对引物有扩增带，占设计引物的93%，35对引物有多态性，占可扩增引物的87.5%。在有多态性的35对引物中，27对引物在核桃种内有多态性；8对引物在核桃种内无多态性，而在核桃、核桃楸和黑核桃种间有多态性。应用UPGMA方法对检测样品进行聚类分析，结果与传统分类一致。

Development of EST-SSR Markers in Juglans regia

Five thousand and twenty five ESTs of Juglans regia from the database of dbEST were screened using SSR-Hunter software, and 540 SSRs in 485 ESTs, accounting for 10.75% of ESTs were mined out. The SSR-ESTs occupied 9.7% of the total number of ESTs. Forty three primer pairs were designed for polymorphism analysis in 6 genotypes of J. regia, 1 genotype of J. nigra and 1 genotype of J. mandshurica. 40 primer pairs showed the amplification, accounting for 93% of designed primers, and 35 primer pairs showed polymorphisms, accounting for 87.5% of primers available. In the polymorphic 35 primer pairs, 27 primers showed polymorphisms in J. regia, the other 8 primers did not display polymorphism in J. regia, but showed polymorphisms among J. regia, J. nigra and J. mandshurica. Cluster analysis of the 8 genotypes was performed by UPGMA method, the result accords with the conventional taxonomy.