Development Of Est-derived SSR Markers In Actinidia Arguta And Genetic Diversity Analysis

As one of the best development prospects fruit trees, the molecular biology research ofActinidia arguta is very few, it even can’t meet the needs of breeding. The amount of Actinidiaarguta wild germplasm resources is extremely large, but that of cultivars is very few. Actinidiaarguta EST-SSR markers were developed from Actinidia ESTs based on the NCBI database, andused to analyze36female Actinidia arguta accessions genetic diversity. The major results are asfollows:1. A total of132,593Actinidia ESTs were downloaded from NCBI database and were processedto get27,101unique sequences by using the CAP3assembler software. The identification andlocalization of SSRs were carried out in27,101sequences by SSRIT. The result showed that5,755sequences containing6,413SSRs.100types of motifs were found in Actinidia ESTs andthe dominant motifs types were dinucleotide and trinucleotide repeats, accounting for78.84%inall SSRs. Among the dinucleotide repeats, AG/CT was the most common motif (89.03%).Among trinucleotide repeats, AAG/CTT was the most common motif (26.57%).2.3,038SSRs containing ESTs with enough flanking were used in a search of homology forproteins in the NCBI database by the blastx approach.1,029(33.87%) sequences showedhomology with known proteins. The gene ontology focused on three categories includingbiological process, molecular function, and cellular component, accounting for353,678and372,respectively. On the Level2, the results of functional annotation were divided into19subcategories.3.199primer pairs were designed by Primer5.0software and commercially synthesized. Five A.arguta accessions DNA were randomLy selected to test the suitability of all the primers by PCR.141pairs among the199primer pairs successfully amplified high-quality bands and used togenetic diversity analysis on36accessions of A. arguta. The result showed that110primer pairswere polymorphic markers, accounting for78.01%. The number of alleles ranged from one tosix, with an average of2.35alleles per primer pair.4. The dendrogram was constructed from the binary data matrix, by using the unweighted pairgroup method with arithmetic averages (UPGMA), and the genetic similarity coefficient wereanalysed by the software Numerical Taxonomy Multivariate Analysis System (NTSYS-pc)version2.10e. On the level of0.68, the dendrogram classified all the36accessions into sevenmain clusters. This report will be valuable resource for future genetical studies and molecular breeding of A. arguta.