Theanalysis Of Genetic Diversity In Fifteen Fruitmulberry Resources By EST-SSR And SRAP Markers

Fruit mulberry’s genetic background is rather complicated, making assession identification difficult using the traditional morphological or other methods. Molercular marker techniques could be used in identification and genetic diversity analysis to reveal polymorphisms at the DNA level. In order to reveal the genetic relationship of fruit mulberry germplasm at molecular level and provide a scientific basis for germplasm identification,utilization and breeding novel quality varieties. SRAP and EST-SSR markers were employed in this study to investigate the genetic diversity and relationship among fruit mulberry germplasm resources. The main results were as followed:1. The improved CTAB method is a suitable way for genomic DNA extraction of fruit mulberry.2. 306 bands were obtained using 17 pairs of SRAP primers which were selected from42 pairs of SRAP primers and 253 bands were polymorphic, so the percentage of polymorphic bands was 82.68% and bands size ranged 100 bp to 1000 bp.3. 18 polymorphic primers selecting from 42 pairs of EST-SSR primers were used for PCR amplication. 297 bands were got amplification including 236 polymorphic bands and the percentage of polymorphic bands was 79.46%. Each pair of primers amplified 16.5 bands on average, DNA fragment size was between 100 to 400 bp.4. The genetic similarity coefficients among materials ranged from 0.3909 to 0.8111 with a mean of 0.6199 analysed by SRAP; the genetic similarity coefficients among materials ranged from 0.3801 to 0.8581 and its changed in the magnitude was 0.4780 analysed by EST-SSR.5. Based on the amplication bands analysised by EST-SSR and SRAP, the DNA fingerprints were then converted into binary codes based on band presence or absence. In the DNA fingerprints, each of fruit mulberry germplasm material had its unique binary code which could be distinguished between each other.6. Unweighted Pair-Group Method Arithmetic Average was used to develop the dendrogram and all materials were divided into three major groups. Correlation analysis was conducted between EST-SSR, SRAP and the combination data, the result showed that the correlation between EST-SSR and the combination data, SRAP and the combination datawere significant.