The RAPD And ISSR Analysis On Genetic Diversity Of Rubus Parvifolius And R. Coreanus Varieties And Preliminary Identification Of A Suspected Hybrid

The genus Rubus is one of the largest genera in the Rosaceae, consisting of 750-1000 species in many parts of the world, of which about 200 species with more than 130 native have been recorded in China. The southwest part of China which is abound in resources, is now the center of distribution of Rubus. The disease resistance, easily activity and fruit flavors in its wild plants which have important cultural and breeding value, are all superior than cultivars introduced from abroad. In this study, RAPD and ISSR were used to analyze the total 33 accessions with 16 taxa from Subsect. Stimulantes Yii & Lu,16 taxa from Subsect. Pungentes (Focke) Yii & Lu and 1 taxa from the progeny originated from R. parvifolius cross R. coreanus. The results were as follows:1. Through optimizing the ISSR reaction system, the optimal annealing temperatures for ISSR primers were found. The annealing temperatures were related to the bases of each primer, while were less related to the Tm value. The selected range of temperature,55.2-59.1℃, would be helpful for utilizing ISSR on R. parvifolius and R. coreanus.2.12 primers screened from UBC#9 primers, which amplified 358 repeatable loci, including 339 polymorphic loci, were applied on the 33 materials. The percentage of polymorphic bands was 92.77% and the long of fragments were between 200bp and 4000bp, mostly between 400bp and 2000bp. The ISSR fingerprints from 12 Primers can identify the relationships between interspecies and intraspecies exactly.3.18 primers which amplified 498 repeatable loci, including 462 polymorphic loci, were applied on the 33 materials. The percentage of polymorphic bands was 92.77% and the long of fragments were between 200bp and 4000bp, mostly between 400bp and 2000 bp. The RAPD fingerprints from 18 Primers can identify the relationships between interspecies and intraspecies exactly.4. According to RAPD and ISSR markers, genetic distance was computed. All materials can be divided into 2 groups which were in consistence with that of the analysis of morphology. Division of subsets in some groups were related to the geography difference of R. parvifolius and R. coreanus.5. The possible parents of suspected hybrid was concluded by RAPD and ISSR analysis, and it was considered that the suspected hybrid was a natural hybrid between R. parvifolius and R. coreanus.6. In this study, reproducibility and stability of RAPD and ISSR was proved. ISSR showed the better polymorphic compared with RAPD, and this would be helpful for DNA molecular maker.