Research About RAPD Of Genetic Relationship And Genetic Diversity For Bougainvillea Spectabilis

This paper analyses the genetic diversity of 23 samples from Xichang,Pan zhihua and Ya'an by RAPD analysis and compared on the genetic diversity. Major results were as follows:1. The CTAB method was used to extract DNA from the leaves of Bougainvillea spectabilis. This method was the best and perfectly suitable for RAPD analyze.2. Through comparing with the optimized experiments of six factors(such as template DNA,Buffer,dNTP,primer,Taq DNA polymera and Mg2+ concentration)which influenced PCR amplification, an optimized reaction system for RAPD—PCR analysis was established. PCR was performed in a 20μL reaction system mixture with 1.8mmol/L Mg2+, IU/μL Taq DNA polymera,0.2mmol/L dNTP, 0.6μmol/L primer,20ng/μL template DNA. The temperature profile for PCR was 94℃for 3min, followed by 40 cycles of 94℃for lmin,36℃for 30s and 72℃for lmin, and was terminated with a 10 min DNA extension step at 72℃;save at 4℃.3.14 primers were screened from 78 ten-bp random primers. A total of 145 DNA fragments were ranged which distributing between 0.1 to 2.0kb, among which 137(94.48%)was polymorphic, using these 20 primers, The result of genetic similarity analysis for 23 Bougainvillea spectabilis showed that the Nei's coefficient ranged from 0.3699-0.9452, and the average Nei's coefficient was 0.6609.4. Drawing of genetic affinity dendrogram of 23 samples of Bougainvillea spectabilis by UPGMA. When divided by the similarity coefficient of 0.62, the 23 samples of Bougainvillea spectabilis could be parted into 3 species. The first species are the 8 samples of Bougainvillea glabra, the second species are the 14 samples of Bougainvillea spectabilis and the third species are the 1 sample of Bougainvillea peruviana. The results of cluster are very well with the 3 species which are divided by the configuration, and the second and third species clustered before clustered with the first species. That is to say the genetic relationship between Bougainvillea spectabilis and Bougainvillea peruviana is further than the genetic relationship between Bougainvillea spectabilis and Bougainvillea glabra. The results show that the 23 samples of Bougainvillea spectabilis are not strictly clustered by the geographical position, the pertinence of provenance and geographic origin are not obvious.