RAPD And ISSR Analysis Of 20 Species In 6 Genera From Magnoliaceae

Randomly amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were used to analyse the genetic diversity and relationships of 20 species in 6 genera from Magnoliaceae and compare the genetic difference among generas with inner genera, combining the other research results, the systematic of 20 species in 6 genera was primarily discussed. The purpose of this study was to provide scientific basic data for systematic and other research on Magnoliaceae.The results showed as follow: (1) The method of improved CTABâ… equal to extract Magnoliaceae genomic DNA was developed, because the extracted DNA by the method was suitable for RAPD and ISSR analysis. (2) Single factor design combing uniform design was used to obtain optimum scheme on reaction system for RAPD and ISSR of Magnoliaceae. The obtained optimum scheme on reaction system for RAPD: Mg²⁺ 3.00 mmol/L,dNTP 0.15 mmol/L,primer 0.40μmol/L,template DNA 20 ng/20μL,1U Taq DNA polymerase; The obtained optimum scheme on reaction system for ISSR: Mg²⁺ 1.00 mmol/L,dNTP 0.20 mmol/L,primer 0.40/μmol/L,template DNA 40 ng/20μL,1 U Taq DNA polymerase。(3) The analysis of RAPD marker showed that: fourteen RAPD primers amplified a total of 287 scorable markers, percentage of polymorphic loci is 99.30%, Nei's gene diversity and Shannon's information index were 0.3591 and 0.5334, respectively. The analysis of ISSR marker showed that: twelve ISSR primers amplified a total of 222 scorable markers, all of which was polymorphic loci, Nei's gene and Shannon's were 0.3477 and 0.5218, respectively. The results of RAPD and ISSR showed that the genetic diversity of 20 species in 6 genera from Magnoliaceae was enriched. (4) The matrixes of genetic distance were established on RAPD and ISSR fingerprint, respectively. The results of UPGMA duster analysis based on RAPD and ISSR fingerprint had the approximate trend, but not the same. (5) The synthetical comparison of RAPD and ISSR sustained the independency of Liriodendron, Manglietia, Parakmeria and Tsoongiodendron, and advised to redefine the range of Magnolia, subgen. Yulania indepent from Magnolia, then established Yulania, and abolished the division of subgenera and section Michelia, and set up Michelia.