Studies On The Oringin And Genetic Diversity In Zanthoxylum Armatum V. Novemfolius

Zanthoxylum armatum v. novemfolius which belongs to the genus of Zanthoxylum L. in Rutaceae was found in Jiangjin of Chongqing. it's a variety of Zanthoxylum armatum and it's mainly planted in Chongqing,Sichuan and Guizhou Province. Z.armatum v. novemfolius shows a pleasant odor, fertility and highly Stress Resistance, which gradually becomes the preferred species for Conversion of Cropland to Forest Project (CCFP) in Parts of counties in Chongqing.At present, researches on Z. armatum v. novemfolius mainly focus on its budding, breeding, fertility, etc. Its origin and genetic background of diversity never be researched, which confines the exploitation and using of its idioplasmic resource. Therefore, in this thesis the Z. armatum v. novemfolius, Z.bungeanum and Z. armatum were selected as experimental materials. The traditional numerical analysis, RAPD(Random Amplified Polymorphic DNA)makers techniques, Anderson pictorialized Pictorial scatter diagram, index value, cluster analysis and software such as SPSS,NTSYS—pc2.02a,POPgene32 were used in the thesis to study on the origin and genetic diversity from the phenotype to the genotype. The main results were summarized as followings:(1)Studies on morphologic and molecular leval both showed that introgressive hybridization occurred among Z. armatum and Z.bungeanum. The complicated population-hybrid complex is Z. armatum v. novemfolius. and Z. armatum contributes more to the population-hybrid complex than Z.bungeanum. its origin area is Jiangjin in Chongqin. (2)For Z. armatum v. novemfolius, more morphological differentiation in the nutrition organ and the production organ are relatively steady.(3)In RAPD experiments, the optimum concentration of five important components such as Taq DNA polymerase, template DNA, primer(8pmol/μl), dNTP (10mM)and 10×PCR buffer(20mM MgCl₂)in25μl RAPD reaction system were 2.0U, 50ng, 1μl ,0.5μl, 2.5μl respectively. The reaction program was as follows: pre-denature at 94℃for 2 min, then 94℃for 30s, 37℃for 30s 72℃for 80s, for 40 cycles, finally extended at 72℃for 10 min.(4)62 random primers were used to select the primers that could produce polymorphic bands with the experimental materials DNA. 6 primers were selected. 137 polymorphic bands were obtained which accounts for 84.08ï¼…among total 157 bands. The observed number of alleles is 1.85 and the effective number of alleles is 1.50.(5)Based on the proportion of polymorphic loci,Shannon's index and Nei's index,the four Z.armatum v. novemfolius were arranged in the degree of genetic diversity: C＞B＞A＞D.According to the Shannon's index and Nei's index, genetic diversity of Z.armatum v. novemfolius was on relative high level and genetic variation mainly distributed within population. Gene flows are in a higher degree. Cluster analysis shows that the nearest distance was found between population A and population B, the distance between population C and population D was the second. 28 individuals clustered into a bunch displaying the genetic homogeneity are in a higher degree.(6)At present, Z.armatum v. novemfolius has his own steady morphologic character And it's a classified group different from Z.armatum and Z.bungeanum. So, it's scientifically and feasibly to describe Z. armatum v. novemfolius as a variety.