A Study On Variance Of Isozymes Of Alpine Plant Arenaria Pulvinaa Edgew. In Tibet

In this paper, the alpine plant Arenaria pulvinata Edgew. of Sejila Mount is used as the material, selecting three populations of Arenaria pulvinata Edgew. distributing the elevation of 4500-4650m for research. The technology of Polyacrylamide agar electrophoresis is used to determine and code the bands of isozyme such as Peroxidase, Cytochrome oxidase, Alcohol dehydrogenase, Esterase and so on , which are from the 48 individual functional leaves of three populations of Arenaria pulvinata Edgew. and then according to the results of the enzymatic bands, we do cluster analysis. At the same time, with three genetic indicators of the four isozymes , Peroxidase, Cytochrome oxidase, Alcohol dehydrogenase, and Esterase, correlation analysis is done. The results indicate:1.Peroxidase IsozymesFrom the same populations of the individual, not only similarity of isozyme bands, small genetic heterozygosity (HeA=0.716;HeB=0.709;HeC=0.705), particularly the coefficient of similarity is larger and genetic distance is small in populations of B, C,This also shows that the individual's genetic differentiation in populations smaller enough. The Peroxidase, which coefficient of similarity's average of four isozyme is relatively bigger in different populations and genetic distance is small(IAB=0.637;IAC=0.587;IBC=0.646;DAB=0.451;DAC=0.533;DBC=0.437),These data indicate that the peroxidase isozyme of Arenaria pulvinata Edgew. being certain degree of genetic differentiation in different populations, and also lack of effective gene flow.2. Cytochrome oxidase isozymesThe cytochrome oxidase isozymes of Arenaria pulvinata Edgew. in the populations of the individual, which isozyme bands is similar, and the genetic heterozygosity is higher than peroxidase (HeA=0.752;HeB=0.815;HeC=0.815), The bands of gene frequency above 0.50 is relatively more than others in the populations of A,B,C, and there is 6 bands in populations of A, B, each other ,and there is 5 bands in populations of C, its maximum value could reach 0.94, and the genetic distance is small, it also shows that populations of genetic differentiation within the individual is small; The coefficient of similarity of cytochrome oxidase being the maximum in different populations and a factor in the entire population of the four types of isozyme minimum, the same is true of genetic distance (IAB=0.418;IAC=0.304;IBC=0.673;DAB=0.873;DAC=1.192;DBC=0.396). The maximum of genetic distance is DAC = 1.192; These data shows that the cytochrome oxidase Isozymes of Arenaria pulvinata Edgew. being larger genetic differentiation in different populations.3. Alcohol dehydrogenase isozymesThe alcohol dehydrogenase isozymes of Arenaria pulvinata Edgew. in the populations of the individual, which isozyme bands is similar, and the genetic heterozygosity is lower than cytochrome oxidase isozymes (HeA=0.766;HeB=0.872;HeC=0.736), The bands of gene frequency above 0.50 is relatively more than others in the populations of A,B,C, and there is 7 bands in populations of A, its maximum reach to 1.00, there is 3 bands in populations of B, its maximum reach to 1.00 too, there is 7 bands in populations of C ,its maximum reach to 0.88, but its genetic distance is small, it also shows that populations of genetic differentiation within the individual is small, with a high degree of genetic homogeneity。The coefficient of similarity of Alcohol dehydrogenase are smaller and relatively larger genetic distance in different populations (IAB=0.539;IAC=0.367;IBC=0.513;DAB=0.618;DAC=1.002;DBC=0.667). The maximum of genetic distance is DAC = 1.002; These data show that the alcohol dehydrogenase Isozymes of Arenaria pulvinata Edgew. being larger genetic differentiation in different populations.4. Esterase IsozymesThe Esterase isozyme of Arenaria pulvinata Edgew. in the populations of the individual, which isozyme spectrum is similar, and the genetic heterozygosity is lowest in these four isozyme. (HeA=0.735;HeB=0.765;HeC=0.726), The bands of gene frequency above 0.50 is relatively more than others in the populations of A,B,C , and there is 10 bands in population of A ,there is 8 bands in population of B , C each other, and the maximum could reach to 0.99, furthermore, there is 3 bands ,which gene frequency is 1.00 and the genetic distance is small, it also shows that populations of genetic differentiation within the individual is small; However, the coefficient of similarity of EST isozyme have different degrees of change in different populations, and the gentic distanceis so (IAB=0.392;IAC=0.542;IBC=0.610;DAB=0.937;DAC=0.613;DBC=0.495). The maximum of genetic distance is DAB = 0.937; These data show that the EST isozyme of Arenaria pulvinata Edgew. being larger genetic differentiation in different populations. The shown on changes in trends and ranges of the four isozymes is not exactly simility, whether in the genetic factors or the isoenzymatic patterns or the clustering, which shows in the process of long-term evolution of Arenaria pulvinata Edgew.,the different genes which control kinds of isozymes have no co-evolution. This phenomenon is widespread in nature. Because of the special climatic conditions of Qinghai- Tibet Plateau and the geographical distribution pattern of Arenaria pulvinata Edgew., the variant characteristics of isozymes of Arenaria pulvinata Edgew. are formed.