Study On Correlation Between Genetic Diversity Of Artemisia Ordosica Krasch. Population And Environment In Mu Us Sandy Land

Artemisia ordosica which belong to Artemisia L. of Compositae is main constructive and dominant species in temperate deserts and steppes in Northern China.So it is one of important sand-fixation plant in dessert area. In this research, ISSR are applied to investigate genetic diversity and genetic differentiation of different population of A.ordosica in Mu Us Sandy Land. We also try to investigate the correlation of genetic diversity with environmental factor to understand the mechanism of adaptation to environment and the feedback to growth and reproduction. The results are shown as below.1. The environmental factor and morphological characteristics have a big effect on growth of A.ordosica, while environmental factor has a greater impact. The crown size is highly correlated to sunshine time. Above-ground biomass, plant height content is highly correlated to the soil moisture.2.10 primers are selected to assess the gene of 9 populations of A. ordosica by ISSR molecular marker. We detected 273 fragments amplified products, in which all of them are polymorphism bands. The total percentage of polymorphic lci is 100% between all population of A.ordosica.The highest percentage of polymorphic lci is 92.66% of the population of S9 which is in fixed sandy land.3. The total percentage of polymorphic lci is 100% between all population of A.ordosica,So the A.ordosica has abundant genetic diversity of populations.The Shannon index of population is 0.2241.The Nei’s index is 0.1586. The rank of the PPB is fixed sandy, semi fixed sands, mobile sand. The rank of the I and H is semi fixed sands, fixed sandy, mobile sand. H has the same trend with I, slightly different from PPB.4. The genetic variation of A.ordosica emerged in the population compatible with a similar trend of most higher plants. The total genetic diversity of all population of A.ordosica is 0.2567. The genetic diversity in the population is 0.1225. The coefficient of gene differentiation (GST) was 0.1657. The gene flow (Nm) is 3.0913. The genetic differentiation among population account 16.57% for genetic variation of all population. The rate of genetic variation among the population is 83.43%.5. It’s easy to see that there is a correlation between genetic variation of A.ordosica populations with geographical distances.The genetic identity between 9 populations range from 0.917 to 0.993. The genetic distance range from 0.007 to 0.084. Previous studies suggested that genetic relationship of plants change orderly along with the genetic distance. Those populations who have closer relationship have short genetic distance. The cluster analysis show that the population who gather early have short geographical distances, who gather late have long geographical distances.6. Analysis the genetic diversity of A.ordosica population in different habitats and ecological factors correlation,showed that there is highly significant correlation between the percentage of polymorphic loci and annual average precipitation in shifting sandy land;there is significantly negative correlation between the percentage of polymorphic loci and the peak season of relative humidity in fixed sandy land.