Genetic Diversity Study Of Caragana Microphylla And Caragana Intermedia In Inner Mongolia Plateau

Caragana microphylla Lam. and Caragana intermedia are plants for Caragana, Caragana microphylla Lam. for typical steppe and desert steppe xerophytic shrub, while the Caragana intermedia for typical steppe、desert steppe and grassland desertification desert xeric shrubs. Caragana microphylla and Caragana intermedia genetic relationship among remains one of the highlights in agro-scientific research in the plants of the genus caragana, with the alternation of grassland types, these two kinds of plants show diversity in form and molecular level. This study selected 7 natural populations of Caragana microphylla,8 natural populations of Caragana intermedia in Inner Mongolia plateau, analyzed the phenotypic characteristics,and using ISSR molecular marker technology analyzed the genetic diversity, and combined with the meteorological factors and soil factors analysis of the influence of environment on the genetic diversity and relationship. The main results are as follows:1 The 15 Caragana populations morphological characteristics:differences in height, coverage and crown in 15 populations were significant, and the differences are:crown width>height>coverage. Correlation analysis of morphological characteristics and meteorological factors,soil factors showed that the crown and the annual precipitation that a meteorological factors was significantly associate,height have a significant correlation with 10-20cm soil total nitrogen and 0-10cm soil total phosphorus,and the crown with 20-30 cm soil total carbon significantly correlated. Therefore, in addition to genetic factors, morphological characteristics of differences of the population is the outcome of combined action of meteorological factors and soil factors.2 ISSR analysis of genetic diversity: Nei’s genetic diversity index and Shannon information index showed that Caragana microphylla and Caragana intermedia have abundant genetic diversity; the genetic differentiation coefficient between populations of Caragana microphylla and Caragana intermedia is 0.1190 and 0.1881, shows that the genetic variation within populations is caragana microphylla and caragana intermedia the main source of genetic variation; gene flow between the populations is larger and genetic differentiation between the populations are not caused by genetic drift.Caragana intermedia has more abundant genetic diversity and genetic differentiation than Caragana microphylla, which is the genetic basis of caragana intermedia can adapt to bad environment and expand its distribution range.3 The influence factors of genetic diversity:Mantel test results show that the geological barriers and caragana no significant correlation between the genetic differentiation of population; The average temperature that is the heat condition is the impact factors of caragana populations genetic differentiation.4 Cluster analysis results:Caragana microphylla and Caragana intermedia populations among the overall clustering analysis, showed that Caragana microphylla and Caragana intermedia were respectively divided into two categories, it can able to clearly distinguish, illustrate that they belong to different species According to the results of the two cross phenomenon exists, explain the close genetic relationship.