Study On The Population Characteristics And Genetic Diversity Of Five Rared And Endangered Species Of Angiopteris In China

Southeast of Yunnan was the center distribution area of Angiopteris plants, which occupied high diversity and endemic species. A. subrotundata, A. bipinnata, A. sparsisora, A. chingii, and A. latipinna were endemic to China, of which A. bipinnata and A. sparsisora were narrow distribution areas and habitats destruction seriously to tend to extinction nearly. According to the field investigation and ISSR molecular markers, we drew their populations structures by heights, cluster diameters, petioles, and horseshoes, which compiled life tables for A. subrotundata and A. chingii populations on the basis of population demography, as well as survival curve and other important parameters. Based on the analysis of each species on the basis of genetic diversity and genetic distance, the main reasons which caused the Angiopteris species endangered were also analyzed. The main results were as follows:1. Clear and stable10primers of ISSR were selected from50random primers, to sample6species of Angiopteris genome DNA. The all bands amplified were162bands. Polymorphism bands ratio were100%; Nei genetic diversity index (H) was0.3000, Shannon diversity index (Ⅰ) was0.4569, Index of genetic differentiation (Gst) was0.1557. Population genetic consistency and genetic distance were0.8642～0.9704and0.0289-0.9704. We found that A. subrotundata had the higer genetic diversity, and A. sparsisora had the lower genetic diversity.2. A. subrotundata and A. latipinna populations had rich individuals. Young individuals were abundant. Adult individuals were relatively few. The population structure changed with height, and the number of the horseshoes was stable. Population quantity was relatively more and population structure was stability. A. latipinna populations growed in the secondary forest, the young individual mortality was higher. Based on analysis of molecular markers, A. subrotundata and A. latipinna’s polymorphism bands ratio respectively were93.83%and91.98%; Effective number of alleles were respectively1.4521and1.4608; Nei genetic diversity index was respectively0.2819and0.2819; Shannon diversity index was respectively0.4355and0.4226. Generally, A. subrotundata and A. latipinna population structures were stability.3. A. bipinnata and A. chingii populations were stable characteristic, but the populations were small. Population size was limited. The survey sample area was at the edge of village and farmland, especially A. bipinnata population was extremely vulnerable to the destruction of human activities. Based on analysis of molecular data, A. bipinnata and A. chingii polymorphism bands ratio respectively are70.99%and87.65%. The effective number of alleles were respectively1.4099and1.4540. Nei genetic diversity index was respectively0.2384and0.2720. Shannon diversity index was respectively0.3575and0.4146. A. subrotundata and A. latipinna population structures were stable. Nei genetic diversity index of A. bipinnata was low, and the population genetic structure was not stable in danger of extinction.4. A. sparsisora grows at an altitude of1550～1580m on the hillside, only a wild populations was found outside for a specific locality. This population had a total of7individuals. Population structure of the brink of extinction was unstable. A. sparsisora polymorphism bands ratio was51.85%. The effective number of alleles was1.2858. Nei genetic diversity index was0.1707. Shannon diversity index was0.2594. Nei genetic diversity index was lowest among the all species. This population was doomed to be extinction.5. Static life table and survival curve showed that A. subrotundata quantity change from seedlings to adults was relatively stable in the process, and population survival curve tended to be Deevey Ⅱ type. A. latipinna quantity change from seedlings to adults was not relatively stable in the process, and population survival curve tended to be Deevey Ⅲ type.6. Cluster analysis by UPGMA indicated that the population genetic distance and geographic distance had no relevance. Henli, Ruanji, Qinshi and Rrhui populations genetic distance was close. Fujian and Fadou populations were separated firstly. The result supports the Archangiopteris genus in Ching systems may be split from the Angiopteris genera.