An Investigation On The Distribution And Environmental Interpretation Of The Wild Fagopyrum Species In Longzhou Mountain

Wild Fagopyrum species are important wild agricultural plant resources to investigate the evolution, origin and biodiversity of Fagopyrum species. As a result of environment deterioration, wild Fagopyrum resources are decreasing or endangered. Hengduan Mountains, known as its complicated climate due to special mountain topography and various natural environment, nourishing lots of wild Fagopyrum species, As a typical area of Hengduan Mountains, with relatively enclosed environment, Longzhou Mountain also contains many kinds of wild Fagopyrum species (Fagopyrum cymosum, Fagopyrum gracilipes, Fagopyrum gracilipes var. odontopterum, Fagopyrum pugense and lots of bridging species). There are many reports on the presence and distribution of wild Fagopyrum species, few based on ecologically investigation, especially on the distribution and genetic diversity of wild Fagopyrum species in enclosed environment. In this study, quantitative ecology method including two-way indicator species analysis (TWINSPAN), detrended canonical correspondence analysis (DCCA) and partial canonical correspondence analysis (PCCA) were used on the research of relationship between ecological factor and the presence and distribution of wild Fagopyrum species, furthermore the ISSR gene diversity from different environment were analysised to discuss the influence of ecological factor to the evolution of wild Fagopyrum species, aimed at provides theoretical basis for efficiency protection and utilization of wild Fagopyrum species. The results were as follows:(1) The factors which influence wild Fagopyrum plant community were spatial factor (the main factor was altitude) and habitat factor (the main factor was total N of soil). There were an obviously tendency of the distribution of the fagopyrum species, F. cymosum distributed in a wide range from 2000m to 2450m; F. pugense distribute the altitude range from 1800 to 1900m, bridging specie Fagopyrum I distribute the altitude range from 1900m to 2000m; F. gracilipes var. odontopterum and bridging species Fagopyrum II, III, IV, V distribute the altitude range from 2000m to 2300m; F. gracilipes distribute the altitude over 2300m.(2) habitat factor and spatial factor explained 58.98% of the distribution pattern of wild Fagopyrum plant community in Lognzhou Mountain, while the other 41.02% can not be explained might be interfere by human activities. The habitat factor explained 38.65% of vegetation distribution pattern, the spatial factor explained 16.55%, the reciprocal action of habitat factor and spatial factor explained 3.78% of the vegetation distribution pattern. For the plants of communities in Longzhou Mountain, habitat factor was the dominant factor infected their distribution, but for the wild Fagopyrum species, altitude, as the main spital factor was the most dominant factor.(3) The total wild Fagopyrum populations in Longzhou Mountain contains a considerable genetic diversity, the percentage of polymorphic bands was 98.46%, the Nei’s gene diversity was 0.3663, Shannon’s Information index was 0.5450, but the genetic diversity within populations were far below the total populations, the average percentage of polymorphic bands of total populations was 72.87%, the average Nei’s gene diversity was 0.2348, the average Shannon’s Information index was 0.3571. The 35.95% genetic variation of wild Fagopyrum population variance among populations, the other 64.05% varitation variance within populations, the gene flow was respectively low, only 0.8907. The wide range of altitude and complicated environment in Longzhou Mountain made the low gene flow among populations of wild Fagopyrum species, which promoted the occurrence of large amount of bridging Fagopyrum species in Longzhou Mountain.The result showed that genetic distance among the wild Fagopyrum populations were effect by the geographic distance by the method of UPGMA. The genetic diversity of wild Fagopyrum resources in Longzhou Mountain were significant influenced by altitude, the wild Fagopyrum populations distribute in 2115 to 2276m contains higher genetic diversity than populations distribute below 2100m of exceed 2300m. In addition, there were an important influence on the wild Fagopyrum populations caused by human activities.(4) Integrate the result of the morphological difference, genetical relationship and the regularities of distribution under altitude change among wild Fagopyrum species in Longzhou Mountain, the result showed that, in relatively enclosed environment, under the stress of altitude gradient, there were a tendency of the bridging Fagopyrum species. With the elevate of altitude, the type of wild species varied from F. pugense to F. gracilipes, which leads the tropism of its evolution.(5) The wild Fagopyrum populations in Lognzhou Mountain were distribute scattered, the habitat was discontinued and lack of gene exchange, the species distribution and genetic diversity variation showed up respectively evident difference under altitude gradient. Therefore, with the permission of available resources, the wild Fagopyrum resources should be protect as many as possible from the elevation direction. Wild Fagopyrum resources nature protection area should be build in Hengduan Mountains where concentrate with Wild Fagopyrum germplasm resources.