Genetic Diversity of Bombax Malabaricum in Dry-hot Valleys of Yunnan
|School||Xishuangbanna Tropical Botanical Garden|
|Keywords||Bombax malabaricum Dry and Hot Valley ISSR Genetic Diversity Genetic differentiation|
Dry and hot valley is located in the southwest of the Hengduan Mountains and its eastern neighboring regions in recent years due to the destruction of human activities, the native vegetation of the dry and hot valley has remnants of the same, and in many places has become a bare barren Ridge. The destruction and degradation of the vegetation, and serious damage to the ecological conditions and biodiversity of the area. In addition, It is predicted that global climate change will lead to expansion of dry and hot valley area of ??southwest China, the dry hot valley will become more hot and dry, restore its ecological imperative. Kapok (Bombax malabaricum) is the dominant species of the dry hot valley region, to study their genetic diversity will dry hot valley ecological restoration is important. Exploring from the population level the kapok genetic diversity and its level of differentiation, and their genetic diversity and dry heat adaptive to the dry hot valley ecosystem restoration provide genetic information, provide critical scientific basis for the selection and breeding of hot and dry plant varieties. In this study, using ISSR molecular marker technology to study the Yunnan dry hot valley region (Yuanjiang, Yuanmou, Qiaojia, Baoshan 4 ranking group), hot and dry regions (Guangxi, Hainan 2 ranking group), hot and humid areas (Banna ranking group) kapok population genetic diversity and adaptability of its on hot and dry habitats. 154 individuals screened 10 primer material amplified total detection to 138 sites, the percentage of polymorphic loci PPB = 89.86%, Nei's genetic diversity index H = 0.2552, the Shannon's information index I for 0.3905 ; coefficient of genetic differentiation among populations GST = 0.1173, the derived Фst AMOVA analysis = 0.111; results show that the the kapok has a high level of genetic diversity, low genetic differentiation between the door group. Mantel test results show that the geographic distance and genetic distance between populations, there is no significant positive correlation (r = 0.3191, P = 0.1760 gt; 0.05); using SPSS12.0 software on five ecological factors (altitude, ≥ 10 ℃ annual accumulated temperature, annual precipitation, annual relative humidity and annual average temperature) and five genetic diversity indicators (observed number of alleles Na, effective number of alleles Ne percentage of polymorphic loci PPB, Nei's genetic diversity index The correlation between H and Shannon's information index I) Pearson correlation test results show that the five ecological factors and genetic diversity were not significant. We infer the kapok rich genetic diversity and gene flow is an important factor in its adaptation to the dry heat of adversity, and their genetic diversity of dry and hot habitats neutral or near-neutral. Moreover, taking into account the the kapok genetic diversity is mainly distributed in the population, we recommend that the dry and hot valley of kapok introduction to a large sampling within populations and sampling as much as possible of the different populations.