Genetic Diversity And Differentiation Among Populations Of Flaveria Bidentis In Hebei Province

Flaveria bidentis (L.)Kuntze is a new invasive species in China in recent years. It is a good material for the study of mechanism of invasion and adaptation, the study is conducive to a accurate assessment of their invasion, and contribute to take effective control measures before the populations spread to a large area.In the present study, the AFLP technique and POPGENE software was used to characterize genetic diversity and differentiation of Flaveria bidentis (L.)Kuntze populations throughout Hebei province in China and populatons under different environment. Combined with the time of invasion, climatic conditions and different environment to explore the formation of populations, genetic diversity and differentiation of Flaveria bidentis (L.)Kuntze. This test has developed a set of optimized response system of amplified fragment length polymorphism, which provides a powerful tool for investigation of genetic variation of Flaveria bidentis (L.)Kuntze populations. 9 primer combinations with good repeatability,stability and polymorphism were screened from 64 AFLP primer combinations to amplified by PCR on 220 DNA samples from 7 geographical populations and 4 populations under different environment .The research result shows at present, the genetic diversity of Flaveria bidentis (L.)Kuntze is very abundant, but there is relatively low inter-population genetic differentiation. in early stages of invasion , higher gene flow is not able to impede the differentiation among populations, geographical isolation, genetic drift and selection pressure made the differentiation among populations; the differences of the level of diversity in different populations was significant. In the areas where bottleneck effect take effect genetic diversity maintain a relatively low level for a long time, but in appropriate areas, population can quickly reach a very high level genetic diversity; light and harmful metal stresses can reduce genetic diversity, and in the wet populations can maintenance of high genetic diversity; Flaveria bidentis (L.)Kuntze spreaded in Hebei Province mainly in two ways, Hengshui-Changzhou-Langfang and Handan-Xingtai-Shijiazhuang-Baoding.