Genetic Diversity And Molecular Phylogeography Of The Invasive Plant Cenchrus Calyculatu In Inner Mongolia

Cenchrus calyculantus,belongs to Gramineae Cenchrus,a perennial herbaceous plant with resistant to drought distributed widely in the tropical coastal areas of North America.In China,Cenchrus calyculantus has been found in several Provinces,including Liaoning,Guangdong,Hannan and Inner Mongolia.However,only in two regions of Inner Mongolia,Tongliao and Chifeng city,Cenchrus calyculantus grow into an invasive plant which caused widely damage to the agriculture and animal husbandry and resulting in huge economic losses.In this study,we used Inter-simple sequence repeats(ISSR)and the intergenic spacer sequences of chloroplast DNA,analyzing the genetic diversity and genetic structure of Cenchrus calyculantus,and then to predicate the locations of the Cenchrus calyculantus derived from in Inner Mongolia province,furthermore,results of the above,will help us to build a reasonable control strategy for Cenchrus calyculantus.The results showed:ISSR markers were used to analyze genetic diversity and genetic differentiation in fourteen populations of Cenchrus calyculantus.ISSR markers revealed the Nei's gene diversity(h)were 0.3450,and Shannon's informatoin index(I)were 0.5177,both indicating a high-genetic diversity in Cenchrus calyculantus populations.Popgen software computing results showed the 36% of genetic variance among populations.Gene flow among population was 0.8889.AMOVA analysis based the cpDNA sequence revealed most of the variation existed within population.In the results,the variation comes from 81.89% of among population,and 18.11% belong to the within population.Combined the characteristics of genetic diversity and TCS haplotype network map analysis,it was revealed that the herb of Cenchrus calyculantus was formed by a few individuals which build up the populations,and the original haplotype was retained during the expansion process.The possible invasion site was a small village named halunhudun,kezuohouqi,Tongliao city,comparing with the grazing process,Cenchrus calyculantus repeatedly spread to the surrounding regions.