Haplotype and genetic diversity analysis of Spodoptera frugiperda invading in three provinces of central and southern China

Objective  To reveal possible genetic variation among Spodoptera frugiperda populations in three provinces of central and southern China, trace the invasion source and spread pathway of S. frugiperd, and provide the theoretical basis and genetic information for effectively controlling this insect.

Method  The samples of S. frugiperda were collected from Guangdong, Guangxi and Hunan of China. Haplotype analysis was carried out using CO I and Tpigene markers. Nine microsatellite (SSR) markers were used to analyze the genetic diversity and genetic structure of S. frugiperda populations.

Results  Expect that two samples of S. frugiperda populations from Zhangjiajie of Hunan were characterized to be CO I corn strain and one sample to be hybrid strain, other samples were CO I rice train. The results of SSR markers showed that lower genetic diversity was detected for each population compared with those in South America populations, and the genetic differentiation across populations was no significant. However, the genetic distance was the nearest between Guangdong Dongguan population and Hunan Zhangjiajie population, and the farthest between Guangdong Dongguan population and Guangxi Nanning population.

Conclusion  There is no significant relationship between genetic distance and geographic distance. The genetic structure analysis helps to speculate on the role of weather background field, geographical isolation and human transmission in the process of S. frugiperda spread. S. frugiperda invading in central-south China might be original from multiple locations. The short time of S. frugiperda colonization in the invasive lands leads to the low genetic diversity. No obvious genetic differentiation has formed at present.