Platevindex mortoni I) gene sequences. Groups of nucleotides T, C, A, G contents to an average of39.54%, 17.56%, 23.07%, 19.83%, showing A + T (62.61%) content is significantly higher than G + C content(37.39%); mitochondrial genome showed obvious anti G migration characteristics.A total of 84 individuals representing5 collection sites were included in the analysis. Overall, 41 haplotypes were defined and 117 polymorphic sites wereobserved. In addition to Hap1 and Hap28 which shared haplotype and 39 haplotypes for each group specific haplotypes,Hap1 is the most widely distributed haplotype, except HN group, distributed in all groups, accounting for 39.3% of allhaplotypes. Xiamen group (XM) and Cangnan population (CN) has the most number of haplotypes, which were 12, andHN group haplotypes at least (6), and 117 polymorphic loci, including 23 single variable sites and 94 parsimony informativesites. Each group of polymorphic loci () show obvious differences, displayed the span from 10 to 85. TheGroups of Zhanjiang (ZJ) and Guangxi (GX) polymorphic loci at least (10), and the Cangnan group (CN) showed themost polymorphism loci in number, followed by the Hainan group (HN). Overall, Cangnan population (CN) haplotypediversity () are the group of high level. Each group of haplotype diversitywas 0.625~0.889, and the difference was not obvious; the nucleotide diversity was 0.002 0~0.057 2, showing obviousdifferences. The populations had both high haplotype diversity(0.835±0.039) and nucleotide diversity(0.057 2±0.006 0). The group number of nucleotide differences (was low, only more than 1, while in HN and CN groups, was high value, which was greater than 30; theentire group also belonged to a higher level, 33.820 7. The AMOVA test of populations based on haplotypefrequencies revealed that 34.02% of the genetic variation occurred within the populations, whereas 65.98% of the geneticvariation occurred among populations. Pairwise fixation index () and genetic distance analysisshowing significant genetic divergence appeared in populations. HN group and the other four groups showedsome genetic distance, and CN group and other groups also showed a large genetic distance. Among small inter groupsof ZJ, XM and GX, the genetic distance between ZJ group and GX group had the minimum genetic distance. No obviousgenetic differentiations occurred among populations of XM, ZJ and GX (>5). While the other group had significantgenetic differentiation, especially in HN group, CN group and other groups generated a high level of geneticdifferentiation of 0.051 3~0.138 6; gene exchange was very small. The occurrence of a moderate geneticdifferentiation in CN group and HN group were = 1.422 2. Whereas, the significant genetic divergencewas found among HN, CN and the other populations, respectively. Haplotype network and phylogenetic treeanalyses also indicated genetic divergence occurred among populations. IBD analysis showed no significant correlationbetween genetic distance and geographical distance. Neutrality test and demographic analyses indicated bottleneck effectmight occur in populations ZJ and GX, population expansion in XM population. The time of expansion of XMpopulation could be 0.12 Ma BP. The phenomenon might occur in Pleistocene period with changes of climate warmingand rising of sea level. In this study, based on the analysis of flat wart mulberry gene, toinvestigate the genetic diversity and genetic differentiation process, aiming for the species conservation of germplasm,and provides the basic data and theoretical basis of the reasonable development of resources and biological evolution.