Studying The Effect Of Salinity And Landscape Features To Genetic Structure Of Populations Of Suaeda Salsa In Panjin

Suaeda salsa, belonging to Chenopodiaceae, is an annual herbaceous. Panjin salt habitats are mainly restricted to the maritime coast but scattered occurrences can also be found inland. Human activities have caused losses and isolations in the size of natural salt sites, which may cause loss of plant population genetic diversity and increased genetic differentiation between populations.Therefore, The genetic diversity and genetic structure of 9 populations of Suaeda salsa,102 individuals were analyzed at both total and population level by using microsatellites(SSR). Our Study investigated the impact of the salinity, the natural landscape, and landscape fragmentation to genetic structure of Suaeda salsa. Using PopGene3.2, Arlequin3.11, GENALEX6.1 and Structure2.2 statistical software analysis of experimental data, get the following results:(1) The genetic diversity of populations of Suaeda salsaThe genetic diversity index analysis showed that the percentage of polymorphic bans of 9 populations was 91.11%, allelic richness (Ar) of 2.59, Shannon information index (Ⅰ) was 0.769, the effective allele (Ne) was 2.09, the Nei’s index of genetic diversity (H) was 0.437, the alleles gene (Na) was 2.96.(2) The genetic variation of 9 populations of Suaeda salsaAnalysis of molecular variance (AMOVA) showed that, the genetic variation among poputations was 1.65%, the genetic variation within populations 79.43%,the genetic variation between different areas was 18.92%, and the Fst was 0.206,which showed that the genetic variation of Suaeda salsa was mainly from intra-populations. There was a variation maritime coast and inland. Medium level gene flow among population (Nm=1.330) was found.(3) The genetic structure of 9 populations of Suaeda salsaBased on the STRUCTURE,9 populations of Suaeda salsa put into two genetic groups, a group including the majority of populations (maritime coast and LD1), another group including LD2 and LD3 LD4, which was consistent with the result of PCA.(4) The relationship between soil salt concentration and genetic diversityThe correlation analysis between genetic diversity indexes and concentration of salt showed that there was no significant correlation. The of evolutionary relationship constructed by Neighbour-Joning method showed that the nine Suaeda salsa populations were distributed according to the consistence of salt.(5) Genetic distance and geographic distance correlation researchMental test revealed that a significant negative correlation between genetic distances with geographic distances among populations was found (r= 0.20195, P< 0.05). This result accord with isolation by distance model. Distribution of the smallest two groups, genetic distance is not the smallest, indicated that the genetic structure of the population is affected by other factors.