The Ecological Differentiation And Changes Of Genetic Structure In Rumex Crispus Grown In Metal Mining Area

Plant morphology,physiology and genetic changes under normal or stress environment have been well studied,but the eco-genetic response of plants to longtermed pollution has been rarely reported.In order to explore the ecological differentiation characteristics of plants that continue to experience pollution,as well as changes in population genetic structure and gene pools and to reveal the adaptation mechanism of natural populations under long-term continuous pollution environment,this study selected the populations of Rumex crispus in long-term growth in metal mining areas were investigated,and populations in the surrounding that had not been exposed to pollution were selected as controls.Through research methods of field investigations and homogeneous garden planting,the analysis results of morphological,physiological and ISSR molecular markers were obtained to study the variation characteristics of plant populations with different pollution experiences.The impact of metal pollution on genetic diversity and genetic structure of plant populations were revealed,and the strategies for plants to adapt to the polluted environment were discussed.The research results are as follows.(1)The six morphological traits of R.crispus naturally growing in the wild have significant differences among and within populations,and the average coefficient of variation among morphological traits was 46%.The interpopulation variability was the main source of morphological variation in R.crispus(92.69%).And root diameter was positively correlated with metal factors,but leaf traits were negatively correlated with them,indicating that underground growth is superior to aboveground growth in populations in the mining area,and there were morphological differences between R.crispus populations in mining area and non-mining area.R.crispus is adapted to the heterogeneous environment caused by pollution through rich morphological variation.(2)In order to eliminate the interference of environmental heterogeneity,the homogenous garden is planted with R.crispus populations with different pollution experiences.The average coefficient of variation of the six morphological traits was reduced to 37%,and the average phenotypic differentiation coefficient was reduced(84.94%),which increased the source of variation within the R.crispus populations(15.00%)and reduced the source of variation among populations(84.53%).The morphological variation still exists,and the main source of variation still among populations,indicating that there is genetic variation in the morphological variation of R.crispus,and morphological differentiation occurs among populations.(3)A total of 618 detection sites were obtained from twenty primers in nine R.crispus,populations,and the percentage of polymorphic sites was 96.07%,indicating that the R.crispus showed rich genetic diversity.The average polymorphism(PPB% = 37.42%)and genetic diversity(He = 0.119)of populations in the mining area is higher than that in the non-mining area(PPB% = 22.41%;He = 0.073),indicating that the genetic variability of the population in the mining area is high.Compared with non-mining area populations,the genetic diversity of mining area populations has increased.Interpopulation variability is the main source of genetic variation in R.crispus.populations.There was a significant degree of genetic differentiation among the nine R.crispus populations(Gst = 0.641),and there was a large degree of genetic differentiation between the two groups of R.crispus populations in mining areas and non-mining areas(Gst = 0.152).By integrated analysis it is concluded that R.crispus has adapted to long-term continuous pollution by increasing underground growth and reducing aboveground growth,and its morphological development in the direction of dry biochemical,And it is by increasing genetic variation and genetic diversity that the plants improve resistance to disturbed the environment.R.crispus altered the genetic structure of the population in order to adapt to the harsh environment of continuous pollution in the mining area.There was not only phenotypic differentiation but also genetic differentiation and microevolution occurred between the R.crispus populations in mining area and the nonmining area.R.crispus in the mining area had a higher adaptability and endurance to the polluted environment.