Analysis On The Population Genetic Diversity Of Desert Super-xerophytic Shrub Reaumuria Soongorica

Extreme drought and salt resistant plant Reaumuria soongorica is of great potentialfor revealing genetic bases unique to naturally stress-tolerant plants. A preliminarygenome survey, including chromosome number, karyotype, chromosomal localization of45S rDNA loci and genome size was conducted with R. soongorica collected fromLanzhou, China. Chromosome counting showed that R. soongorica is diploid withchromosome number of22. Karyotypical analysis illustrated that the chromosomes sizeranges from3.38to5.51lm, and the chromosomal formula is2n=2x=22=4m+14sm+4st. Fluorescence in situ hybridization revealed that four pairs of45SrDNAsignals were detected at the end of R. soongorica chromosomes.SDS-PAGE was employed for this study among90R. soongorica accessions. ThePIC value of17glutelin bands showed that only52.9%of them were moderatepolymorphism bands. The value of genetic distance between the populations variedfrom0.0419to0.4073with an average of0.1775. The population3and4had thehighest genetic variations. Most of genetic variance existed within populations wasobserved based on the coefficient of gene differentiation (GST=0.3827). Clusteranalysis found nine groups can’t be clustered together, indicate the genetic differences.Selected40PLUG primers for test molecular polymorphism of4populations R.soongorica, results show that the molecular polymorphism sites of primers PLUG for4populations R. soongorica were not many, but the experiment for the detection of R.soongorica molecular polymorphisms in the establishment of the of molecular markersreaction system and the R. soongorica genetic diversity for further research on themolecular level has laid a good foundation; The gene sequence an evolution analysis ofR. soongorica Nad7gene, show that Nad7gene is relatively young, and its sequencesimilarity to desert species proved Nad7gene has significance for R. soongorica adaptto extreme environmental.In summary, the genetic polymorphism analysis of R. soongorica populations andaccessions from different ecological environments conducted in this study showed arich genetic diversity in the accessions and adaptive differentiation characteristics, which laid the foundation for in-depth analysis on the formation of important agronomictraits and functional genomics in cereal plants.