| Based on the natural distribution of Caragana korshinskii Kom. in China, ten populations of C. korshinskii (PG, HQ1, HQ2 from Shanxi province; SM, YL, JB, DB from Shaanxi province; ETK, HJ, DS from Inner Mongolia) were selected and investigated. Genetic diversities were evaluated and compared at three levels of morphology (i.e., leaves, pods, and seeds etc.), allozyme and DNA. Main results obtained are as follows:(1) Morphological diversities among/within populations were discussed by analyzing characters such as leaves, pods, and seeds. Analysis of variance for all characteristics was significantly different among populations and among individuals within population. The mean phenotypic differentiation coefficient (Vst = 0.195) shows that the variation among populations (80.5%) is significantly higher than that within populations. The correlations between the phenotypic traits and ecological and geographic factors are not significant. 1000-seed mass, pod width and leaf length were the main traitss account for the phenotypic variations according to the PCA and disciminant analysis. Based on the cluster analysis and PCA, the populations of C. korshinskii investigated may be divided into four groups by phenotypic traits.(2) A gel electrophoresis method was used to study the genetic diversity of ten C. korshinskii populations. Eight of 11 loci from seven enzymes assayed were polymorphic. C. korshinskii maintained high level of genetic variation as compared with the average other species. At species level, the mean number of alleles per locus (A) was 1.727, the mean effective number of alleles per locus (Ae) was 1.533, the percentage of polymorphic loci (P) was 72.7%, the observed heterozygosity (Ho) was 0.425, the expected heterozygosity (He) was 0.292. At population level, the estimates were A = 1.618. Ae = 1.470. P = 61.8%, Ho = 0.408, and He = 0.263. The mean gene differentiation coefficient (Gst) was 0.14, indicating that approximately 84.8% of the total allozyme variation occurred within populations. The gene flow among populations (Nm) was 1.5. According to the UPGMA cluster analysis based on the genetic distance, ten populations of C. korshinskii were divided into three groups, there was no significant relationship between genetic distance and geographic distance among populations.(3) Clear and high resolution DNA fingerprints were obtained by SDS method. The optimized AFLP reaction system include extracted genomic DNA(200ng/μl) was digested with EcoRI and Msel restriction enzymes; a total volume of 20μl reaction mixture, the preamplfication contain 2 μl of the digestion/ ligation mixture, 0.6 μl each of the pre-amplification primers (50ng/μl), 2μl 10xPCR buffer, 1.2μl Mg2+ (25mM), 0.16μl dNTPs (25mM), 0.12μl Taq polymerase (5U/μl); Selective amplification reaction mixture (20μl) was prepared with 2μl diluted pre-amplification production, 0.8 μl each EcoRI and MseI primer (50ng/μl), 2μl 10xPCR buffer, 1.2μl Mg2+(25mM), 0.18 μl dNTPs (25mM), 0.2μl Taq polymerase (5U/μl). Four primer combinations produced 358 bands across a total of 98 individuals. High genetic diversity was both observed at species level (P = 93.9%, H = 0.3168, I = 0.477) and populations level (P = 69.5%, H = 0.244, I = 0.365). A significant correlationships were found among all genetic diversity parameters and latitude and the annual mean temperature. Based onGst and AMOVA analysis, most of genetic variation of C. korshinskii was within population (77.3%, 77.8%, respectively). The gene flow among populations (Nm) of the species was 1.7. Based on the cluster analysis and PCA, the populations of C. korshinskii investigated may be divided into two groups. There was significant relationship between genetic distance and geographic distance among populations of C. korshinskii...
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