A Study On Population Ecology And Genetic Diversity Of Stemona Shandongensis

Stemona shandongensis was the plant that was endemic to Shandong province. Four Stemona shandongensis populations were sampled. The studies were carried out by spatial distribution pattern, age structure, static life table, phenotypic differentiation and genetic diversity:Four natural populations of Stemona shandongensis were analyzed by T test of coefficient of dispersion, F test of Morisita's index and X² test of Poisson distribution. Their aggregated intensities were measured by using the following indices: Negative binomial parameter (K), Cassie index (1/K), Green index (GI), Lloyd's index (m*) and Patchness index (PAI). The influences of block size and seedling age on the distribution pattern and assemble intensity were revealed using hose indexes. The result indicated that the distribution patterns of S. shandongensi total populations were clumped. The pattern scale of was about eight square meters. The assemble intensity of 1-year-old plant population was higher than the assemble intensity of perennial plant population. The evolutionary of S. shandongensis total populations was becoming higher in assemble intensity.In order to determine the population state of S. shandongensis, analyze its past population structure and pre-disturbance situation and forecast its future population dynamics, the static life table, fecundity schedule, survival curve and mortality curve were compiled using underground growth part amount to represent the age class structure of S. shandongensis. The results showed that the survival curve of the population appeared to be of the Deevy- I type. The population survives dropped rapidly in the earlier stage and couldn't self-renew, presented as the decline population.Four Stemona shandongensis populations were analyzed using morphological markers. Morphological diversities among/within populationswere discussed on the basis of traits such as the leaf length, leaf width, leaf length leaf width, number of leaf vein, number of whorled leaves, node length.Analysis of variance for all traits showed that there was significantly difference among populations and among individuals within populations. The mean phenotypic differentiation coefficient(V_ST=45.8362%) showed that the variation within populations was slightly higher than that among populations. According to the UPGMA cluster analysis based on the euclidean distance, the populations of four S.shandongensis populations investigated could be divided into three groups.Genetic variation and structure of 120 individuals of 4 S. shandongensis populations were investigated by AFLP method with 4 primer combination. A total of 170 bands were observed including 91 polymorphic bands. The percentage of polymorphic bands(P) was 53.50%; for the S. shandongensis population, Nei's gene diversity index(H) was 0.1441, Shannon's information index(I) was 0.1682; total gene diversity (H_t) was 0.1646, population gene diversity(H_s) was 0.1682, gene differentiation coefficient (G_st) was 0.0210; there was no significant correlation between genetic distance(D) and geographic distance based on the UPGMA method.The results showed that there was an abundant genetic diversity and genetic differentiation among S. shandongensis populations.