Genetic Variations Of Plus Tree Open-Pollinated Progenies In Quercus Variabilis

Quercus variabilis has a widespread distribution area in temperate and subtropical areas in China. It is the most important cork resources species and has important ecological and economic value. It plays an important role in forestry. In this paper, 4-year-old plus trees open-pollinated progenies from six Q. variabilis natural populations as materials, phenotypic traits differences were invesitigated for different populations and families. With analyzing peroxidase isozyme, genetic variation levels and construction for different populations were determinated. Genetic diversity was studied by using RAPD molecular markers.The main results are as follows:(1)There were abundant genetic variations in Q. variabilis species.There were significant difference in seedling height,leaf length,leaf width, petiole length,leaf areas etal traits among populations. There were significant difference in seedling height between families within populations, but diameter has no significant difference.Coefficients of variance of seedling height and diameter were larger among families. Variations are bigger between individuals. There were significantly positive or weak positive correlation.The phenological period of different populations in Q.variabilis also has differences.(2)Based on the analysis of character variation ,with seedling height as the main character, 10 superior families were seclected primitively from 57 tested families. Their height growth increased by 31.7% - 85.2% than the overall populations average.(3)Q.variabilis population has a high variation level, the mean of alleles is 2.479 and the expected heterozygosity is 0.282, within population genetic variations accounted for 54% of the total genetic variations. Through UPGMA cluster analysis, six natural populations of Q. variabilis might be divided into two sorts,Xinyang population and Baotianman population from Henan province was classified as a sort,three populations from Shanxi and Baojiaxiang population from Anhui province were classified as a sort.(4)With 11 polymorphic primers selected from 70 to amplify and analysis the samples from six Q. variabilis populations,a relatively high level of genetic diversity was detected in Q.variabiliss pecies.Average observed numer of alleles(na) and effective number of alleles (ne) were 1.840 and 1.577 at the species level, respectively .The mean Nei's diversity index(h) was 0.324 and Shannon information index was 0.437 on average. Polymorphic loci, percentage of polymorphic loci, average observed number of alleles, Shannon information index and Nei's genetic diversity index showed that the changes of genetic diversity of all populations were consistent. Genetic distance of among six populations was large and genetic similarity was small.