Allozyme diversity and population genetic structure of Pinus densata Master in northwestern Yunnan, China.
We investigated the levels and patterns of genetic diversity of Pinus densata Master in Yunnan. Horizontal starch-gel electrophoresis was performed on macrogametophytes collected from nine populations in northwestern Yunnan, China. Compared with other gymnosperm species, P. densata has higher mean values for all measures of genetic diversity. Allozyme polymorphism (0.99 criterion) was 97.0% and 71.4% at the species and population levels, respectively. The average number of alleles per locus was 3.1 and 2.0 at the species and population levels. Mean expected heterozygosity was substantially higher in P. densata than average values investigated for other gymnosperms both at the population (Hep = 0.174 +/- 0.031) and at the species (Hes = 0.190) levels. Of the total genetic variation, less than 12% was partitioned among populations (GST = 0.112). Our allozyme survey supports the suggestion that the observed higher diversity in P. densata may be attributed partly to its hybrid origin between two genetically distinct species, P. yunnanensis and P. tabulaeformis. In addition, we suggest that introgression would give rise to the increase in genetic diversity occurring in P. densata.
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Laboratory of Systematic and Evolutionary Botany, Chinese Academy of Sciences, Beijing, P.R. China.
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D000483:Alleles; D002681:China; D032462:Cycadopsida / Q000201:enzymology* / Q000235:genetics*; D004592:Electrophoresis, Starch Gel; D014644:Genetic Variation / Q000235:genetics*; D006579:Heterozygote; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics; D012639:Seeds / Q000201:enzymology / Q000235:genetics; D013223:Statistics as Topic