TITLE	High levels of genetic variation in Korean populations of Sasamorpha borealis (Poaceae)
AUTHOR	Nam Won Lee Department of Biology, Gyeongsang National University, Chinju 660-701, The Republic of Korea Myong Gi Chung Department of Biology, Gyeongsang National University, Chinju 660-701, The Republic of Korea
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ABSTRACT	Genetic and genotypic diversity of Korean populations in Sasamorpha borealis (Hack.) Nakai were investigated using allozymes as genetic markers. In Korea, S. borealis usually grows on hillsides under pine-oak understory. Many species of bamboos have the intermast period of "mast seeding." After spreading by extensive rhizomes for a specific period, nearly all adults in one area produce wind-pollinated flowers, set large quantities of seeds, and die. This study was undertaken to infer relationships between levels of genetic diversity and the reproductive biology of the species. Populations of S. borealis maintain high levels of genetic diversity: 51% of the loci examined were polymorphic and of mean genetic diversity (HeP = 0.219). The mean number of multilocus genotypes per population was 18.4, and the mean genotypic diversity index (DG) was 0.720. However, 31% of the total genetic variation was found among populations (GST = 0.310). Allele frequencies for all loci examined differed significantly among populations (p < 0.001). Average genetic identity for all pairs of populations was 0.833 (SD = 0.046). Indirect estimates of the number of migrants per generation (Nm) were 0.56 (calculated from GST) and 0.20 (calculated from the mean frequency of ten private alleles). Several biological and ecological traits found in S. borealis (widespread geographical distribution, long-lived habit, clonal reproduction with relatively high genotypic diversity, wind-pollinated breeding system, death of adults bearing large quantities of seeds, probable low gene flow among populations, selection for heterozyous genotypes in some of the sampled populations, the patterns of recolonization, effects of genetic drift, and local selective forces) may have played roles in shaping the population genetic structure of the species.
KEYWORD	Allozymes; Clonal diversity; Genetic diversity; Mast seeding; Sasamorpha borealis; Selection;
ARTICLE INFO	Botanical Bulletin of Academia Sinica, Volume 40 Number 4 October 1999, page 311-317, 7 pages
PUBLISHER	Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China