ALLOZYME VARIATION IN 4 GEOGRAPHIC AREAS OF CINNAMOMUM-KANEHIRAE

The once dominant endemic broadleaf tree species in Taiwan, Cinnamomum kanehirae Hay., has become a rare and endangered species due to overc utting. A clone bank, consisting of at least 220 clones collected isla ndwide, was established at the Liukuei station, Taiwan Forestry Resear ch Institute. Genetic diversity within and genetic differentiation amo ng four geographic areas of C. kanehirae were investigated using 164 c lones collected from the clone bank. Seven out of the 11 loci examined were polymorphic. The average proportion of polymorphic loci per area was 51% at the 99% criterion for polymorphism. Mean expected heterozy gosity ranged from 0.188-0.261 in the different areas, and 0.238 at th e species level. On average the percent heterozygous loci per individu al ranged from 13.9-21.6%, the number of alleles per locus ranged from 1.7-1.9, and the effective number of alleles per locus ranged from 1. 34-1.54 at the area level. The much higher expected heterozygosity and higher number of alleles per locus compared to other local woody spec ies investigated may support the hypothesis that Taiwan was a distribu tional center of Cinnamomum. Partitioning the genetic variability into within-and among-geographic area components with F statistics and gen e diversity analysis led to an estimate of within-area variation amoun ting to 88% of the total variation. A slight barrier to gene flow amon g areas could be due to the large seed size and to insect pollination. The limitation of seed dispersion, erratic flowering times, and sever al subpopulations within the same geographic areas may contribute to t he lower levels of observed heterozygosity than expected heterozygosit y among the seven polymorphic loci, indicating some degree of inbreedi ng and the Wahlund effect and thus a slight deficiency of heterozygote s (F-is = 0.157). Area 4, located in southeastern Taiwan has a much lo wer elevational distribution and showed a higher proportion of polymor phic loci, implying that genetic variation of area 4 may have develope d under different climate conditions.