Patterns of Genetic Variation of Formosan Alder (Alnus formanason (Burk.) Makino) in Taiwan

• Main Authors: Chian-Yi Sue, 蘇倩儀
• Other Authors: Shong Huang
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/68144868520367958027

碩士 === 國立師範大學 === 生物學研究所 === 83 === Electrophoretically demonstrable diversity of 15 enzymes encoded by a total of 23 structural loci was analyzed in 22 sexually mature populations of Alnus formosana(Burk.) Makino (Betulaceae) in Taiwan. On average, 46.2% of the loci per population were polymorphic, with a mean of 1.8 alleles per locus. The observed heterozygosity was not significantly different from expected heterozygosity(Ho=0.181,He=0.175). Approximately 98% of the total genetic diversity resided within populations. Genetic distance between populations waslow, ranging from 0 to 0.019 with a mean of 0.004. F-statistics showed very low differentiation between populations (Fst=0.038). Inbreeding coefficient (Fis=-0.057) revealed that non-assortative mating was common in this species. Most populations however, appeared homogeneous, implying that high level of gene flow occurred among populations them. On the other hand, heterogeneity of allele frequencies among populations along elevational gradient was noted at seven loci. The finding that significant correlations between allelic frequences and elevational gradient revealed at SOD and PGM-1 loci suggest that genetic variation tends to be partially corresponded with temperature changes. Low genetic differentiation among popula- tions in Formosan alder may be attributed to the factors such as mating system, pollen and seed dispersal. Differential selection pressures and life-history seemed to be the main factors that maintaining theobserved genetic variability of this species.