AOBPreview originally published online on June 27, 2006
Annals of Botany 2006 98(3):601-608; doi:10.1093/aob/mcl135
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Allozyme Variation of Populations of Castanopsis carlesii (Fagaceae) Revealing the Diversity Centres and Areas of the Greatest Divergence in Taiwan
1 Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan, 2 Graduate Institute of Biotechnology, Chinese Culture University, Yangmingshan, Taipei 111, Taiwan and 3 Division of Forest Biology, Taiwan Forestry Research Institute, Taipei 100, Taiwan
* For correspondence. E-mail tpl{at}ntu.edu.tw
Received: 22 March 2006 Returned for revision: 10 April 2006 Accepted: 18 May 2006 Published electronically: 27 June 2006
• Background and Aims The genetic variation and divergence estimated by allozyme analysis were used to reveal the evolutionary history of Castanopsis carlesii in Taiwan. Two major questions were discussed concerning evolutionary issues: where are the diversity centres, and where are the most genetically divergent sites in Taiwan?
• Methods Twenty-two populations of C. carlesii were sampled throughout Taiwan. Starch gel electrophoresis was used to assay allozyme variation. Genetic parameters and mean FST values of each population were analysed using the BIOSYS-2 program. Mean FST values of each population against the remaining populations, considered as genetic divergence, were estimated using the FSTAT program.
• Key Results Average values of genetic parameters describing the within-population variation, the average number of alleles per locus (A = 2·5), the effective number of alleles per locus (Ae = 1·38), the allelic richness (Ar = 2·38), the percentage of polymorphic loci (P = 69 %), and the expected heterozygosity (He = 0·270) were estimated. High levels of genetic diversity were found for C. carlesii compared with other local plant species. Genetic differentiation between populations was generally low.
• Conclusions From the data of expected heterozygosity, one major diversity centre was situated in central Taiwan corroborating previous reports for other plant species. According to the mean FST value of each population, the most divergent populations were situated in two places. One includes populations located in north central Taiwan between 24·80°N and 24·20°N. The other is located in south-eastern Taiwan between 22·40°N and 23·10°N. These two regions are approximately convergent with the most divergent locations determined for several other plant species using chloroplast DNA markers published previously. An important finding obtained from this study is that unordered markers like allozymes can be used to infer past population histories as well as chloroplast DNA markers do.
Key words: Diversity centre, allozymes, Castanopsis carlesii, Fagaceae, genetic divergence