The population genetic structure of Centaurium japonicum (Maxim.) Druce in Taiwan

• Main Authors: Lin, Chih-Hao, 林志浩
• Other Authors: Sheng Huang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/38607286308331890734

碩士 === 國立臺灣師範大學 === 生物學系 === 84 === Abstract Centaurium japonicum (Maxim.) Druce (Gentianaceae) is an annual herb distributed in Yakushima of Japan, Rukyu archipelago and Taiwan. In Taiwan, many small and isolated populations are found on seashores og Lue Tao, Lan Yu and along the northern and eastern coastlines of the main island. Allozyme analysis of 11 C. japonicum populations revealed relatively low level of genetic diversity: 4 of 37 loci were polymorphic (P= 3.45 in population level ), mean number of alleles per locus was 1.06 and the mean expected heterozygosity was 0.013. According to the result of F-statistics, there was 16.8% of variation between populations and 83.4% of variations within populations (Fst= 0.168). Lack of gene flow among populations, estimated to be almostly 1 migrating individual per generation for C. japonicum is a likely cause of low genetic variation in populations. Gene flow can hardly occure between islands and the populations in Lue Tao and Lan Yu reveal lower level of genetic diversity than that in Main island (He= 0.006 VS 0.017). The decrease in genetic variation is attributed to inbreeding and restricted gene flow.