Oenothera laciniata Hill, one of the rapid expanded exotic weed, was found of restricted distribution initially in northern Taiwan. It had been reported in the sandy coast of Taoyuan and I-Lan counties, but has since been invading rapidly along the coastaline highway and the mountain traits. Patterns of genetic variation were studied at 15 isozyme loci in five sampled populations. Realitively low percentage of polymorphic loci (12.0%) and mean heterozygosity (0.062) indicated little of genetic variability across loci in overall populations. Based on inbreeding estimation, O. lacianata was found nearly complete outcrossing. Moderate population differentiation (FST=0.102) was existed among populations for three polymorphic loci. Results of genetic diversity analysis indicated that nearly 91% of total variation was distributed within populations (GST=0.09). This suggests a lack of barriers to gene flow among populations. The parameter of genetic distance (D) showed population divergence was low between populations (D<0.05) and to be identity in eastern Taiwanese populations (D=0.00). Moreover, linkage disequilibrium was found merely present in the Taoyuan population. However, since O. laciniata is a newly naturalized species, the founder's effect as well as the isolation between eastern and western local populations, may play roles on the differentiation between populations.
Oenothera laciniata Hill, one of the rapid expanded exotic weed, was found of restricted distribution initially in northern Taiwan. It had been reported in the sandy coast of Taoyuan and I-Lan counties, but has since been invading rapidly along the coastaline highway and the mountain traits. Patterns of genetic variation were studied at 15 isozyme loci in five sampled populations. Realitively low percentage of polymorphic loci (12.0%) and mean heterozygosity (0.062) indicated little of genetic variability across loci in overall populations. Based on inbreeding estimation, O. lacianata was found nearly complete outcrossing. Moderate population differentiation (FST=0.102) was existed among populations for three polymorphic loci. Results of genetic diversity analysis indicated that nearly 91% of total variation was distributed within populations (GST=0.09). This suggests a lack of barriers to gene flow among populations. The parameter of genetic distance (D) showed population divergence was low between populations (D<0.05) and to be identity in eastern Taiwanese populations (D=0.00). Moreover, linkage disequilibrium was found merely present in the Taoyuan population. However, since O. laciniata is a newly naturalized species, the founder's effect as well as the isolation between eastern and western local populations, may play roles on the differentiation between populations.