Genetic variations within and among Rhizophora apiculata populations in the Greater Sunda Islands of Indonesia were studied using microsatellite markers. The study found 38 alleles on five loci in 15 populations. The observed (H(o)) and expected (H(e)) heterozygosity values are 0.338 and 0.378, respectively. Inbreeding effect from self-pollination might explain its heterozygote deficiency. Population genetic differentiation (F(ST) = 0.381) was similar to other mangrove species. The genetic diversity of R. apiculata populations along the coastline inside the archipelago (e.g., Buleleng, Donggala, Mamuju, and Takalar) was higher than those of population along the coastline outside the archipelago, especially northern Sumatra populations (i.e., Langkat, Tapanuli Tengah, Dumai, and Padang). The isolation by distances and sea currents directions as well as their connectivity might affect the gene flow and genetic exchange. The more isolated with fewer connections by sea currents, the smaller gene flow and genetic exchange observed between populations. The higher genetic exchange, on the contrary, occurred when population location was closer to the meeting point of the sea currents. The study also showed that the patterns of sea current movement seemed to have influence genetic clustering of populations which fell into three main groups (Sunda Shelf Mangroves) and one isolated population (New Guinea Mangroves).

We applied eight primer-restriction enzyme combinations to investigate genetic diversity, genetic differentiation, and genetic structure of Carpinus laxiflora populations with AFLP markers. The average of effective alleles (A e), the proportion of polymorphic loci (%P), Shannon's diversity index (I), and the expected heterozygosity (H e) were 1.4, 82.2%, 0.371, and 0.241, respectively. The expected heterozygosity (Hj) from Bayesian method was 0.270. The level of genetic diversity was high compared to those of Carpinus species and other species with a similar life history. The inbreeding coefficient (F IS) from approximated Bayesian method was 0.618, which was smaller than that for Acer pseudosieboldianum (F IS ¼0.712). Genetic differentiation was 0.060 from AMOVA (U ST) and 0.056 from Bayesian method (h II). The level of genetic differentiation was very small compared to that of Carpinus species and other species with a similar life history. According to UPGMA and Bayesian clustering, 10 populations were divided into two genetic groups. Except Mt. Chilgap and Minjuji, most of the populations were detected as weak genetic structures according to the geographical distribution such as mountain ranges. We might consider that demographic disturbance, local specific vegetation change history, and forest succession interrupted the genetic structure of C. laxiflora in South Korea.

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Pinus densiflora Siebold & Zucc. is a widely distributed conifer species in the Republic of Korea with economic and ecologic importance. However, P. densiflora is negatively influenced by various factors, such as forest fires, clearing of large numbers of trees infected with Pinus disease, and dieback. We aimed to use microsatellite markers to estimate the genetic diversity, differentiation, and structure of P. densiflora populations in the Republic of Korea. A total of 1844 samples from 60 populations were evaluated using 11 polymorphic microsatellite markers. The observed heterozygosity and expected heterozygosity were 0.652 and 0.673, respectively. The mean genetic differentiation among the populations was 0.013. Moreover, P. densiflora showed high genetic diversity and low genetic differentiation compared with conifer species, including Pinus species with similar life histories. Principal coordinates analysis and Bayesian clustering showed that P. densiflora has a weak geographical structure. The P. densiflora population at Mt. Halla, Jeju Island, showed the lowest genetic diversity and significant genetic differentiation compared with other mainland populations due to genetic drift and restricted gene flow. These findings can be useful for designing new conservation, management, and breeding strategies for P. densiflora populations in response to future environmental changes.