PHYLOGEOGRAPHIC STRUCTURE OF THE COMMERCIALLY IMPOR- TANT TROPICAL TREE SPECIES, DRYOBALANOPS AROMATICA GAERTN. F. (DIPTEROCARPACEAE) REVEALED BY MICROSATELLITE MARKERS

Dryobalanops aromatica Gaertn. F. (Kapur) is an economically important timber     species in Southeast Asia that can serve as a good model for studying the impact of the Pleistocene glaciations on the genetic diversity and distribution of species in tropical regions. Seven polymorphic microsatellite markers were        analyzed in five natural populations of D. aromatica (N = 120 individuals): Gunung Panti in Malay Peninsula, Lingga Island in Lingga Archipelago, Lambir Hills National Park, Limbang and Similajau National Park in Borneo. The level of gene diversity (HE) for the five populations was relatively high with a range from 0.571 (Similajau) to 0.729 (Gunung Panti). The high genetic diversity in the present study could be attributed to the larger refugia population sizes of D. aromatica than that of other species. The population genetic structure revealed two distinct groups: the Malay Peninsula-Lingga Archipelago and Borneo. This pattern suggests that populations in each geographical area might be the consequence of post-glacial expansion from one or two refugia, but that gene flow between different glacial refugia was fairly restricted. </p

Determinants of Smallholder Farm Households

The global concerns on climate change adaptation has now shifted from a high-level advocacy o

Genetic Variation and Genetic Structure of Two Closely Related Dipterocarp Species, Dryobalanops aromatica C.F. Gaertn. and D. beccarii Dyer

Large-scale genetic structure revealed in tree populations in SE Asia, as well as in many temperate forests, has been shaped by climatic fluctuation in the late Pleistocene, most importantly by that in the last glacial period. In a comparative study of the phylogeographic patterns of two closely related dipterocarp species, Dryobalanops aromatica C.F.Gaertn. and D. beccarii Dyer, we investigated how changes in land area associated with changes in climate affected large-scale genetic structure. We examined the genetic variation of D. aromatica, collected from nine populations throughout the Sundaic region, and of D. beccarii, collected from 16 populations mainly in Borneo, using seven polymorphic microsatellite markers. The two species were clearly distinguishable in the STRUCTURE analysis, although hybridisation probably occurred in sympatric populations and also in several other populations. The D. aromatica populations were divided into two main groups by the STRUCTURE analysis: Malay–Sumatra and Borneo. Mixing of the Sumatra and Borneo clusters occurred on the Malay Peninsula, supporting the hypothesis that tropical rainforests expanded over a dried Sunda Shelf during the last glacial period. The two main genetic clusters might have been formed by repeated cycles of fluctuation in land area. The D. beccarii populations in Borneo were divided into four geographically distinct groups: western Sarawak, central inland Sarawak, central coastal Sarawak and Sabah. The population on the Malay Peninsula (Gunung Panti) was an admixture of the four Bornean clusters. This suggests that this population is a relic of the recent range expansion of D. beccarii during the last glacial period

Population Genetic Diversity in The Genus Dryobalanops Gaertn. f. (Dipterocarpaceae) Based on Nuclear Microsatellite Markers

Abstract The genus Dryobalanops Gaertn. f. is a small but important genus that contains seven species and is found in the Southeast Asian tropical rain forests. Seven polymorphic nuclear microsatellite markers were analyzed in 46 natural populations of six extant Dryobalanops species (N = 700 individuals) covering the distribution range in Western Malesia. The mean gene diversity at the species level ranged from 0.392 in D. rappa to 0.635 in D. aromatica. The F ST value ranged from 0.156 in D. keithii to 0.283 in D. beccarii and all F ST values were highly significantly greater than zero. These results suggest that gene flow between populations has been limited and intensive genetic drift has occurred in all of the species. Plants with narrowly distributed species such as D. keithii and D. rappa, which are endemic to Borneo, tend to have lower levels of genetic diversity compared with widespread species such as D. aromatica. STRUCTURE analysis revealed that at least two of the six species could be effectively discriminated each other. The results of this study will be helpful for building effective conservation schemes as well as for providing basic data for future provenance trials of Dryobalanops species

Phenotypic and Genetic Diversity Evaluation of Sengon (Falcataria moluccana (Miq.) Barneby & JW Grimes) from Solomon Provenance on Progeny Trial in Cirangsad Experimental Forest, West Java

Initial evaluation of phenotypic variability and genetic diversity was conducted on the progeny test of 2 years-old sengon from Solomon provenance, which derived from nine families of mother tree and were then planted in 4 blocks in the Cirangsad Experimental Forest. Phenotypic assessment on eight traits was conducted on 36 trees using a scoring system, while genetic diversity of 15 selected individuals which represented high and low-score phenotypic traits was analyzed using 5 selected RAPD primers. The result on phenotypic assessment showed that family 3 (57.25 points) has the highest average score of phenotypic quality and family 4 has the lowest average score (7.50 points). Furthermore, genetic analysis showed that the low-scoring sengon population had a greater mean genetic diversity (He = 0.2535) than the high-score population (He = 0.2345). The analysis of molecular variance (AMOVA) revealed a significant genetic differences (p-value &lt; 0.001) among high and low-score populations and the dendrogram of genetic distance revealed clustering of individuals having similar superior phenotypic against those having non-superior, indicating the selection based on phenotypes in this study had succeeded in pooling the good quantitative alleles in the selected population. This evaluation results can be used as a reference in determining the best families to produce superior sengon (from Solomon provenance) offspring in the future that have desired adaptability, productivity, and diversity

PHYLOGEOGRAPHIC STRUCTURE OF THE COMMERCIALLY IMPOR- TANT TROPICAL TREE SPECIES, DRYOBALANOPS AROMATICA GAERTN. F. (DIPTEROCARPACEAE) REVEALED BY MICROSATELLITE MARKERS

DWIYANTI, F.G., KAMIYA, K. & HARADA, K. 2014. Phylogeographic structure of the commercially important tropical tree species Dryobalanops aromatica Gaertn. F. (Dipterocarpaceae) revealed by microsatellite markers. Reinwardtia 14(1): 43 – 51. ? Dryobalanops aromatica Gaertn. F. (Kapur) is an economically important timber species in Southeast Asia that can serve as a good model for studying the impact of the Pleistocene glaciations on the genetic diversity and distribution of species in tropical regions. Seven polymorphic microsatellite markers were analyzed in five natural populations of D. aromatica (N = 120 individuals): Gunung Panti in Malay Peninsula, Lingga Island in Lingga Archipelago, Lambir Hills National Park, Limbang and Similajau National Park in Borneo. The level of gene diversity (HE) for the five populations was relatively high with a range from 0.571 (Similajau) to 0.729 (Gunung Panti). The high genetic diversity in the present study could be attributed to the larger refugia population sizes of D. aromatica than that of other species. The population genetic structure revealed two distinct groups: the Malay Peninsula-Lingga Archipelago and Borneo. This pattern suggests that populations in each geographical area might be the consequence of post-glacial expansion from one or two refugia, but that gene flow between different glacial refugia was fairly restricted

Chloroplast Genome Draft of Dryobalanops aromatica Generated Using Oxford Nanopore Technology and Its Potential Application for Phylogenetic Study

Kapur (Dryobalanops aromatica) is an important dipterocarp species currently classified as vulnerable by the IUCN Red List Threatened Species. Science-based conservation and restoration efforts are needed, which can be supported by new genomic data generated from new technologies, including MinION Oxford Nanopore Technology (ONT). ONT allows affordable long-read DNA sequencing, but this technology is still rarely applied to native Indonesian forest trees. Therefore, this study aimed to generate whole genome datasets through ONT and use part of these data to construct the draft of the chloroplast genome and analyze the universal DNA barcode-based genetic relationships for D. aromatica. The method included DNA isolation, library preparation, sequencing, bioinformatics analysis, and phylogenetic tree construction. Results showed that the DNA sequencing of D. aromatica resulted in 1.55 Gb of long-read DNA sequences from which a partial chloroplast genome (148,856 bp) was successfully constructed. The genetic relationship was analyzed using two selected DNA barcodes (rbcL and matK), and its combination showed that species of the genus Dryobalanops had a close relationship as indicated by adjacent branches between species. The phylogenetic tree of matK and the combination of the matK and rbcL genes showed that D. aromatica was closely related to Dryobalanops rappa, whereas the rbcL gene showed group separation between D. aromatica and D. rappa. Therefore, a combination of the matK and rbcL genes is recommended for future use in the phylogenetic or phylogenomic analysis of D. aromatica