Search

The successful isolation of DNA (Deoxyribonucleic Acid) is essential for the investigation process of forestry molecular genetics. Samples used are usually retrieved either from soft or juvenile plant organs because of their excellent DNA source. However, in certain cases, aforesaid samples are hard to obtain, as for forensic purposes. Alternatively, woods possess potential as alternative source of DNA whose extraction method has been developed with varying degrees of success. However, to date, effectiveness on tropical wood grown in Indonesia has not been widely reported. Therefore, objective of this study was to compare the results of DNA isolation of various dried and fresh wood samples by using two isolation methods: Cetyl Trimethyl Ammonium Bromide (CTAB) and Qiagen DNeasy Plant Mini Kit (QDPMK). Extraction results were visualized in agarose gels and quantified using Nanophotometer NP80 Implen which were then amplified using two universal primers: ITS and rbcL for detecting DNA signals. Extraction results from dried wood indicated no visualization in the gel, while fresh wood samples showed thick smeared bands on both extraction methods. Quantity test results denoted higher concentration in CTAB-extracted samples compared to samples extracted using QDPMK, in both types of samples, even though both resulted in optical density ratios outside the range of purity (λ260/280: 1,8–2,0 and λ260/230: 2,0, respectively). Success rates of ITS and rbcL primary amplification in dried wood samples were quite low yet outputs from the two methods did not differ significantly. Meanwhile, outcome of ITS and rbcL amplification on fresh wood samples had a fairly high success.

Ebony (Diospyros celebica Bakh.) is an endemic plant on Celebes (Sulawesi) island. Extractive compounds within ebony wood cause it to have durability, strength, and beautiful patterns. In this study, we used near-infrared (NIR) spectroscopy to discriminate between ebony wood samples, based on their origins at different growth sites on Celebes island, and to develop quantitative models to predict the extractive content of ebony wood. A total of 45 wood meal samples from 11 sites located in West, Central, and South Celebes were collected in this study. NIR spectral data were acquired from hot water and ethanol&ndash, benzene soluble extracts from ebony wood in this study. The extractive content of the ebony was 10.408% and 10.774% based on hot water solubility and treatment with ethanol&ndash, benzene solvent, respectively. Multivariate analysis based on principal component analysis&ndash, discriminant analysis revealed that ebony wood from West Celebes differed from most of the wood from South Celebes, however, it was only slightly different from ebony wood from Central Celebes based on NIR spectra data. These findings were in line with the extractive contents obtained. Partial least square regression models based on wood meal spectra could potentially be used to estimate the hot water and ethanol&ndash, benzene extractive contents from ebony wood.

Istomo, Kusmana C, Dwiyanti FG, Malik D. 2020. Comparison of several methods of stands inventory prior to logging towards the yield volume of mangrove forest in Bintuni Bay, West Papua Province, Indonesia. Biodiversitas 21: 1438-1447. The difference between the estimated volume and the actual harvested volume is the reason that mangrove forest management is unsustainable. To overcome this discrepancy, it is important to do what so called Inventarisasi Tegakan Sebelum Penebangan (ITSP) or stands inventory prior to logging for logging concession. However, the study on suitable ITSP methods for mangrove forests has been limited. This study aims to assess three ITSP methods (namely Line Strip Sampling Method, Line Systematic Sampling Method, and CIFOR’s Modified Method) using two allometric equations (i.e., equation developed specifically by a logging concession and equation developed that has specific formula for each species), and to select the combination of method and allometric equation that produce the highest accuracy for logging concession in mangrove forest, especially in Bintuni Bay, West Papua. The results showed that CIFOR’s Modified Method produces the lowest discrepancy between the estimated volume and the actual harvested volume, followed by Line Strip Sampling Method. In addition, regardless the ITSP methods employed, the allometric equation by Cole et al. (1999) outperforms the equation developed specifically by a logging concession. While producing the lowest discrepancy with plot size is the smallest than other methods, CIFOR’s Modified Method has a disadvantage when applied in the field due to difficulties in making a circular plot. As such, we recommend ITSP method to be used is the Line Strip Sampling method with allometric equation.

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.