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Susilowati A, Hartini KS, Elfiati D, Rachmat HH, Kusuma YS, Sinaga MZE, Suhartati T. 2020. Macropropagation by shoot cutting of raru (Cotylelobium melanoxylon), a highly utilized dipterocarp in North Sumatra, Indonesia. Biodiversitas 21: 724-730. Cotylelobium melanoxylon (Hook.f.) Pierre, or locally named raru, is one of native tree species from North Sumatra that has many uses for its wood and medicinal purposes for anti-diabetic, anti laxative and blood coagulation. C. melanoxylon has been experiencing short supply due to its limited natural distribution, forest degradation, illegal harvesting for its wood and bark and uncertain fruiting season of the species. Along with these alterations, C. melanoxylon population has been decreasing. The objective of this research was to determine the effectiveness of C. melanoxylon propagation by shoot cutting. Randomized factorial design with 2 factors was employed in this research. The first factor (factor A) was the cutting media (i.e. topsoil only; topsoil and sand with proportion of 1:1 v/v), and the second factor (factor B) was commercial auxin addition (i.e. 1g/100cuttings; without auxin). The observed parameters were survival percentage, rooted percentage, number of primary and secondary root, length of primary and secondary root and root histology. The results showed that the interaction between media and auxin addition did not have any significant effect on all tested parameters. The average survival percentage was 70-90% and rooting percentage was 50-90%. Adventitious root formation on C. melanoxylon cutting was originated from cell differentiation on wounded area near cambium, followed by root primordia formation and root meristem formation. The success of artificial propagation technique for this species will provide basic practice of C. melanoxylon cultivation and may contribute to the effort of ex situ conservation for valuable and threatened tree species.

Rachmat HH, Susilowati A, Elfiati D, Hartini KS, Faradillah WN. 2017. Short Communication: Strong genetic differentiation of the endemic rosin-producing tree Styrax sumatrana (Styracaceae) in North Sumatra, Indonesia. Biodiversitas 18: 1331-1335. Styrax sumatrana is an economically important rosin-producing tree endemic to North Sumatra, Indonesia. Distribution of this species is very limited, and the high rate of forest degradation in Sumatra is increasing the necessity for conservation. To quantify genetic variation and population structuring, we collected individuals from 3 populations namely Pakpak Bharat, Humbang Hasundutan (Humbahas) and Tapanuli Utara in which each of the population was represented by 10 individuals. However, the successful rate of amplification was varied among populations and for later analysis, we only took an account those sequences showing clear electropherograms and disposed those which showed ambiguity. We sequenced trnL-trnF chloroplast DNA (cpDNA) region yielded 941 bp after alignment. The trnL-trnF assigned the species into 4 haplotypes in which Pakpak Bharat was differentiated significantly and not shared any similar haplotypes with two others populations. Humbahas and Tapanuli Utara was shared one common haplotype. Mean nucleotide diversity at silent sites ranged 0 - 3.33 x 10-3, while nucleotide diversity at non-synonymous site ranged 0 - 5.9 x 10-4. Strong genetic differentiation was also found among 3 origin populations, with the highest pairwise genetic differentiation found on Pakpak Bharat and Tapanuli Utara (FST= 0.80952). Clear and apparent genetic structuring was possibly caused by geographical barriers such as highland and mountain ranges (Bukit Barisan mountain ranges) which acted as effective barriers to gene flow among population. The findings suggest that conservation efforts should focus on every population because each of the population maintains distinct genetic identity.

Taxus sumatrana or commonly known as Sumatran yew is native endangered taxol producing trees from Indonesia and promising drug for cancer source. Due to very limited and restricted natural growing habitat, small population size and the tendency of habitat deterioration, their sustainable occurrence is facing a serious threats. Urgent task for conserving this species was needed. Shoot cutting is promising methods for solving natural regeneration problems of this species. This research was conducted to determine appropriate shoot cutting technique for propagating the species and hence conserving Sumatran yew. Completely Randomized Design Factorial with 2 factors and 20 replications was used in this research. The first factor was cutting medium the second factor was auxin addition. The observed parameters were survival rate, rooting percentage, primary root number and primary root length. The result showed that the percentage of rooted cuttings were varied from 50 to 65 percent depend on the treatment. Cutting media and auxin treatment significantly only affected primary root number. Combination of soil and husk with auxin addition produced the highest rooting percentage.

The purpose of this research was to analysis an association between Daun Sang and other vegetation in Resort Sei Betung, Gunung Leuser National Park. According to its conservation status, Daun Sang was including on vulnerable categories (VUD2) and its presence was limited, then the action to conserve this species in nature is very important and urgent. This species includes understorey palm, which is need to shade by other species. Purpossive sampling was used with 30 plots, sized 20 x 20 meters for Daun Sang and other vegetation at tree stage, 10 x 10 meters for other vegetation at pole stage, 5 x 5 meter for other vegetation at sapling stage and 2 x 2 meter for other vegetation at seedling stage. Analysis of vegetation was used to determine Importance Value Index, Diversity Index, Evennes Index and Richness Index. Then analysis of association was done with an interspesific association analysis, continued with Jaccard Index. The highest Importance Value Indexes for each stage of species were Aglaia edulis for seedlings and saplings, Shorea sp for poles and Shorea dealbata for trees. Diversity Index measured by Shannon Wienner Index was high (3.5-4.02), while the range of Evennes Index was 0.8-0.97 and the range of Species Richness Index was 9.04-14.43. There was an association between Daun Sang and other vegetation on seedlings and poles, which is not strong enough, and no specific association with particular species. This fact is an evidence that if there is forest disturbance, then the population of Daun Sang will be decreased.