• 식물병연구
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• 제28권3호
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• pp.132-142
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• 2022

Plantation forests are established by planting Eucalyptus tree species to provide timber and pulp for the construction industries and to meet the energy needs in Ethiopia. Besides the extensive Eucalyptus plantations in the country, fungal pathogen-related diseases are the main challenges to successful production and management. The disease survey was conducted in the Eucalyptus growing areas of Ethiopia during 2019/2020 and 2020/2021. The objective of this research was to assess the diseases associated with Eucalyptus plant species and identify the causal fungal species. Plants of E. camaldulensis were the dominant species in the survey fields and were severely associated with stem and branch canker diseases. Diseased samples were collected and fungal species were identified as Didymellaceae according to culture morphology and affirmed by internal transcribed spacer sequence analysis. In phylogeny, isolates in the study and a reference strain formed supportive monophyletic clades with strong 90% and 95% support with Didymella coffeae-arabicae and Didymella pinodella respectively. Pathogenicity tests revealed that Didymellaceae could infect E. camaldulensis. The findings are the first reports of Eucalyptus stem canker disease caused by Didymellaceae in Ethiopia.

• The Plant Pathology Journal
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• 제16권5호
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• pp.286-289
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• 2000

Mechanol extracts of three cold-tolerant eucalyptus trees-Eucalyptus darlympleana, E. gunnii and E. unigera were screened for antimicrobial activity against twenty two phyto-pathogenic fungi and six food-borne bacterial pathogens. E. unigera showed the antagonistic activity against all the tested pathogens. Among the tested fungal pathogens, Pythium species were highly sensitive to the leaf extracts. Especially, P. vanterpoolii, a causal agent of leaf blight in creeping bentgrass (Agrostis palustris), was completely inhibited by the extracts. The eucalyptus extracts were also effective in inhibiting the fungal growth of Botrytis cinerea and Phomopsis sp. isolated from the lesions of kiwifruit soft rot during post-harvest storage. Escherichia coli O-157 was less sensitive to the inhibition than the other bacterial pathogens tested. It was likely that Gram positive bacteria-Bacillus subtilis and Streptococcus mutans were more sensitive to the eucalyptus extracts than Gram negative bacteria-Escherichia coli, Salmonella enteritidis and Pseudomonas aeruginosa. Our findings suggest that the cold-tolerant eucalyptus species have antimicrobial properties that can serve the development of novel fungitoxic agents or food preservatives.

• Natural Product Sciences
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• 제14권1호
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• pp.27-31
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• 2008

We have evaluated the combined antifungal effects of the essential oil from Eucalyptus globulus or its main component 1,8-cineole with ketoconazole. Checkerboard microtiter tests were used to analyze their effects against three Candida and six Trichophyton species. The susceptibility of the Trichophyton species to E. globulus essential oil differed distinctly. The fractional inhibitory concentration indices (FICIs) against the tested Candida species ranged between 0.09 and 0.38 for ketoconazole combined with E. globulus essential oil or 1,8-cineole, indicating significant synergism between ketoconazole and the oil samples. Similar experiments using Trichophyton species resulted in FICIs between 0.28 and 0.63, indicating relatively weaker combined effects than those observed with Candida species. Thus, the data reported here show that the anti-Candida effects of ketoconazole can be significantly improved in the presence of E. globulus essential oil or 1, 8-cineole.

• Journal of Ecology and Environment
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• 제44권1호
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• pp.8-25
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• 2020

Background: Species of the genera Eucalyptus, Cupressus, and Pinus are the most widely planted tree species in the country in general and in Chilimo dry Afromontane forest in particular. Eucalyptus covers 90% of the total planted forest area in the country. However, only limited information exists in the country regarding aboveground biomass (AGB), belowground biomass (BGB), growth, and yield. This study was conducted to assess the variables on 25 and 30 years of age for three planted species: Cupressus lusitanica, Eucalyptus saligna, and Pinus patula in Chilimo plantation forest, in the Central Highlands of Ethiopia. A two-times inventory was conducted in 2012 and 2017. A total of nine square sampled plots of 400 ㎡ each, three plots under Cupressus lusitanica, 3 Eucalyptus saligna, and 3 Pinus patula were used for data collection. Data on height, diameter, soil, and tree stumps were collected. Percent C, % N, and bulk density was performed following chemical procedure. Results: The aboveground biomass ranged from 125.76 to 228.67 t C ha^-1 and the basal area and number of stems from 3.76 to 25.50 ㎡ ha^-1 and 483 to 1175 N ha^-1, respectively. The mean annual basal area and volume increment were between 0.97 and 1.20 ㎡ ha^-1 year^-1 and 10.79 and 16.22 ㎥ ha^-1 year^-1. Both carbon and nitrogen stock of the planted forest was non-significant among the tree species. Conclusion: The aboveground biomass, growth, and yield significantly varied among the species. Cupressus lusitanica had the highest aboveground biomass, volume, and basal area, while Eucalyptus saligna had the lowest value. To a depth of 1 m, total carbon stored ranged from 130.13 to 234.26 t C ha^-1. The total annual carbon sequestration potential was 12,575.18 t CO₂ eq. Eucalyptus has the highest carbon stock density and growth rate than other species.

• 한국산림과학회지
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• 제99권3호
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• pp.414-422
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• 2010

본 연구에서는 Eucalyptus pellita와 Acacia mangium 용기묘를 대상으로 관수 주기 처리를 통해 3가지 수준(1회/1일, 1회/2일, 1회/3일)으로 수분 조건을 달리하여 광합성, 수분이용효율, 기공전도도 및 생장 특성 변화를 조사 분석하였으며, 열대림 두 수종에 대한 용기 양묘 시 최적의 수분 환경을 구명 하고자 하였다. 그 결과, E. pellita는 1회/1일 관수 처리구에서 우수한 광합성 능력을 보였으며, A. mangium은 세 처리구 모두 좋은 광합성 능력을 나타냈다. 두 수종 모두 관수 주기가 짧을수록 기공전도도는 높아진 반면, 수분이용효율은 낮은 값을 보였다. 근원경과 간장 생장은 두 수종 모두 1회/1일 관수 처리구에서 높았으며 관수 주기가 짧을수록 높은 생장을 나타냈다. H/D율, 물질생산량 및 묘목품질지수(DQI)도 같은 경향을 보였으나, T/R율은 반대의 경향을 나타냈다. 1회/1일 관수 처리구는 건전하게 양묘된 묘목으로 평가할 수 있으며, 세 처리구 중 가장 우수한 묘목을 생산할 수 있는 수분 조건으로 판단된다.

• Natural Product Sciences
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• 제3권1호
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• pp.1-7
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• 1997

Eucalyptus is a rich source of biologically active compounds. Among these, phloroglucinol compounds such as sideroxylonals, macrocarpals, euglobals, and robustadials are unique to Eucalyptus species. Sideroxylonal A is a very potent attachment-inhibitor. Macrocarpals show very strong antibacterial activity against gram positive bacteria. Macrocarpals also show HIV-RTase inhibitory activity. Euglobals are potent inhibitors of Epstein-Barr virus activation and are developed as skin and antitumor agents. They also show granulation inhibitory activity. In this review we aim to remove the existing confusion in literature on macrocarpals and discuss the biological activities and structure-activity relationships of phloroglucinol compounds.

• 한국가구학회지
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• 제23권3호
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• pp.298-304
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• 2012

Since 1990's, a flooring based on plywood has gotten customers' demand. Costs of raw material and production increased because of changed environment of industry. Tropical timber such as Red Meranti (Shorea acuminate) used for raw material of the floor has been depleting beside countries in South Eastern Asia changed species of afforestation. As a result, it gets hard to secure good quality of raw material for plywood. Moreover plywood price is increased suddenly after earthquake in Japan. Eucalyptus (Eucalyptus globulus) in china has been using for raw material as a countermeasure of changed environment of industry. In this study, possibility of using flooring consisted of Eucalyptus veneer as a core layer was checked by heat transfer experiments. Flooring consisted of Red Meranti was used for comparison. Two factors which impact on heat transfer are a type of density gradient and density difference between Long-grain veneer and Short-grain veneer. Red Meranti samples are 'M' type of density gradient on the other hand Eucalyptus samples are 'W' type of density gradient.

• Journal of Plant Biotechnology
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• 제30권3호
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• pp.269-273
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• 2003

In order to develop an efficient micropropagation protocal for Eucalyptus pellita, on in vitro culture system has been was established by inducing axillary buds from greenhouse stock materials. Among 6different media tested, DKW medium was the best ot induce bast induce both shoot proliferation and growth. Average number of proliferated shoots of 403per explant was obtained at the concentration of 0.1mg/LBA. Most of the stem materials excreted phenolic compounds at the proximal part of the explant and caused darking of the media. Therefore, it was necessary to transfer frequently to a fresh medium and/or to add activated charcoal at the concentration of 0.02％(w/v). Generally on vitro roots were formed easily on 1/2DKW medium with NAA treatment. All the explants rooted at the medium containing 0.2mg/L NAA and displayed vigorous root growth in vitro culture conditions. After transferred to an artificial soil mixture (peatmoss: vermiculrite: perlite, 1:1:1, v/v/v) in the greenhouse, most rooted plantlets survived well without any morphological abnormalities. The results show that the species can be micropropagated effectively by the application of axillary bud culture system.

• Journal of the Korean Wood Science and Technology
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• 제51권3호
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• pp.222-237
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• 2023

Eucalyptus pellita is one of the fast-growing tree species and has become predominant in Indonesian forest plantations. Meanwhile, tree breeding programs with clone development are the best way to provide greater genetic advantages. A better understanding of genetic control on growth and basic density in E. pellita is important for increasing wood productivity and quality. In this study, growth characteristics (tree height, diameter, and volume), basic density and its genetic parameters (heritability, genetic gain and genetic correlation) were determined. The number of clones tested in both trials was 50, divided into 5 blocks, and 5 trees/plot. The results showed that there were significant differences in growth and basic density among clones. There was an interaction between genetics and the environment further indicating the existence of unstable clones. The high heritability was found in tree height (0.82-0.86), diameter (0.82-0.90), and basic density (0.91-0.93). This implies that E. pellita has good opportunities for genetic improvement to increase wood productivity and quality. In addition, the results of genetic correlations among growth characteristics (height, diameter, and volume) and basic density showed positive moderate to highly significant value. It is suggested that these characters may be used to the advantage of the breeder for bringing improvement in these traits simultaneously. Therefore, this study provides important information of the genetic improvement of wood quality in E. pellita in Indonesia.

• Genomics & Informatics
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• 제19권3호
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• pp.33.1-33.10
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• 2021

Eucalyptus is one of the major plantation species with wide variety of industrial uses. Polymorphic and informative simple sequence repeats (SSRs) have broad range of applications in genetic analysis. In this study, two individuals of Eucalyptus tereticornis (ET217 and ET86), one individual each from E. camaldulensis (EC17) and E. grandis (EG9) were subjected to whole genome resequencing. Low coverage (10×) genome sequencing was used to find polymorphic SSRs between the individuals. Average number of SSR loci identified was 95,513 and the density of SSRs per Mb was from 157.39 in EG9 to 155.08 in EC17. Among all the SSRs detected, the most abundant repeat motifs were di-nucleotide (59.6%-62.5%), followed by tri- (23.7%-27.2%), tetra- (5.2%-5.6%), penta- (5.0%-5.3%), and hexa-nucleotide (2.7%-2.9%). The predominant SSR motif units were AG/CT and AAG/TTC. Computational genome analysis predicted the SSR length variations between the individuals and identified the gene functions of SSR containing sequences. Selected subset of polymorphic markers was validated in a full-sib family of eucalypts. Additionally, genome-wide characterization of single nucleotide polymorphisms, InDels and transcriptional regulators were carried out. These variations will find their utility in genome-wide association studies as well as understanding of molecular mechanisms involved in key economic traits. The genomic resources generated in this study would provide an impetus to integrate genomics in marker-trait associations and breeding of tropical eucalypts.