• Mycobiology
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• v.50 no.4
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• pp.254-257
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• 2022

Wolfiporia cocos is a wood-decay brown rot fungus belonging to the family Polyporaceae. While the fungus grows, the sclerotium body of the strain, dubbed Bokryeong in Korean, is formed around the roots of conifer trees. The dried sclerotium has been widely used as a key component of many medicinal recipes in East Asia. Wolfiporia cocos strain KMCC03342 is the reference strain registered and maintained by the Korea Seed and Variety Service for commercial uses. Here, we present the first draft genome sequence of W. cocos KMCC03342 using a hybrid assembly technique combining both short- and long-read sequences. The genome has a total length of 55.5 Mb comprised of 343 contigs with N50 of 332 kb and 95.8% BUSCO completeness. The GC ratio was 52.2%. We predicted 14,296 protein-coding gene models based on ab initio gene prediction and evidence-based annotation procedure using RNAseq data. The annotated genome was predicted to have 19 terpene biosynthesis gene clusters, which was the same number as the previously sequenced W. cocos strain MD-104 genome but higher than Chinese W. cocos strains. The genome sequence and the predicted gene clusters allow us to study biosynthetic pathways for the active ingredients of W. cocos.

• Resources Recycling
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• v.18 no.5
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• pp.52-62
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• 2009

This research was carried out to formulate environmentally friendly wood preservatives with okara and to investigate the effects of the acid concentration used for the hydrolysis of okara and salt type on the decay resistance of the preservatives. Okara-based preservatives were formulated with okara hydrolyzates, which were prepared with 0, 1%, and 2% sulfuric acid at $25^{\circ}C$ for 1 hr, and salts such as copper chloride and/or sodium borate. The preservatives were treated into wood blocks by vacuum-pressure method, and then the treated wood blocks were leached in $70^{\circ}C$ hot water for 72 hrs. The fungal treatments of the leached wood blocks were conducted by brown-rot fungus, Tyromyces palustris, and white-rot fungus, Trametes versicolor, to examine the decay resistance of the preservatives. As the acid concentration used for hydrolysis of okara increased, the treat-ability and decay resistance of the preservatives were improved, which the leachability was decreased. Wood blocks treated with the okara/copper or okara/copper/borax, showed very good decay resistance against T. palustris and T. versicolor. However, wood blocks treated with the okara/borax and okara-free preservative solutions, were observed the fungal decay by T. palustris. The optimal conditions for the preparation of okara-based wood preservatives were formulated with okara hydrolyzed with 1% sulfuric acid, copper chloride and borax.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.82-90
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• 2007

In an attempt to establish the appropriate ventilation device for the bottle culture of king oyster mushroom (Pleurotus eryngii), we investigated carbon dioxide concentration and fruiting body formation according to the various ventilation systems within the mushroom house. In addition to, the efficiency of air circulation and growth rate as well as the appearance of physiologically abnormal phenotypes during their growth stage were also evaluated. four different ventilation devices, parallel-pressure type, positive-pressure type, negative-pressure type, and positive- and negative-pressure type were applied in this study. The positive-and negative-pressure type showed the highest efficiency of air circulation as $CO_2$ concentration was 800 ppm and the level of air current was relatively low compared to the other types (the $CO_2$ concentration of parallel-pressure type was 1,400 ppm). Moreover, the stipe length, the cap diameter, yield, and general quality grown in positive- and negative type ventilation device were also better than in the other three devices though it took slightly longer period for harvesting (18.4 days) than the others (17.6, 17.9 and 18.3 days). The appearance of physiologically abnormal phenotypes such as fruiting body lump, soft rot, and brown rot were significantly decreased in positive-and negative type compared to other types, while the appearance rates were not much different for other symptoms of bacterial ooze, stipe limb and stipe bumpy. In summary, we propose that the optimal ventilation system for the bottle culture of king oyster mushroom is positive- and negative type, and this device is expected to increase the total quality as well as yield all year around.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.16-25
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• 2009

Cauliflower mushroom (Sparassis crispa) is recently recognized as a new edible and/or medicinal mushroom cultivated with conifers. By the way, the mushroom is notorious as a brown-rot fungus that causes a buttrot of larch. So, there should be a careful consideration to apply the mushroom cultivation in coniferous stand. This study was conducted to clarify the seriousness of heartwood decay on conifers such as larch by cauliflower mushroom with surveying the mushroom producing environment and to examine whether the cultivation of cauliflower mushroom produce any problem in conifer stands or not. The mushroom occurred in various coniferous stands such as Larix kaempferi, Pinus koraiensis, P. densiflora and Abies holophylla on fertile soils with adequate moisture. Soil texture of the mushroom producing site was comparatively fine compared to general forest soils; sandy loam, loam and silty loam. Soil pH ranged from 4.6 to 5.2, and organic matter contents were 4~11%, which showed relatively wide range. We could find S. crispa by a DNA technique from the wood that seemed to have no heartwood decay by naked eyes. The damaged wood showed 30% higher moisture contents than that of sound wood, while the compressive strength was 30% lowered down compared to that of sound wood. The fungus may invade conifers through the scars occurred on roots or stems, in this case spore dispersion of the mushroom takes a great role. Thus, we concluded that forest tending activities need to be applied with considering the invasion of S. crispa, and cultivation of cauliflower mushroom in forest should be attempted very carefully. By the way, we also infer that conifer stands can be nurtured without heartwood decay by S. crispa if the stand be managed in good aeration conditions by proper silvicultural practices such as sanitary thinning.

• Journal of Life Science
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• v.22 no.2
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• pp.177-183
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• 2012

Bacterial wilt (brown rot) caused by Ralstonia solanacearum (Rs) is one of the most devastating bacterial plant diseases in potatoes. To isolate bacterial wilt disease resistance-related genes from the potato, the StACRE (HM749652) gene was isolated and a sequenced search was performed using functional orthologs of Solanaceae from potatoes. StACRE is homologous to the tobacco NtACRE 132 protein and belongs to the ATL family involved in ubiquitination. To analyze the expression pattern of this gene, RT-PCR was performed with potato treated with salicylic acid (SA) and Rs (KACC 10722). StACRE was strongly induced 3 hours after treatment with SA and 12 hours after infection with Rs. To investigate its biological functions in the potato, we constructed a vector for overexpression in the potato by the Gateway system, and then generated transgenic potato plants. The gene expression of transgenic potato was analyzed by northern blot analysis. In the results of disease resistance assay in relation to bacterial wilt, StACRE overexpressed transgenic potato plants were shown to have more resistance than wild-type potato.

• Korean Journal of Organic Agriculture
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• v.25 no.3
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• pp.603-617
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• 2017

The occurrence and management of disease and pests in six organic peach orchards were surveyed from March 2015 to March 2017. In this period, the number of certified organic and non-chemical peach farms increased to 65.5% and 31.7%, respectively. Certified organic peach farms were selected based on more than $4,000m^2$ of cultivation area and three tons of production, and their cultivation status was examined. All of the farms were either cultivated green manure crop or sod, and limited vegetation control to a minimum. For the management of soil nutrients, many farmers used livestock manure, oilcake and self-manufacturing liquid fertilizer. It was surveyed that bordeaux mixture, lime sulfur, pheromone for mating disruption of moths and plant extract were used for disease and pest control. The damage caused by the pests and diseases were 31.6% and 24.1%, respectively. The oriental fruit moth showed the highest damage rate (13.5%) in the organic peach orchards, followed by the brown rot (13.0%), peach fruit moth (7.3%) and bacterial shot hole (7.3%).

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.191-198
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• 1985

Sixty one commercial seed samples of three cruciferous vegetable crops were examined for seed-borne Alternaria spp. by deep freezing blotter method. Alternaria raphani, A. brassicicola and A. brassicae were detected from 7, 6 and 1 seed samples of chinese cabbage out of 20 with average infection ratio of 3.8, 1.8 and 0.5, respectively. A. raphani and A. brassicae were detected from 11 and 2 seed samples of radish out of 38 with average infection ratio of 7.2 and 1.0, respectively. A. brassicicola was detected from 3 samples of cabbage seed with average infection ratio of 21.8. Most of the Alternaria spp. detected were recovered from the seed coat and caused seed rot and seedling infections. A. brassicicola was recovered from the embryos of radish, chinese cabbage and cabbage in low infections and A. raphani was recovered from the embryos of radish. In inoculation experiments, A. brassicicola, A. brassicae and A. raphani produced black leaf spots on old leaves of three creciferous vegetable crops and the spots gradually increased in size appearing gray to light brown lesions which later coalesce and caused defoliation.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.776-784
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• 2016

In this study, green Larix kaempferi lumber was heat-treated by using superheated steam (SHS) at a pilot scale and then various physico-mechanical properties of the heat-treated wood were evaluated and compared with the properties of conventional hot air (HA) heat-treated wood. Decay resistance of brown rot fungi and compressive strength parallel to the grain of the SHS heat-treated wood without occurrence of drying check from green lumber were increased. On the other hand, density, equilibrium moisture content, shrinkage, and bending strength of the SHS heat-treated wood were lower than those of the conventional HA heat-treated wood. Because heat transfer and thermal hydrolysis of SHS heat treatment was accelerated by a large amount of water, the effect of SHS heat treatment on the physico-mechanical properties was higher than that of HA heat treatment at the similar conditions of temperature and time. From the results of this study, because green lumber can be heat-treated without occurrence of cracks or checks by using SHS and similar heat treatment effect on the physico-mechanical properties of wood can be produced despite a low temperature or short time of heat treatment, it is expected that heat time and energy consumption could be reduced by using SHS.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.74-80
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• 1993

Survey on the status of cultivation and production of medicinal crop was studied on 18 medicinal herbs and 5 medicinal trees in 66 major crop producing complexes. Native seeds or seedlings of the crops obtained from self-seed or neighbored farmer were cultivated and organic fertilizer was preferred to chemical fertilizer in the complexes. More than 60.7% of farmers were applied compost among the organic fertilizers, while 34.8% of them cultivated without any organic fertilizers. Both of using the compound chemical fertilizers and urea and urea only used were showed 51. 5% and 40.9%, respectively. Ostericum koreanum, Angelica gigas, Phellopterus littoralis, and Bupleurum fulcatum belonging to the family Umbeliferae and Aralia continentalis, Polygonatum sibiricum and Eucommia ulmoides in the complexex were not damaged by insect pests and plant diseases. Mite, aphid, grub, cutworm, onion magot fly and european corn borer were known to as major insect pests and anthracnose, powdery mildew, brown leaf spot, leaf blight and root rot as major plant diseases. Productivity and income of a farm by medicinal crops in the complex were greatly different from seeding time, planting distance, year yielded, and selling routes even in the same cultivation method and in the same cultivated area.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.255-269
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• 2018

Armillaria is a white-rot fungus that decomposes organics; it is also a root pathogen that kills trees. Recently, since the forest tending practice, the incidence of Armillaria infections on tree stumps has been increasing. Herein, we have examined the morphological features of Armillaria solidipes and A. gallica collected from 10 areas in Korea, and investigated the activities of the decomposing enzymes cellulase and laccase of these two Armillaria species. A. solidipes was found in eight host tree species including Pinus densiflora, Quercus serrata, and Castanea crenata at the altitude of 107~1,396 m, while A. gallica was found in three host species including P. densiflora and Fraxinus rhynchophylla at the altitude of 119~556 m. The fruiting bodies of A. solidipes are close with lamellae, and have brown to black hairs on the stipe, while those of A. gallica are distant with lamellae and clavate-shaped, and have yellow hairs on the base. The activites of cellulase of the two species were not different, but the activity of A. solidipes laccase was higher ($12.94{\pm}0.4U/mL$) than that of A. gallica laccase ($9.14{\pm}0.3U/mL$).