• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.243-264
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• 2013

Antheraea mylitta Drury is a commercial silk producing forest insect in India and Xanthopimpla pedator Fabricius is its larval-pupal endoparasitoid, which causes pupal mortality that affects seed production. Effects of host plants, rearing season and their interactions on parasitic behaviour of X. pedator were studied here, as influence of these factors on biological success of X. pedator is not known. Seven forest tree species were tested as food plants for A. mylitta, and rate of pupal parasitization in both the rearing seasons were recorded and analysed. Results showed that rearing season and host plants significantly affected the rate of pupal parasitization in both the sexes. Pupal mortality was found significantly higher (14.52%) in second rearing season than the first (2.89%). Likewise, host plants and rearing seasons significantly affected length, diameter, and shell thickness of cocoons in both sexes. Out of all infested pupae, 85.59% were found male, which indicated that X. pedator chooses male spinning larva of A. mylitta for oviposition, but we could not answer satisfactorily the why and how aspect of this sex specific parasitic behaviour of X. pedator. Multiple regression analysis indicated that length and shell thickness of male cocoons are potential predictors for pupal parasitization rate of X. pedator. Based on highest cocoon productivity and lowest pupal mortality, Terminalia alata, T. tomentosa, and T. arjuna were found to be the most suitable host plants for forest based commercial rearing of A. mylitta in tropical forest areas of Uttarakhand state, where it has never been reared earlier. Sex and season specific interaction of X. pedator with its larval-pupal host, A. mylitta is a novel entomological study to find out explanations for some of the unresolved research questions on parasitic behaviour of X. predator that opens a new area for specialised study on male specific parasitization in Ichneumonidae.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.637-649
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• 2011

Soil microorganisms play a major role in improving soil fertility and plant health. Symbiotic arbuscular mycorrhizal fungi (AMF) form a key component of the soil microbial populations. AMF form a mutualistic association with the host plant and exert a positive influence on its growth and nutrient uptake. The establishment of mycorrhizal symbioses with the host plant can positively be influenced by plant growth promoting rhizobacteria through various mechanisms such as increased spore germination and hyphal permeability in plant roots. Though there are evidences that combined interactions between AMF and PGPR can promote the plant growth however mechanisms of these interactions are poorly understood. Better understanding of the interactions between AMF and other microorganisms is necessary for maintaining soil fertility and enhancing crop production. This paper reviews current knowledge concerning the interactions between AMF and PGPR with plants and discusses on enhanced nutrient availability, biocontrol, abiotic stress tolerance and phytoremediation in sustainable agriculture.

• Research in Plant Disease
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• v.27 no.2
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• pp.49-60
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• 2021

Cashew (Anacardium occidentale L.) is an important cash crop in Tanzania as a source of income to cashew growers and provides foreign exchange for the country. Despite its significance, the crop is threatened by fast spreading disease known as cashew Fusarium wilt caused by Fusarium oxysporum. Field assessment and laboratory tests were conducted to determine incidences of the disease, severity, ecological factors that influence them and explored the pathogen host specificity in six cashew growing districts. The results revealed significant (P<0.001) variation of disease incidences and severity among the studied districts. The results further revealed that there is both positive and negative correlation between the incidence and severity of the disease versus the evaluated ecological factors. The soil pH, soil temperature, air temperature, and relative humidity depicted positive correlation of disease incidence and severity versus ecological factors at ρ=0.50 and ρ=0.60, ρ=0.20 and ρ=0.94, ρ=0.11 and ρ=0.812, ρ=0.05 and ρ=0.771 respectively while nitrogen, phosphorus, and carbon depicted negative correlations at ρ=-0.22 and ρ=-0.58, ρ=-0.15 and ρ=-0.94, ρ=-0.19 and ρ=-0.12 respectively. In terms of host range, none of the weed species was found to be a carrier of Fusarium pathogen implying that it is host specific or semi selective. The results revealed that the tested ecological parameters favor the growth and development of Fusarium pathogen. Thus, management of the disease requires nutrients replenishment and soil shading as essential components in developing appropriate strategies for the control and prevention of further spread of the disease.

• International Journal of Industrial Entomology and Biomaterials
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• v.29 no.1
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• pp.135-144
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• 2014

Rearing of tropical tasar silkworm, Antheraea mylitta Drury is mainly conducted in outdoor on Terminalia tomentosa W. & A. a nature grown primary host plant available in forest and also on raised primary host plant Terminalia arjuna Bedd. Temperature, relative humidity and rainfall are the main environmental factors for occurrence of pests (parasites and predators) of tasar silkworm during I, II and III crop rearing in the tropical tasar producing zones. The present study was aimed to study the influence of abiotic factors on prevalence of tasar silkworm pests. The study was conducted at different agro-climatic regions viz., Central Tasar Research &Training Institute, Ranchi, Jharkhand, Regional Extension Centre, Katghora, Chattisgarh and Regional Extension Centre, Hatgamaria during 2010-13 covering 3 seed crop and 6 commercial crops. Data on incidence of tropical tasar silkworm endo-parasitoids like Uzi Fly, Blepharipa zebina Walker and Ichneumon fly (Yellow Fly), Xathopimpla pedator, Fabricius and Predators such as Stink bug (Eocanthecona furcellata Wolf), Reduviid bug (Sycanus collaris Fabricius) and Wasp (Vespa orientalis Linnaeus) was recorded Weekly. The meteorological data was collected daily. Data was collected from 4 different agro-climatic zones of tasar growing areas. Analysis of the data revealed a significant negative correlation between abiotic factors and incidence of ichneumon fly and uzi fly. Based on the 3 years data on prevalence of pests region-wise pest calendars and prediction models were developed.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.245-258
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• 2000

Somatic embryogenesis has become a major tool in the study of plant embryology, as it is possible in culture to manipulate cells of many plant species to produce somatic embryos in a process that is remarkably similar to zygotic embryogenesis. Traditionally, the process has been studied by an examination of the ex vitro factors which influence embryo formation. Later structural, physiological and biochemical approaches have been applied. Host recently, molecular tools are being used. Together, these various approaches are giving valuable information on the process. This article gives an overview of somatic embryogenesis by reviewing information on the morphogenesis, physiology, biochemistry and molecular biology of the process. Topics covered include a brief description of the factors involved in the production of embryogenic cells. Carrot cell suspension is most commonly used, and the development of a high frequency and synchronous system is outlined. At the physiological and biochemical lev-els various topics, including the reactivation of the cell cycle, changes in endogenous growth regulators, amino acid, polyamine, DNA, RNA and protein metabolism, and embryogenic factors in conditioned medium are all discussed. Lastly, recent information on genes and molecular markers of the embryogenic process are outlined. Somatic embryogenesis, the best example of totipotency in plant cells, is not only an important tool in studies in basic biology, but is potentially of equal significance in the micropropagation of economically important plants.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.419-428
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• 2023

Several endophytic fungal strains were isolated from Taxus cuspidata and identified by molecular analysis of the internal transcribed spacer and RNA polymerase II second largest subunit. This study aimed to determine the relative abundance and compare the species diversity of endophytic fungal communities within needle leaves and twigs. We identified a total of 49 endophytic fungal species. Notably, two species, Trichoderma dingleyae and Xylaria cubensis, were discovered to be previously unrecorded in Korea. The fungal communities in both plant tissues demonstrated distinct species composition. Differences were observed in the relative abundance and species diversity index between needle leaves and twigs. Our findings suggest that the host plant tissues influence the species diversity of endophytic fungal communities.

• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.251-257
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• 2010

Influences of environment (indicated by plant associations) and forest management practices on the distribution of Armillaria spp. and genets (vegetative clones) were investigated. A total of 142 isolates of Armillaria was collected from various host trees on pristine and managed sites (thinned and/or fertilized) growing in relatively wet and dry environments in eastern Washington, U.S.A. The incidence of Armillaria spp. was significantly higher in the relatively wetter sites than the relatively drier sites, as indicated by plant associations. However, no differences in Armillaria occurrence were found among different forest management practices (control vs. thinned vs. thinned and fertilized) within both wetter and drier sites. Incidence of Armillaria was significantly different among conifer and shrub species. The highest proportion with Armillaria was found on grand fir (Abies grandis). Based on pairing tests and rDNA sequencing, the 142 isolates were comprised in a total of 20 genets representing three Armillaria species. More diverse Armillaria spp. were found in both relatively wetter and relatively drier sites within the undisturbed control plots, compared to plots disturbed by forest management practices. The results from this study provide baseline information toward understanding how environment and forest management practices influence incidence and diversity of Armillaria species and genets.

• Mycobiology
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• v.49 no.4
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• pp.385-395
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• 2021

Fungal endophytes have been recorded in various plant species with a richness of diversity, and their presence plays an essential role in host plant protection against biotic and abiotic stresses. This study applied the Illumina MiSeq sequencing platform based on the amplification of fungal ribosomal ITS2 region to analyze fungal endophytic communities of two oak species (Quercus mongolica and Q. serrata) with different oak wilt disease susceptibilities in Korea. The results showed a total of 230,768 sequencing reads were obtained and clustered at a 97% similarity threshold into 709 operational taxonomic units (OTUs). The OTUs of Q. serrata were higher than that of Q. mongolica with the number of 617 OTUs and 512 OTUs, respectively. Shannon index also showed that Q. serrata had a significantly higher level of fungal diversity than Q. mongolica. Total of OTUs were assigned into 5 fungal phyla, 17 classes, 60 orders, 133 families, 195 genera, and 280 species. Ascomycota was the dominant phylum with 75.11% relative abundance, followed by Basidiomycota with 5.28%. Leptosillia, Aureobasidium and Acanthostigma were the most abundant genera detected in Q. serrata with the average relative abundance of 2.85, 2.76, and 2.19%, respectively. On the other hand, Peltaster, Cladosporium and Monochaetia were the most common genera detected in Q. mongolica with the average relative abundance of 4.83, 3.03, and 2.87%, respectively. Our results indicated that fungal endophytic communities were significantly different between two oak species and these differences could influence responses of host trees to oak wilt disease caused by Raffaelea quercus-mongolicae.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.409-413
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• 2013

This study was performed to understand whether host-plant feeding had an influence on subsequent prey consumption in the zoophytophagous mirid Nesidiocoris tenuis, which has the potential for biological control of greenhouse whiteflies. Potted plants of paprika and sesame and cotton balls soaked with water were provided to the test insects for 24 h, then, frozen eggs of Ephestia kuehniella were presented to adult mirids for 24 h, and the number of eggs consumed by them was counted. No significant difference in prey consumption was observed between the mirids previously provided with water ($49.2{\pm}30.58$ eggs) or paprika ($55.7{\pm}31.19$ eggs), whereas those previously fed with sesame ate significantly less prey ($24.2{\pm}34.70$ eggs) than the mirids that were provided with paprika or water.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.71-78
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• 2004

This study was conducted to investigate the diversity and occurrence frequency of ectomycorrhizal fruit bodies by planting sites from June 2000 to October 2001. A total of 3 classes 3 subclasses 8 orders 22 families 41 genera and 72 species (including two varieties) including saprophytic and ectomycorrhizal fungi was investigated. The mushrooms are classified into 9 families 21 genera and 48 species in Agaricales, 5 families 11 genera and 13 species in Aphllophorales, 3 families 3 genera and 4 species in Heterobasidiomycetes and 5 families 6 genus and 7 species in Gasteromycetdae. A total of 7 families 11 genera 30 species (2,451 ea.) of ectomycorrhizal mushroom was investigated. The occurrence frequency of mushrooms was 1,225, 179 and 130 times for Laccaria vinaceoavellanea, Amanita longistriata and Laccaria amethystea, respectively. The mushroom occurrence of ectomycorrhizal fungi was closely related to climatic conditions such as high air temperature, relative humidity and lots of rainfall from July to August. Diversity and distribution of ectomycorrhizal fungi by plots were very different because of variable local environments and different host plants in experimental plots. Laccaria vinaceoavellanea has showed very low host range of plant specificity because of mushroom occurrence in only Quercus sp. and Amanita longistriata, Russula bella and Inocybe sp. have showed wide host range of plant specificity because of mushroom occurrence in coniferous and broadleaved trees. The environment which has a favorable influence of mushroom occurrence was soil pH, organic matter and T/N ratio of soil enviromental and humidity of climatic environment.