• Title/Summary/Keyword: host specialization

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Variability in Virulence of Calonectria ilicicola Isolates on Soybean (콩에 대한 Calonectria ilicicola 균주의 병원성 변이)

  • ;J. s. Russin;J. P. Snow
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.571-577
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    • 1998
  • Variability in virulence of Calonectria ilicicola isolates form different hosts and geographic origin provides important information for breeding cultivars resistant to red crown rot. A wide range in virulence for 25 isolates of C. ilicicola from soybean and peanut was observed on six soybean cultivars. Soybean isolates were pathogenic on soybean although some were less virulent. Virulence of isolates was not affected greatly by cultivar and relatively consistent regardless of virulence level. Soybean isolates were more virulent on soybean than were peanut isolates. When virulence of two soybean and tow peanut isolates was compared between laboratory and greenhouse tests, it was stable across a range of cultivars. Mycelial growth of isolates from either soybean or peanut was reduced significantly on potato dextrose chlorate showed significant reduction of fungal growth than isolates from peanut did although their growth on potato dextrose agar was not significantly different. Evidence for physiologic specialization was not recognized in this system. However, the findings that soybean isolates of C. ilicicola were more virulent on soybean and reduction of fungal growth on potato dextrose chlorate than were peanut isolates suggest that host specialization may exist in this fugus.

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Differential Roles of Lung Dendritic Cell Subsets Against Respiratory Virus Infection

  • Kim, Tae Hoon;Lee, Heung Kyu
    • IMMUNE NETWORK
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    • v.14 no.3
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    • pp.128-137
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    • 2014
  • Respiratory viruses can induce acute respiratory disease. Clinical symptoms and manifestations are dependent on interactions between the virus and host immune system. Dendritic cells (DCs), along with alveolar macrophages, constitute the first line of sentinel cells in the innate immune response against respiratory viral infection. DCs play an essential role in regulating the immune response by bridging innate and adaptive immunity. In the steady state, lung DCs can be subdivided into $CD103^+$ conventional DCs (cDCs), $CD11b^+$ cDCs, and plasmacytoid DCs (pDCs). In the inflammatory state, like a respiratory viral infection, monocyte-derived DCs (moDCs) are recruited to the lung. In inflammatory lung, discrimination between moDCs and $CD11b^+$ DCs in the inflamed lung has been a critical challenge in understanding their role in the antiviral response. In particular, $CD103^+$ cDCs migrate from the intraepithelial base to the draining mediastinal lymph nodes to primarily induce the $CD8^+$ T cell response against the invading virus. Lymphoid $CD8{\alpha}^+$ cDCs, which have a developmental relationship with $CD103^+$ cDCs, also play an important role in viral antigen presentation. Moreover, pDCs have been reported to promote an antiviral response by inducing type I interferon production rather than adaptive immunity. However, the role of these cells in respiratory infections remains unclear. These different DC subsets have functional specialization against respiratory viral infection. Under certain viral infection, contextually controlling the balance of these specialized DC subsets is important for an effective immune response and maintenance of homeostasis.

Phylogeographic Messages Encoded in the rDNA of the Commercial Mushroom Zhenghonggu@ From Fujian, China

  • Chen, Yu H.;Chen, Peng D.;Chen, Liu Y.;Ma, Li Z.
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.45-45
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    • 2014
  • Individualities of precious health mushroom called Zhenghonggu@ from respective protections scattered among all main mountains of Fujian China were collected and recognized locally, then compared with Russula griseocarnosa. Their internal transcribed spacer (ITS) region (ITS1, ITS2 and 5.8S rDNA) of the nuclear rDNA were amplified, AMOVA analyzed, nested clade analyzed and then compared with the ITS sequences of relative Russula species from other regions of China to confirm the taxonomic status of Zhenghonggu$^@$ and its population structure. Total 23 haplotypes from different protections of Fujian can be clustered into three clades similar to the three lineages of Dahongjun$^@$ from southeastern China reported by Li et al. The geographic distribution characteristic of these three phylogeny clades may be closely coupled with the vegetation regionalization and/or the differences of coenosium construction of Fagaceae that is the host of Russula griseocarnosa. The correlation of taxonomy, phylogeny and geographical distribution of Russula are discussed.

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List of beetles (Coleoptera) associated with the oyster mushroom, Pleurotus ostreatus Fr., in the Onon-Balj National Park of Mongolia

  • Jung, Boo Hee;Park, Sun-Jae
    • Journal of Species Research
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    • v.3 no.2
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    • pp.123-126
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    • 2014
  • We present a list of the beetle species associated with the oyster mushroom, Pleurotus ostreatus Fr. in the birch forest of Onon-Balj National Park in Mongolia. A total of 21 species in seven families were found in this fungus, including fungivorous species: Litargus japonicus Reitter and Mycetophagus antennatus (Reitter) (Mycetophagidae), Pseudamblyopus similis (Lewis) (Erotylidae), and Lordithon sp. (Staphylinidae) etc. Both adult and larval forms are presented in the checklist along with the type of fungal association, of which approximately 52 percent are obligate mycetobionts. The main trends of the ecological and trophic specialization of the mycetophilic beetles are discussed.

Occurrence and Characterization of Stem Rot of Chrysanthemum zawadskii var. latilobum Caused by Sclerotium rolfsii (Sclerotium rolfsii에 의한 구절초 흰비단병의 발생 및 특징)

  • Kim, Chang-Su;Lee, Wang-Hyu;Kim, Jeong-Man
    • Research in Plant Disease
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    • v.17 no.2
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    • pp.225-227
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    • 2011
  • The stem rot of Chrysanthemum zawadskii var. latilobum occurred in the landscape field of Sanggwan-myeon, Wanju-gun, Jeonbuk, Korea in September 2009. The typical symptoms of the disease were water-soaking and dark brown rot on the stem, wilting and blighting. Most infected plants died of the disease. White mycelial mats were spread over lesions and brown sclerotia were formed on stems and near soil surface. The sclerotia were spherical or irregular, 0.8-3.5 (mean 1.8) mm in size on potato dextrose agar, brown in color. The optimal temperature range of hyphal growth was $25-30^{\circ}C$ and the hyphal diameter was 4-9 ${\mu}m$. Clamp connections were observed in the hyphae of the fungus grown on potato dextrose agar. Pathogenicity of the casual organism was provided on C. zawadskii according to Koch's postulate. The fungus was identified as Sclerotium rolfsii on the basis of mycologiclal characteristics and pathogenicity test to host plants. This is the first report on the stem rot of C. zawadskii caused by S. rolfsii in Korea.

Diversity, Phylogeny, and Host-Specialization of Hyaloperonospora Species in Korea

  • Lee, Jae Sung;Lee, Hyang Burm;Shin, Hyeon-Dong;Choi, Young-Joon
    • Mycobiology
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    • v.45 no.3
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    • pp.139-149
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    • 2017
  • The genus Hyaloperonospora (Peronosporaceae; Oomycota) is an obligate biotrophic group that causes downy mildew disease on the Brassicaceae and allied families of Brassicales, including many economically relevant crops, such as broccoli, cabbage, radish, rape, and wasabi. To investigate the diversity of Hyaloperonospora species in northeast Asia, we performed a morphological analysis for the dried herbarium specimens collected in Korea, along with molecular phylogenetic inferences based on internal transcribed spacer rDNA and cox2 mtDNA sequences. It was confirmed that 14 species of Hyaloperonospora exist in Korea. Of these, three species, previously classified under the genus Peronospora, were combined to Hyaloperonospora: H. arabidis-glabrae comb. nov. (ex Arabis glabra), H. nasturtii-montani comb. nov. (ex Rorippa indica), and H. nasturtii-palustris comb. nov. (ex Rorippa palustris). In addition, finding two potentially new species specific to northeast Asian plants is noteworthy in support of the view that the species abundance of Hyaloperonospora has been underestimated hitherto.

Relationship between Virulence and Cultural Characteristics in Calonectria ilicicola (Calonectria ilicicola의 병원성과 배양적 특성간의 상호관계)

  • Kim, K.D.;Russin, J.S.;Snow, J.P.;Valverde, R.A.
    • The Korean Journal of Mycology
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    • v.26 no.3 s.86
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    • pp.387-395
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    • 1998
  • Mycelial growth, production of microsclerotia and perithecia, and presence of double-stranded RNA were examined in Calonectria ilicicola isolates from several hosts to detect morphological and/or genetic markers for comparison with levels of virulence. Variability in disease severity, production of microsclerotia and perithecia, and mycelial growth was observed across all isolates. None of 35 isolates of C. ilicicola examined contained detectable levels of double-stranded RNA. Disease severity on soybean cultivars correlated positively with production of both microsclerotia and perithecia. Mycelial growth correlated negatively with production of perithecia. Virulence on the cultivars and production of microsclerotia and perithecia were greater in isolates of C. ilicicola from soybean than those from peanut. These results suggest that the ability of isolates to produce microsclerotia and perithecia is a component of inoculum potential. Perithecia production may serve as a useful marker for characterizing virulence or host specialization in this homothallic fungus.

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