• The Plant Pathology Journal
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• v.15 no.6
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• pp.323-329
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• 1999

Anthracnose of pepper casued by Colletotrichum spphas been a great problems for pepper production in Korea and China. Especially Colletotrichum gloeosporioides was found predominantly over cultivation areas during infection periods and caused severe rots on bath unripe and ripe fruits that resulted in major yield losses. In this study, comparison of Colletrichum spp.isolated from Korea and China in morphology and pathgenicity, and RAPD-PCR analysis were conducted. Based on morphological characteristics, the pathogen isolates, K1 and C1, K2 and C2, and K3 and C3 were identified as Colletotrichum gloeosporioides (G) type, C. gloeosporioides (R) type and C. coccodes, respectively. in pathogenicity test, K1 and C1, and K2 and C2 were found to attack mainly fruits and to be the most virulent among isolates. K3 and C3 were strongly virulent to leaves and seedling. Pathogenicity between Korean and Chinese isolates. K3 and C3 were strongly virulent to leaves and seedling. Pathogenicity between Korean and Chinese isolates did not show any difference. Results of the RAPD-PCR analyses indicate the varying levels of molecular diversity within and between Colletotrichum spp.of Korea and China. The similarities between K1 and C1, K2 and C2, and K3 and C3 were 85.71%, 71.43% and 50.0% respectively.

• Research in Plant Disease
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• v.14 no.1
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• pp.15-20
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• 2008

Three isolates of Cucumber mosaic virus (CMV) were isolated from weed hosts showing typical mosaic symptoms, and some properties of the viruses were investigated. CMV isolates, designated as Is-CMV, Jd-CMV and Pla-CMV from Isodon inflexus, Jeffersonia dubia and Phryma leptostachya var. asiatica, respectively, were identified and characterized by biological reaction in several host plants, serological property, dsRNA analysis, reverse transcription-polymerase chain reaction (RT-PCR), restriction fragment-length polymorphism (RFLP). All isolates systemically infected in Nicotiana benthamiana, Cucurbita pepo cv. Black beauty and Cucumis sativus, and did not reveal any differences in these host plants between the isolates. However, remarkable difference in the symptoms was found between the CMVs in Capsicum annuum. Is-CMV induced an asymptomatic symptoms, while Jd-CMV and Pla-CMV produced severe mosaic symptoms in C. annuum plants. In dsRNA analysis, all isolates revealed four major bands with estimated molecular size of 3.4, 3.2, 2.1 and 1.0 kbp. The cDNAs of coat protein gene of the isolates were amplified by RT-PCR using a genus-specific single pair primers that designed to amplify a DNA fragment of approximately ranging from 938 to 966 bp. By restriction mapping analysis using RFLP of the RT-PCR products as well as by serological properties of gel diffusion test, the CMV isolates belong to a typical members of CMV subgroup IA. This is the first report on the occurrence of CMV in the three weed hosts.