Study on the Ecology of Necrotic Spot Disease of Melon in Greenhouse.
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Accession number;02A0503197
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| Title;Study on the Ecology of Necrotic Spot Disease of Melon in Greenhouse. |
| Author;
MATSUO KAZUTOSHI
(Nagasaki Agric. and For. Exp. Stn.)
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Journal Title;Bulletin of the Nagasaki Agricultural & Forestry Experiment Station. Sect of Agriculture. Sect of Agriculture
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Journal Code:Z0543A
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ISSN:0388-8398
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VOL.;NO.;PAGE.113P(2002)
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| Figure&Table&Reference;FIG.74, TBL.77, REF.102 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;1. Distribution and occurrence circumstances of the disease in Nagasaki Prefecture. In Nagasaki Prefecture, necrotic spot disease of melon was first found in 1978. Since 1983 the disease spread wider every year and the occurrence of the disease was observed in 12 cities including Iki and Hirado islands by 1988. The disease was found only in melon grown in greenhouse. Melon necrotic spot virus(MNSV) causing this disease was transmitted mainly by the soil-inhabiting fungus Olpidium sp., but the transmission to a distant place seemed to be seed-borne. As a symptom, crevicies in fruits, was newly found. The symptoms of this disease were classified into 11 types. The disease occurred more frequently and severely on melon under semi-forcing culture planting in spring than under late raising culture. The infection time of this disease in Nagasaki Prefecture differed from one in other districts, because in some districts this disease was mainly prevalent in winter. 2. Characteristics of the causal virus. Two different isolates of MNSV, designated as MNSV-NK and MNSV-NH were isolated from infected melons in Nagasaki Prefecture. The host ranges of these isolates were restricted to the Cucurbitaceae and were similar to that of an isolate of MNSV from Shizuoka Prefecture(MNSV-S), but they produced a different type of local lesion on cotyledons of melon. The rate of systemic infection induced by MNSV-NK, MNSV-NH and MNSV-S in melon were 9.1%, 90.9% and 3.6%, respectively. MNSV-NK and MNSV-NH were designated as a new serotype N, because these isolates were serologically related but not identical to MNSV-S (sero-type S) with double diffusion test in agar gel. All three isolates had a single coat protein with molecular weight of 41K dalton. MNSV-NK and MNSV-NH had two species of single-stranded RNAs (RNA1 and RNA2), while MNSV-S had three (RNA1,RNA2 and RNA3). Only RNA1 (MW 1.51*106) of each isolate retained pathogenicity. The function of other RNAs was unknown.... (author abst.) |
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