Cucurbit Genetics Cooperative Report 6:99 (article 50) 1983
R. Provvidenti and D. Gonsalves
New York State Agricultural Experiment Station, Geneva, New York 14456
H. S. Humaydan
Joseph Harris Company, Inc., Rochester, New York 14624
A new viral disease occurred in 1982 in a field of ‘Multipik’, a cultivar of yellow summer squash (Cucurbita pepo) situated near Warehouse Point, Connecticut. Plants were severely affected by a prominent foliar yellow mosaic, distortion, necrosis and stunting. Fruits were small, malformed, and green mottled.
Electron microscopy of leaf extracts revealed the presence of long flexuous virus particles similar in size to those usually associated with infection of watermelon mosaic virus 1 (WMV-1) or watermelon mosaic virus 2 (WMV-2) in the Northeast (3). However, serological tests with antisera to these two viruses were negative. This new virus strongly reacted with an antiserum to zucchini yellow mosaic virus (ZYMV), kindly supplied by Vittoria Lisa, of the Instituto di Fitovirologia Applicata, of Turin, Italy.
The American isolate of ZYMV incited similar symptoms in cultivars of C. pepo, C. maxima, C. moschata, Cucumis sativus, C. melo, Citrullus lanatus, Lagenaria siceraria and other cultivated and wild cucurbit species to those described for ZYMV in Italy (1) and for muskmelon yellow stunt virus (MYSV) in France (2).
This virus, which appears to be present in other European, North African and Middle Eastern countries, is very destructive and poses a new challenge to plant pathologists and cucurbit breeders of four continents.
None of the genes for resistance to WMV-1 or WMV-2 appear to be able to control this virus, thus an extensive search is under way for sources of resistance in cultivated and wild species of the genus Cucurbita. Cucumis and Citrullus. A few sources of resistance have already been found.
Literature Cited
- Lisa, V., G. Boccardo, G. D’Agostino, G. Dellavalle, and M. d’Aquilio. 1981. Characterization of a potyvirus that causes zucchini yellow mosaic. Phytopathology 71:667–672.
- Lecoq, H., M. Pitrat, and M. Clement. 1981. Identification et caracterisation d’un potyvirus provoquant la maladie du rabougrissement jaune du melon. Agronomie 1:827–834.
- Provvidenti, R. and W. T. Schroeder. 1970. Epiphytotic of watermelon mosaic among Cucurbitaceae in Central New York in 1969. Plant Dis. Reptr. 54:744–748.