Phytoparasitica (2002) 30 (3) - Colonization of melons grafted ...

Carmela Horev, R. Cohen, M. Edelstein, Y. Burger, A. Porat, Shoshana Shriber and J. Katan (2002)
Colonization of melons grafted onto squash plants by the fungus Fusarium oxysporum f.sp. melonis
Phytoparasitica 30 (3)
The 23rd Congress of the Israeli Phytopathological Society - February 11-12, 2002
Abstract: Colonization of non-grafted melon plants, squash plants used as rootstocks and melon (Cucumis melo) plants grafted onto squash (Cucurbita spp.), by the fungus Fusarium oxysporum f.sp. melonis (FOM), was observed in greenhouse experiments conducted in order to understand better the interaction between the pathogen and the grafted host. Two methods for evaluating the fungus level inside the plants were compared: counting the colony-forming units (CFU) and evaluating the percentage of colonization in the plants' organ segments. High correlation was found between the two methods and thus the segments method – that was easier to use – was employed in all experiments. Colonization rate of resistant, susceptible and partially resistant melon plants by FOM was studied in the first stage of the research. High colonization of the roots and the stem (95–100%) of the susceptible melon cv. 'En Dor was observed as compared to lower colonization of roots (40–60%) and stems (0–20%) of the resistant cv. 'Hemed'. Colonization percentages of the partially resistant cv. 'Noy Yizre'el' were intermediate. Root colonization of the squash rootstocks 'Brava' and 'TZ 148' were as high as in roots of the susceptible melon. The colonization of the lower part of squash stems was similar to that of the partially resistant melons. Colonization of the upper stem by the pathogen was similar to that of resistant melons. The grafting procedure did not affect plant colonization significantly. Colonization pattern was similar in non-grafted resistant or susceptible melons and in self-grafted genotypes. Roots of TZ 148 were highly colonized (65–80%) when they served as rootstocks to resistant and to susceptible melon plants, whereas stems of both resistant and susceptible melons grafted on this rootstock were colonized in only 0–45% of cases. A similar colonization pattern was evident in grafted melons grown in a field naturally infested with FOM. Fusarium-resistant melons used as rootstocks were more effective than squash rootstocks in suppressing both scion colonization and disease incidence.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Jaacov Katan, Menahem Edelstein

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fusarium oxysporum f.sp. melonis	Melon (Cucumis melo)
	Fusarium oxysporum f.sp. melonis	Squash/pumpkin (Cucurbita)
	Fusarium oxysporum