Phytoparasitica (2002) 30 (3) - Phytophthora infestans ...

Evgenia Rubin, A. Baider and Y. Cohen (2002)
Phytophthora infestans produces oospores in fruits and seeds of tomato
Phytoparasitica 30 (3)
The 23rd Congress of the Israeli Phytopathological Society - February 11-12, 2002
Abstract: Tomato fruits at the mature green stage co-inoculated with A1+A2 sporangia of Phytophthora infestans, the late blight causal fungus, showed abundant oospores in the vascular tissues, pericarp, columella and placenta. Their density may reach as many as 160 oospores per 1 mm² of fruit tissue, similar to or even higher than their number in leaves of potato or tomato floating on water, and much higher than potato leaves in the field. Abundant oospores were formed at 12–17° C and a few at 23° C. Green fruits enabled faster blight development and oospore production than mature red fruits. Isolates of P. infestans which originated from tomato were more fertile than those which originated from potato. Oospores were also formed on the surface of infected fruits when kept in a moisture-saturated atmosphere. Occasionally, oospores were enclosed between epidermal hairs of the seed coat. In a few seeds, oospores were detected inside the embryo. The data suggest that blighted tomato fruits may carry a large number of oospores, thus making them a threatening source of blight inoculum. Such fruits may also release airborne oosporic inoculum which may introduce recombinant genotypes within a growing season. Although P. infestans is known to be seedborne in tomato, this is the first report on the occurrence of oospores in tomato seeds. Current experiments are aimed at elucidating whether such tomato fruits or seeds produce blighted seedlings in the following season.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Yigal R. Cohen

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
population dynamics/ epidemiology

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora infestans	Potato (Solanum tuberosum)
	Phytophthora infestans	Tomato (Solanum lycopersicum)