Phytoparasitica (2000) 28 (2) - Resistance mechanism of ...

H. Eizenberg, D. Plakhine, Y. Hershenhorn, Y. Kleifeld and B. Rubin (2000)
Resistance mechanism of sunflower (Helianthus annuus) to Orobanche cumana
Phytoparasitica 28 (2)
XIVth International Plant Protection Congress (IPPC), July 25-30, 1999, Jerusalem, Israel, poster
Abstract: Orobanche cumana is a root parasite that causes severe damage to sunflower (Helianthus annuus L.) in eastern Europe and the Mediterranean countries. Recently, new cultivars of Orobanche-resistant sunflowers have been introduced into Israel. In this study we established information about their mechanism(s). Pot experiments conducted under controlled conditions have shown that cv. 'Ambar' sunflower is highly resistant to O. cumana. The resistance exists at a temperature regime of 21°/29°C (night/day) but not at 9°/17°C. Observations have shown that Ambar plants induced O. cumana seed germination at all temperature regimes, but the attachment of the parasite to the Ambar root ceased after establishment. In the susceptible genotype 'Adi', the attachments advanced and developed into normal flowering shoots of the parasite. Only extracts of Ambar roots associated with the parasite were toxic to O. cumana seedlings grown in vitro, whereas extracts from Ambar roots without the parasite or from Adi roots with or without the parasite were not toxic. We assume that the resistance mechanism of Ambar is associated with substances that are produced only by the infected host plant and selectively inhibit the parasite's growth.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Baruch Rubin, Hanan Eizenberg

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.
	Orobanche cumana (weed)	Sunflower (Helianthus annuus)	Israel