Phytoparasitica (2001) 29, 252-253

Y.M. Shiboleth, T. Arazi and A. Gal-On (2001)
Weed control in field-grown cucurbits inoculated with an attenuated ZYMV virus-vector expressing phosphinothricin acetyltransferase
Phytoparasitica 29 (3), 252-253
22nd Congress of the Israeli Phytopathological Society, February 12-13, 2001, Bet Dagan, Israel, lecture
Abstract: Weeds reduce crop yield and quality of cucurbit fields by competing for space, light, moisture, nutrients and pollinating insects. Cucurbits are highly sensitive to a wide range of herbicides; thus no selective herbicide for broadleaved weed eradication can be applied. Current weed control measures in cucurbits include preplanting methyl bromide fumigation, plastic mulching, and weeding. Expression of a phosphinothricin acetyltransferase (PAT) in plant tissues leads to tolerance of these plants to glufosinate-ammonium-based herbicides. We have engineered an attenuated zucchini yellow mosaic virus (ZYMV-AGII) virus-vector to express the PAT gene bar, to protect inoculated cucurbits from these herbicides. This vector, AGII-Bar, has been rendered environmentally safe by both symptom attenuation and aphid transmission abolishment. An experiment with potted melons revealed that protection is imparted one week after mechanical inoculation of the plant but not 4 days post-inoculation. Herbicide resistance was maintained over a period of at least 60 days, and at least three passages in potted plants. AGII-Bar also afforded protection from 0.2% glufosinateammonium (1% Basta) applied constitutively through the roots of systemically infected squash. To test the applicability of AGII-Bar in a weed-infested field, a controlled experiment including more than 450 plants, inoculated by bombardment with a virus-encoding construct, was performed. A single application of glufosinate-ammonium at doses up to 900 ml/ha (1.5% Basta at 300 l/ha) was sprayed on the foliage of two types of melons, two types of watermelons, cucumbers, and squash. AGII-Bar provided protection to all inoculated plants, of all varieties tested, at all dosages, including the highest, which totally eradicated all weeds. Yield of squash and of melons was measured. Weeds inhibited yield drastically in the control. Relief of this inhibition was positively correlated to the glufosinate-ammonium concentration applied. Our results demonstrate the feasibility and efficacy of AGII-Bar to enable weed control in cucurbits.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Yoel M. Shiboleth, Amit Gal-On, Tzahi Arazi

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Zucchini yellow mosaic virus