Identification of fungi causing grapevine decline in west Azerbaijan province

Moshari, S. (2011) Identification of fungi causing grapevine decline in west Azerbaijan province. Masters thesis, University of Zabol.

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Decline disease of grapevine is a complex disease with worldwide distribution. The disease affects young and old vines. Several species of hyphomyecetous genus, Phaeoacremonium, and Phaeomoniella chlamydospora together with two basidiomycete species viz., Stereum hirsutum and Fomitiporia Mediterranean are major fungal species involved in decline disease. Phaeomoniella chlamydospora occurs on young vines; while, Phaeoacremonium spp. and the two other basidiomycete species are mainly associated with old vines. In addition to above mentioned species, several other fungal species have been isolated from grapevines with decline disease symptoms, of those, some species have proven to be pathogenic on grapevine. In present study, fungal species associated with decline disease of grapevine were studied in West Azarbaijan province of Iran. During 2009 and 2010 growing seasons, 45 vineyards were subjected to study the decline disease in this Province. A total of 150 fungal isolates were recovered from diseased grapevine samples showing decline symptoms such as stunting growth, dieback, canker and wood decay including brown to black streaking or spots and white rot. Morphological characterization of fungal isolates revealed a wide a range of fungal species associated with decline disease of grapevines in this province. The most common pathogenic fungal species isolated in this study were Phaeomoniella chlamydospora, Phaeoacremonium aleophilum, Pm. cf. mortoniae, Lasiodiplodia cf. theobromae, Neofusicoccum sp., Truncatella angustata., and Pestalotiopsis sp. Phaeoacremonium spp. and Botryosphaeriaceae spp. were the most important fungi isolated from grapevine dieback in this study followed by Acremonium strictum, Acremonium sp., Truncatella spp., T. angustata, Pestalotiopsis sp. and Cytospora spp. Pathogenicity of Phaeoacremonium and Acemonium species were verified by inoculation of cutting root and stems under glasshouse condition and pathogenicity of others were examined on excised mature lignified dormant canes under controlled laboratory conditions. Data from the pathogenicity assay was analyzed by using SPSS and revealed that isolates of Pm. aleophilum and Pm. cf. mortoniae are the most virulent based on appearance of esca symptoms on leafs as the median of symptoms severity in this species were about 80% and length of vascular necrosis on woody stems in these species were more than of 170mm; that followed by Acremonium strictum and Acremonium sp. Botryosphaeria spp. were the most virulent based on length of vascular necrosis in the wood that revealed more than 130mm vascular necrosis on wood and proximately 95% re- isolated from these necrosis. Truncatella sp., T. angustata, Pestalotiopsis sp. isolates followed in virulence to L. cf. theobromae and Fusiccocum sp. that displayed about 60mm vescular necrosis. Cytospora chrysosperma and Cytospora sp. were shown to be virulent and capable in colonizing mature wood and cause vascular necrosis with more than of 30mm length, wood bleaching and white rots of grapevines. All these fungal species represent newly recorded fungal pathogens of grapevines in West Azerbaijan province.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Esca, Grapevine Dieback, Trunk Diseases, Vitis vinifera
Subjects: Q Science > QK Botany
Depositing User: admin admin1 admin2
Date Deposited: 26 Oct 2016 10:28
Last Modified: 26 Oct 2016 10:28

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