DIAGNOSIS OF VERTICILLIUM SP. FUNGUS FROM SEA BUCKTHORN (HIPPOPHAE RHAMNOIDES L.) PUBLISHED

Cotuna Otilia, Renata Șumălan, Veronica Sărățeanu, Mirela Paraschivu, Carmen Durău
Sea buckthorn is a plant that has few diseases. Among the diseases that can occur in sea buckthorn plantation we mention: verticillium wilt (Verticillium albo - atrum, Verticillium dahliae), fusariosis (Fusarium sp.) and decay caused by fungi from the genera Phytium, Alternaria and Botrytis. Verticillium wilt can occur quite often in sea buckthorn plantations, the pathogen Verticillium sp. being dangerous and able to kill the shrubs during two years. This study was performed on sea buckthorn plantation suspected of being infected with Verticillium sp. from Variaş locality (Timiș County,Romania) belonging to the farm S.C. Classic Agro SRL Variaş. In order to establish an accurate diagnosis there were collected six samples of sea buckthorn (shoots of affected plants, entire plants) from the six cultivated varieties. The most affected variety was Clara (2.5 ha), the samples collected being only entire plants. Sea buckthorn samples were first analyzed visually, followed by microscopic analysis (stereomicroscope and microscope). The visual analysis of the sea buckthorn plants has highlighted the following symptoms: wilting leaves and twigs, yellowing of leaves followed by necrosis, poor developed plants collected and healthy plants, dry shoots, necrotic, primary root cortex soft, putrid, reddish brown in section, 25% of the roots of diseased plants have shown symptoms of decay, in section was observed vascular tissue getting brown, low actynorrhizae colonization, most of the active roots were not affected. The microscope analysis was performed on tissue sections from affected roots and shoots. There were placed tissue samples on different culture media (SAB, DRBC, water agar), which were then incubated for 6 days at 220C - 240C, obtaining laboratory cultures that have facilitated the correct diagnosis, because the fungal structures weren’t visible on diseased plants. On the culture media have appeared fructifications of the fungus Verticillium sp. From the tissues infected with Verticillium sp. have grown mycelia and conidia of Fusarium sp. Both fungi are vascular being particularly dangerous and being able to lead to the plant death. Fusarium sp. has been installed on dead tissue from other causes. In laboratory tests it was confirmed the diagnosis of Verticillium wilt produced by de fungus Verticillium sp. in sea buckthorn shrubs from the cultivar Clara. The fungus was also present in other varieties of sea buckthorn from the plantation. The variety Clara is totally compromised, only 6% from the plants were healthy aspect and the remaining 94% were affected by the pathogen.
sea buckthorn, Verticillium wilt, Verticillium sp., diagnosis, vascular, analysis.
Presentation: oral

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