نوع مقاله : مقاله کامل پژوهشی
نویسندگان
1 بخش گیاهپزشکی، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران
2 دانشگاه ایالتی آریزونا، مؤسسه علوم اقیانوسی برمودا، ایستگاه زیستشناسی ۱۷، سنت جورج، برمودا
3 عضو هیئت علمی/دانشگاه شیراز
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Water hyacinth (Pontederia crassipes) is one of the most important invasive weeds in aquatic ecosystems, whose rapid spread severely affects ecological balance, water quality, and the functioning of aquatic systems. The present study was conducted to identify the fungi associated with this plant, determine their phylogenetic position, and assess the pathogenicity of selected isolates in the Tigris River ecosystem in the Nasiriya region of Dhi Qar Governorate, Iraq. For this purpose, samples were collected from infected or suspected infected tissues of water hyacinth, together with surrounding water and sediments. The fungal isolates were purified and identified based on morphological characteristics. Following ecological analyses and pathogenicity assays, the pathogenic species were also phylogenetically examined using the ITS region through Bayesian inference, Maximum Likelihood, and Minimum Evolution methods. In total, nine fungal taxa were identified, including Alternaria alternata, Bipolaris sp., Colletotrichum truncatum, Curvularia lunata, Cu. spicifera, Fusarium chlamydosporum, Stemphylium botryosum, Stilbocrea sp., and Ulocladium chartarum. Among them, four fungi, namely Bipolaris sp., Co. truncatum, Cu. spicifera, and F. chlamydosporum, caused brown lesions and reduced the fresh and dry weight of the plant in pathogenicity tests. Among these taxa, Bipolaris sp. showed the greatest ability to weaken water hyacinth,.The results indicated that water hyacinth in the Tigris River ecosystem hosts a diverse spectrum of fungi with different ecological roles, some of which may be considered as potential candidates for the biological control of this invasive weed. However, the use of these fungi in biological control requires evaluation of their host range and biosafety.
کلیدواژهها [English]
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