Nấm Phytopthora Cinnamomi gây bệnh thối rễ cây keo tai tượng (Acacia Mangium) ở Yên Sơn, tỉnh Tuyên Quang

The Occurence of Phytopthora Cinnamomi Caused the Root Rot Disease on the Acacia Mangium in Yen Son, Tuyen Quang Province

The name Phytophthora is derived from Greek and literally means “plant destroyer”. Phytophthora species are among the most destructive pathogens of agricultural crops and forests in the world. There are currently more than 80 described species of Phytophthora worldwide, and the vast majority are plant pathogens. Of these, P. cinnamomi has the largest host range, nearly 1000 species of host plants. P. cinnamomi has caused damage to many forests in the world. The disease is difficult to detect at the early stage because it is soil borne, attacking small and woody roots, preventing the absorption of water and nutrients which leads to plant wilt and death. In Viet Nam P.cinnamomi has been recorded as a virulent pathogen on agricultural crops such as pepper and lemon. In this paper, P. cinnamomi is a new record on a new host, Acacia mangium in Yen Son, Tuyen Quang province. The pathogen was isolated by the soi baiting and it was identified based on disease symptoms and morphological characteristics of mycelia on nutrient media, oogonia, sporangia and chlamydospores. Some biological characteristics of P. cinnamomi such us optimal temperature, pH and relative humidity were investigated and pathogenicity test on seedlings in nursery. The article presented some characteristics of Phytophthora cinnamomi which would be a basis for research on the prevention and control of this dangerous diseases.