铁皮石斛黑斑病病原鉴定及生物学特性研究

摘要

[Objective] The pathogen of black spot in Dendrobium offcinale was identified from Pingbian county of Yunnan province,and its biological characteristics was investigated.[Method] Morphologic observation combined with molecular biological techniques were employed in the present paper.[Result] The black spot in Dendrobium offtcinale was caused by Alternaria alternata and Alternaria tenuissima,and the optimal growth condition for pathogens was 25-27 ℃ and pH 6,and the most suitable medium was PDA,and the optimal N sources were peptone and NaNO3.The most suitable medium was PCA for sporulation,and the optimal pH was 8 for conidial germination.The presence of light had little effect on the mycelial growth of pathogens.[Conclusion] This study could provide a theoretical basis for prevention and control of black spot in Dendrobium officinale.%[目的]文章对铁皮石斛叶片黑斑病的病原进行分离鉴定,并对其生物学特性进行研究.[方法]采用形态学观察与分子生物学相结合的方法进行分析.[结果]引起铁皮石斛黑斑病的病原有链格孢(Alternaria alternata)和细极链格孢(Alternaria.tenuissima)2种真菌;菌丝在25 ～ 27℃生长速度最快,最适pH为6,最适培养基为PDA,最适氮源为蛋白胨和硝酸钠;产孢最适培养基为PCA,分生孢子萌发最适pH为8;光照的有无对病原菌的茵丝生长影响不大.[结论]研究可为铁皮石斛黑斑病的防治提供理论依据.