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甜菜褐斑病,又名斑点病,全省都有。严重的使块根减产40%以上,含糖量降低3—4%或更多,给甜菜和制糖业造成巨大的经济损失。病症主要在叶片上,里褐色或紫色的圆斑,从针尖大扩展到直径3—4厘米,中间灰色的霉是分生孢子丛。叶柄上的病斑为梭形,花序和种球上也有。常使叶片干枯死亡。病原菌属真菌、半知菌类,黑色菌科,尾孢霉属。菌丝灰褐色,有分隔,蔓延在细胞间隙,形成小的菌核结构。产生褐色的分生孢子梗,顶端着生透明的分生孢子,成熟的分生孢子有6—11个分隔,呈鞭状。残存在病株组织中的菌丝团生活力强,是越冬的主要方式。越冬后的菌丝团,条件适宜时产生分生孢子,借风传播,落在甜菜叶上,遇水滴产生芽管,由气孔侵入,在细胞间隙扩展,经7—15天潜育期,叶片上出现病斑。以后又产生分
Beet spots brown spot, also known as spot disease, the province has. Serious to make more than 40% reduction in root mass, sugar content decreased by 3-4% or more, to the sugar beet and sugar industry caused huge economic losses. Symptoms are mainly on the leaves, brown or purple round spots, extending from the needle tip to a diameter of 3-4 cm, the middle gray mold is conidial plexus. Petiole lesions on the fusiform, inflorescence and bulbs also. Leaves often dry dead. Pathogenic fungi, semi-known fungi, black bacteria, Coccidioides. Mycelium taupe, separated, spread in the cell gap, the formation of a small sclerotia structure. Produce brown conidiophores, the top of the students with transparent conidia, mature conidia have 6-11 separate, whip. Mycelium remaining in the diseased plant tissue has strong vitality and is the main method of overwintering. After overwintering mycelium, condiospores produced when appropriate conditions, the wind spread, falling on the beet leaves, water droplets generated germ tube, stomatal invasion, expansion in the intercellular space, after 7-15 days of latent period, leaves Appear on the spot. Later, there are points