影响甜菜黑腐丝囊霉的几种生态学和生物学因子

通过对河西灌区甜菜(Beta vulgaris L.)黑腐病(Sugar Beet Black Rot)为期3a的研究，探讨了甜菜栽培品种与病害发病率及病原菌黑腐丝囊霉（Aphanomyces cochlioides)分离频率的关系以及3种环境因子即温度、pH值、不同天然培养基与甜菜黑腐丝囊霉的关系。结果表明：各栽培品种在田间的发病率与室内病原分离频率不同，其中工农2号田间发病率为1．3％，室内分离频率为93％，工农5号分别为1％和7．2％，宁甜301分别为2％和6．1％，工农2号具有更大的耐病性；甜菜黑腐丝囊霉的生长温度范围为5—30℃，最适温度为25—27℃，对高温敏感，33℃为其致死温度；甜菜黑腐丝囊霉可在pH3．5—11范围内生长，最适pH为5—9．9；甜菜黑腐丝囊霉在PDA、玉米粉琼脂、甜菜汁、麦芽糖—胨、麦芽糖酵母汁及燕麦琼脂培养基上均可生长，其中在甜菜汁培养基上生长最好．图4表3参11

ECOLOGICAL AND BIOLOGICAL FACTORS AFFECTING APHANOMYCES COCHLIOIDES

Aphanomyces cochlioides was studied ecologically for 3 years in a field plot in the Hexi irrigation area in Gansu, China. The relationship between cultivars of sugar beet( Beta vulgaris L.) and black rot disease, three factors (temperature, pH and composition of medium) and A. cochlioides were investigated. The results showed that both disease incidence and pathogen isolation rate of cultivars were different, such as disease incidence of Gongnong 2 was 1.3% in the field, isolation rate was 93% in laboratory, but those of Gongnong 5 were 1% and 7.2%, Ningtian 301 were 2% and 6.1%, respectively. As for its growth temperature, the minimum was 5 ℃, the optimum was 25～27 ℃ and the maximum was 30 ℃. A. cochliodes grew at a relatively wide pH range (3.5～11) with optimum pH of 5～9.9. It grew best on sugar beet juice medium. Fig 4, Tab 3, Ref 11