不同诱导因素对玉米大斑病菌附着胞产生的影响

Effect of Different Induction Factors on Appressorium of Setosphaeria turcica

附着胞是许多叶部病原真菌的重要侵染机构。在不同温度、光照条件、基质和培养时间下,对玉米大斑病菌1号小种和2号小种分别在玻璃平板和玉米叶片上进行附着胞的室内诱导,发现分生孢子的水悬浮液在玻璃平板和玉米叶片的上表面及下表面都可产生附着胞,附着胞都能正常萌发并产生侵入丝,但在玉米叶片上附着胞和侵入丝的产生时间要晚于玻璃平板,产生数量也少。玉米大斑病菌分生孢子在PD培养基中产生的附着胞数目少于清水处理。影响玉米大斑病菌附着胞生长和发育的决定因素是温度,在玻璃平板上10～36℃培养24h后就可以产生附着胞,但最适宜的温度是18～25℃,低于15℃和高于30℃都不利于附着胞的产生。不同菌株在同一玉米品种的叶片上产生的附着胞数量不同,但是同一菌株在抗病品种和感病品种间产生的附着胞数量差异不显著。

Many foliar pathogenic fungi gain entry into their host via appressoria. The effect of temperature, light,media and time of treatment on the induction of appressorium of race 1 and race 2 of Setosphaeria turcica was evaluated.The results revealed that the appressorium can be induced in glass slide and on the both sides of the maize leaf, and theappressorium can be normally germinate and produce invasion hypha. The production of appressorium and invasion hyphaon leaf surface is later than that on glass slide. The conidia diluted by potato dextrose (PD) liquid medium produce lessappressorium than the conidia diluted by water. The key factor determining the growth of appressorium is temperature.Appressorium can be found at the range of 18-25℃ when the fungal tube or hypha was suspended more than 24 hours inthe water or potato dextrose (PD) liquid medium on the surface of glass or leaf. Little appressorium produced when thetemperature was lower than 10℃ or higher than 36℃. There is a distinct difference of appressorium number betweenisolates on the leaf of the same maize variety, but for a given isolate, there are no significant difference between resistantvariety and susceptible variety.