玉米灰斑病研究方法:Ⅰ.玉米灰斑病菌孢子的培养

Research methodology for maize gray leaf spot:Ⅰ.sporulation of Cercospora zeae-maydis

为了明确玉米灰斑病菌的产孢条件，将玉米灰斑病菌接种到马铃薯蔗糖（PSA）、燕麦番茄碳酸钙（OTCA）、玉米叶粉碳酸钙（MLPCA）、燕麦粉（OA）、粗面粉（CWPA）等5种培养基上，于25℃下培养，测定该菌生长速度、产孢时间和产孢量。结果表明，菌丝在上述培养基上生长速度均较慢，每天平均生长0．33ITEm左右，其中以在0A和PSA上生长速度相对较快。基于上述结果，构建了玉米灰斑病菌孢子培养的二级分段培养法，即将菌丝块接种于加有10-15粒直径为5mm玻璃珠的马铃薯蔗糖（PS）液体培养基三角瓶里，在25℃，180r／min条件下振荡培养15d，形成菌丝悬液，再取菌丝悬浮液涂布在MLPCA培养基上，避光培养13d左右，可获得大量供接种的分生孢子。长期光照促进菌丝生长，不利于孢子的形成，而长期黑暗不利于菌丝生长，但有利于孢子的形成。

The pathogen of maize gray leaf spot, Cercospora zeae-maydis, was inoculated on potato sucrose agar （PSA）, oat tomato plus CaCO3 agar（OTCA）, maize leaf powder plus CaCO3 agar（MLPCA）, oatmeal agar（OA） and crude wheat powder agar （CWPA）, and incubated at 25 ~C for measuring the mycelial growth, sporulation time and number. The results showed that the mycelia grew very slow on the media, with an average of 0.33 mm per day. They grew fastest on OA and PSA, slower on CWPA and most slowly on MLPCA. Based on the results, a sporulation method was set up, namely two-step culturing method. The mycelia were inoculated into flask with PS and 10--15 glass balls of 5ram diameter, and shaken at 25 ~C and 180 r/min for 15 days, to culture the mycelial fragment suspension. Then the suspension was smeared on MLPCA medium and incubated for about 13 days at 25℃ without light. By this way, a large number of spores could be produced for inoculation. Long illumination promoted the mycelial growth, but on the contrary, long darkness was conducive to sporulation.