【摘要】 【目的】研究不同因素对分生孢子产生的影响,以期获得大量分生孢子或带大量分生孢子的菌粒接种体,为大田开展抗病性鉴定接种提供参考。【方法】以从玉米大斑病典型病斑中分离出来的菌株为试材,探索25种谷物粒培养基、8个温度梯度、7个培养时间段、5种不同光照、菌株代数从第3至10代等条件对分生孢子产量的影响。【结果】培养基的成分组合对分生孢子产生起决定性作用。配方为小麦100 g、甘露醇2. 5 g、玉米叶15 g的9号培养基最佳,产孢量最多,产孢量为1. 69×105个/g; 20℃温度条件下培养产孢量最多;培养时间在11 d内,培养时间越长产孢量显著增加,培养时间在11～25 d,培养时间越长,产孢量显著减少;光暗交替各12 h光照强度为2000 lx,分生孢子产孢量最高;供试菌株不同代数产孢量差异显著,以第3代产孢量最多,第3～10代产孢量随着代数的增加而递减。【结论】能促进玉米大斑病菌分生孢子产量增加的最佳谷物粒培养基配方为小麦100 g、甘露醇2. 5 g、玉米叶15 g的9号培养基;该培养基在20℃、光暗交替各12 h光照强度为2000 lx条件下,分生孢子产量最高;培养时间在11 d内,培养时间越长产孢量越高;菌株不同代数产孢量随着代数的增加而递减。更多还原

【Abstract】 【Objective】To get abundant conidia or bacteria inoculum with a large number of conidia and provide a reference for carrying out the disease resistance identification and inoculation in field experiment,the effects of different factors on conidia were studied.【Method】The strains isolated from typical disease spots of northern corn leaf blight were used as materials,and the effects on conidia under the different conditions of the 25 kinds of grain culture media,8 temperature gradients,7 periods,5 kinds of illumination as well as strain generations from third to tenth were explored.【Result】The composition of culture medium was crucial for the production of conidia. The No. 9 culture medium composed of wheat 100 g,mannitol 2. 5 g and corn leaf 15 g worked best with the highest-yield spores of 1. 69 × 105 spores/g. The conidia production peaked at 20 ℃. The conidia production obviously augmented with the increase of culture duration within 11 days,while the situation became opposite when the culture duration was between 11-25 days. The maximum in sporulation occured under 12 hours alternation of light and dark at illumination intensity of 2000 lx. The conidia production of different strain generations varied,the third generation was most productive,while from the third generation to the tenth,the production was reduced with the decrease of generation.【Conclusion】The best formula of grain medium was No. 9 medium composed of 100 g wheat,2. 5 g mannitol and 15 g maize leaves,which promoted the boost of conidia production of northern corn leaf blight. The formula yielded the maximum conidia at 20 ℃ with 12 hours alternation of light and dark of 2000 lx. Within 11 days,the longer the culture duration,the higher the conidia yield. The amount of conidia decreased with the increase of strain generation.更多还原