绿豆叶斑病菌分生孢子的产生和萌发条件研究

为了明确绿豆叶斑病病原菌变灰尾孢菌(Cercospora canescens)分生孢子形成及萌发的最适条件，研究了变灰尾孢菌在9 种供试培养基上，在不同培养条件下分生孢子的产生及分生孢子的萌发情况。结果表明，在高粱粒培养基上25℃，光暗交替条件下培养10 天后即可产孢，培养14 天后产孢量可达9×105个/mL，玉米粉培养基和小麦粒培养基产孢较少，其他培养基不产孢。分生孢子在25℃、pH 6~7、连续黑暗条件下无菌水中培养20 h 后萌发率可达76.0%，不同温度、不同光照处理间萌发率差异显著。在蔗糖溶液和蛋白胨溶液中培养20 h 后萌发率分别达87.0%和86.3%。变灰尾孢菌的最适产孢条件为高粱粒培养基上25℃光暗交替培养；分生孢子最适萌发条件为25℃、pH 6~7、连续黑暗培养，蔗糖和蛋白胨可适当提高分生孢子的萌发率。

Conidia Production and Germination Conditions of Mung Bean Leaf Spot Pathogen

To understand the optimal condition for the development and germination of conidium in mung bean leaf spot caused by the Cercospora canescens, nine culture media and different culture conditions were studied. The results showed that Cercospora canescens could be sporulated in sorghum grain culture medium at 25℃with 10 days post incubation (dpi). The amount of conidium sporulated could reach 9 × 105 conidium/mL at 14 dpi. There was less production of conidia with corn meal and wheat grain media, whereas no sporulation with other media. Additionally, a suitable condition for conidia germination was 25℃, pH 6-7 under dark condition, where germination rate could reach 76.0% after 20 h incubation, and there were significant differences in germination rates among different light and temperature conditions. In sucrose and peptone media, the conidia germination ratio was 87.0% and 86.3%, respectively. The optimal condition for sporulation of Cercospora canescens was at 25℃on sorghum grain culture medium, and the optimal condition for spore germination was 25℃, pH 6-7 in darkness. Conidia germination radio could be mildly improved with the addition of sucrose and peptone.