梨轮纹病菌的生物学特性及药剂的毒力测定
Biological Characteristics of Macrophoma kuwatsukai Hara and Toxicity of Tungicides

研究了梨轮纹病茵的生物学特性,结果表明,梨轮纹病菌在接种的梨果上能产生分生孢子;PDA培养基、PSA培养基、麦芽糖琼脂培养基和察贝克氏培养基最适合病菌菌丝的生长;菌丝生长的适温为5~40 ℃(最适25~30 ℃),适宜pH 3~10(最适3~6);菌丝致死温度为52 ℃;光照条件对菌落生长影响不大;在测试的碳源中,淀粉和蔗糖最适宜菌丝生长;氮源中以蛋白胨、酵母膏和硝酸钾最适宜菌丝生长。生理生化特性测定结果表明,梨轮纹病菌对孔雀石绿不敏感,能利用淀粉和硝态氮。14种杀菌剂的毒力测定表明,苯醚甲环唑、烯唑醇、戊唑醇、多菌灵、氟啶胺和氟硅唑的毒力较高,EC50分别为0.1593、0.1684、0.1931、0.1946、0.2853和0.3245 mg/L。
Studies on the biological characteristics of Macrophoma kuwatsukai showed that M.kuwatsukai could produce spores after inoculation on pear.The suitable media for mycelial growth were PDA,PSA,maltose agar medium and Czapex-doxagar medium.The optimum temperature was 5-40 ℃(the most favorite temperature was 25-30 ℃)and the optimum pH was from 3 to 10(the most favorite pH was 3-6)for mycelial growth.The thermal death temperature of mycelium was 52 ℃.Light had no influence on the growth of mycelia.Among the tested carbon sources,amylum and sucrose were the most favorable for mycelial growth.Among the tested nitrogen sources,peptone,yeast extract and niter were the most favorable for mycelial growth.Studies on the physiological and biochemical characteristics showed that M.kuwatsukai was insensitive to malachite green and could utilize starch and nitrate nitrogen.The toxicity of 14 fungicides on M.kuwatsukai showed that difenoconazole,diniconazole,tebuconazole,carbendazim,fluazinam and flusilazole showed high toxicities with EC50 of 0.1593,0.1684,0.1931,0.1946,0.2853 and 0.3245 mg/L,respectively.