虫生真菌玫烟色棒束孢PF904表面活性剂的筛选

为筛选适用于玫烟色棒束孢Isaria fumosorosea PF904菌株的表面活性剂,采用OWRK法和表面张力法测定了甘蓝、苹果、茄子和黄瓜叶片的表面自由能以及添加4种表面活性剂后玫烟色棒束孢孢子悬浮液的表面张力和临界胶束浓度(CMC),并采用量角法和重量差值法测定了4种不同植物叶片上的接触角和最大稳定持留量,同时对筛选获得的表面活性剂进行了安全性评价。结果表明:PEG-12聚二甲基硅氧烷(OFX-0193)、ɑ-烯基磺酸钠(AOS)和二异丁基萘磺酸钠(Nekal)3种表面活性剂在125~500 mg/L下均可提高玫烟色棒束孢孢子悬浮液在4种供试植物叶片上的润湿性能;其中250 mg/L的Nekal在甘蓝和苹果叶片上的最大持留量(11.90和13.28 mg/cm^2)和接触角(29.5°和27.5°)均显著优于OFX-0193和AOS,润湿效果最好;在茄子叶片上,添加125 mg/L的OFX-0193时持留量最大(9.45 mg/cm^2);而添加普鲁兰多糖(Pullulan)达到临界胶束浓度时的溶液表面张力大于甘蓝、苹果和茄子叶片的表面自由能,润湿性能最差。孢子萌发抑制率的测定结果表明:添加Nekal和OFX-0193对玫烟色棒束孢PF904的孢子萌发无抑制作用,而AOS则对其表现为抑制作用。因此,在玫烟色棒束孢PF904中添加OFX-0193和Nekal 2种表面活性剂可用于防治苹果、甘蓝类害虫,添加OFX-0193还可用于防治茄类害虫。

Screening of surfactants for entomogenous fungus Isaria fumosorosea PF904

In order to identify effective surfactants for Isaria fumosorosea PF904, the surface free energies of the leaves of cabbage, apple, eggplant and cucumber were measured by the OWRK method. When 4 different surfactants were added respectively into the spore suspension of Isaria fumosorosea, the surface tension and critical micelle concentration (CMC) of each solution were determined by the surface tension method. Their contact angle and maximum retention (R_m) on plant leaves were measured by angle measuring and weight difference method. Safety assessments of these screened surfactants were also conducted. The results showed that the wetting ability of Isaria fumosorosea spore suspension on 4 types of the tested plant leaves were improved when 125-500 mg/L of OFX-0193, AOS or Nekal was added. Nekal (250 mg/L) functioned best on cabbage and apple leaf surfaces(R_m: 11.90±0.23 and 13.28±0.28 mg/cm2; contact angle: 29.5°, 27.5°), indicating its advantage in promoting the wetting ability of Isaria fumosorosea PF904. OFX-0193 showed the best maximum retention at the concentration of 9.45 mg/cm2 on the surface of eggplant leaf at the concentration of 125 mg/L. Pullulan surface tension values were greater than the surface free energy values of cabbage, apple and eggplant leaves. Its contact angles were greater than 90° when reaching the concentration of CMC, which revealed that it was not effective in the activating of the wetting ability of PF904. The results of the inhibition rates of spore germination measurement showed that Nekal and OFX-0193 did not restrain Isaria fumosorosea PF904 germination, but AOS did. In conclusion, surfactants Nekal and OFX-0193 can be employed to assist Isaria fumosorosea to protect apple and cabbage from pests, OFX-0193 can also be used to control eggplant pests.