【作者】 张晓梅；

【导师】 林华峰；

【作者基本信息】 安徽农业大学 ， 农业昆虫与害虫防治， 2002， 硕士

【摘要】 为探索虫生真菌和细菌两种重要杀虫微生物应用的新途径，延长药效期，提高防治效果，改善两种药剂在自然界中易受紫外线损伤的缺陷，本实验配制出细菌和真菌的12种复合乳剂、10种复合粉剂，并通过大量对其生物活性和杀虫毒力的测定，筛选出2-3种对紫外线等环境因子敏感性低、作用速度快、杀虫效果好、残效期长的乳剂配方和粉剂配方。同时从烟青虫蛹上分离出具有高致病力的青霉菌，对该菌的生物学和生态学特征进行了探讨。 1 杀虫真菌的生物学和生态学研究 虫生真菌青霉菌适宜于低温生长、生命力强，在生长过程中，菌落具有从白色至灰色、粉色，最终形成绿色四种颜色变化的真菌。分生孢子球形，绿色或黄色。在15℃、25℃、35℃三个温度条件下，以15℃生长最为旺盛，25℃次之，35℃条件下几乎不生长而后死亡。在SDAY和PDA两种培养基上，以SDAY培养基上生长较为迅速，但在PDA培养基上产孢迅速而且产孢量大。用菌液接种法比用菌粉接种法生长势好。青霉菌在25℃、SDAY培养基上用菌液接种法接种，菌落日平均增长量达0.67cm／d。青霉菌在培养液中培养，由于形成酸性物质，培养液pH值降低，颜色变浅，生长势为白僵菌5S03＞青霉菌P.s＞绿僵菌Ma4，但青霉菌的产孢量大。设计了四种粗培养料配方，观察青霉菌的生长情况，得出：青霉菌在四种培养料中的生长速度依次为：D(麦麸：玉米粉：马铃薯滤液——4:1:4)＞B(麦麸：马铃薯滤液——5:1)＞A(麦麸：玉米粉——5:1)＞C(麦麸：玉米粉：马铃薯滤液——4:1:1)。 2 几种真菌对害虫的毒力 用青霉菌感染桃蚜和棉铃虫2龄幼虫，与其它真菌的致死中时相比，四种真菌对桃蚜的作用速度依次是P.s＞5S03＞Ma4＞Nr96-1。用六种真菌对棉铃虫2龄幼虫的处理，作用速度依次是5S03＞B-9-9＞P.s＞Nr96-1＞Ma4＞Ma3。用各真菌对桃蚜的致死效果进行相关分析，可得出Ma4与5S03对桃蚜的致死率最高，P.s对桃蚜的作用效果最不理想，与Ma4形成显著性差异。对棉铃虫2龄幼虫，5S03致死率最高，P.s次之，Ma4最低，P.s与5S03、Ma4都有显著性差异，杀虫效果处于中等水平。综合分析，选定5S03、P.s与细菌配制复合剂型。 3 细菌和真菌复合乳剂的检测与评价 分别将青霉菌Ps、白僵菌5503和苏云金杆菌Bt乳剂相混合，加入其它乳化剂和保护剂，共配制成12种复合乳剂。分别在贮存一个月、四个月、一年后的三个阶段，对其中的微生物活性成分进行检测，对两种目标害虫进行毒力测定，测得：在各个阶段，细菌和真菌活性比前一个阶段都有所下降。a、A复合乳剂中细菌的活性下降最多，B、E、e、f细菌的活性保持最为良好，D、Fb、c细菌的活性也比较高。真菌活性下降最多的是A、E、F、e，一年以后真菌几乎全部死亡。C、D、E、C、f中仍有部分真菌存活。各乳剂在各阶段对目标害虫的毒力均有所下降，乳剂保存一个月时，对桃蚜的毒力都比较高，致死速率快，平均死亡率均超过Bt原液的作用效果或与Bt原液相差无几。一年后，A、。对蚜虫的毒力下降最多，其中。与其它的＊s复合乳剂之间有显著差异。A、a均为没有添加任何辅助成分的细菌和真菌的混合液，说明各复合乳剂的添加成分均增强了复合乳剂对桃蚜的致病力。在对棉铃虫的毒力测定中，一个月时，B毒力下降最多，与其余各乳剂成极显著差异。说明复合乳剂B中的辅助成分严重削弱了对棉铃虫幼虫的毒力作用，不利于真菌和细菌药剂的发挥。四个月后，b毒力下降最为显著，与其余巩剂有显著差异，说明b虽然在一个月时对棉铃虫有较高的毒力，但到四个月时毒力己显著下降，因而它只能作为细菌和真菌复配时短期使用的配方选择，长期贮存，尤其是夏季高温天气的长期贮存，对药效的性能影响较大。一年后，各乳剂之问的毒力水平己相差不大，多种乳剂的颜色都变浅，保护剂的作用衰退，对棉铃虫2龄幼虫的平均死亡率维持在70％左右。最终筛选出对桃蚜和棉铃虫效果最好，性状最优，同单用细菌和真菌相比，有明显增效作用的乳剂的E、F，它们的配方分别是：E一【5503（0二s）＋ Bt乳剂（20ml）十乳化齐 2（30m）＋罕化齐 二添加剂（0＊olsg）＋保护剂3（0＊sg）］F一［5503（0．Zg）＋Bt乳剂（20ffil）＋乳化齐3（30ffil）十保护齐1（0．059）］E、F对桃蚜、棉铃虫幼虫都有较强的杀伤力，受外界环境的影响较小，适且长期贮存，因而这两个配方组合对5503、PS、Bt乳剂都有较好的保护作用，并且利用各成分共同发挥作用，提高了杀虫效果。4 细苗和真菌复合粉剂的检副与评价 10种复合粉剂在贮存半年后，对其中的活性成分进行检测，对目标害虫进厅毒力测定，测得E；细菌活性降低最多，a；、c；、d；、e；的真菌活力最低。各粉剂对桃蚜没有明显的增效作用，d；对桃蚜的致死率最低，与Bt原粉和其它复合粉剂有显著差异。在对棉铃虫的毒力测定中，E；、b；的毒力下降最多，与其余粉剂间有显著差异。c；、人略有增效作用，c；和4的配方分别是：c；一【Rs（0．ig）十 Bt粉齐（10g）十罕化齐 1（ig）＋保护齐 2（ODlg）］d；一IPS（0．ig）＋ Bt粉更多还原

【Abstract】 In order to find out new application approaches of two important microbial insecticides -entomogenous fungus and bacteria,to prolong their effective periods,to enhance insecticidal results and to counterbalance the deffects of the two kinds of microbe which were liable damaged by ultraviolate in nature,we devised 12 kinds of cimposited latexes and 10 composited powders of fungus and bacteria.Through a great many experiments to measure their biological activity and virulence to pests,we come to two to three groups of components which were insensitive to environmental factors such as ultraviolate etc. These groups can quickly output their effects . They are highly effective to pests and can be stored for a long time .We also isolated a validly pathogenic fungus from the pupae of Hilicoverpa assulta.lts biological and ecological characteristics were studied as well. 1 The biological and ecological characteristics of several fungal strainsThe entomogenous fungus P.s is adaptive to low temperature,has a sticky growing potency. In the progress of its growth,the shape of its spore is sphere,its color is green or yellow. On conditions of 15,25 and 35 centigrade,it grows best at 15 centigrade,follows by 25 centigrade. It stops growing at 35 centigrade and soon died. On two kinds of medium of SDAY and PDA,it grows stronger on SDAY media than on PDA. but on PDA it can produce spores earlier and has a larger sporulation. Transplanting P.s with conidium suspension grows better than with conidium powder. So the best cultivating way to P.s is to transplant it with conidium suspension on media SDAY at the temperature of 15 centigrde. In this manner P.s grows 0.67 centimeter per day averagely.The Penicillium strain P.s can produce acid substances and lower the liquid pH as well as shallow the liquid media colors when cultured in it. The growth circumstance is that the Beauveria bassina strain 5S03 shows the best,P.s is next to it and the Metarhi-ium anisopliae strain Ma4 shows the poorest. On the other hand. P.s’s sporulation is most significant. The growth circumstances can also deprived from four artificial medium. Among them. P.s grows best on the D component,the next is the B and A component,component C shows poorer. The four artificial medium’s compositions are respectively as follows:D-(wheat bran:maize powder:filtered potato liquid =4:1:4)B-(wheat bran:filtered potato liquid =5:1)A-(wheat bran:maize powder =5:1)C-(wheat bran:maize powder:filtered potato liquid =4:1:1)2 The virulence of Penicillium strain P.s to pestsTo treat Myzus persicae and second -instar larvae of Helicoverpa armigera with P.s conidium suspension,according to their LT of four strains of fungi against Myzus persicae,the results showed that P.s strain actived most quickly,following 5S03 and Ma4,the Nomuraea rileyi strain Nr96-l is next to them. The significant analysis of the four fungus strains against Myzus persicae showed that the mortality rates of Ma4 strain and 5803 strain are most magnificent,P.s is the poorest and has significant difference compared with other fungi. To treat against second -instar larvae of Helicoverpa armigera with six strains of fungi,it can be put forward that 5S03’s mortality rate is higher than other strains,P.s is next to 5S03,the poorest is Ma4. The mortality rate of P.s against second -instar larvae of Helicoverpa armigera is average. As analysed above,we selected fungi of 5S03 and P.s to composite with bacteria in the end.3 Measurement and evaluation of composited latexes of bacteria and fungus Put P.s strain powder and 5S03 strain powder respectively into the Bt latexes,thenput other surfactants and UV-protectants into them. In the whole we obtained 12 kinds of equable composited latexes. After storing them for one month,four months and a year,the tests of their microbial activity and their virulence to object pests were made. During every stage,the vitality of the bacteria and fungus were lowered comparing it with the former stages. The bacterial viatality of composited latexes a and更多还原