不同基质多代培养对蚧虫病原真菌蜡蚧霉致病力的影响  

Effect of multi-generation culture on virulence of Lecanicilliurn lecanii in different media

作　　者：韩珍珍[1] 谢映平[1] 薛皎亮[1] 樊金华[1] 

机构地区：[1]山西大学生命科学学院,太原030006

出　　处：《微生物学报》2010年第2期211-221,共11页Acta Microbiologica Sinica

基　　金：国家自然科学基金(30671693);山西省留学基金([2007]13)~~

摘　　要：【目的】研究昆虫病原真菌蜡蚧霉Lecanicilliurn lecanii(Zimmermann.)菌株No.V3.4504在不同培养基上继代培养,对菌种的菌落生长特性、胞外酶活力和对蚧虫致病力的影响。【方法】试验菌种蜡蚧霉菌株No.V3.4504是从染病蚧虫上分离的。试验蚧虫是沙里院褐球蚧Rhodococcus sariuoni Borchsenius和日本龟蜡蚧Ceroplastes japonicus Green。采用7种培养基继代培养多代。观察菌落形态特征、测定生长速率、产孢量、胞外蛋白酶和几丁质酶活性及对蚧虫的致死率。【结果】在PDA培养基上,菌落生长速率最快,但产孢量最低,胞外蛋白酶和几丁质酶的活性均呈逐代下降趋势,对两种蚧虫致死率也最低;增加蛋白胨对改善菌种致病力没有明显效果;在增加蚧虫尸体的D、E、F培养基上,菌落生长速率虽然较慢,但产孢量上升为8.83×106-9.13×106孢子/cm2。蛋白酶和几丁质酶的活性平均达到2.16-2.13 U/g和1.01-1.03 U/g,对两种蚧虫的致死率分别在55%-58%和39%-42%;在活蚧虫上连续培养3代,蛋白酶和几丁质酶的活性最高,为3.08-2.92 U/g和1.45-1.42 U/g,是PDA培养基上的1.6倍。对两种蚧虫的致死率也最高,分别达到71.30%和58.89%。蛋白酶和几丁质酶的活性与蚧虫死亡率呈正直线相关关系。【结论】采用PDA培养基连续多代培养会引起菌株No.V3.4504明显退化;在培养基中加入蚧虫尸体,对于保持菌种活力有明显效果;在活蚧虫体上继代培养对复壮菌种,提高菌种毒力的效果最佳。[ Objective ] The strain No. V3. 4504 of Lecanicilliurn lecanii （ Zimmermann）, an entomopathogenic fungus, was studied on the effect of successive multi-generation culture in seven different media on its colony growth characteristics, extracellular enzyme activities and the virulence against scale insects. [ Methods] The strain No. V3. 4504 of L. lecanii was original isolated from a natural infected scale insect. The two species of scale insects used were Rhodococcus sariuoni Borchsenius and Ceroplastes japonicus Green. Seven media were used and fungus colony characteristics,growth rate and sporulation,extracellular protease and chitinase activity, and infective effect against the two species of scale insects were conducted. [ Results] The fungus cultured on PDA medium for successive nine generations showed the most fast in colony growth, the minimal in sporulation, straight decline of extracellular protease and chitinase activity with generation increasing, and the minimal mortality of the scale insects. There was no significant effect to promote virulence of the fungus by increasing peptone into medium. On the media D, E and F,that with the body materials of the two scale insects, although the fungus appeared lower in the colony growth rate,its sporulation was higher upward 8.83 × 10^6 -9.13 × 10^6 spores/cm^2,extracellular protease and chitinase activities averagely reached 2. 16 - 2. 13 U/g and 1.01 - 1.03 U/g respectively,and the mortalities of the two scale insects were 55% -58% and 39% -42% respectively. Cultured three generations in vitro of the two scale insects,the fungus exhibited the highest activities in its protease and chitinase that were 3.08 - 2.92 U/g and 1.45 - 1.42 U/g respectively and the best infection effect against the two scale insects with mortalities of 71. 30% and 58. 89% respectively. A linear correlation was found between extracellular protease and chitinase activities of the fungus and the mortalities of the scale insects. [ Conclusion ] Cultured on PDA medium successive multi

关 键 词：昆虫病原真菌 蜡蚧霉 蚧虫 胞外蛋白酶 几丁质酶 

分 类 号：S476.1[农业科学—农业昆虫与害虫防治]