楚雄腮扁叶蜂的虫生真菌分离鉴定及其致病性研究

发布时间：2018-04-24 02:25

本文选题：楚雄腮扁叶蜂 + 虫生真菌　；参考：《西南林业大学》2015年硕士论文

【摘要】：楚雄腮扁叶蜂(Cephalcia chuxiongica)是云南省一种新的针叶林食叶害虫。由于该虫危害重、扩散快、防治难,已成为近年来严重制约云南林业可持续发展的危险性害虫之一。至今未见对其科学有效防治方法的报道。虫生真菌是害虫种群自然调节的重要因子和害虫生物防治的重要材料,利用虫生真菌防治害虫,已逐步成为一种以生物防治为主导的综合治理重要途径。旨在为该害虫的生物防治提供菌种资源,本文开展了其虫生真菌的分离、鉴定及高致病性菌株的筛选研究,取得了如下主要研究结果:(1)虫生真菌的分离与鉴定。采用组织分离法,从云南省寻甸县采集到的自然罹病死亡的楚雄腮扁叶蜂幼虫虫尸上分离到5株虫生真菌:SWYH01,SWYH02,SWYH06,SWYH07和SWYH09;经形态学和分子生物学方法鉴定,5株菌分别为布氏白僵菌Beauveria brongniartii(Sacc.)Petch、淡紫拟青霉Paecilomyces lilacinus(Thom)Samson)、淡色丛赤壳Bionectria ochroleuca(Schwein)SchroersSamuels、粉质棒束孢Isaria farinose(Holmsk.)Fr.)、球孢白僵菌Beauveria bassiana(Balsamo)Vuillemin。(2)高致病性菌株的筛选。以经回接验证后对楚雄腮扁叶蜂幼虫具有致病性的5株虫生真菌为研究对象,分别以5株菌的浓度为108个孢子/mL的孢子悬浮液对楚雄腮扁叶蜂幼虫进行致病力测试。通过对5株菌的主要侵染部位观察,发现除菌株SWYH06是主要从气门侵入,其余4株菌首先主要侵染楚雄腮扁叶蜂幼虫的体壁、节间褶以及头和尾等部位。处理16d后,结果表明,该5株虫生真菌对楚雄腮扁叶蜂幼虫均有一定的致病效果,菌株SWYH06对楚雄腮扁叶蜂幼虫的致病速率、校正死亡率及僵虫率都高于其余4株菌;死亡率、校正死亡率都可达100%,僵虫率可达91.65%。菌株SWYH02对楚雄腮扁叶蜂的致病力最弱,死亡率和校正死亡率都不到50%,僵虫率为25%。(3)菌株SWYH06的生物学特性研究。通过对菌丝生长和产孢的营养及环境条件筛选,确定其菌丝生长和产孢的最适培养基为PPDA;实验所选择的碳源对菌丝生长的影响差异不明显,菌丝生长的最适氮源、无机盐分别是酵母粉和MnSO4,产孢最适碳源是葡萄糖、氮源是NH4NO3和尿素、无机盐是ZnSO4和MgSO4;在实验所设置的温度范围内,菌丝生长、产孢及孢子萌发的适宜温度是25℃;分生孢子萌发的较适湿度为90%以上;光照对菌丝生长、孢子萌发影响不明显,但可促进菌株产孢。(4)菌株SWYH06对楚雄腮扁叶蜂和黄粉虫(Tenebrio molitor)的毒力测定。用SWYH06菌株不同浓度梯度的孢子悬浮液处理楚雄腮扁叶蜂幼虫和黄粉虫幼虫,结果表明,2种幼虫的死亡率随孢子浓度的增加而增加,死亡率与孢子悬浮液的浓度呈正相关。采用1.5×108个孢子/mL的孢子悬浮液处理楚雄腮扁叶蜂和黄粉虫幼后,幼虫的死亡高峰分别出现在第4~6d和2~4d;死亡率和僵虫率分别为98.35%、96.65%和93.33%、96.65%。(5)楚雄腮扁叶蜂的室内防治实验。使用成分为棉籽壳:麦麸:锯末:葡糖糖:CaSO4=40:40:18:1:1的固体培养基,对SWYH06菌株进行固体发酵。结果表明,SWYH06菌株在该培养基上菌丝生长和产孢情况良好,10~15d菌丝可长满瓶,第20d时,固体发酵物的含孢量达到4.5×108个孢子/g~6.7×108个孢子/g。用3种不同施菌方法对楚雄腮扁叶蜂进行了处理。结果表明,使用固体发酵物拌土和在幼虫入土前在土表层施用固体发酵物2种方法处理楚雄腮扁叶峰幼虫,3个月后,校正死亡率可达74.08±7.64%和63.33±12.58%,说明SWYH06菌株在楚雄腮扁叶蜂生物防治方面具有良好的应用前景。
[Abstract]:The Cephalcia chuxiongica (Cephalcia chuxiongica) is a new leaf eating pest of coniferous forest in Yunnan province. Because of its heavy harm, rapid spread and difficult control, it has become one of the dangerous pests which seriously restrict the sustainable development of forestry in Yunnan in recent years. The important factors of the festival and the important material of pest biological control, and the use of entomophyll fungi to prevent and control pests have gradually become an important way to control the biological control. The aim is to provide bacterial resources for the biological control of the pest. The isolation, identification and screening of highly pathogenic strains of the insect fungi are carried out in this paper. The main results are as follows: (1) isolation and identification of entomotic fungi. Using tissue separation method, 5 strains of entomophytic fungi were isolated from the naturally sick and dead SWYH01 gills larvae from Xundian County of Yunnan Province: SWYH01, SWYH02, SWYH06, SWYH07 and SWYH09; 5 strains of bacteria were identified by morphological and molecular biological methods. Beauveria brongniartii (Sacc.) Petch, Paecilomyces lilicus Paecilomyces lilacinus (Thom) Samson), light colored plexus Bionectria ochroleuca (Schwein) SchroersSamuels, powdery Beauveria bassiana (2) screening of highly pathogenic strains. The pathogenicity of 5 strains of entomotic fungi in the larva of Chuxiong gills were tested. The pathogenicity test was carried out on the larvae of Chuxiong gills by 5 strains of spore suspension with 108 spores /mL, respectively. Through the observation of the main infection sites of 5 strains of bacteria, it was found that the other 4 strains were mainly from the valve and the other 4 strains. First, it mainly infects the body wall, internode fold and head and tail parts of the larva of Chuxiong parietal beeleaf bee. After treating 16d, the results show that the 5 strains of entomotic fungi have certain pathogenic effect on the larva of Chuxiong parietal beeleaf bee, and the strain SWYH06 is higher than the rest of the other 4 strains, and the death rate and the rate of ossified insect are higher than those of the other 4 strains. The rate of correction can reach 100%, and the rate of 91.65%. strain SWYH02 is the weakest, the mortality and correction mortality are less than 50%, and the biological characteristics of 25%. (3) strain SWYH06 are studied. The growth and sporulation of mycelia and the sporulation are selected to determine the growth and sporulation of the mycelia. The optimum medium is PPDA; the difference of the influence of the carbon source selected by the experiment is not obvious. The most suitable nitrogen source of mycelial growth, the inorganic salt is yeast powder and MnSO4, the most suitable carbon source of the sporulation is glucose, the nitrogen source is NH4NO3 and urea, the inorganic salt is ZnSO4 and MgSO4; in the temperature range set, the mycelium growth, spore producing and spores The suitable temperature for germination was 25, and the suitable humidity of conidia germination was more than 90%. The effect of light on mycelium growth and spores germination was not obvious, but it could promote the sporulation. (4) the virulence of strain SWYH06 to Chuxiong cheek flattened bee and Huang Fenchong (Tenebrio molitor). The treatment of Chuxiong gills with SWYH06 strains with different concentration gradient of spore suspension. The results showed that the mortality of the 2 larvae increased with the increase of spores concentration, and the mortality rate was positively correlated with the concentration of spore suspension. The death peaks of the larvae were in 4~6d and 2~4d respectively after the treatment of 1.5 x 108 spores /mL of spore suspension. And the rate of ossified insects were 98.35%, 96.65% and 93.33%, 96.65%. (5) Chuxiong cheek wasp indoor control experiments. The components were cottonseed shell: wheat bran: sawdust: glucose: solid medium of CaSO4=40:40:18:1:1, solid fermentation of SWYH06 strain. The results showed that the mycelium growth and sporulation of SWYH06 strain on this medium were good, 10~15d At 20d, the sporulation of solid fermentations reached 4.5 x 108 spores, /g~6.7 x 108 spores /g. were treated with 3 different kinds of spore application methods. The results showed that 2 methods of solid fermenting with solid fermenting and 2 methods of solid fermentation on the soil surface before the larva were applied to the soil were used to treat the larva of the flat leaf peak of Chuxiong cheek. After 3 months, the corrected mortality rate reached 74.08 + 7.64% and 63.33 + 12.58%, indicating that the SWYH06 strain has a good application prospect in the biological control of Chuxiong.

【学位授予单位】：西南林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S763

【相似文献】