21第二篇微生物与农业可持续发展.ppt

颗粒体征病毒（GV，granulosis virus) GV是双链DNA杆状病毒。包涵体圆形或椭圆形，一般只含一个（偶尔两个）病毒粒子，易在寄主的细胞核和细胞质内发育。感染昆虫的表皮、脂肪组织和血细胞等，昆虫吞食病毒后停止进食，血液变为乳白色而死亡。可用于防治菜青虫、小菜蛾及地老虎的危害。 无包涵体病毒（NIV，noninclusion virus) 病毒粒子球状，不形成包涵体。侵染的宿主范围广泛，除昆虫纲外，还可侵染蜘蛛纲、甲壳纲等动物，如柑橘红蜘蛛和蟹等，其中以防治柑橘红蜘蛛较为有效。 虹彩病毒寄生双翅目、鳞翅目和鞘翅目昆虫。该类病毒最大的特点是提纯的病毒或在寄主组织中的病毒均对光反射产生虹彩。经口和血腔接种传染，侵染脂肪体和其他多种组织细胞而致昆虫死亡。 浓核病毒传染途径同于虹彩病毒，感染力强。寄生鳞翅目、双翅目、鞘翅目、膜翅目昆虫。能侵染寄主昆虫各个虫态和所有组织，在细胞核内增殖。 由于病毒为昆虫的专性病原体，杀虫范围又窄；需通过寄主昆虫才能繁殖，生产困难；作用速度慢，昆虫致死时间长等原因，所以在很大程度限制了病毒杀虫剂的发展。 被真菌所寄生的线虫多为土壤中的植物病原线虫及动物体内的病原线虫，这些线虫对于植物的地上部以及地下部与畜牧业的直接影响或者是间接的致病效应是影响农业生产成本高低的重要因素。 第四节 线虫病原真菌和原生动物杀虫剂 Nematophagous fungi(线虫病原真菌)are natural enemies of nematodes. They comprise three main groups of fungi: the nematode-trapping and the endoparasitic fungi that attack vermiform living nematodes by using specialized structures, and the egg- and cyst-parasitic fungi that attack these stages with their hyphal tips. nematode-trapping fungi endoparasitic fungi egg- cyst-parasitic fungi spore (S) that adhered near the nematodes mouth and then germinated and penetrated the cuticle to produce a bulb (B) A thin infection hypha (H) has started to colonise the host Nematode trapped (arrow) by A. oligospora Adhesive network of A. oligospora, developed from digested nematode Adhesive branches of M. gephyropagum Adhesive knobs of M. haptotylum Constricting ring of A. brochopaga Nematode infected by conidiospores of D. coniospora Zoospores of Catenaria anguillulae D. coniospora spores with adhesive buds (arrows). 腐生 寄生 Nematophagous fungi are found in all major groups of fungi, including lower (oomycetes卵菌纲, chytridiomycetes壶菌纲,zygomycetes接合菌纲) and higher fungi (ascomycetes子囊菌纲, basidiomycetes担子菌纲and deuteromycetes半知菌) For plant-parasitic nematodes the early experiments concentrated on using nematode-trapping fungi, e.g. Arthrobotrys or Monacrosporium species, and later shifted towards endoparasitic fungi, e.g. H. rhossoliensis and D. coniospora, and egg-parasitic fungi, e.g. P. chlamydospo