植物病理第五章+植物病原线虫及原生动物.ppt

H. avenae - line drawing: Reproduced from Williams TD, Siddiqi MR, 1972. CIH Descriptions of Plant-Parasitic Nematodes. Set 1, No. 2. Wallingford, UK: CAB International. 1. 粒线虫属（Anguina） 雌、雄虫均为线形，虫体较长，垫刃型食管，口针较小。 大都寄生禾本科植物的地上部，破坏茎、叶或子房形成虫瘿，如小麦粒线虫（A．tritici）。 Symptoms on wheat spikes: Galled and healthy wheat spikes. Three wheat spikes infested with A. tritici on left compared with healthy spike on right. Infected wheat seed: Healthy wheat seeds (top) and seed galls infected with A. tritici (below). 2. 茎线虫属（Ditylenchus） 雌、雄虫都为线形，垫刃形食管。主要危害地下的球茎、块茎、鳞茎、块根等，如引起我国甘薯茎线虫病的破坏性茎线虫（D．destructor）。 Symptoms on pods and seed of groundnut of Ditylenchus africanus Section of nematode: Ditylenchus africanus in endocarp of mature groundnut hull prior to harvesting. (N= Nematode in cross section: NH=Nematode head in longitudinal section: MF=Malformed cell walls) SEM: Ditylenchus africanus (arrowed) on the embryo of groundnut seed, close-up. Symptoms - Ufra disease: Ufra disease on deepwater rice, Bangladesh; note partial emergence and distorted panicles due to nematode infection. Nematodes in bulb tissue: Nematodes infesting Narcissus bulb. Symptoms on Narcissus bulb: Damage to Narcissus bulb. Infested bulbs usually have brown rings when sliced. Symptoms on bean: Damage to pods of Vicia faba. Newly formed pods take on a dark-brown appearance. Ditylenchus destructor on potato Ditylenchus dipsaci on garlic  3. 滑刃线虫属（Aphelenchoides） 雌、雄虫都是线形，滑刃型食管，口针较长。主要危害植物的叶、芽，如引起水稻干尖线虫病的贝西滑刃线虫（A．bessey）。 Symptoms on leaves: Left: Characteristic white tip symptom on rice leaf. Right: Necrotic patches and crinkled rice leaves. CHLOROSIS:Aphelenchoides fragariae Aphelenchoides fragariae on African violet, healthy in center  CURLING AND TWISTING OF LEAVES AND STEMS:Aphelenchoides fragariae on strawberry 4. 异皮线虫属（Heterodera） 又称胞囊线虫属。 雌、雄虫异形，即雄虫细长，雌虫柠檬形。具突出的阴门锥。后期雌虫角质层变厚，呈深褐色，体内充满卵，这种含有大量的雌虫尸体称为胞囊（cyst）。 该属线虫是危害植物根部的一类重要线虫，如大豆胞囊线虫（H．glycines）等。 Symptoms induced by Heterodera glycines Symptoms