植物微生物学真菌界.ppt

真菌界 植物微生物学第四讲 Eumycotan Fungi真菌界 Unlike chromistan fungi - most have no motile stages so best adapted to land lPhylum Chytridiomycota（壶菌门） exception - do have flagellae - 1 posterior whiplash, lPhylum Zygomycota（接合菌门） most have coenocytic hyphae (ie no septae) lPhylum- Dikaryomycota（双核菌门） septate hyphae. Largest and most important group. 真菌界一般性状 By far the largest group of fungi: lover 100,000 sp known lprobably well over 1,000,000 exist! lmany capable of digesting very complex substances (cellulose, lignin， chitin ) - due to extracellular enzymes（胞 外酶） lhyphae （菌丝） can penetrate into solid masses e.g wood and decompose it rapidly lproduce vast numbers of spores so capable of spreading rapidly.（产孢繁殖） Phylum Chytridiomycota壶菌门 mostly live in water or soil - decomposers single cell or hyphae, 营养体为简单细胞或 菌丝sometimes develop rhizoids（根状体） often parasitic lSynchytrium（集壶菌属） causes wart disease of potatoes（马铃薯癌肿病） Chytrid fungi on decaying leaf in river This type is eucarpic（分体产果） having separate rhizoids and reproductive parts. Others are holocarpic（整体产果） - only have reprod. parts Potato wart disease Synchytrium endobioticum severe effect on yield resistant varieties available - but new virulent strains of fungus arising warts contain sporangia which release zoospores - infect new potatoes - cause rapid cell division = wart 马铃薯癌肿病症状 接合菌门主要特征 lwide, thin-walled multinucleate coenocytic hyphae 粗大的薄壁多核无隔菌丝 llimited ability to digest complex substrates lsexual spore = a thick walled zygosporangium （接合孢子） - germinates by meiosis to form new hyphae. Phylum Zygomycota Phylum Zygomycota接合菌门 lclass Zygomycetes 接合菌纲 Mucorales毛霉目 腐生 - saprobic (eg bread moulds) lcommon saprophytes - but limited ability to degrade complex compounds compared to Dikaryomycota lLife cycle - see Rhizopus stolonifer (Fig 3.5) lclass Trichomycetes 毛菌纲- parasites of arthropods 节肢动物的寄生物 Eumycotan Fungi Bread Mould - Rhizopus stolonifer面包霉 Life cycle of Rhizopus stolonifera 根霉生活史 Mucor - Life Cycle Sexual stages - teleomorph Asexual stages - anamorph 毛霉生活史 Zygospore of Rhizopus (diploid - will go through meiosis) 接合孢子 Sporangium in Rhizopus sporangiophore Sporangium containing many sporangiospores (asexual)孢子囊内含许多 孢囊孢子（无性的） 无性孢子（孢囊孢子） Anamorphs in Zygomycetes 无性阶段 双核菌门-子囊菌亚门 lChromistan Fungi lEumycotan Fungi. 1. Chytridiomycota 2. Zygomycota 3. Dikaryomycota Ascomycotina Basidiomycotina phylasub-phyla Dikaryomycota 子囊菌亚门 Compared to Zygomycota :- 1. have thinner hyphae菌丝细- thicker walls 壁厚 divided into compartments by 有隔 septae which contain pores.隔板有孔 2. This makes them tougher and much more able to thrive in drier situations更耐干旱 3. More capable of utilizing complex substances - e.g cellulose., lignin, keratin, chitin. 4. Many important pathogens of plants Dikaryomycota二核菌门 l5. Very important in mycorrhizal菌根 associations l6. Many species have developed an association with algae to form lichens地衣. l7. Hyphae can fuse and exchange nuclei and form heterokaryons 异核体, particularly dikaryons 二核体- necessary stage to sexual reproduction. Dikaryon = cells have 2 haploid nuclei of different origins in a stable state - continued on each cell division Ascomycotina - main features (cf. Basidiomycotina)担子菌主要特征 restricted dikaryophase (only in special fruiting bodies - ascoma)二核阶段不长（与担子菌比） Many cells within the ascoma develop into asci. Nuclear fusion and meiosis occurs to form 4, 8, 16 etc ascospores子囊 孢子 inside each ascus子囊. simple septal pores 2-layered cell walls双层壁 no clamp connections无锁状结构 molecular differences from Basidiomycotina (GC content etc.) many pathogenic fungi 许多是病原菌 leg humans (ringworm, athletes foot - attack keratin)如足癣 lplants - southern corn blight, powdery mildews玉米小斑 病和白粉病 rots and moulds of wood and cotton etc木材和棉花霉烂 producers of mycotoxins (eg aflatoxin)产毒素如黄曲霉 beneficial decomposers of material in soils 土中的分解者 insect and nematode predators and parasites昆虫和线虫的捕 食者和寄生物 useful in food (yeast, cheeses) or antibiotic prep. (penicillin, cyclosporine)用于食品（酵母和奶酪）或生产抗生素 important in molecular and classical genetics分子和经典遗传 学的模式生物。 Taphrina deformans - peach leaf curl Claviceps purpurea - ergot of Rye caused outbreaks of St Anthonys Fire in Middle Ages. Source of LSD 毒麦和桃缩叶病 Highly prized edible Morels 高价值的食用菌 引起植物病害 Ascomycotina - main groups分纲 l l Class -Class -AscomycetesAscomycetes 子囊菌纲 filamentous species丝状菌 l l Class - Class - SaccharomycetesSaccharomycetes 酵母纲 unicellular yeast species单细胞的菌 l l Class Class DeuteromycetesDeuteromycetes - 半知菌“纲” catchall group for species without sexual stages lmost Lichen fungi are Ascomycetes l大多数地衣真菌是子囊菌纲 Holomorph = Anamorph + Teleomorph 生活史分无性阶段和有性阶段 lAnamorph = asexual stages - mitosis - usually haploid l无性阶段，有丝分裂，通常是单倍体 lTeleomorph = sexual stages - involves dikaryons, diploidy and meiosis l有性阶段，涉及二核阶段、二倍体阶段和 减数分裂三个阶段 Teleomorphs of Ascomycetes 子囊菌有性阶段 Teleomorph begins when hyphae anastomose (= fuse together), become dikaryotic and aggregate into compact masses (ascoma). 有性阶段始于菌丝融合时，变成二 核体，聚集成紧密的一团。 4 kinds of ascoma 4种子囊果 lapothecia - open cups l子囊盘，开放的杯状物 lperithecia + pseudothecia - narrow opening flasks l子囊壳+假囊壳- 小口烧瓶状 lcleistothecia - closed spheres or flasks. l闭囊壳 - 封闭的瓶状物或烧瓶状物 4. cleistothecium 2. perithecium 3. pseudothecium Types of ascoma 子囊果的类型 1. Apothecium 子囊盘 Life cycle of typical Ascomycete Life cycle of typical Ascomycete 典型子囊菌的生活史 Ascomycetes Basidiomycetes ascusascus basidiumbasidium clamp connection every time a hyphal cell divides crozier only found just before ascus formation 子囊菌有性生殖（上）和担子菌（下 ）有性生殖的比较（钓状体和锁状联 合） bitunicate ascus双 层壁的子囊 unitunicate 单 层壁inoperculate 无孔口 unitunicate 单 层壁operculate ascus有孔口 原囊态 的子囊 The 4 main types of asci 子囊的4种主要形态 lIn Ascomycetes, anamorphs and teleomorphs often develop at different times and places. Each stage is therefore often collected in ignorance of the existence of the other lNormal classification is based on telomorph stages, but mycologists have had to classify specimens in which they only find anamorph stages. lThus parallel systems of nomenclature have sprung up - we have teleomorph genera and anamorph genera and mycologists try to draw connections between them where possible. lDNA analyses will make this much easier in future. l有性和无性阶段在不同时间和地点发生，采集到的标本或是有性 或是无性态，正常的分类 是根据有性态，但有些菌只发现了无性 态，只好根据无性态分类。因而有两个并行的命名体系。菌物学 家试图找到两者间的联系。将来DNA分析技术将使得更容易。 The anamorph-teleomorph probleme 有性和无性阶段问题 lIn some cases it has been possible to connect the anamorph name with the teleomorph name - but in many others this has not yet been done and may never be possible because the organism may have lost the ability to reproduce sexually. lOf 30,000 known Ascomycetes only 5,000 have been connected to their anamorphs - results often messy leg teleomorph genera, Nectria and Gibberella, both have anamorphs which have been classified in the anamorph genus Fusarium lMany anamorphs (85%) have no known teleomorph - are termed Deuteromycetes. l有时将有性与无性联系容易，许多情况下难甚至做不到，因为 有的菌丧失了有性生殖的能力。30 000种已知的子囊菌只有5 000种与无性态挂上了勾，结果往往是杂乱的，如有性阶段的丛 剌壳属和赤霉属的无性阶段都是镰霉属。许多（85%）无性态 已知但不知有性态，归到半知菌纲。 Recombination during MITOSIS has been observed in many fungi - it may be particularly well developed in Deuteromycetes 减数分裂时发生重组已在许多真菌中发现，但半知菌尤多。 两个不同核的细胞偶尔融合成为双核细胞，通过核 融而成体细胞二倍体，有丝分裂时发生交换而分离 或丢失染色体成单倍体。 Mitotic crossing-over diploid segregants Mitotic divisions Haploid mycelium Dikaryotic cells Somatic diploids arise through nuclear fusion Chromosome loss = haploidization Parasexual cycle 准性循环 The anamorph 无性阶段 The typical anamorph spore in Ascomycetes = conidia produced outside a specialized hyphal cell. 典型无性孢子是分生孢子，外 生于特殊菌丝细胞。 compare with Zygomycetes which produce sporangiospores inside a sporangium.而接合菌的无性孢子是在孢子囊内产生孢 囊孢子。 conidia = asexual spores produced in vast numbers by mitotic divisions 分生孢子是通过有丝分裂大量产生的无性孢子 classification of ascomycete anamorphs based on 子囊菌无性态分类依据是 lconidial features分生孢子特征 HyphomycetesHyphomycetes丝孢纲丝孢纲 - conidiophores never enclosed分生孢子梗 生 CoelomycetesCoelomycetes 腔孢纲- conidiophores enclosed in a covering. 分生孢子梗被封闭 lconidial shape and septation important l孢子形态和分隔数是重要依据 lconidiophore details also used l分生孢子梗的细节也用于分类 Coelomycetes have their conidia in a covered structure. Covered either by host cells (acervulus分生孢子盘) or by fungal hyphae in flask shape (pycnidium分生孢子器) acervulus pycnidium conidium 分生孢子器（右）和分生孢子盘（左 ） conidium 分生孢子梗的类型 单梗、分支、束生、座状 Conidia of 孢子 Aspergillus sp. Conidiophore 孢子梗 曲霉菌分生孢子和孢子梗 七种孢子类型 Yeasts 酵母菌 lYeasts are fungi which typically form unicellular cells which divide by budding i.e not filamentous hyphae lMost are Ascomycetous - many form asci, but there are some yeast- like forms in the Zygomycetes and Basidiomycetes lBudding yeast cells considered to be conidia lVery important in ecology and for man (brewing and baking) l酵母菌典型情况下形成单细胞的菌体，即没有丝状菌丝，出芽 繁殖。大多数是子囊菌，许多形成子囊，但在 1. Plant pathogens植物病原菌 over half of important crop pathogens are Ascomycetes. 作物病原菌一半是子囊菌 lHelminthosporium maydis - southern corn blight玉米小斑 lCryphonectria - chestnut blight - all but eliminated chestnuts in N. America栗疫病 lFusarium sp. - cause many wilt diseases, produce mycotoxins镰刀菌，造成萎蔫病，产毒素 lBotrytis - several plant diseases - can also produce very expensive sweet wine (ice wine)灰霉菌，引致几种病害， 但也生产昂贵的甜葡萄酒。 lClaviceps - ergot fungus - causes madness - LSD source l麦角菌，造成人类疾病 Some important Ascomycetes 一些重要的子囊菌 1. Plant pathogens植物病原菌（续） lErysiphe - powdery mildews of plants - haustoria penetrate epidermal cells of host plant 白粉菌-引致 植物白粉病-吸器穿透到寄主植物表皮细胞中 lOphiostoma - Dutch Elm disease 荷兰榆疫病 lVenturia - apple scab disease 苹果疮痂病 lTrichoderma - mycoparasite - use in biological control of plant disease l木霉菌-真菌寄生物-用于植物病害生物防治 一些重要的子囊菌（续） 2. Food and Health 食品与健康（续） lPenicillium and Aspergillus - used in cheese making The enzymes of Penicillium camembertii produce the soft, smooth texture of Camembert and Brie cheeses. Penicillium roquefortii puts that strong flavour in blue cheeses such as Roquefort, Danish Blue, Stilton and Gorgonzola. l青霉菌和曲霉菌-用于奶酪生产。青霉菌的酶产生软光滑的布里白奶酪 lAspergillus oryzae used in the Far East to turn soya protein into soy sauce l米曲霉在远东用于将大豆蛋白转娈成酱油 lMorchella (morels) - highly prized mushroom 高价的蘑菇 lTuber (truffles) even more highly prized and priced ! 块菌，价格还要高 lTrichophyton and other dermatophytes (keratin- attacking fungi) eg ringworm. athletes foot, jock itch etc 癣菌-足癣等 一些重要的子囊菌（续） 2. Food and Health（食品与健康） lAspergillus flavus (grows on peanuts and many other substrates,producing a mycotoxin called aflatoxin, which contaminates food and causes liver damage - the most potent carcinogen (cancer-inducing) substance known. l黄曲霉（在花生和其它许多基质上生长，产生称为黄曲霉的 毒素，污染食品、造成肝病-最烈性的致癌剂） l Fusarium graminearum, growing on feed corn, produces another mycotoxin, zearalenone, which is a steroid, and causes oestrogenic syndrome - vaginal and rectal prolapse - in young female pigs. l禾谷镰刀菌，在饲料玉米上生长，产生另一种霉菌毒素即玉 米烯酮，是一种固醇，造成雌激素综合症，母猪直肠下垂 lPenicillium italicum - example of the moulds that spoil food in storage .意大利青霉-储藏的食物变质 一些重要的子囊菌（续）一些重要的子囊菌（续） 玉米烯酮 l3. Rots and decomposition 腐烂与分解 lCellulolytic hyphomycetes cause blue stain and soft rot of wood, discolouration and loss of strength of cotton materials and moulding of almost any damp organic substrate. 分解纤维素的丝孢纲真菌木材蓝点和软腐、棉花变色和强度降低、造成 任一种潮湿的有机质发霉。 lAscomycetes are prime colonizers and decomposers of soft plant debris, playing a vital role in the carbon and nitrogen cycles. Dominate the soil mycota in most forests. Dead leaves are colonized by aquatic hyphomycetes - tolerant of low temperatures so can grow during the winter and even under ice - make the dead leaves much more palatable and nutritious for the various detritivorous invertebrates w