植物微生物学真菌界ppt课件

1、植物微生物学第四讲By far the largest group of fungi:over 100,000 sp knownprobably well over 1,000,000 exist!many capable of digesting very complex substances (cellulose, lignin， chitin ) - due to extracellular enzymes胞外酶胞外酶hyphae 菌丝菌丝 can penetrate into solid masses e.g wood and decompose it rapidlyproduce v

2、ast numbers of spores so capable of spreading rapidly.产孢繁衍产孢繁衍l mostly live in water or soil - decomposerslsingle cell or hyphae, 营养体为简单细胞或菌丝sometimes develop rhizoids根状体loften parasiticlSynchytrium集壶菌属 causes wart disease of potatoes马铃薯癌肿病Potato wart diseaseSynchytrium endobioticum severe effect on

3、 yield resistant varieties available - but new virulent strains of fungus arising warts contain sporangia which release zoospores - infect new potatoes - cause rapid cell division = wartPhylum Zygomycotalclass Zygomycetes 接合菌纲lMucorales毛霉目 腐生 - saprobic (eg bread moulds)lcommon saprophytes - but lim

4、ited 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 FungiLife cycle of Rhizopus stoloniferaMucor - Life CycleSexual stages - teleomorphAsexual stages - anamorphZygospore

5、 of Rhizopus (diploid - will go through meiosis)Sporangium in RhizopussporangiophoreSporangium containing many sporangiospores (asexual)孢子囊内含许多孢子囊内含许多孢囊孢子无性的孢囊孢子无性的Anamorphs in ZygomyceteslChromistan FungilEumycotan Fungi.l1. Chytridiomycotal2. Zygomycotal3. Dikaryomycotaphylasub-phylaCompared to Zy

6、gomycota :-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 impor

7、tant pathogens of plantsl5. 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

8、 have 2 haploid nuclei of different origins in a stable state - continued on each cell divisionrestricted 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 eac

9、h ascus子囊.simple septal pores2-layered cell walls双层壁no clamp connections无锁状构造molecular differences from Basidiomycotina (GC content etc.)many pathogenic fungi 许多是病原菌eg humans (ringworm, athletes foot - attack keratin)如足癣plants - southern corn blight, powdery mildews玉米小斑病和白粉病rots and moulds of wood a

10、nd 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消费抗生素important in molecular and classical

11、 genetics分子和经典遗传学的方式生物。Taphrina deformans - peach leaf curlClaviceps purpurea - ergot of Ryecaused outbreaks of St Anthonys Fire in Middle Ages. Source of LSDHighly prized edible MorelslAnamorph = asexual stages - mitosis - usually haploidl无性阶段，有丝分裂，通常是单倍体lTeleomorph = sexual stages - involves dikar

12、yons, diploidy and meiosisl有性阶段，涉及二核阶段、二倍体阶段和减数分裂三个阶段Teleomorph begins when hyphae anastomose (= fuse together), become dikaryotic and aggregate into compact masses (ascoma). 有性阶段始于菌丝交融时，变成二核体，聚集成严密的一团。apothecia - open cups子囊盘，开放的杯状物perithecia + pseudothecia - narrow opening flasks子囊壳+假囊壳- 小口烧瓶状clei

13、stothecia - closed spheres or flasks.闭囊壳 - 封锁的瓶状物或烧瓶状物4. cleistothecium2. perithecium3. pseudothecium1. ApotheciumLife cycle of typical AscomyceteAscomycetesBasidiomycetesclamp connection every time a hyphal cell dividescrozier only found just before ascus formationbitunicate ascus双层壁的子囊unitunicate

14、单层壁inoperculate无孔口unitunicate 单层壁operculate ascus有孔口原囊态的子囊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 otherlNormal classification is based on telomorph stages, but mycologists hav

15、e 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

16、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。因此有两个并行的命名体系。菌物学家试图找到两者间的联络。未来DNA分析技术将使得更容易。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 lo

17、st the ability to reproduce sexually. lOf 30,000 known Ascomycetes only 5,000 have been connected to their anamorphs - results often messyleg teleomorph genera, Nectria and Gibberella, both have anamorphs which have been classified in the anamorph genus FusariumlMany anamorphs (85%) have no known te

18、leomorph - are termed Deuteromycetes.l有时将有性与无性联络容易，许多情况下难甚至做不到，由于有的菌丧失了有性生殖的才干。30 000种知的子囊菌只需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

19、现，但半知菌尤多。两个不同核的细胞偶尔交融成为双核细胞，经过核融而成体细胞二倍体，有丝分裂时发生交换而分别或丧失染色体成单倍体。Mitotic crossing-over diploid segregantsMitotic divisionsHaploid myceliumDikaryotic cellsSomatic diploids arise through nuclear fusionChromosome loss = haploidizationThe typical anamorph spore in Ascomycetes = conidia produced outside a

20、 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分生孢子是经过有丝分裂大量产生的无性孢子lconidial features分生孢子特征lHyphomycetes丝孢纲 - conidiophores never en

21、closed分生孢子梗 生lCoelomycetes 腔孢纲- conidiophores enclosed in a covering.分生孢子梗被封锁lconidial shape and septation importantl孢子形状和分隔数是重要根据lconidiophore details also usedl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 f

22、lask shape (pycnidium分生孢子器)acervuluspycnidiumconidiumconidiumConidia of 孢子孢子Aspergillus sp.Conidiophore孢子梗孢子梗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

23、 Zygomycetes and BasidiomyceteslBudding yeast cells considered to be conidialVery important in ecology and for man (brewing and baking)l酵母菌典型情况下构成单细胞的菌体，即没有丝状菌丝，出芽繁衍。大多数是子囊菌，许多构成子囊，但在1. Plant pathogens植物病原菌植物病原菌 over half of important crop pathogens are Ascomycetes.作物病原菌一半是子囊菌作物病原菌一半是子囊菌Helminthospo

24、rium maydis - southern corn blight玉米小斑玉米小斑Cryphonectria - chestnut blight - all but eliminated chestnuts in N. America栗疫病栗疫病Fusarium sp. - cause many wilt diseases, produce mycotoxins镰刀菌，呵斥萎蔫病，产毒素镰刀菌，呵斥萎蔫病，产毒素Botrytis - several plant diseases - can also produce very expensive sweet wine (ice wine)灰灰

25、霉菌，引致几种病害，但也消费昂贵的甜葡萄霉菌，引致几种病害，但也消费昂贵的甜葡萄酒。酒。Claviceps - ergot fungus - causes madness - LSD source麦角菌，呵斥人类疾病麦角菌，呵斥人类疾病1. Plant pathogens植物病原菌续植物病原菌续Erysiphe - powdery mildews of plants - haustoria penetrate epidermal cells of host plant 白粉菌白粉菌-引引致植物白粉病致植物白粉病-吸器穿透到寄主植物表皮细胞中吸器穿透到寄主植物表皮细胞中Ophiostoma -

26、Dutch Elm disease 荷兰榆疫病荷兰榆疫病Venturia - apple scab disease 苹果疮痂病苹果疮痂病Trichoderma - mycoparasite - use in biological control of plant disease木霉菌木霉菌-真菌寄生物真菌寄生物-用于植物病害生物防治用于植物病害生物防治2. Food and Health 食品与安康续食品与安康续Penicillium and Aspergillus - used in cheese makingThe enzymes of Penicillium camembertii pr

27、oduce 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. 青霉菌和曲霉菌青霉菌和曲霉菌-用于奶酪消费。青霉菌的酶产生用于奶酪消费。青霉菌的酶产生软光滑的布里白奶酪软光滑的布里白奶酪Aspergillus oryzae used in the Far East to turn soya pro

28、tein into soy sauce 米曲霉在远东用于将大豆蛋白转娈成酱油米曲霉在远东用于将大豆蛋白转娈成酱油Morchella (morels) - highly prized mushroom 高价的蘑菇高价的蘑菇Tuber (truffles) even more highly prized and priced ! 块菌，价钱还要高块菌，价钱还要高Trichophyton and other dermatophytes (keratin- attacking fungi) eg ringworm. athletes foot, jock itch etc 癣菌癣菌-足癣等足癣等2.

29、Food and Health食品与安康食品与安康Aspergillus 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. 黄曲霉在花生和其它许多基质上生长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，产生称为黄曲霉的毒素，

30、污染食品、呵斥肝病、呵斥肝病-最烈性的致癌剂最烈性的致癌剂 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. 禾谷镰刀菌，在饲料玉米上生长，产生禾谷镰刀菌，在饲料玉米上生长，产生另一种霉菌毒素即玉米烯酮，是一种另一种霉菌毒素即玉米烯酮，是一种固醇，呵斥雌激素综合症，母

31、猪直肠固醇，呵斥雌激素综合症，母猪直肠下垂下垂Penicillium italicum - example of the moulds that spoil food in storage .意大意大利青霉利青霉-贮藏的食物蜕变贮藏的食物蜕变l3. Rots and decomposition 腐烂与分解腐烂与分解lCellulolytic hyphomycetes cause blue stain and soft rot of wood, discolouration and loss of strength of cotton materials and moulding of almo

32、st any damp organic substrate.分解纤维素的丝孢纲真菌木材蓝点和软腐、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、呵斥任一种潮湿的有棉花变色和强度降低、呵斥任一种潮湿的有机质发霉。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 ar

33、e 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 which eat them, l子囊菌主要定殖和分解软的植物残体，在碳子囊菌主要定殖和分解软的植物残体，在碳氮循环中起至关重要的作用。在大多数森林氮循环中起至关重要的作用。在大多数森林中制约土壤微生物区系。死叶被水中的丝孢中制约土壤微生物区系。死叶被水中的丝孢菌定殖菌定殖 耐低温因此可在冬天生长甚至在冰耐低温因此可在冬天生长甚至在冰下生长下生长 使死叶成为食粪类无脊椎动物的美使死叶成为食粪类无脊椎动物的美食。食。4. Genetics and Biote