植物学 第二章菌类

1、第二章 菌 类,1.细菌门（Bacteriophyta）：单细胞， 原核，细胞壁为肽聚糖（peptidoglycan），以直接分裂的方式繁殖，无有性生殖。 2.粘菌门（Myxomycota）:裸露而多核的原生质团，其营养 体的构造、运动和摄取方式与原生动物中的变形虫相似。但 繁殖时产生具纤维素细胞壁的孢子。 3.真菌门（Eumycota）:单细胞或菌丝体，多核或1核，细胞 壁为几丁质或少数为纤维素，繁殖时产生多种类型的孢子,菌类植物的分门,第一节 细菌门,一、细菌的特征,细菌属原核生物。个体十分微小，常在1m左右，杆菌长23m。繁殖方式为细胞直接分裂，一般2030min可分裂一次。细菌约有20

2、00种，依其形态可分为球菌、杆菌和螺旋菌,二、形态 杆菌 球菌,螺 旋 菌,三、细菌的繁殖：裂殖四、细菌在自然界中的作用 和经济意义,第二节粘菌门,一、主要特征：是介于动物和植物之间的一类生物，它们的生活史中，一段是动物性的，另一段是植物性的,二、 主要类群与分布,大多数粘菌为腐生菌，无直接的经济意义，只有极少数粘菌寄生在经济植物上，危害寄主。 如：发网菌属(Stemonitis)、芸苔根肿菌(Plasmodiophora brassicae,第三节 真菌门(Eumycota,第三节 真菌门 （Eumycota,一、真菌的通性 (一)真菌的营养体 少数为单细胞（酵母菌），多数为菌丝体。 菌丝体

3、：原始类群，无隔，多核； 高等类群，有隔，1或2个核。 细胞壁成分：原始类群，纤维素； 高等类群，几丁质。 贮藏物:主要是肝糖，少量的蛋白质、 脂肪和微量的维生素等,菌丝的功能：吸收养分。 方式：借助于多种水解酶（胞外酶），把大分子物质分解为可溶性的小分子物质，然后借助于高的渗透压。 腐生菌：直接吸收或产生假根。 寄生菌：细胞内寄生，直接与原生质接触而吸收。胞间寄生菌，菌丝上产生吸器，伸入细胞中,菌丝组织体（营养变态），菌丝紧密排列而形成两种组织：拟薄壁组织和疏丝组织。菌丝组织体有三种变态： 根状菌索（rhizomorph）：菌丝体密结呈绳索状，外形似根。 子座（stroma）：容纳子实体的褥

4、座，是从营养阶段到繁殖阶段的过渡形式。 菌核（sclerotium）：由菌丝密结成颜色深、质地坚硬的核状体。 子实体：含有或产生孢子的菌丝组织体,营养繁殖：细胞直接分裂、菌丝的断裂；或产生以下孢子：芽孢子、厚壁孢子、节孢子。 无性生殖：游动孢子（水生真菌，具鞭毛）、孢囊孢子、分生孢子 有性生殖：经过有性配合而形成。卵孢子、接合孢子均为2n，子囊孢子、担孢子均为n,二）真菌的繁殖,二）真菌的繁殖,1、营养繁殖： 芽生孢子 厚壁孢子 节孢子 2、无性生殖： 游动孢子 孢囊孢子 分生孢子,孢子的类型,三）真菌的生活史,真菌繁殖方式多种多样，无性生殖产生各种类型的孢子，有性生殖有同配、异配、卵式生殖等

5、。 因而，真菌的生活史也多种多样,二、 真菌门的主要类群,真菌是生物界中很大的一个类群。据统计，世界上已被描述的真菌约有1万属12万余种，估计我国约有4万种。目前将真菌分为5个亚门,鞭毛菌亚门：菌丝无隔，（无性）游动孢子，（有性）卵孢子； 接合菌亚门：菌丝无隔，（无性）孢囊孢子，（有性）接合孢子； 子囊菌亚门：菌丝有隔，（无性）分生孢子，（有性）子囊孢子； 担子菌亚门：菌丝有隔，（无性）分生孢子，（有性）担孢子； 半知菌亚门：菌丝有隔，以无性生殖为主，产生分生孢子，无有性 生殖或没发现,真菌的分类：Ainsworth 等(1973) 的系统,一） 鞭毛菌亚门（Mastigomycotina）:

6、 略 （二） 接合菌亚门（Zygomycotina）: 1. 特征： 由水生发展到陆生，菌丝无隔，无性生殖时产生孢 囊孢子，有性生殖时产生接合孢子。 2. 代表植物：匍枝根霉（Rhizopus stolonifer） 生于面包、馒头等富有淀粉质的食物上。 菌丝体：具气生菌丝（匍匐枝）、假根。 无性生殖：孢囊孢子。孢子囊基部具孢囊梗，中心具囊轴。黑色的孢囊孢子散播于空气中，遇到合适的环境，即可萌发成新的菌丝体。 有性生殖：异宗配合。两条异宗的菌丝上产生配子囊，接触后，壁溶解。先质配，后核配，产生接合孢子：多数二倍体核，厚壁，黑色，具疣状突起,In Rhizopus stolonifer, as

7、in most other lygomycetes, asexual reproduction by means of haploid spores is the chief mode of reproduction. Less frequently, sexal reproduction occurs. In this common species, it involves genetically differentiated mating strains, which have traditionally been labeled -t- and - types.(Although the

8、 mating strains are morphologically indistinguishable from oneanother, they are shown here in two colors.) The zygosporangium in Rhizopus develops a thick, rough, black coat and becomes dormant, often for several months,匍枝根霉（Rhizopus stolonifer）的生活史,Rhizopus stolonifer, black mold.(a) Gametangia, th

9、e gamete-producing structures, are in the process of fusing to produce a zygosporangium. (b) A zygosporangium, or sexual resting strut. ture. Such a zygosporangium contains one to several diploid nuclei, the zygotes,1、特征： （1）营养体除酵母菌以外，均是多细胞有机体，菌丝有膈，分枝多，菌丝体白色，棉絮状。 （2）无性生殖：单细胞类群为出芽繁殖，多细胞类群以分生孢子（即分枝菌丝顶

10、端产生孢子）。 （3）有性生殖：形成具多核的精子囊和卵囊，结合后形成子囊。合子在子囊内减数分裂产生子囊孢子。 （4）单细胞类群，子囊裸露，不形成子实体；多细胞类群子囊包于子实体内，子实体又称为子囊果。子囊果通常有三种：闭囊壳（cleistothecium）、子囊壳(peithecium)、子囊盘(apothcium)。 2、代表植物：火丝菌（Pyronema confluens）的子囊、子囊孢子、子囊果的形成过程,三） 子囊菌亚门（Ascomycotina,The typical life cycle of an ascomycete. Asexual reproduction occurs

11、by way of specialized spores, known as conidia, which are usually multinucleate. Sexual reproduction involves the formation of asci and ascospores. Karyogamy is followed immediately by meiosis in the ascus, resulting in the production of ascospores,ycetes. (a)A morel, Morchella ioJlenta. The true mo

12、rels are among t choicest edible fungi. Mushroom lOerers look for them when the oak are the size of a mouses ear.“ ,. ls were first grown successfully in lture in 1983 but have not yet been loped into a commercial crop. (b) Scarlet cup, Sarcoscypha coccinea, a beautiful fungus with an open ascoma (a

13、pothecium). (c) The highly prized,edible ascoma of a black truJJle, Tuber melanosporum. In the truJJtes, this spore-bearing structure is produced below ground and remains closed, liberating its ascospores only when the ascoma decays or is broken open by digging animals.Truffles are mycorrhizal (see

14、page 238), mainly on oaks and hazelnuts, and are searched for by specially trained dogs and pigs. Recently, they have been cultivated commercially on a small scale by inoculating the roots of seedling host plants with their spores,羊肚菌属 A stained thin section through the hymenial layer of a morel (Mo

15、rchella), showing asci with ascospores,子囊与子囊果 (a)An electron micrograph showing two i of Ascodesmis nigricans in which ascospores are maturing. (b) Ascoma o/Erysiphe aggregata, showing the elosed asci and ascospores. This completely enclosed type of ascoma is aUed a cleistothecium. (c) An ascoma of

16、Coniochaeta, showing the enclosed asci and ascospores. Note the small pore at the top. This sort of ascoma, with a small opening, is known as a perithecium,Yeasts. (a) Budding cells of bread yeast, Saccharomyces cerevisiae. (b) Asci with ascospores of Schizosaccharomyces octosporus,Penidllium and As

17、pergillus-two of the common genera of Deuteromycota. (a) A culture of Penicillium notatum, the original penicillin-producing fungus, showing the distinctive colors produced during growth and spore development. (b) A culture of Aspergillus fumigatus, a ungus that causes respiratory disease in humans.

18、 Notice the concentric growth pattern produced by successive pulses of spore production.青霉、烟曲霉,The conidiogenous cells ana conidio- phores of deuteromycetes are used in their classification. (a) Penicillium (brushlike) and (b) Aspergillus (tightly clumped and arising from the swollen top of the coni

19、diophore). Note the long chains of small, dry conidia,四）担子菌亚门（Basidiomycotina,1. 特征： （1）营养体：全为菌丝，有横隔；分为两种： 初生菌丝体：细胞单核，生活时间很短； 次生菌丝体：双核，生活时间长。由次生菌丝形成子实体，称为担子果。双核菌丝进行分裂时，为锁状联合。 （2）无性生殖：进行芽殖、粉孢子、分生孢子和厚壁孢子。 （3）有性生殖：产生担子和担孢子。 担子和担孢子、双核菌丝和锁状联合为担子菌亚门的三个主要特征,the basidiomycetes, dikaryotice characteristicall

20、y are distined by the presence of clampnections over the septa. Clamp conl!dons are formed during cell division;j presumably ensure the proper distri- bution of the two genetically distinct typesnuclei in the basidioma. (b) Electron graph of a clamp nnection andcteristic septa in a hypha of lcularia

21、 auricula,锁状联合的过程,Life cycle of a mushroom (division Basidiomycota, class Hymenomycetes). Monokaryotic mycelia are produced from basidiospores, and dikaryotic mycelia from them, often following the fusion of different mating types, in which case the mycelia are heterokaryotic. Dikaryotic mycelia for

22、m the basidioma, within which basidia form on the hymenia that line the gills, ultimately releasing up to billions of basidiospores,蘑菇属（Agaricus）的生活史,Scanning electron micrographs of basidiospores of the inky cap mushroom, Coprinus cinereus. (a) The hymenium showing numerous basidia frozen at the ti

23、me of basidiospore release. (b) The top of a basidium, with an elongate basidio- spore attached asymmetrically to each of its four sterigmata. (c) Close-up of two basidiospores. A droplet forms at the base of each basidiospore prior to its release from the sterigma. The basidiospore on the right is

24、shown at a later stage than the one on the left. (d) Detail of the base of two basidiospores. On the right, two pores are visible, one where the basidiospore was attached to the sterigma, the other through which the droplet was secreted. In the basidiospore on the left, the droplet is still in place,2. 担子菌亚门的分类及代表植物： 1973年，Ainsworth的系统： 冬孢菌纲Teliomycet