Chapter 3
Pathogens
Section 1 Plant Pathogenic
Fungi
1. Conspectus of Fungi
1.1 Modern conception of Fungi
Heterotrophic ( Non-photosynthesizing )
eukaryotic organism.
Usually filamentous (forming a mycelium).
Cell walls mainly composed of chitin.
（卵菌Oomycota----纤维素Cellulose）
Reproduce spores by sexual
and/or asexual.
Produce extra celluar enzymes .
Absorb their nutrition.
The organism with above
characteristics is called Fungi.
Fungi(真菌) vs. “fungi”(菌物)
Concept of "fungi": "fungi" is a
loose concept including the
oomycota, the slime mold and the
fungus those are studied by the
fungus scientist (more than one
evolutionary origin ).
The fungi on plant and culture medium
1.2 Number of fungi
To 1995 Ainworth ( in dictionary of the
fungi eighth edition) estimated that the world
fungus discovered has 10000 genera, 72,000
species. Hawksworth deduced that the number
of the world fungus is 1.5 million species.
1.3 Plant pathogenic fungi
Those fungi may cause plant disease.
There are 8,000 kinds plant pathogenic
fungus recorded which may cause
30,000 kinds of plant diseases,
occupied 75% of all the plant disease.
Fungus is the first big pathogen. In the
history the serious epidemic plant
diseases are caused by the fungus.
1.4 Fungal general characters
1.4.1 Vegetative body
Hypha(菌丝) : (pl. hyphae; adj. hyphal)
Single, tubular filament of a fungal thallus or mycelium;
the basic structural unit of a fungus
Mycelium(菌丝体) (pl. mycelia, adj. mycelial)
Mass of hyphae
Colony(菌落)
A discrete mycelium of a fungus, often
derived from a single spore, especially
as a pure culture.
Hyphal abnormality

Fungus‘s mycelium forms some special
abnormal structure which has special
functions.

Haustorium: (pl. haustoria)
In parasitic fungi, a specialized
absorptive structure that penetrates
and draws nutrition from the host cell .
Including global （球状）、finger
（指状）、palm （掌状）and silk （丝状）.
White powdery
Rust
Frost mildew
Haustorium
Albugo
假根Rhizoid
Special structure formed by Fungal
tissue body
1. Sclerotium菌核 (pl. sclerotia)
A vegetative resting body of a
fungus, composed of a compact mass
of hyphae usually with a darkened rind.
2. Stroma子座: (pl. stromata)
Compact mass of mycelium that
supports fruiting bodies or in which
fruiting bodies are embedded.
3. Rhizomorph根状菌索
Macroscopic rope-like structure of
compacted tissue formed by certain
fungi.
sclerotia of
Sclerotium rolfsii
1. Synnema
2. Sporodochium
rhizomorphs of Armillaria sp.
1.4.2 Reproduction of fungi
Fruiting body
 Any of various complex,
spore-bearing fungal
structures.

真菌的产孢机构无论是无性
繁殖或有性繁殖均叫子实体。
Asexual reproduction
 Any type of reproduction not involving
the union of gametes and meiosis .
 Each kind of spore produced by asexual
reproduction is called the asexual spore.
 (the imperfect fungi or anamorphic stage
of some fungus).
The types of asexual spore
1. Zoospore (游动孢子) ：form in
zoosporangium游动孢子囊内---- (fungi
with flagellum ).
 2. Sporangiospore (孢囊孢子) : form in
sporangium孢子囊内-----zygomycete .
 3. Conidia (分生孢子) ：form on
conidiophore—ascomycetes,
Basidiocetes and imperfect fungi.
 4. Chlamydospore (厚垣孢子) : resting
spore, thick wall----all kinds of fungi.

1. zoospore
2. sporangiospore
3. conidia
4. Chlamydospore
Sexual reproduction
Any type of reproduction involving the
union of gametes and meiosis.
Sexual organ of fungi is called
gametangium (配子囊)，the sexual cell is
called gamete (配子).
Each kind of spore produced by the sexual
reproduction is called the sexual spore.
The process of sexual
reproduction
(1) Plasmogamy (质配)
(2) Karyogamy (核配)
(3) Meiosis (减数分裂)
2.Types of sexual spore
(1) 卵孢子(Oospore) Produce by different type
gametangium mating配子囊交配---Mastigomycete 鞭毛菌。
(2) 接合孢子(Zygospore) Produce by same type
gametangium mating ----Zygomycetes。
(3) 子囊孢子(Ascospore)----Ascomycetes
异型配子囊交配形成的，每个子囊ascus通常
产生8个子囊孢子。
(4)担孢子(Basidiospore)----Basidiocetes。
haploid (1N) sexual spore produced on a basidium.
1.Oospore 2. Zygospore 3. Ascospore 4.Basidiospore
1.4.3 Life-cycle (生活史)
 The process that fungal spore
after sprouting, growth and
development,
finally
forms
the identical kind of spore is
called life cycle. Typical life
cycle
including
reproduction
and
asexual
sexual
reproduction, two big stages.
1.4.4 Fungal status in biosphere
Biology five kingdom systems
植物界Plantae
真菌界Myceteae
原生生物界Protista
原核生物界Monera
动物界Animalia
1.4.5 Taxon of Fungi
Taxonomic rank of fungi ：
 界 Kingdom
无后缀 (No postfix)

门 Phylum
(-mycota)

亚门 Subphylum (-mycotina)

纲 Class
(-mycetes)

亚纲 Subclass (-mycetidea)

目 Order
(-ales)

科 Family
(-aceae)

属 Genera
no

种 Species
no

1.4.6 Nomination of fungi
The nomination of fungus is same with
other living thing, uses the Latin twoname law which Carolus Linnacus
proposed.
 The generic name + specific name +
(the person name who named at first )
the person name who named finally.

Pseudoperonospora cubensis (Berk.et Curt.)
Rostov.
2 鞭毛菌 Fungi with flagellum
Summarization
1．Same character: zoospore with 1-2
flagellums.
2．Sexual---testing sporangium和卵孢子
Oospore，asexual---zoospore.
3. Thallus : plasmodium to no septa hypha
4．Hydrophily habit.
Plasmodiophora(根肿菌属)


resting spore
disperse in host，
roe-shape鱼卵状，
parasite in root to
form tumour，
obligate parasite
in cell.
典型病害：白菜根
肿病
(Plasmodiophora
brassicae Woron)
1.腐霉属(Pythium)




sporangiophore and
hypha no difference，
sporangium bag-shape。
after maturation, not
falling
germinating to form
vesicle，then producing
zoospore，sexual
reproduce to oospore.
Lead to Root rot and
seedling damping off.
2. Phytophthora (疫霉属)



Zoosporangium游动孢
子囊 lemon-shape柠檬形、
oval椭圆形、egg-shape
卵圆形。
萌发直接产生游动孢子
germination to
production of
zoospores，不产生泡囊
vesicle 。有性生殖产生
一个卵孢子Oospore
马铃薯晚疫病、番茄疫
病(P.infestans)。
3.霜霉属(Peronospora)

Sporangiophore(孢囊
梗)two fork sharp angle
ramification 二叉状锐角
分枝，tip taper，
sporangium germination
to germ tuber。
葱shallot 紫罗兰violet、

Cabbage 霜霉病

3. 接合菌亚门真菌
Zygomycotina
Summarization
1.Habit: The land lives, parasitic
weakly, more saprophytic.
2.Thallus: The hypha no septa, some
have rhizoids and stolon.
3.Asexual reproduction: Produces
sporangiospore .
4. Sexual reproduction : Produces
Zygospore .
根霉属 Rhizopus

causes
sporangium
sporangiospore
the sweet
potato
and lily
bulb soft
rot
axes
stolon
Sporangiophore
opposite to
rhizoids 。
Zygospore
毛霉属 Mucor
 no
rhizoids ，
no stolon
 Stored
rot
fruits
4. 子囊菌门 （Ascomycota）
Brief introduction
There are 32,000 species discovered in
the world, occupying 1/3 the fungus, all
is the higher fungus, the shape is varied,
but the common characters is forming
the ascus and Ascospore.
Some thallus is simple, i.e. yeast only is
a single cell, but majority has the
developed mycelium, the hypha has
septa, some hyphas may directly produce
powder spore and bud spore.
Ascus-fungus sexual reproduction
1.Ascus子囊
 2.Ascus spore子囊孢子
 3.Ascocarp子囊果

Bare ascus
Cleistothecium
Apothecium
Perithecium
Ascostroma
外囊菌属Taphrina
Erysiphales (白粉菌目)
All are higher plant's obligate parasitic
fungus,The exogenous hypha and the
reproduction structure forms the white
powdery sign in surface of plant ,plant
disease be called powdery mildew.
Appendage of
Cleistothecium
格孢腔菌属 Pleospora

Ascospore oval or
round ， vertical
long
and
horizontal septa，dark。
Asexual
generation
development ，包括茎点
菌 属 Phoma 、 葡 柄 霉 属
stemphylium。

代 表 病 害 ： G r e e n
C h i n e s e o ni o n 黑 斑 病
P.herbarum
核盘菌属



菌丝体可以形成菌核
Sclerotium
bourgeon
to Apothecium with
long stipe ， 子 囊 棍 棒
状，平行排列，有拟侧丝。
子 囊 孢 子 ellipse or
fusar 或 仿 缍 形 ，单胞无
色。无性世代不发生。
The asexual generation
does not occur.
Host scope is very
broad, may invade 160
kinds of plants.
Sclerotinia
5 Introductio of basidiomycetes



The highest grade fungi in evolution
Sexual reproduction produce basidiospore,
every basidium form 4 basidiospore
Higher basidiomycetes basidium forms in
highly organized structure to form the
hymenium(子实层), this structure producing
spore is called the basidiocarp(担子果).
Uredinales(锈菌目)
The plant disease causeed by rust called
rust disease, mainly damages the plant
stem, the leaf, often causes crops' heavy
loss. Known approximately 6,000 species.
Many rust-fungi have the obvious polymorphism
phenomenon, complete life cycle may produce 5
types spore.like puccinia
性孢子pycniospore（n）产生于性孢子器pycnium
锈孢子aecidiospore（n+n）(锈孢子器acidium)
夏孢子Urediospore（n+n）产生于夏孢子堆
uredium
冬孢子Teliospore(n+n---2n)（冬孢子堆Telium）
担孢子basidiospore(n)
( 担子basidium)
Basidiospore__basidium
Teliospore---Telium
Aecidiospore--acidium
Pycniospore--pycnium
Urediospore----uredium
胶锈菌属（Gymnosporangium)

Teliospore two cell，有
gel
long
stipe.
No
Urediospore

Pear rust 冬孢子阶段在
桧柏cypress上，性孢子
和 锈 孢 子 在 梨 pear 树 上
引起梨锈病。
多胞锈菌属（Phragmidium ）


Teliospore 3至多细
胞，壁厚，表面光
滑或有瘤状突起，
柄的基部膨大。
[玫瑰多胞锈菌（P.
rosae-multiflorae ）
引起玫瑰锈病]。
单胞锈菌属（Uromyces ）


Teliospore one cell，
tip wall thick ；
Urediospore
spinosity or tuber
[ 瘤 顶 单 胞 锈 菌
（ U.appendiculatu
s ） 引 起 菜 豆 bean
锈病]。
层锈菌属（Phakopsora）


Teliospore single cell，
no stipe ， arrange
sever layers out of
order ； Urediospore
spinosity。
[枣层锈菌（P. ziziphivulgaris ） 引 起 枣
jujube树锈病]。
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6 Introduction of
Deuteromycotina

Only known the asexual stage or the sexual
stage of fungus not yet discovered.
Because people only known its half of the
life cycle, therefore this kind of fungus is
called fungi imperfecti.

The types of conidiomata(载孢体)：
conidiophore、synnema、sporodochium、
acervulus 、 pycnidium。
半知菌的分生孢子
Asexual reproduction very
developed, produce conidia
by the manners of bud芽殖、
rupture 断裂, split裂殖
Conidia shape include
amerosporae, didymosporae,
phragmosporae, dictyospore
scolicospore, helicospore
staurospore.
葡萄孢属(Botrytis )

conidiophore无色，顶
端细胞膨大成球形，上面有
许多小梗；

Conidia单胞，无色，椭圆形，
着生小梗上聚集成葡萄穗状。

[ 灰 葡 萄 孢 (B.cinerea) 引 起
多种植物灰霉grey mildew
病。]
轮枝孢属(Verticillium )

conidiophore轮状分枝，
产孢细胞基部略膨大；

Conidia 为 内 生 芽 殖 型 ，
单细胞，卵圆形至椭圆
形，单生或聚生。

〔黄萎轮枝孢(棉黄萎病
菌 V.albo-atrum ) 引 起
棉花黄萎病]。
链格孢属(Alternaria )



conidiophore 深 色 ，
顶端单生或串生淡褐色至
深 褐 色、 砖 隔 状 的分生孢
子。
Conidia倒棍棒形、椭圆形
或卵圆形，顶端有喙beak
状细胞。
[ 大 孢 链 格 孢 (A.
macrospora )引起棉花轮
纹斑病]。
小核菌属(Sclerotium )

菌核圆形或不规则形，表面
光滑或粗糙，外表褐色或黑
色，内部浅色，组织紧密。

[齐整小核菌(S.rolfsii)引起
花生等200多种植物白绢病]。
镰孢属(Fusarium )
 sporodochium


大 型 Conidia 多 细 胞 ，
镰 刀 型 ； 小 型
Conidia 单 细 胞 ， 椭
圆形至卵圆形。
麦类赤霉病
瓜类枯萎病
炭疽菌属(Colletotrichum )

Acervulus
生在寄主
表皮，有时生有褐色、具分
隔的刚毛；

Conidia 无色，单胞，长椭
圆形或新月形。

胶
孢
炭
疽
菌
(C.
gloeosporioides ) 引 起 苹
果、梨、棉花、葡萄、冬瓜、
黄瓜、辣椒、茄子等的炭疽
病]。
叶点霉属(Phyllosticta )

pycnidium形态与茎点
霉属(Phoma)相似。

寄生性较强，主要为害叶
片引起叶斑病。

棉小叶点霉(P.gossypina )
引起棉花褐斑病]。
拟茎点霉属(Phomopsis)


pycnidium 内产生两种
分生孢子：甲型conidia卵
圆 形 至 纺 锤 形， 单细胞 ，
能萌发； conidia线形，一
端弯曲呈钩状，不能萌发。
茄 褐 纹 拟 茎 点 霉 (P.
vexans )引起茄褐纹病]。
壳针孢属(Septoria)

conidia多细胞，细长
筒形、针形或线形，
直或微弯，无色。

[ 颖 枯 完 针 孢 (S.
nodorum)引起小麦颖
枯病]。
色二孢属(Diplodia)

pycnidium散生或集生；

conidia初时单细胞，无色，
椭 圆 形 或 卯 圆 形，成熟后
转 变 为 双 细 胞， 深褐色至
黑色。

[棉色二孢(D. gossypina)
引起棉铃黑果病]。