第二节 鞭毛菌亚门真菌 Mastigomycotina

1. 第二节 鞭毛菌亚门真菌Mastigomycotina

2. 特点：Fungi having flagellated zoospores and gametes are included under the sub-division mastigomycotina. These have coenocytic hyphae. Some of them live in water. 常见病害：根肿、猝倒、霜霉病、疫病，在潮湿多雨低洼积水，通风透光差的条件下易发生

3. 多数水生，少数陆生．营养体主为无隔菌丝和原生质体，无性生殖产生游动孢子，多数有性繁殖产生卵孢子多数水生，少数陆生．营养体主为无隔菌丝和原生质体，无性生殖产生游动孢子，多数有性繁殖产生卵孢子 1、生活习性及营养菌丝： They have coenocytic hypha or plasmodium. 2、有性繁殖及无性繁殖：无性生殖产生游动孢子，有性生殖产生休眠孢子囊和卵孢子。

4. 3、分类： 根肿菌纲 Plasmodiophoromycetes壶菌纲 Chytridiomycetes丝壶菌纲 Hyphochytridiomycetes卵菌纲 Oomycetes

5. 游动孢子类型图

6. 一、根肿菌纲 Anteriorly biflagellate zoospores; both of whiplash type but unequal in length. 1、基本特点： 营养体为原生质体，有性繁殖产生休眠孢子囊，全部为专性寄生。游动孢子双鞭毛，尾鞭，顶生，长短不等。

7. 2、代表菌 根肿菌属：十字花科根肿病 粉痂属： 马铃薯粉痂症状、 病原

8. 根肿菌属：Plasmodiophora • 芸薹根肿Plasmodiophora brassiae • 引起十字花科根肿病。 症状 病原 发生规律 防治方法

9. 白菜根肿病 根肿菌属

10. 白菜根肿病

11. 白菜根肿病原图

12. 白菜根肿病原图

13. 粉痂属：Spongspora 马铃薯粉痂病 Spongsporasubterranea

14. 二、壶菌纲 Chytridiomycetes Zoospores with a single posterior whiplash flagellum and a conspicuous nuclear cap. 1、基本特点：营养体多为多核的单细胞，有假根。有性繁殖复杂。游动孢子单尾鞭。大多数水生，有四个目，其中壶菌目最为重要。

15. 壶菌目菌体图

16. 2、代表病菌：节壶菌属：玉米褐斑病病状 病原 • 集壶菌： 马铃薯癌肿

17. 节壶菌属：Physoderma • 玉米节壶菌：P. maydis引起玉米褐斑病。 • 症状 病原 发生规律 防治方法

18. 玉米褐斑病图

19. 节壶菌休眠孢子图

20. 集壶菌属Synchytricum内生集壶菌引起马铃薯癌肿病集壶菌属Synchytricum内生集壶菌引起马铃薯癌肿病

21. 三、卵菌纲 Oomycetes Laterally biflagellate, flagella of equal size; one whiplash the other of tinsel type. Sometimes anteriorly biflagellate.

22. 1、基本特点: (1) 营养体多数为发达的二倍体的无隔菌丝 (2) 细胞壁为纤维素 (3) 无性繁殖产生游动孢子囊和游动孢子，有性繁殖产生卵孢子 (4) 分为四个目： Saprolegniales，Leptomitales， lagenidiales, Peronosporales. 其中Saprolegniales和Peronosporales是重要的 植物病原

23. 2 、水霉目 Saprolengniales • 以水生为主，少数陆生游动孢子囊丝状、圆筒状或梨状，具有孢子囊层出现象和 游动孢子两游现象。 如 ，水霉和稻绵霉。 • Asexual reproduction is accomplished by the zoospores. Cylindrical zoosporangia develop at the tips of hyphae which produce numerous biflagellate zoospores.When mature, they canbe seen jostling one another within the zoosporangium.

24. 水霉属图

25. 孢子囊层出现象： • Sporangial proliferation: It is an interesting phenomenon characteristic of Saporlegnia,which eables the formation of several sporangia at the same site. When a zoosporangium has liberated the primary zoospores, a second zoosporangium is formed within the old one, which pushes out of the remnants of the previous sporangium,and so on.

26. 游动孢子两游现象 • Dimorphism (Diplanetism):. The apically-biflagellate primry zoospores, which are liberated through a pore at the tip of the zoosporangium, swim about for sometime,come to rest and encyst,withdraw the flagella and form a thin wall. After a short period of rest, a papilla develops on the cyst; its tip dissolves and a reniform zoospore bearing two lateral flagella creeps out leaving the empty cyst behind.The second zoospore comes to rest and forms a cyst. The cyst germinates by forming a hypha which forms a new colony

27. 水稻绵霉病 幼 苗 期 发 病

28. 水稻绵霉症状1

29. 水稻绵霉症状2

30. 水霉属Saprolegnia • 主要引起鱼（动物）病等

31. 感染水霉病的鱼

32. 丝囊菌属Aphanomyces

33. 丝囊菌引起萝卜根腐

34. 3、霜霉目Peronosporales 无两游现象，游动孢子囊大多数为球形。卵孢子为单卵球。 The genera belonging to Peronosporales show morphological changes which are more suited to the amphibious or terrestrial habitat of these fungi. Sporangia in dry weather instead of forming zoospores germinate directly by germ thbe, thus behaving as conidia. The intercellular hyphea of parasitic genera form haustoria which enter host cells and absorb nutrients. Pythiaceae, Peronophthoraceae, Albuginaceae, Peronosporaceae.

35. （1）腐霉属Pythium： 重要病原，主要引起腐烂如引起腐烂的瓜果腐霉和幼苗猝倒。主要存在于土壤中。 P. debaryanum—Damping off of tobacco and chillies. P. aphanidermatum—Soft rot of papaya, damping off of potato. P. graminicolum—Rhizome and root rot of turmertic. P. myriotylum—‘Foot rot’ of ginger.

36. 瓜果腐霉图

37. 猝倒病原

38. 猝倒病图

39. 猝倒病图

40. 猝倒病图

41. 猝倒病图

42. 腐霉引起腐烂

43. 病害控制 • Control: Damping off of seedlings and root rots caused by Pythium are more common in soils of high water and humus content, Thus, water logging in fields should be avoided. Soil sterilization to kill the fungus is done through fungicides.But better method of control is to treat the seeds before sowing with protective fungicides.

44. （2）疫霉属 Phytophthora • Phytophthora survives in the dead host tissues left in the soil. P. infestans, as a rule, survives as dormant mycelium in infected potato tubers. However, it can be cultured in laboratory 番茄晚疫病 辣椒疫病 等

45. 疫霉属（Phytophthora) • 游动孢子囊梨形．为害根，茎基部，也有为害地上部，引起腐烂称为疫病．如牡丹疫病，五色椒疫病等，高温高湿易发病．土传或气传

46. Phytophthora infestans: • these disese is world wide in occurrence and is reported also from all parts of world. A low temperture (18~20), accompanied by high relative humidity (91~100%), are the requisites for sporangial production. Sporangiophores emerge through the stomata from the lower surface of infected leaves and bear terminally, lemon shaped sporanga with a distinct beak. The sporangia are highly susceptible to desiccation.

47. 晚疫病（图）

48. 晚疫病原图

49. 辣椒疫病

50. 番茄晚疫 番茄晚疫