ASCOSPORE AND BASIDIOSPORE

Spore formation and development in the Phylum Ascomycota and Basidiomycota with their spores

1. ASCOSPORE AND BASIDIOSPORE COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), Via Vaigai Dam, Theni-625 562 STUDENT Miss. GOWSIKA P R ID. No. 2017021019 COURSE TEACHER Dr. PARTHASARATHY.S Asst. Prof. (Plant Pathology)

2. SEXUAL REPRODUCTION Sexual reproduction in the Phylum Ascomycota and Basidiomycota produces ascospores and basidiospores as their sexual spores. Both the spores are haploid resting sexual spores. Sexual reproduction process follows Plasmogamy Karyogamy Meiosis

3. CROZIER FORMATION AND DEVELOPMENT OF ASCOSPORES It takes place in the Phylum Ascomycota . Antheridium – Male structure Ascogonium – Female structure Antheridium and ascogonium comes in contact and becomes heterokaryon – Plasmogamy. Karyogamy doesn’t take place immediately after Plasmogamy.

4. Now the ascogonium developes a number of papilla and the nuclei form the ascogonium begin to pass into them. Each papilla enlarges into ascogenous hyphae and they contain a pair of nuclei at the tip. The binucleate ascogenous hyphae elongate and bends over to form a crozier. The binucleate hook cell is called ascus mother cell. Karyogamy occurs within the ascus mother cell (Zeugites ). The diploid nucleus divide meiotically first to form four haploid nuclei.

5. It again undergo mitosis and form eight haploid nuclei. Each haploid nucleus is enveloped by a wall and develops as ascospore by free cell formation. (Photo courtesy of M. E. Stanghellini. Univ. Calif. Riverside)

6. ©M. Piepenbring , CC BY-SA

7. ASCUS A sac, typically cylindrical in shape in which the spores of ascomycete fungi develop. Usually an ascus contain 8 ascospores. UNITUNICATE ASCUS – Ascus wall is uniformly thick and the ascospores are released one by one through the pore at the tip. BITUNICATE ASCUS – It has two walls ectoascus and endoascus . Ectoascus break only at the tip and the endoascus comes out as long cylindrical sac during dehiscence.

8. ASCUS WITH ASCOSPORES Source : Wikipedia

9. ASCOCARP AND ITS TYPES Ascocarp is the fruiting body of the Phylum Ascomycota which contains ascus in which the ascospores are maintained. Types: Cleistothecium Chasmothecium Perithecium Apothecium Ascostroma Thyriothecia Hysterothecia Pseudothecium

10. CLEISTOTHECIUM CHASMOTHECIUM Source: Wikipedia Source: www.botany.hawaii.edu

11. PERITHECIUM APOTHECIUM Study Solutions Copyright © 2018 Copyright © 2018 (lizcullen.com)

12. ASCOSTROMA THYRIOTHECIA © 2018 The American Phytopathological Society. © 2008-2018 ResearchGate GmbH.

13. HYSTEROTHECIA PSEUDOTHECIUM © ResearchGate 2018 Source: Wikimedia Commons

14. NAKED ASCI © Visuals Unlimited / naturepl.com

15. BASIDIUM IT It is unicellular and club shaped formed terminally on dikaryotic hyphae . It bears exogenoulsy , usually on projections called sterigmata . The point at which the basidiospore attached to the sterigmata is called hilum . The hilum usually found at the tip of the basidium , called hilar appendages. The number of spores per basidium is typically four, but two spored basidia are quite common.

16. Nine spores per basidium in Phallus impudicus . Basidium is divided into three parts Probasidium Metabasidium Epibasidium or sterigmata At probasidium nuclear fusion takes place. Metabasidium is that portion where meiosis occurs. Epibasidium is the region where transfer of haploid nuclei takes place.

17. Source: elte.prompt.hu

18. CLAMP CONNECTION It was first observed by Hoffman in 1856 The clamp connections are formed during cell division in the dikaryotic secondary mycelium having dolipore septa. It happens especially at the tip cell. During clamp connection a hook/clamp bending towards the base of the hyphae . The nucleus in the hook cell undergo mitosis simultaneoulsy .

19. Finally the clamp bent over and finally touches the base of the hyphae and a pore is formed at the point of contact. Two septa are formed to delimit the hook cell and the binucleate ultimate tip cell forms the binucleate penultimate cell.

20. © 2018 The American Phytopathological Society

21. BASIDIOSPORE The portion of the basidiospore in contact with the sterigmata is called hilum . A hemispherical or conical protrusion near hilum is called hilar appendix. It contains an electron dense within plasma membrane called hilar appendix body.

22. Development of basidiospore is completed in four stages and its growth is asymmetric. They are as follows Inception Assymmetric growth Enlargement Elongation

23. INCEPTION The tip of the sterigmata expands to form a small spherical knob the apophysis . ASSYMETRIC GROWTH Hilar appenidx develops on the adaxial side and growth of basidiospore occurs towards the abaxial side. ENLARGEMENT Hilar appendix body projects further into spore wall and the spore enlarges. ELONGATION The spore grows in length and spore wall matures.

24. Source: sites.google.com

25. BASIDIOMA OR BASIDIOCARP In the phylum basidiomycota except smuts and rusts produces highly attractive, beautiful fruiting body called fungus flower. The edible basidioma are Mushrooms and the poisonous basidioma are toadstools. The basidiocarps are the fruiting bodies of the Phylum Basidiomycota .

26. MUSHROOMS CORAL FUNGI LinkedIn Corporation © 2018 Copyright © 2018 BBC

27. PUFF BALLS EARTH STARS Source: Wikipedia Source: David George Haskell

28. STINKHORNS BIRDS-NEST FUNGI © Copyright 2006-2018 Gatehouse Media, LLC. © 1995-2018 First Nature

29. REFERENCES: Tripathi D P,2013. Introductory Mycology. Kalyani Publishers, Ludhiana (294-297,322-324) Aneja K R,Mehrotra R S,2015. An Introduction to Mycology. New age International (P) Limited, New Delhi. (158-165,287-295)