Sporangia - Mucor Figure . : Reproduction in Fungi (h) Gametangial copulation - Rhizopus ‘+’ Strain ‘ _ ’ Strain Progametangium Zygospore Zygosporangium Trichogyne Microconidium Archicarp (i) Spermatisation - Neurospora Figure . : Reproduction in Fungi . .
Classification of Fungi Many mycologists have attempted to classify fungi based on vegetative and reproductive characters. Traditional classifications categorise fungi into classes – Phycomycetes, Ascomycetes, Basidiomycetes and Deuteromycetes. Among these ‘Phycomycetes’ include fungal species of Oomycetes, Chytridiomycetes and Zygomycetes which are considered as lower fungi indicating algal origin of fungi. Constantine J.
Alexopoulos and Charles W. Mims in the year proposed the classification of fungi in the book entitled ‘Introductory Mycology’. They classified fungi into three divisions namely Gymnomycota, Mastigomycota and Amastigomycota. There are subdivisions, classes, form class and form subclasses in the classification proposed by them.
The salient features of some of the classes – Oomycetes, Zygomycetes, Ascomycetes, Basidiomycetes and Form class Deuteromycetes are discussed below. Oomycetes Coenocytic mycelium is present. The cell wall is made up of Glucan and Cellulose. Zoospore with one whiplash and one tinsel flagellum is present.
Sexual reproduction is oogamous. Example: Albugo. Zygomycetes • Most of the species are saprophytic and live on decaying plant and animal matter in the soil. Some lead parasitic life (Example: Entomophthora on housefly).
• Bread mold fungi (Example: Mucor, Rhizopus ) and coprophilous fungi (Fungi growing on dung Example: Pilobolus ) belong to this group (Figure . ). Columella Sporangium Sporangiospore Sporangiophore Rhizoids Figure . : Zygomycetes – Rhizopus • The mycelium is branched and coenocytic.
• Asexual reproduction by means of spores produced in sporangia. • Sexual reproduction is by the fusion of the gametangia which results in thick walled zygospore. It remains dormant for long periods. The zygospore undergoes meiosis and produce spores.
Ascomycetes • Ascomycetes include a wide range of fungi such as yeasts, powdery mildews, cup fungi, morels and so on (Figure . ). • Although majority of the species live in terrestrial environment, some live in aquatic environments both fresh water and marine. • The mycelium is well developed,