Introduction
Class Zygomycetes
General characters of Zygomycetes
Order Mucorales
Order Entomophthorales
Order Zoopagales
Life cycle of zygomycetes in Rhizopus stolonifer
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Presentation Topic: Kingdom Fungi Phylum Zygomycota Class Zygomycetes
Presented by :Sohail Presented To : Ma`am Hira Fatima
Content : Introduction Class Zygomycetes General characters of Zygomycetes Order Mucorales Order Entomophthorales Order Zoopagales Life cycle of zygomycete s in Rhizopus stolonifer
Scientific classification: Kingdom – Fungi Division _ Zygomycota ( C. Moreau 1954 informal) Class _ Zygomycetes (Winter 1881 ) Order _ Mucoromycotina Kicixellomycotina Entomophthoromycotina Zoopagomycotina
Introduction : Zygomycota or zygote fungi is a division of fungi It is also known as conjugated fungi They are mostly terrestrial in habitat Zygomycota has two classes: 1. Zygomycetes 2. Trichomycetes
Zygomycota
Classes of Zygomycota: Zygomycetes: Trichomycetes : .Its has so many economics importance and has many orders. It includes individuals belonged to insects. It is not very important economically
Introduction: Zygomycota , a group of 1090 species included in 181 genera is defined by the presence of a thick walled resting spores are called zygospores and the absence of falagellum Asexual reproduction takes places usually by the aplanospores (non motile) or arthrospores. Spores are produced in sporangia Spores are dispersed by the wind , water, brusting of sporangia ,rain or animals
Zygomycota :
Characteristics of Zygomycota: Zygomycota , all true fungi, produced cell wall contain chitin Somatic phase as mycelia, hyphae which are generally coenocytic because they lack cross walls of septa Gametangial copulation is a type of sexual reproduction in Zygomycota in general the gametangia fuse with each other, lose their identity and develop into a zygospore Most reproduce asexually by producing sporangiospores
Class Zygomycetes: It is characterized by the presence of conenocytic hyphae,absence of motile cells Asexual reproduction ususlly by non-motile sporangiospores Sexual reproduction is done by gametangial copulation that results in the formation of a zygospores with in zygosporangium The members may either be saprobic in nature or weak parasite of plants, or specialized parasites of animals or obligates parasites of fungi including other members of Zygomycetes
General characters: Life cycle is non motile It can reproduced both asexually and sexually. Asexually reproduced by: 1.Aplanospores 2.Sporangiospores It comprise about 1060 species,including commom bread molds,as well as both freshwater and marine species Most have rapidly growing hyphae, but some are unicellular
Continue … Zygomycetes hyphae may be coenocytic, forming septa only where reproductive structure are formed. Most species of Zygomycetes are live in soil . Or on decaying plant and animal matter Aquatic species are primarily found in sediments or algae, but some species are free-floating or attached to aquatic animals or decaying leaves Some are parasites of plants, insects, or small soil animals. Still other causes serious infections in human and domestic animals
Continue … The different genera may be distinguished based on the size and shape of the sporangia, presence or absence of rhizoids and their location Zygomycetes carry out the sexual reproduction by means of spores produce thick walled sexual structures called Zygosporangia which can remain dominant for long time
Continue … These sporangia, many Zygotes produce multiple sporangiospores inside a single sporangium Some multiple small sporangia that contain only few sporangiospores , even a single one.
Pictures From left to right Zygospores Pilobolus Sporulation
Classification of Zygomycetes : Traditionally ,earlier zygomycetes was classified into 7 orders Following are the names of these 7 orders: 1. Mucorales 2. Entomophthorales 3. Zoopagales 4.Glomales
1.Mucorales The order Mucorales is characterized by chiefly scprobic forms which reproduced by nonmotile but sometimes appendaged sporangiospores born in sporangia , merosporangia or as one-spored sporangia or ‘ conidia’ This order contain 47 genera and 130 species The member of this order are commonly known as ‘pin mold’ because of their sporangia which appear as black dots in the cobweb like hyphae
Mucorales: Some are important in spoiling food common bread molds, storage diseases of fruit and vegetables . Some infects human and animals opportunistic pathogens.
Black Bread Mold: Species of Rhizopus are important in the soft rot of the sweet potatoes and in the so called ‘leak’ of strawberries , raspberries , peaches and other fruits Some other members of the Rhizopus are found in stored grain like Rhizopus , Mucors , Abisidia Rizopus species commonly cause rapid spoilage of bread and one of its species R.solonifer referred to as the Black bread mold
Black bread Mold:
12 Families recognized by Kirk et al in this order: 1.Chaetocladiaceae 2.Choanephoraceae 3.Cunnighamellaceae 4.Gilbertellaceae 5.Mucoraceae 6.Mycotyphacea 7.Phycomycetaceae 8.Pilobolaceae 9.Radiomycetaceae 10.Saksenaeaceae 11.Syncephalastraceae 12.Thamnidiaceae
2.Entomophthorales: This is the small group of fungi, consisting of 22 genera and 182 species These species are chiefly parasitic on insects while others may be parasitic on desmids or ferns prothalli , a few being saprobic in soil , drugs or plants debris. Asexual reproduction is take place by asexual propagules that are termed both ‘ spores’ and ‘ conidia’ Sexual reproduction takes place by the fusion of equal or unequal gametangia and results in thick-walled zygospore with two to three layers
6 Families of this order: 1.Ancylistaceae 2. Basidiobolaceae 3. Completoriaceae 4. Entomophthoraceae 5. Neozygitaceae 6. Meristacraceae
Insects:
Order Zoopagales: Zoopagales is a large order consisting of 21 genera and 163 species of economics importance These mostly occurring as mycoparasites and predacious parasites of nematodes, amoebae and other small terrestrial animals Asexual reproduction takes place by conidia or meroporangia that may be of five kinds Sexual reproduction results in the formation of zygospores
5 Families of Zoopagales 1.Cocholonemataceae 2.Helicocephalidaceaa 3.Piptocephalidaceae 4.Sigmoideomycetaceae 5.Zoopagaceae
Asexual Reproduction in Zygomycota: Reproduction asexually by sporangiospores within a special sac called sporangium in most of the order of zygomycetes , conidia in the Entomophthorales and arthospores in some Trichomycetes Sporangium types (4types): 1.True Sporangium 2.Sporangioles 3. Monosporous sporangium 4.Merosporangium
Types of sporangium: 1. True sporangium _ True large spores containing 2. Sporangiols _ Much smaller in size than true sporangia No columella produced and few spores (1-50) 3.Monosporous sporangium _(one-spored sporangium) 4 . Merosporangium _ sac containing 10-15 sporangiospores that occur
Group of Mucorales : 1. Multispored sporangia _ Mucoraceae, Pilobolaceae, Mortierellaceae (also produces few-spored and monoporous sporangiola), Saksenaeaceae, Choanephoraceae (also produces monosporous sporangiola). 2. Few-spored sporangiola _ Radiomycetaceae, Thamnidiaceae.
Continue …. 3. Monos p orous sporangiola on vesicles: Choanephoraceae, Cunninghamelaceae, Helicocephalidaceae Few-spored merosporangia: Syncephalastraceae
Sexual reproduction: Gametangial copulation is a type of sexual reproduction Sexual spores are called zygospores contained with in a zygosporangium Most of them are heterothallic Heterothallism: requiring a partner for sexual reproduction Homothallism: able to reproduce sexually without a partner exhibited among species in phylum They reproduce sexually when environmental conditions becomes unfavorable
Sexual reproduction of Zygomycota:
To produce sexually , two opposing mating strains must fuse or conjugate, leading to karyogamy . To developing diploid zygospore have thick coats that protects them from other hazards. They remain dormant until environmental codition become favorable. When the zygospores germinates , it undergoes meiosis and produce haploid spores. Grown in to a new organism.
Asexual reproduction:
Life cycle of Zygomycota: Vegetative mycelium is haploid, reproduces asexually by producing sporangiospores in sporangia. In a heterothallic species, when two compatible strains come together, hyphal progametangia. Septa form, producing multinucleate gametangia and suspensors. Plasmogamy occurs end wall of gametangia dissolve and cytoplasm of gametangia mixes.
Structure of Rhizopus :
Life cycle….. Zygospores forms the inside zygosporangium . Zygospores develops thick wall, warty appearance, dark in color. Karyogamy occurs at different times in zygospores formation in different species, so zygospore in diploid at some point. When zygospores germinates, meiosis occurs to start the haploid portion of the life cycle.
Cycle… Mycelia of different mating types (-) and (+) forming hyphal extension (gametangia) which each of the mycelia encloses several haploid nuclei. During plasmogamy, a zygosporangium forms, containing multiple haploid nuclei from the two parents.
Cycle… The zygosporangium develops a rough and thick-walled coating that can resist harsh condition for month. When the condition are favorable , karyogamy occurs, then later, the meiosis also occurs. During meiosis, the zygosporangium germinates into a sporangium on a short stalk.
Cycle…. Next, the sporangium disperses genetically diverse haploid spore. The spores germinate and grow into new mycelia. Asexual reproduction : Mycelia can also reproduce asexually by forming sporangia that produce genetically identical haploid spore.