Question

what is the distinguish sexual and asexual reproduction method of fungi with examples ??

Answer 1

Ans. 1. Sexual reproduction in fungi:- When a fungus reproduces sexually then two haploid hyphae of compatible mating type come together and fuse.Nuclei of their cells can fuse simultaneously which results to diploid cell or they can undergo an intervening dikaryotic phase ( having two nuclei per cell as in ascomycetes and basidiomycetes).The fungi form fruiting bodies in which reduction division occurs which results to the formation of haploid spores.

It consists of following three sequential stages:-

(1) Plasmogamy: It is the process of fusion of protoplasms between two motile or non motile gametes.

(2) Karyogamy: It is the process of fusion of two nuclei of the gametes.

(3) Meiosis: It occurs in zygote which results to formation of haploid spores.

e.g. Ascomycetes endogenously produce ascospores for sexual reproduction in a sac like asci which are arranged in ascocarps/fruiting bodies.Common examples are Aspergillus,Claviceps,etc.

e.g. In basidiomycetes basidiospores are sexual spores and common examples are Agaricus,Ustilago,etc.

e.g. A zygospore is formed by fusion of two gametes and they may be isogamous,anisogamous or oogamous depending on their morphology.Common examples are Albugo,Mucor,etc.

2.Asexual reproduction:- Apart from vegetative reproduction including fragmentation,budding, fission,etc asexual reproduction occurs via spores only called conidia or sporangiospores or zoospores.

e.g. Deuteromycetes are called imperfect fungi because in them only asexual or vegetative reproduction is known. Some common examples are Alternaria,Trichoderma,etc.

e.g.In phycomycetes asexual reproduction takes place by aplanospores (non motile) or zoospores (motile) which are endogenously produced in sporangium.Some common examples are Mucor, Rhizopus,etc.

e.g. In ascomycetes conidia are asexual spores which are produced exogenously on conidiophores. Common examples are morels,Neurospora,etc.

Apart from these other different types of asexual spores also form such as Arthospore(a primitive type of spore formed by breaking of fungal mycelium) as in Trichosporium and Chlamydospores which are usually forms in unfavourable conditions.