Fungi Sexual Reproduction

Criteria for Sexual Reproduction in Fungi Two mating type haploid nuclei (n + n) or a diploid nucleus

(2n) Two haploid nuclei fuse to form diploid meiosis Spores formation (resting spore)

By Assoc.Prof.Dr.Mohd Noor Abd.Wahab

Generalized Life Cycle of Fungi

Chytridiomycetes Production of spores after gametic or somatic fusion of two different mating types

germinate => diploid vegetative mycelium Spores

meiosis => haploid mycelium Diploid mycelium produces resting sporangia meiosis

generating haploid zoospore germinate to produce

haploid vegetative mycelium

Zygomycetes Two possible nuclear states in the mycelia

~ Homothallism ~ Heterothallism Homothallic fungi undergoes conjugation Secretion of inducer molecules form zygospores

modified hyphal tips conjugation meiosis 4 haploid nuclei 3 degenerate

Eg, Rhizopus (Black Bread Mold)

Ascomycetes No specialized organs of hyphal fusion Different mating types fuse to form dikaryons Dikaryotic mycelium differentiate to form sterile mycelium that becomes the fertile tissue of the fruting body

Eg, Penicillium

Basidiomycetes Formation of fruiting body primodium Primodium expands and differentiate to form large fruit bodies, mycelium remain as dikaryon Diploid formation only occur within the modified hyphal tip, basidium