Question

Fungal hyphae from a typical Basidiomycete can be either haploid or dikaryotic. What happens in their life cycle which makes there unlikely to be any fungal hyphae made up of diploid cells?

Answer 1

• The lifecycle of basidiomycetes contains alternations of generations, and the spores produced are from sexual and not asexual reproduction. The club shaped basidium carries spores called sporangia and develops to sporangium.
• the hyphal tips will form into gametangium, a sexual structure and the nuclei inside the fungal hyphae are haploid unlike most of the diploid cells in other plants, and hence fungi doesn't undergo meiosis before fertilization.
• through conjugation or sexual reproduction, nuclei fuses and the gametangia meet and fuses together, and nuclei from each strand fuses to form diploid zygote which is the only diploid stage in its life cycle, then undergo meiosis to give rise to 4 haploid spores, which contains sporangia.
• This spore turns into an adult haploid organism. Each hyphal strand contains 2 nuclei and hyphae of this fungi are hence dikaryotic, and also they can asexually reproduce by forming conidiophores, to form haploid spores known as conidia.