Explain the process of sexual reproduction in kingdom Fungi.

Solution:

Sexual reproduction in fungi involves following steps:

• Plasmogamy − fusion of protoplasm of two gametes

• Karyogamy − fusion of two nuclei

• Meiosis in zygote resulting in haploid spores

• During sexual reproduction in fungus,

  • fusion of two haploid hyphae of compatible mating types takes place which may result

    • in a diploid cell (2n) in some fungi or

    • an intervening dikaryotic stage (n + n) called dikaryon and a phase called dikaryophase occurs - mainly in classes Ascomycetes and Basidiomycetes.
      
      Dikaryotic phase is a unique stage in sexual reproduction shown by fungi. During this unusual phase, which is common in many species of fungi, cells contain two distinct nuclei. These two nuclei divide simultaneously as the mycelium grows; growth continues until fusion occurs during karyogamy resulting in diploid condition. It occurs due to delay of karyogamy after plasmogamy( fusion of gametes).