Spores are cells that, by mitosis , give rise to new individuals. In general, they are immobile , with the exception of those found in chytrids, and produced by structures that rise above the mycelium (a coiled mass formed by a set of hyphae), called sporangia , or in hyphal cells (filaments of cells), being called conidia .
Spores are a very effective method of propagation , as they can be carried by wind , water and animals over great distances. When they fall in a suitable place, with water and nutrients, they develop. This ease of propagation helps explain the wide distribution of many species.
→ Asexual reproduction
Asexual reproduction can occur in several ways. A common form of reproduction displayed by unicellular organisms , such as yeasts , is budding , in which a bud grows from the parent cell. Yeasts can also reproduce by simple cell division .
Molds , or mildews , commonly found in decaying foods , produce spores asexually , which gives rise to new fungi . However, many species can also reproduce sexually.
→ Sexual reproduction
Sexual reproduction occurs in three stages: plasmogamy , karyogamy , and meiosis .
- Plasmogamy : in this stage, the fusion of the cytoplasm of two mycelia occurs. As in many species the nuclei do not fuse immediately, the two haploid nuclei remain in pairs in the cell. This mycelium is called a dikaryotic . Over time, these nuclei begin to divide without fusion;
- Karyogamy: This phase can take hours and even years. Here the fusion of haploid nuclei occurs , which forms diploid cells. In the fungal life cycle, only the zygote is a diploid phase;
Meiosis: this step is extremely important, as it restores the haploid form and gives rise to spores with greater genetic variability .