Overview of Fungi Reproduction

The way fungi reproduces is rich in variety according to genetics.  The environment  has the strongest influence and can trigger the formation of specialized reproductive structures.

Many fungi  have both sexual and asexual forms of reproduction, it is said that at least one third of species reproduce using both ways. Some others reproduce using only one way, either sexually or asexually.

Most fungi rely on both sexual and asexual reproduction while other rely only on one or the other. This diagram shows a generalized life cycle having both sexual and asexual components.
Sourcehttps://www.boundless.com/biology/fungi/the-reproductive-cycles-of-fungi/introduction-to-fungal-reproduction/

Their reproductive structures producing gametes are known as gametangia,  whereas the ones producing asexual spores are called sporangia. 

Spores are the reproductive structure of fungi and are produced in large numbers to be carried by wind or water.

 Heterokaryon describes the mycelium of fused hypha that contain genetically different nuclei that are able to coexist. The nuclei can exchange chromosomes in some species.

A dikaryotic mycelium refers to the process of haploid nuclei pair off (two per cell). Though these differ from diploid cells in that they retain two different nuclei that never fuse.

Karyogamy is the stage that follows plasmogamy and can take anywhere from hours to years. During this phase, the haploid nuclei fuse to result in diploid cells and zygotes.

Meiosis occurs and the haploid spores are released. The karyogamy phase is a source of genetic variation in fungi.

Spores are  dry and tiny. A single fruiting body can release millions of spores that remain floating in the air and are carried away long distances.

The spores exploding from an sporangium are capable of traveling up to 2 meters, which is a huge distance considering proportions. Some spores are sticky and travel on the bodies of insects  and other animals. 

The haploid stage predominates in the life cycles of most fungi. The haploid organism produces gametes by mitosis that fuse to produce a diploid stage, but meiosis quickly follows. 

Depending on the species or life cycle stage, spores may form sexually or asexually and so can be either diploid or haploid.

Spores miotically divide to form individual gametophytes. These gametophytes produce haploid gametes that form a diploid zygote, which undergoes mitosis to form sporophyte. The sporophyte produces haploid spores through meiosis  Source: https://www.boundless.com/biology/fungi/the-reproductive-cycles-of-fungi/introduction-to-fungal-reproduction/

Vocabulary

Spore. A minute, typically one-celled, reproductive unit capable of giving rise to a new individual without sexual fusion, characteristic of lower plants, fungi, and protozoans.
Haploid.  Having a single set of unpaired chromosomes. 
Gamete. Mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
Sporangia.  A receptacle in which asexual spores are formed.
Karyogamy. 
The fusion of two nuclei within a cell, especially as the second stage of syngamy.
Dikaryotic. 
Containing two nuclei.
Heterokaryon. 
A cell having two or more genetically different nuclei
Meiosis.  A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores. 
Mitosis.  A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
Gametophyte. The gamete-producing and usually haploid phase, producing the zygote from which the sporophyte arises.
Zygote. A diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.