How do Mushrooms reproduce?
As I have mentioned in an earlier post (see The Mushroom Life Cycle), when trying to cultivate mushrooms, it is important to know about their life stages and how mushrooms reproduce. You can use this knowledge not only to provide the best conditions to grow your mushrooms, but also to improve and maintain the quality of your strains.
Fungi reproduce either a) sexually or b) asexually.
a) During sexual reproduction, the hyphae of two different mating types fuse before forming a new fruiting body (the above ground part of a fungi which is commonly referred to as the Mushroom).
b) Asexual reproduction occurs either through bi) spores or bii) mycelial fragmentation/budding (fungal mycelium separates into pieces and each component grows into a separate mycelium).
bi) Asexual spore formation takes place at the ends of specialised structures called conidiophores. A random number of nuclei is divided into individual cells with thickened cell walls as a protective coat. Just like in sexual reproduction, the spores break off and are dispersed.
bii) Budding is the process of separation of an outgrowth of the parent into a new cell. Any cell in the organism can bud.
Why asexual and sexual reproduction?
Environmental conditions trigger developmental states that lead to the creation of specialized structures for sexual or asexual reproduction. Via asexual reproduction, fungi produce clones, which allows more rapid overgrowth of a certain environment than sexual reproduction. However, in order to adapt to an environment, genetic variation (from sexual reproduction) is necessary.
Species that lack an observable sexual cycle are called “Fungi imperfecti” (Deuteromycota).
What do I need this knowledge for?
So how does this relate to mushroom cultivation? You can use strain selection and tissue cultures in order to improve your strain.
If you already have a perfect strain, you can take a piece of tissue and clone it on agar, and the new mushrooms will have the same genetic information as your parent mushrooms.
However, if you want to combine two different strains, you have to grow each one starting with haploid spores on agar and let them germinate and mate. Remember, this can only occur during the haploid stage. When hyphae from spores first germinate, they are haploid, so they only have half the DNA they need to produce a fruiting body and reproduce. After the fusion of two haploid hyphae of compatible genders, their cells are diploid, containing a full set of genetic information. If two diploid hyphae meet, they will not fuse but fruit side by side with one strain becoming dominant.
Stay tuned for more on this topic and a blog on how to isolate a strain.
Meanwhile, check out Mycolife.com and stock up on everything you need to grow mushrooms.
Chang, S.T. and Hayes, W.A. The Biology and Cultivation of Edible Mushrooms.