The Fungi Kingdom is unique and quite diverse. In this video lesson, you’ll learn about the different groups of fungi and see how fungi are much more than just mushrooms and molds!
Fungi Are Diverse
When you hear the word ‘fungus’ you probably think of a mushroom. But fungi are so much more than that. In fact, when you think of mushrooms, which make up only part of the Fungi Kingdom, you can probably think of several different types: button, chanterelle, shiitake, portabella and so many more!Still not a believer in the diversity of fungi? Think about this: scientists have already described over 100,000 species of fungi, though there may be many more – possibly as many as 1.5 million! The fungi species that have been described are classified into five groups. The names are tricky, but you may notice that each group ends in the suffix ‘mycetes.
‘ So, whether you can remember the tongue-twisting names or not, if you see this suffix, you’ll know it’s a fungus!
The Five Groups of Fungi
Our first group is Chytridiomycetes, thought to be the oldest group of fungi. We often find these fungi in lakes, ponds, estuaries and soil. Many species in this group are decomposers, meaning that they break down dead organic material.
But other species are parasites of plants and animals and are responsible for many infections in amphibians.Next, we have the group Zygomycetes, which you have probably interacted with at some point. Some fungi in this group are fast-growing molds, such as black bread mold and molds that rot the fruit you left sitting out on the counter too long.
So, should you eat that rotting fruit? I wouldn’t go near it!Our third group is Glomeromycetes, which are very important fungi. This is because about 90% of plants form symbiotic relationships with glomeromycetes, which help deliver nutrients to the plant while receiving other necessary nutrients in return. Like a ‘conglomerate’ is multiple parts combined together, Glomeromycetes combine with plants to form a strong team.Fourth, we have the group Ascomycetes, also known as ‘sac’ fungi. These fungi get their name from their sac-like structures called ‘asci.’ ‘Asci’ comes from the Greek ‘asco,’ which means pouch, so literally this group name means ‘pouch-fungus.’ These live in a wide variety of habitats (marine, freshwater and terrestrial) and can range in size from unicellular yeast to fancy morel mushrooms (yum!).
Not always the good guy though, Ascomycetes are also some of the most devastating plant pathogens.Finally, we have the group Basidiomycetes, also known as ‘club’ fungus. This is what most people imagine when they hear the word ‘fungus’ because these are many of the mushrooms, puffballs and shelf fungi. They get their name from their club-like reproductive structure called a ‘basidium,’ which literally means ‘little pedestal’ in Latin. Now imagine these types of fungi again, and you can see how they got their name! Many of these fungi are decomposers, like the shelf fungi that break down wood in forests.
But they also include many devastating plant parasites as well.
Mold, Yeast, Lichen and Mycorrhiza
You just got some big terms that will take some time to digest, so let’s talk about a few that you are probably somewhat familiar with already. I mentioned mold earlier, and this you have likely seen in many forms on your food or on your shower walls. Mold is simply any rapidly growing fungus that produces spores asexually. I’m sure you’ve seen how quickly mold can grow if you went away for the weekend and left some fruit sitting out on the counter.I also mentioned yeast, which are single-celled fungi.
Yeast also reproduce asexually and really like liquid or moist habitats. And, to show you that not all fungi are bad, yeast are responsible for delicious things like beer and bread (before you let it get moldy!).Lichen are really special, because they are a symbiotic partnership of fungi and photosynthetic organisms. In this case, the photosynthetic organisms are photosynthetic algae and cyanobacteria, and you’ve seen this as different forms of moss. The partners are so closely woven together that you’d be hard pressed to see them as separate organisms. In fact, the partnership is so important that these fungi, which partner to form lichens, are rarely able to survive on their own. The two organisms help each other in the symbiosis, providing habitat, nutrients and water.
Similarly, mycorrhiza is a symbiotic relationship between plant roots and fungi. The term ‘mycorrhiza’ literally means ‘fungus root.’ The fungi in this relationship surround the plant root but don’t penetrate the cells.
The fungi absorb nutrients from the soil and share them with the plant. In return, the plant provides sugars from photosynthesis to the fungi, making them both happy campers. And as mentioned before, about 90% of plants have this type of symbiosis with glomeromycetes (since they form a conglomerate of plant and fungi!).
The diversity of fungi is astounding. Though there are already over 100,000 described species of fungi, there are likely hundreds of thousands more that have not been described. Fungi are classified into five groups: Chytridiomycetes, Zygomycetes, Glomeromycetes, Ascomycetes and Basidiomycetes. The Chytridiomycetes are the oldest group of fungi; the Zygomycetes are responsible for food molds; Glomeromycetes helps form the conglomerate group of fungi and plant roots; Ascomycetes are the ‘sac’ fungi (from the Greek ‘asco’ for pouch); and Basidiomycetes are what most people think of when they think of fungi – the ‘little pedestal’ fungi.
Fungi are both beneficial and harmful. Molds are rapidly growing fungi that take over our foods when we leave them sitting out too long, while yeasts are single-celled fungi that make delicious bread and beer. Lichens and mycorrhizae are both symbiotic relationships with photosynthetic organisms, but lichens are symbioses with algae and cyanobacteria, while mycorrhizae are symbioses with plant roots. Both relationships help both the photosynthesizer and the fungi, as they provide habitat and nutrients to each other while they share their space.
You should have the ability to do the following after watching this video lesson:
- Describe the five groups of fungi
- Explain what molds and yeasts are
- Differentiate between lichens and mycorrhizae