A Community of Nematodes
When we explore the microorganisms which populate our soils, we are welcomed into the mystical underworld of nematodes! Using a microscope as our tour guide, we are taking a magnifying glass to the lives of these whirly twirly creatures and their relationship with soil and plants. At the Kinney Center, nematodes are in abundance and thriving alongside other micro flora and fauna. During my project, I identified 6 varieties of nematodes, including: free living, lance, stunt, ring, lesion, and Tylenchus. These nematodes are all unique in physical appearance, but share similar traits in how they interact with plants. When we consider a community of nematodes, it is important to know that nematodes are very independent creatures. In fact, we are more likely to see nematodes in competition at some level rather than acting as a team. However, nematodes do share common tasks beneath the soil.
Lesion head
For the Kinney Center soils, lance, stunt, ring, lesion, and Tylenchus are all plant parasitic nematodes which kill the root cells of plants by probing them with their stylets (see picture below). To get a better understanding, we can picture an energized, wiggly nematode swimming beneath our plants trying to find its next meal. Once the nematode has reached the root tissue of its desired plant, the nematode will use its spear-like stylet and mouth to pierce and munch on those delicious roots. Meanwhile, free living nematodes are more apt to feed on bacteria, algae, fungi, and dead organisms. All of these nematodes contribute to nutrient recycling which plays an integral role in soil health and biodiversity (ScienceDirect, 2017).
The lesion nematode, Pratylenchus, is the most destructive of the bunch due to its ability to burrow into the root of a plant. When it’s burrowing, Pratylenchus can create brown or black lesions to form on plant roots. These lesions can lead to stunted growth, reduced plant vigor, defoliation, or yield declines depending on the abundance and type of plant present (UC Davis, 2024). Whereas, the other plant parasitic nematodes are ectoparasitic, meaning they remain in the soil while still killing the root cells and create less overall damage. All soils are host to plant parasitic and free-living nematodes, but these soils can become more concerning in agricultural settings. Plant parasitic nematodes may be worrisome because, after 10,000 years of selection, our genetically altered plants have lost genes for resistance. It is essential that we closely monitor microorganism activity alongside general observation to get a comprehensive understanding of our plants. The community of nematodes living beneath our soils represent a small fraction of the fascinating biological diversity influencing our plants and soils.
Do you wonder what the point is of these destructive forces? Keep reading to find out more!
