Electronic Thesis and Dissertation Repository

Thesis Format

Monograph

Degree

Master of Science

Program

Biology

Supervisor

Thorn, Richard G

Abstract

Lepista nuda, or the blewit, is a saprotrophic fungus that produces fairy rings and mycelial mats. Studies have revealed its antimicrobial properties including hyphal penetration/consumption of microbes, and reduced incidence of disease on plants with culture filtrates/extracts. However, field studies are limited. Here, soil was sampled before and twice after inoculating with manure and either living or autoclaved Lepista mycelium in coastal regions of Newfoundland Canada. Arthropod, nematode, bacterial and fungal members of the soil community were identified and their relative abundance determined by metabarcoding analyses of soil-extracted DNAs. Community differences were revealed for fungi, bacteria, and nematode samples. Diversity and richness increased for bacteria only. Differential abundance analysis revealed many significant OTUs across sampling seasons for bacteria, fungi, and arthropod samples, many of which are known to be agriculturally or medically significant. Results support future investigations on Lepista potential in intercropping agricultural systems as an edible co-crop and biopesticide/biofertilizer.

Summary for Lay Audience

Lepista nuda, known as the blewit, is a fungus that forms delicious edible purple mushrooms and grows through soil, breaking down dead plant material. Past studies have shown that the threads of the mushroom that grow into the soil beneath (hyphae) can grow towards microbes, such as groups of bacteria, to attack, break down, and absorb them. Chemicals released by the hyphae can also prevent the growth of microbes, and if sprayed on plants infected with microbes, can also decrease the spread of the disease.

There are very few studies on Lepista effects on soil organisms in the field, so this study sampled soil before and twice after adding manure with either living or dead Lepista mycelium (a group of hyphae). This was done in coastal regions of Newfoundland Canada, in the Summer and Fall of 2021, and Summer of 2022. At each time point, DNA was collected from the soil to identify fungi, bacteria, and animals such as insects, small worms and more (arthropods and nematodes), to understand how Lepista changes the communities of these organisms across time. Results show that Lepista can change the overall makeup of communities of these organisms except for arthropod samples. Lepista can also increase the number of different species in bacteria samples. Finally, Lepista can directly or indirectly increase or decrease certain fungi, bacteria, and arthropods in comparison to the plots with the dead Lepista treatment. Some of these organisms are known to be important in agriculture, including organisms that can help plants grow, or cause plant diseases. Some of these species are also known to cause human diseases, which Lepista can somehow stop the growth of.

These results support future studies that investigate Lepista’s potential to grow alongside other plant crops in agriculture. Potential benefits to the plant crop include directly or indirectly increasing the number of organisms that are known to help plants grow and protect from plant disease, and by decreasing some fungi that cause plant disease. Because Lepista nuda is edible, it could be a co-crop in addition to a biopesticide/biofertilizer, an eco-friendly alternative to some man-made chemical pesticides/fertilizers.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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