Influence of Land Use Intensity and Management on Arbuscular Mycorrhizal Fungi-Avocado Symbiosis

This study was done to assess the effect of soil disturbance on arbuscular mycorrhizal fungi spore abundance and root colonization in avocado (Persea americana Mill.). Rhizosphere soil and root samples of avocado were collected from different farms in south Florida and analyzed for degree of mycorrhizal colonization in roots, spore density and diversity in soil along with soil characteristics. There was significant difference in the soil characteristics among the different farms. Similarly, there was a significant difference in the degree of mycorrhizal colonization in the roots and the arbuscular mycorrhizal fungi spore morphotypes among different land use and management practices. However, there was no significant difference in the total number of arbuscular mycorrhizal fungi spores among these sites. There was no correlation between the number of arbuscular mycorrhizal fungi spores and soil characteristics. However, arbuscular mycorrhizal fungi colonization in roots were strongly influenced by soil characteristics such as soil moisture, carbon, nitrogen, and organic matter. Further research is necessary to identify these AMF species and determine the role of in avocado growth tolerance to anthropogenic disturbance in highly disturbed urban soils.