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

P G Soti,Krish Jayachandran,Nina De La Rosa,Bulent Toprak

doi:10.5539/jas.v13n3p10

Abstract

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.

Highlights

After citrus, avocado (Persea americana Mill.) industry is the largest fruit industry in Florida
We analyzed the farm soil status and mycorrhizal spore density and diversity in avocado growing in different land use types in south Florida
This study presents the results of a preliminary study of disturbance in avocado arbuscular mycorrhizal fungi (AMF) symbiosis in South Florida farms

Summary

Introduction

Avocado (Persea americana Mill.) industry is the largest fruit industry in Florida. Tropical climate in south Florida provides an ideal climate for avocado and it is highly localized in the south-eastern Miami Dade County (Ploetz, 2007). Avocado trees are shallow rooted with dense proliferation of fine roots close to the surface (Salazar-Garcia & Cortés-Flores, 1986). These roots are protected by the trees own natural much. Soil disturbance in the root zone can reduce the feeder roots but can influence the avocado-AMF symbiosis through the repeated damage to AMF hyphal matts (Kabir, 2005; Urcelay et al, 2009). Changes in the soil environmental conditions such as soil compaction, nutrients, soil pH, light, and temperature resulting from soil disturbance can influence the mycorrhizal fungi colonization (Dumbrell et al, 2011; That & Sijam, 2012; Verbruggen, van der Heijden, Rillig, & Kiers, 2013; Soti, Jayachandran, Koptur, & Volin, 2015)

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