Student/presenter: Nick Wilson, undergraduate student, Plant and Soil Science
Format: Poster presentation
Title: Interactions between beneficial fungal symbionts in greenhouse tomatoes
Nicholas Wilson (presenting), Jonathan Peters, Catherine Simpson, Lindsey Slaughter
Texas Tech University, Department of Plant and Soil Science
Increased costs of agricultural inputs, such as fertilizer and irrigation, combined with increased demand for high-quality agricultural products has prompted many producers to adopt alternative nutrient and water management practices. One strategy to improve plant nutrient and water uptake is to add beneficial microbial symbionts, such as fungal inoculums, to growth media in greenhouse systems. However, the effects and potential ecological interactions between multiple added microbes that form different associations with plant hosts remains unknown, despite the myriad commercial inoculum products that are marketed to growers. Therefore, the objective of this study was to determine the establishment and production outcomes of two commerciallyavailable products that contain two different mutualistic fungi: Trichoderma sp. (mix of Trichoderma harzianum and Trichoderma viride) which improves plant defense against pathogens, and arbuscular mycorrhizal fungi (AMF; mix of Rhizophagus irregularis, Rhizophagus aggregatus, Rhizophagus proliferum, Rhizophagus clarus, and Claroideoglomus etunicatum.), which colonizes plant roots and increases nutrient and water uptake. We hypothesized that adding these fungi individually would benefit plant growth and fruit yield, but that competitive interactions between the two fungi for plant resources may reduce efficacy when added together. We applied the following treatments to greenhouse tomato seedlings in a soilless media: 1) Trichoderma, 2) AMF, 3) Trichoderma + AMF, and 4) Untreated Control. At fruit harvest, whole aboveground (stem, leaves) and belowground (root) tissues were destructively collected and weighed for biomass. Mycorrhizal colonization rates were assessed in root samples by staining and microscopy. The results of this study help us understand the individual and combined effects of beneficial fungi with different mechanisms of plant symbiosis in tomatoes, and aid in decision-making for producers interested in applying biofertilizer products to greenhouse-grown tomatoes.