COINOCULATION WITH AN ARBUSCULAR MYCORRHIZAL FUNGUS AND A PHOSPHATE SOLUBILIZING FUNGUS PROMOTES PLANT GROWTH AND PHOSPHATE UPTAKE OF AVOCADO PLANTLETS AT NURSERY

Abstract

An experiment was conducted to evaluate the effects of individual and dual with the phosphate solubilizing fungus Mortierella sp. and the arbuscular mycorrhizal fungus Rhizoglomus fasciculatum on plant phosphate uptake and growth of avocado (Persea americana Mill.) plantlets cv. Hass at the nursery. A completely randomized design was used. Treatments consisted of individual and combined inoculations with R. fasciculatum and Mortierella sp. at two concentrations (106 and 108 CFU mL-1) and an uninoculated control. The plant height, shoot dry weight, and shoot phosphate uptake were significantly higher with the co-inoculation with both fungi than with individual inoculation or uninoculated control plants. The colonization of fine roots with both fungi decreased when both were coinoculated in comparison to when they were individually inoculated, which suggest that these fungi compete for root space. Despite this competition, the dual inoculation showed that both fungi had additive effects on plant performance. Thus, shoot phosphate in mycorrhizal plantlets was significantly higher when Mortierella sp. was co-inoculated at both concentrations as compared to individual and uninoculated control plants (mycorrhizal-free).