Alternative for arbuscular mycorrhizal fungi inoculum production in aeroponic culture

Abstract

The generalized use of arbuscular mycorrhizal fungi (AMF) has been quite limited, due to obligatory biotrophic character of these: microrganisms, which demand the use of metabolically active roots for their multiplication. The present work was conducted to evaluate the possibility of AMF inoculum production using an aeroponic system constituted by a tank with 200 1 of nutritive solution pulverizing the root plants through various micro-irrigation nozzles. The: initial results showed that, during the first 28 days of cultivation, the plants suffered an adaptation stress, with a significant reduction of the root colonization rate and spore number. However, after this adaptation period, the AMF colonization rates increased significantly, stabilizing at 56 to 72 days in sweet potato plants inoculated with Entrophosphora colombiana, with 72 % of colonization. The number of spores recovered in the root system of plants infected with E. colombiana was surprising, with values of 5,082 and 156,336 spores per gram of root dry matter at 70 and 98 days, respectively. However, with Gigaspora margarita and Glomus etunicatum, these: values were lower than expected, showing the need of an adaptation of the aeroponic technique for these species.