Association of vesicular-arbuscular mycorrhizal fungi with coffee rangpur lime and molasses grass

Abstract

Using wet sieving and decanting method along with sucrose density gradient column method, spores of vesicular-arbuscular mycorrhizal fungi were isolated from three different rhizospheric soil samples of coffee (Coffea arabica L.), rangpur lime (Citrus limonia Osb.) and molasses grass (Melinis minutiflora Beauv.) in Viçosa, Minas Gerais, Brazil. The specific fungi isolated within the rhizospheric soil established the treatment used on each host. They were isolated and then evaluated in the greenhouse concerning the following aspects: wet and dry foliage weights, root dry weight and total uptake of phosphorus, potassium, calcium and magnesium of the host plants foliage. In all plants tested, at least one treatment increased wet and dry foliage weights. Acaulospora sp. increased these weights more than 100% in coffee plants, Gigaspora margarita increased the wet and dry foliage weight 75% in rangpur lime; Glomus fasciculatus increased the wet foliage weight 80% and the dry foliage weight 65% in molasses grass. Acaulospora sp. showed an increase of 80 to 120% of all the nutrients tested in coffee plants. Glomus fasciculatus showed an increase of 100% in phosphorus and potassium, and 80% for magnesium, but showed no increase for calcium in molasses grass. Gigaspora margarita showed an increase of about 80% in the uptake of all nutrients analized in relation to the check treatment.