Fungos micorrízicos arbusculares no desenvolvimento inicial de genótipos de Coffea arábica L.

Abstract

The aimof this study was to evaluate the development and nutritional response of seedlings of Coffea arabica L. inoculated with arbuscular mycorrhizal fungi (AMF). Thus, two experiments was installed, one in nursery with seedlings propagated by somatic embryogenesis,and another in pots with seedlings propagated by seeds from six genotypes in greenhouse. The experiment 01 aimed to improve the seedling production process by somatic embryogenesis through inoculation with mycorrhizal fungi. The design used was completely randomized in a factorial 2 x 7, with two coffee clones: clone 1 "Catucaí Vermelho" and clone 2 "Acauã", both inoculated with five different inoculants composed of AMF Rhizophagus clarus, Gigaspora margarita and Acaulospora melleaand grown on substrate with reduced fertilizing; and noninoculated control with (Control) and without (Pattern) reduction of fertilizer in the substrate, using four replications. After 180 days were evaluated seedlings of two clones inoculated with and without inoculation AMF (Control) and without (pattern). The conclusions were that the use of mycorrhizal fungi improves the development of seedlings micropropagation of C. arabica L. Clones behaved differently when inoculated with AMF and the clone 1 (Catucaí Vermelho), with better response. In the experiment 02 was evaluated the effect of inoculation AMF Rhizophagus clarusand the mixture of Rhizophagus clarusand Gigaspora margarita on the initial development and the nutritional response of six C. arabica L. genotypes. The experiment was performed in design used was completely randomized in a factorial 3 x 6 ,with C. arabica L. genotypes (IPR100, Paraíso H 419-1, MGS Aranas, Catiguá MG2, Catuai Vermelho IAC 144 and H 29-1-8-5 progeny in F4 generation), and three for the AMF: Rhizophagus clarus, Gigaspora margaritaand treatment uninoculated (Control), with five replications and one plant each. The conclusions were that inoculation favored initial growth of coffee plants and its intensity varied according to the genotypes. The genotypes which highlighted were Catuai Vermelho IAC 144 and Catiguá MG 2 presented the highest accumulationof N and P nutrients, the most promising to be inoculated with arbuscular mycorrhizal fungi. All variables, when the plants were inoculated with mycorrhizal fungi Rhizophagus clarus, and the mixture of fungi Rhizophagus clarusand Gigaspora margarita showed gains over the plants not inoculated.