Estudos da Associação Micorrízica Arbuscular em Mudas de Mangabeira (Hancornia Speciosa Gomes) Estudos da Associação Micorrízica Arbuscular em Mudas de Mangabeira (Hancornia Speciosa Gomes)

by Carneiro Costa, Cynthia Maria

The mycorrhizal association of Hancornia speciosa was investigated in five experiments using Gigaspora albida and Glomus etunicatum as inoculum. Mycorrhizal dependency, inoculum density needed for growth promotion and effect of water stress on gases exchange, solutes concentration and soil microbial activity were evaluated at the greenhouse. Native species, number of spores and infectivity of AMF as well as growth and survival of the mycorrhized plants were investigated in the field. G. albida increased growth of the seedlings, that were dependent of mycorrhization in soil with low P (3 mg dm-3). Reduction on time for transplating was obtained in treatments with 180 spores of G. albida/seedling. Treatments with G. albida presented higher osmotic adjustment in the hour of higher evaporative demandand higher growth with 50% of water stress. The presence of G. albida induced higher concentration of carbohydrates, while seedlings associated with G. etunicatum presentedlower level of proline. The levels of solute concentration induced by mycorrhization allowed osmotic adjustment in each treatment, and higher tolerance to moderate stress. Mycorrhization also contributed for increasing the activity of acid phosphatase in the soil. After 90 days in the field, 100% of the seedlings non inoculated and associated with G. albida and 81% of those with G. etunicatum had survived. Mycorrhization benefited growth, antecipated the time fortransplanting to the field and became the seedlings tolerant to moderate stress