Morphological alterations on root system of maize induced by mycorrhizal fungi and phosphorus

Abstract

The objective of this research, carried out under greenhouse conditions was to evaluate the effect of mycorrhizal fungi (Glomus etunicatum and Glomus clarum) inoculation and P levels (0, 50, 100 e 200 mg/kg of soil) on maize (Zea mays L.) root system morphology, cultivar BR 201, and P plant concentration in two harvest period (18 and 104 days after sowing) in disinfested dystrophic Dark-Red Latosol. The experiment was carried out under greenhouse conditions at Embrapa-Centro Nacional de Pesquisa de Milho e Sorgo, in Sete Lagoas, Minas Gerais, Brazil. Inoculation with mycorrhizal fungi increased root dry weight, number of first and second order lateral roots and P concentration in the plant, but decreased root/shoot dry weight ratio and number of root hairs. These effects were affected by P concentration in the soil and by mycorrhizal fungi species. Root dry weight of inoculated plants showed significative (P£0.05) correlation to root colonization to seminal and adventitious roots. Number of first and second orders lateral roots also showed significative (P£0.05) correlation to root colonization. Glomus etunicatum was most efficient in all P levels, but high P levels reduced these effects for both fungi species due to reduction on mycorrhizal colonization.