Contribution of arbuscular mycorrhizal fungi to growth and nutrient uptake by jujube and tamarind seedlings in a phosphate (P)-deficient soil

Abstract

A pot experiment was carried out in a nursery to determine the influence of an arbuscular mycorrhizal (AM) fungus on plant growth and nutrient uptake in tamarind (Tamarindus indica) and jujube (Ziziphus mauritiana), both of which are multipurpose fruit trees in Sahelian agroforestry systems. Plants were inoculated or not with Glomus aggregatum and grown for four months in a sterilized phosphorus (P)-deficient sandy soil (2.18 ppm P). Tamarind and jujube seedlings grew very poorly in the absence of G. aggregatum, whereas inoculated ones had greater shoot height and total biomass production. The total dry weight of the fruit tree species was increased 3 and 4 fold by G. aggregatum, respectively, in tamarind and jujube compared to the controls. Jujube with the highest AM root colonization had a higher P concentration (8.33 fold) in shoots than in tamarind (1.62 fold), indicating greater mycorrhizal dependency in jujube seedlings. The P concentration in shoots of AM plants contributed probably to enhance significantly plant growth and development more than N, K and Mg, particularly in jujube seedlings. Results suggested that fruit trees inoculated with AM fungi absorbed nutrients more efficiently from the soil, which resulted in improved plant growth and biomass production. These beneficial effects of AM inoculation may be useful for the production of these fruit trees in fields. Further investigations are therefore necessary to elucidate the effectiveness and competitiveness of G. aggregatum in real nursery conditions. Key words: Arbuscular mycorrhizal fungi, fruit tree, mycorrhizal root colonization, mycorrhizal dependency, nutrient uptake.