A.M. Bâ

Growth Response of Different Species and Provenances of Jujube Seedlings to Inoculation with Arbuscular Mycorrhizal Fungi

Many species of Ziziphus are underutilized crops despite their potential usage in agroforestry systems. The aim of our study was to evaluate the effects of arbuscular mycorrhizal fungi (AMF) on the growth and mineral nutrition of Ziziphus spp. and provenances of Z. mauritiana in greenhouse conditions. Three isolates of AMF were used: Rhizophagus irregularis IR27, Funneliformis mosseae DAOM227131, and Rhizophagus irregularis DAOM197198. They were inoculated on seven species of Ziziphus (Z. mauritiana, Z. lotus, Z. spina-christi, Z. mucronata, Z. amphibia, Z. abyssinica, and Z. sphaerocarpa) and six provenances of Z. mauritiana (Senegal, Mali, Mauritania, Burkina Faso, Niger, and India). Plants were grown in nursery receiving 20 g of crude inoculum of AMF. Two greenhouse experiments were set up: (1) a 4×6 factorial design consisting of three AMF, one control (disinfected soil without inoculum), and six provenances of Z. mauritiana and (2) a 4×7 factorial design consisting of three AMF, one control and seven Ziziphus spp. Inoculation by AMF significantly improved growth and mineral nutrition of Ziziphus spp., particularly P nutrition. All the Ziziphus spp. (except for Z. lotus) and provenances of jujube seedlings showed the highest mycorrhizal dependency (MD) values when inoculated with R. irregularis IR27. The differences of MD among the tested Ziziphus spp. seem to be due to the differences in the development of hyphal length in the soil and in P uptake by the external hyphae. Rhizophagus irregularis IR27 constitutes a promising biological tool for the production of higher-quality nursery stock with expected improved performance of Ziziphus spp. and Z. mauritiana provenances in agroforestry systems.

The Nematophagous Fungi Helper Bacteria (NHB): A New Dimension for the Biological Control of Root Knot Nematodes by Trapping Fungi

Many genera and species of plant parasitic nematodes are associated with coffee. These cause great financial losses to the coffee farmers. Among these pathogens, root-knot nematodes (Meloidogyne sp.) are the most abundant group (Table 1) and the most common species are M. exigua, M. incognita and M. coffeicola.