INTERACTION OF MULTIPLE VAM FUNGAL SPECIES ON ROOT COLONIZATION, PLANT-GROWTH AND NUTRIENT STATUS OF TOMATO SEEDLINGS (LYCOPERSICON-ESCULENTUM MILL)

Tomato seedlings were grown in sterile, phosphorus deficient soil and inoculated with four species of vesicular-arbuscular mycorrhizal (VAM) fungi in 15 possible combinations. Mycorrhizal plants exhibited a sig nificantly higher shoot length and biomass, than non-mycorrhizal plant s (P < 0.05). VAM also increased host tissue N and P concentrations. A mong the VAM combinations, inocula containing all four endophytes prom oted markedly better shoot length and biomass than other combinations, although spore yields were lower in mixed inocula. Mycorrhizal depend ency (MD), percentage increase of biomass compared to controls, was al so more in quadruple combination than in either triple or double combi nations. A negative interaction on plant growth and biomass was observ ed between Glomus aggregatum and G. fasciculatum. This effect was null ified when more species were added to this combination.