Some mycorrhizal plants exhibit greater resistance than nonmycorrhizal plants to aluminium toxicity. This has not
yet been shown for banana despite its importance as a cash and food crop in tropical regions, although bananas
are sensitive to aluminium stress. We studied the effects of the arbuscular mycorrhizal fungus Glomus intraradices
in alleviating aluminium toxicity in the banana cultivar Grande Naine grown in a continuous-nutrient-flow
cultivation system using dilute solution. The micropropagated plants, some of which were inoculated with
arbuscular mycorrhizal fungus, were grown for 40 d in pots filled with sand, and continuously irrigated with a
nutrient solution containing up to 180 μM of aluminium. Water and nutrient uptake were measured once a week
for 24 h, and root arbuscular mycorrhizal fungal colonization, biomass production, and mineral content of roots
and shoots were measured at harvest. The root arbuscular mycorrhizal fungal colonization was large, and not
significantly influenced by aluminium treatment. The effects of aluminium on both mycorrhizal and
nonmycorrhizal plants were: decrease in biomass production, water and nutrient uptake, and magnesium content
of roots and shoots; greater aluminium content in roots than in shoots; and increase in potassium and phosphorus
content, particularly in roots. A significant positive effect of arbuscular mycorrhizal fungi on plant growth was
observed with aluminium treatment, and was most pronounced at the highest concentration. The benefits,
compared with nonmycorrhizal plants, included: increase in shoot dry weight, uptake of water and of most
nutrients, and in calcium, magnesium and phosphorus content, particularly in roots; decrease in aluminium
content in root and shoot; and delay in the appearance of aluminium-induced leaf symptoms. These results
indicate that arbuscular mycorrhizal fungi could be effective in alleviating aluminium toxicity to banana plants.