The role of seed reserves in arbuscular mycorrhizal formation and growth of Leucaena leucocephala (Lam.) de Wit. and Zea mays L.

We show here that seed reserves in Leucaena leucocephala (Lam.) de Wit. and Zea mays L. (maize) are important for mycorrhizal formation and seedling g rowth. Seed reserve removal reduced mycorrhizal formation markedly in Leuca ena but not in maize, except at 15 and 45 days after seed reserve removal. Partial or total removal of seed reserves decreased plant growth and tissue nutrient concentrations in both hosts. Nodule number in Leucaena, which wa s related positively to plant biomass and mycorrhizal infection levels, was reduced when one or both cotyledons were severed. Leucaena seedlings witho ut or with partial seed reserves had higher nutrient use efficiencies throu ghout seedling growth. But such an effect was observed only initially in ma ize. Seed reserve removal increased the specific absorption rates of nutrie nts in both hosts. Phosphorus absorption rate was significantly and positiv ely related to root infection levels in both Leucaena and maize. Though the growth rates of plants without seed reserves were low initially, these pla nts had higher growth rates during later stages. We conclude that seed rese rves are not only important for seedling growth, but also for mycorrhizal f ormation and nodulation.