This study was conducted in a greenhouse, with the objective of comparing the growth and mycorrhization of nine corn genotypes and the colonization by autoctonous arbuscular mycorrhizal fungi (AMF), in addition to the AMF soil inoculum potential. Soil was collected on a degraded pasture (originally a 'cerrado' area), fertilized, mixed with river sand, fumigated and placed in 3-kg plastic bags. Five seeds of each corn genotype were seeded in 20 bags, but only 10 received solution with 300 AMF spores ca., collected from the pasture soil. Each bag, containing one single plant, composed a replication. The plant height and stem diameter were evaluated in 15, 30, 45 and 60 days after seeded, plus dry matter weight of roots and canopy, colonization and mycorrhizal dependency. On the same period, the second experiment was prepared to evaluate the soil potential of FMA of pasture soil, with serial dilution of 90, 80, 70, 60, 50, 40, 30, 20 and 10%, including only no sterilized soil (100%) and only sterilized soil (0%), on plastic bags, seeded with Tractor hybrid. After 60 days, roots were collected to quantify the COL. Inoculation of AMF resulted in a differential increase of dry matter, with highest values of dry matter weight of canopy were found on the genotypes Condá, F0, D1 and F8 and lowest weight of roots for genotypes Tractor and D7. The genotypes showed no response or low response to the mycorrhyzae, and exhibited different response to colonization, with the averaging of 60% for Condá, Sol da Manhã, F0 and D1. The pasture area, even degraded, showed a high soil inoculum potential, presenting high root colonization percentage by FMA.
Zea mays; plant breeding; degraded pasture; cerrado vegetation (Brazilian savannah)
