Rapid screening for aluminum tolerance in maize (Zea mays L.)

A significant decrease in maize grain yield due to aluminum toxicity is con sidered to be one of the most important agricultural problems for tropical regions. Genetic improvement is a useful approach to increase maize yield i n acid soils, but this requires a rapid and reliable method to discriminate between genotypes. In our work we investigated the feasibility of using he matoxylin staining (HS) to detect Al-tolerant plants at the seedling stage. The original population along with two populations obtained after one cycl e of divergent selection were evaluated by net root growth (NRG) and HS aft er 7 days in nutrient solution. Results showed a negative correlation betwe en NRG and HS in all populations, in which sensitive plants, characterized by low NRG. exhibited more intense staining than tolerant plants. These res ults indicate that HS is a useful procedure for selecting At-tolerant maize seedlings.