A large number of maize genotypes are currently being evaluated to determine the effect of environmental stress caused by the aluminum found in cerrado soils on meiotic behavior. In the present study we report the occurrence of cell fusion followed or not by chromatin degeneration in meiocytes of some plants of an inbred line of maize grown on acid and corrected soil in the Brazilian central plateau. The results suggest the absence of any soil effect on the irregularities observed since the number of affected plants was higher among those grown on corrected soil. The possible causes of these irregularities and their influence on male sterility are discussed.
Com o objetivo de avaliar o efeito do stress ambiental causado pelo alto teor de alumínio encontrado nos solos de cerrado sobre o comportamento meiótico, um elevado número de genótipos de milho está sendo avaliado. Neste estudo relata-se a ocorrência de fusão celular, seguida ou não de degeneração cromatínica, em meiócitos de algumas plantas de uma linhagem endogâmica cultivada em solo ácido e corrigido no planalto central Brasileiro. Os resultados não sugerem qualquer efeito do solo sobre as irregularidades observadas, pois o número de plantas afetadas foi maior dentre aquelas cultivadas em solo corrigido. As possíveis causas destas irregularidades e suas influências na produção de macho-esterilidade são discutidas

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We report here a new meiotic abnormality recorded in one plant of an inbred line of Zea mays. After an apparently normal prophase I, chromosomes did not congregate in a single metaphase plate. Bivalents remained scattered in the cytoplasm, giving rise to several spindles. Despite the occurrence of multiple spindles, meiosis I proceeded normally, forming a varied number of nuclei at telophase I. The presence of one or a few chromosomes in the nucleus was enough to induce local cytokinesis, which was evident from metaphase I. Each cell resulting from meiosis I expressed its own program and progressed through the cell cycle. Therefore, failure of chromosome congregation on a single plate also occurred at meiosis II, where further irregular cytokinesis was observed. As a consequence of the two abnormalities, polyads occurred, resulting in pollen grains of different sizes and in sterility at a frequency of up to 93.5%.

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