From a genetic perspective, meiosis can be considered as a nucleus differentiation process having the main goals of producing cells spores or gametes with a halved chromosome number and new genetic combinations, two features having a capital significance in the existence of diploidy and in the evolutive success of sexual reproduction in eukaryotes. The large chromosomes present in the economically important plants and the availability of their meiosis especially the male meiosis have greatly stimulated the use of plant chromosomes to study cytologically the basic processes of the meiotic cycle. In spite of the possibility that meiosis or some of its characteristics may differ between the sexes, male meiocytes, which are found in hundreds within the anthers, are the usual choice for studying meiotic chromosome behavior in plants. In most plants where meiotic studies have been extensively conducted, anthers are born in large terminal inflorescences the tassel in maize, and spikes or panicles in cereal grains.