The phenomenon of haploidy in more evolved plants represents nowadays a field with extensive and profound implications for research in genetics and breeding. Obtaining haploids by in vitro culture of pollen, anthers, and unfertilized eggs, represent methodologies whose potential for action on hereditary susbtance is insufficiently exploited. These methodologies provide genetic engineering with the most favorable conditions to detect various genomes and linkage groups, but especially to determine the alleles present, either by controlled change of the genes and action on them, or by substitution and transfer. A common feature of all haploids appearing in species of higher plants is the low vitality and slowed growth due to the so-called " haploid depression " state that is determined by the hemizigotic structure of the haploids. Therefore, there is a general reduction in the quantity of chemical components, reduction which is not always proportional to the degree of ploidy.