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. | 
