Because haploid plants have the gametophytic number of chromosomes, that is, a single set of chromosomes in the sporophyte, they are of great importance,especially in studies on the induction of mutations and also for the production of homozygous plants. It is very
hard to produce haploids and homozygous diploids by conventional methods; however, with the introduction of in vitro culture of excised anthers, isolated pollen, and unpollinated ovules, the production of haploids for breeding programs was considerably speeded up. Since the first haploid Nicotiana tabacum plant was obtained in 1967 [1], the large number of haploid plants have been induced from various species of both herbaceous and ligneous plants, such as Oryza sativa, Setaria italica, Zea mays,and Aesculus hippocastanum [2–5].