Haploid plants have the gametophytic number of chromosomes. They are of great importance
especially in studies on the induction of muta tions and also for the production of homozygous
plants they are needed in large numbers. The conventional methods employed by plant breeders
for their production are cumbersome time-consuming laborious and rather inefficient.
Sometimes it may take years to produce a pure line. However with the introduction of in vitro
techniques especially anther culture for the induction of androgenesis it has become
increasingly evi dent that these methods considerably accelerate the production of haploids for
plant breeding programs. During the last decade in vitro-produced haploids have been incor
porated into breeding programs of many agricultural crops and positive results have been
obtained especially with rice wheat potato barley maize asparagus sunflower brassica
tobacco etc. Among these rice and wheat are the best examples in which a number of improved
varieties have been released. In wheat the breeding cycle can be shortened by three or four
generations when the pollen haploid breeding method is used instead of conventional
cross-breeding. The release of the wheat varieties Jinghua 1 and Florin is a typical example of
what can be achieved with other crops. Taking these developments into considera tion the
present volume Haploids in Crop Improvement I was compil ed.
