ABSTRACT
Agricultural activity demands improved crop varieties with desirable traits such as quality, crop yield, and resistance to environmental stresses. Use of haploids has emerged as a key strategy for crop improvement. Haploids having a single set of chromosomes in the sporophytic phase have become a valuable source to screen for desired traits or to introduce a mutation in their genetic content. Furthermore, doubled haploids (DHs) can be obtained by spontaneous or induced chromosome doubling. DHs are homozygous at all loci, and they can be propagated through seed. DHs achieve complete homozygosity in a single generation. On the contrary, the conventional breeding method requires six to seven generations of self-crossing. In vitro production of haploids for crop improvement has been successfully achieved in many crops such as rice, wheat, barley, maize, tomato, potato, brassicas, grapes, sunflower and so on. In addition to crop improvement, DHs are an excellent source for gene mapping, cytogenetic research, and evolutionary studies. This chapter will focus on basic principles and recent advances in haploids production and their use for crop improvement.
