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variation can explain gametoclonal variation such as new genetic variation induced
by cell culture procedures, from segregation and independant assortment, chromo-
some doubling procedures, etc., (Morrison and Evans 1987 ; Huang 1996 ).
7.4   Induction of Mutations
In general, a majority of induced mutations are recessive and, therefore, are not ex-
pressed in diploid cells due to the presence of dominant allele. Since haploid plants
have only one set of chromosomes, their dominant and recessive characteristics can
be seen simultaneously on separate plants. It is extremely advantageous to provide a
convenient system for the induction of mutations and selection of mutants with desir-
able traits in the absence of their dominant counterparts (Bhojwani and Razdan 1996 ).
7.5   Obtaining New Genotypes with Alien Chromosomes
The technique of interspecific and intergeneric hybridization can be combined with
anther culture techniques (Thomas et al. 2003 ) for obtaining new genotypes with
alien chromosomes. Thus new genotypes with various reconstructed chromosome
complements can be obtained after their successful chromosome doubling.
7.6   Genetic Manipulation
As microspore culture is a single cell system, it makes selection at the single cell
level possible and, furthermore, offers new prospects for genetic manipulation like
mutagenesis and transformation. Direct gene transfer by microinjection offers the
possibility of transgenic plant formation by using isolated pollen culture having
high regeneration efficiency (Kasha and Maluszynski 2003 ). Moreover, if trans-
genes can be incorporated into the haploid microspore genome prior to DNA syn-
thesis and chromosome doubling, the doubled haploids may also be homozygous
for the transgenes. Thus isolated microspores not only provide a good target for
bombardment, but also are readily amenable to transgene in vitro selection. Jahne
et al. ( 1994 ) were the first to achieve plants homozygous for the transgenes using
biolistic bombardment of barley microspores.
7.7   Genomics
Doubled haploids play a vital role in genomics, especially, in the integration of ge-
netic and physical maps, thereby, providing precision in targeting candidate genes
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