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Single nucleotide
polymorphism genotyping and its application on mapping and
marker-assisted plant breeding
S. Abdolhamid
Angaji
Tarbiat
Moallem University, Postal Code 19446-84831, Tehran, Iran.
E-mail:
ershad110@yahoo.com.
Accepted
13 February, 2009 |
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The nucleotide diversity across a genome is the source of
most phenotypic variation. Such DNA polymorphism is the
basis for the development of molecular markers, an
indispensable tool in genetic mapping studies. In general,
the high resolution fine mapping of genes is often limited
by lack of sufficient number of polymorphic molecular
markers. This problem is compounded with traits controlled
by multi-genes because in several such studies, QTL cannot
be resolved to a workable resolution that could be feasible
for predicting the candidate gene(s) associated with traits
of interests. The availability of abundant, high-throughput
sequence-based markers is the key for detailed genome-wide
trait analysis. Single-nucleotide polymorphisms (SNP) are
the most common sequence variation and a significant amount
of effort has been invested in re-sequencing alleles to
discover SNPs. In fully sequenced small-genome model
organisms, SNP discovery is relatively straight forward,
although high-throughput SNP discovery in natural
populations remains both expensive and time-consuming. Here
five central biochemical reaction principles that underlie
SNP-genotyping methods specifically for large panel sizes
and an intermediate number of SNPs are reviewed.
Key
words:
SNP, QTL mapping, marker assisted breeding. |
