Record Details

Development and applications of EST-SSR markers in sorghum

OAR@ICRISAT

View Archive Info
 
 
Field Value
 
Relation http://oar.icrisat.org/3288/
 
Title Development and applications of EST-SSR markers in sorghum
 
Creator Ramu, P
 
Subject Sorghum
 
Description Microsatellites or simple sequence repeat (SSR) markers are playing a significant role in
molecular breeding programs. But, conventional methods of SSR markers development
are laborious and expensive. The alternative way is to explore the existing databases for
the development of new markers. Complete genome sequencing projects depositing
numerous amounts of genomic and genic (expressed sequence tag, EST) sequence in the
public databases. This facilitates to explore for the development of new marker systems
including SSRs, SNPs, etc.
In the present study, 600 EST-SSR markers were developed in sorghum by mining the J.
Craig Research Institute [formerly, The Institute for Genome Research (TIGR)] database.
Non-redundant EST sequences which are having the homology with rice genome were
selected for the designing these 600 markers (by exploiting rice-sorghum synteny). PCR
conditions for these primer pairs were optimized on four parental pairs of sorghum
genotypes constituting two mapping populations. About 23% of markers were found
polymorphic in parents of shootfly resistance mapping population (BTx623  IS18551).
These polymorphic markers were screened against the shootfly RIL mapping population.
A total of 82 EST-SSR markers were mapped onto the previously existing skeleton map
of the sorghum using shootfly resistance mapping population. After adding these 82 new
EST-SSR markers, the map distance was extended to 2966.4 cM. This map distance was
~250 cM larger than the previously reported longest linkage map in sorghum. These
EST-SSR markers, however, filled gaps or marker-rare regions in the existing linkage
map of sorghum targeted based on rice-sorghum sequence similarity. This study
demonstrates the utility of comparative genomic information in targeted development of
markers to fill gaps in linkage maps of related crop species for which sufficient genomic
tools are not available...
 
Date 2009
 
Type Thesis
NonPeerReviewed
 
Format application/pdf
 
Language en
 
Rights —
 
Identifier http://oar.icrisat.org/3288/1/4796-Report.pdf
Ramu, P (2009) Development and applications of EST-SSR markers in sorghum. PhD thesis, Osmania University.