Indian Society of Genetics & Plant Breeding

Dynamic mapping of QTLs for rice seedling growth

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QTLs associated with growth of rice seedling were mapped
using a doubled-haploid (DH) population derived from a
cross between lowland indica variety, IR64 and upland
japonica variety, Azucena. Age-specific measures on
seedling growth parameters such as seedling height, root
depth, seedling weight, recorded at seven days interval,
starting from 16th day of sowing, were used to detect the
QTLs. A QTL mapping technique termed as ‘conditional
mapping’ has been described and the utility of the
technique has been illustrated. Altogether 11 QTLs each
for seedling height and root depth and 10 QTLs for
seedling weight were detected. The number of QTLs varied
according to stages of growth indicating age-specific
action of QTLs. The number of QTLs detected by
conventional mapping at different stages of observation
varied between 4 to 7 for seedling height and 2 to 4 for
root depth and seedling weight with few QTLs for all the
traits appearing consistently over the stages of
observation. The conditional mapping technique allowed
detection of three QTLs for seedling height and four QTLs
each for root depth and seedling weight which remained
undetected by the conventional mapping technique.

Keywords: Rice (Oryza sativa L.), seedling height, root depth, seedling weight, quantitative trait loci (QTL), conditional mapping


Year: 2008
Volume: 68
Issue: 4
Article DOI: N/A
Print ISSN: 0019-5200
Online ISSN: 0975-6906



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