Indian Society of Genetics & Plant Breeding
QTLs associated with growth of rice seedling under
favourable and low temperature affected environments
were mapped using a DH population derived from a
cross between lowland indica variety, IR64 and upland
japonica variety, Azucena. A dynamic approach to
conventional mapping technique was employed in
conjunction with a novel mapping technique termed
as 'conditional mapping' using age-specific measures
for seedling height, seedling weight and root depth.
Among 15, 12 and 17 QTLs detected for seedling height,
seedling weight and root depth, respectively, only 7, 6
and 2 QTLs for the respective traits were common to
favourable temperature and low temperature affected
environments indicating that, while a set of QTLs could
hold the key to growth irrespective of growing
environments, few QTLs with situation-specific
expression might determine the differential response
of the genotypes to environmental stress. The study
also indicated that the difference in time of expression
of some of the QTLs detected across growing
environments might be additional feature of differential
response of genotypes to varied growing
environments. The conditional mapping technique
allowed detection of 4 QTLs for seedling height and 6
QTLs each for seedling weight and root depth- which
remained undetected by the conventional mapping
technique indicating temporal pattern of gene
expression and suggesting the importance of this
technique in QTL analysis for developmental traits.
Keywords: Rice, seedling growth, quantitative trait loci (QTl), low temperature stress, conditional mapping
Year: 2007
Volume: 67
Issue: 4
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906
P. K. Pathak and J. Zhu info_circle
Download PDF