Indian Society of Genetics & Plant Breeding
One hundred and sixteen restorers whose hybrid
combinations had been ,evaluated in the national testing
were critically evaluated in the field for two years. Those
were grouped as high, medium and low based on Duncan's
Multiple Range Test (DMRT) and mean and standard
deviation of joint scores. More than 75% of the entries
were found in the same groups in both the years indicating
a very high reproducibility and repeatability of the method
of grouping. Only 50 restorers out of 116 were found
to give heterotic hybrids with an yield advantage of 1.0
t ha-1 or more over the best inbred check variety. Majority
of the restorers (>86%) showing heterosis were from the
medium group emphasizing the need to select restorers
from this group in order to develop heterotic hybrids. In
another experiment, 28 Fs lines derived from a eMS based
hybrid IR 62829A1 WGL 3962 were crossed with IR 62829A
to assess the potential of newly developed iso-cytoplasmic
restorers. The F, crosses were evaluated along with the
original hybrid, IR 62829A1 WGL 3962. Results indicated
that only 32% of the restorers were able to restore the
complete fertility in hybrids implying that the restoration
is governed by more than one gene. Nearly 14% of the
crosses _involving new restorers showed significant
heterosis over the original hybrid from which they were
derived indicating that there were heritable genetic factors
responsible for heterosis. Selection of restorers based
on the joint scores of a number of dependent traits
appears to be a sound criteria to develop heterotic rice
hybrids.
Keywords: Rice, selection criteria for restorers, heterosis, iso-cytoplasmic restorers
Year: 2003
Volume: 63
Issue: 3
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906
C. H. M. Vijayakumar, M. lIyas Ahmed, B. C. Viraktamath, M.S. Ramesha and B. Mishra info_circle
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