Development and evaluation of iso-cytoplasmic rice restorer lines for different agro-morphological traits

Abstract

A set of 390 iso-cytoplasmic restorer lines were developed
from 25 popular rice hybrids grown in India through pedigree
breeding exercising selection for spikelet fertility, yield and
extent of panicle exsertion were evaluated for various agromorphological traits. Correlation analysis showed that yield
per plant was significantly correlated with number of tillers
(0.208), panicle length (0.127) and spikelet fertility (0.134).
Principal component analysis indicated that the first four
principal components had eigenvalue of > 1.0 and
cumulatively explained 74.3% of total variance. Grain
characters namely, test weight (0.451), kernel length before
cooking (0.418), kernel breadth before cooking (0.136) and
spikelet fertility (0.402) contributed positively towards
principal component I. Yield per plant showed a positively
skewed distribution with panicle length and a nearly linear
relationship with spikelet fertility. A core set of 21 genotypes
capturing the entire range of phenotype for different traits,
was identified from 390 genotypes using advanced M
(maximization) strategy and statistically validated. Besides
this, promising iso-cytoplasmic restorer lines originating
from different hybrids were identified for various agromorphological traits. This is the first report on developing
iso-cytoplasmic restorers from popular rice hybrids, which
can be used in developing heterotic hybrids when crossed
with diverse non-parental CMS lines.