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.