Department of Plant Breeding and Genetics, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai-625 104, India
Eight CMS lines were evaluated for morphological characteristics that influence outcrossing rate in hybrid rice under wetland condition. There was a marked variation in out crossing rate (OCR) of CMS lines ranging from 6% to 13% under uniform weather conditions for all the CMS lines. Variation in plant height, number of panicle per plant and panicle length appeared to have an influence on outcrossing rate. Phenotypic acceptability, plant height (cm), days to 50% flowering, Panicles per plant, stability for pollen sterility, panicle exertion rate (PER) and out crossing rate (OCR) here assessed. Among them, IR 58025 A, IR 68888 A, IR 68897 A, TNAU CMS 2A and COMS 24 A recorded significant mean values for some characters and exploited for heterosis breeding since they possess critical outcrossing traits such as panicles per plant and panicle length. Plant height, panicle per plant and plant length, had moderate heritability with low genetic advance expected in the subsequent generation revealed role of additive gene action. The GCV and PCV somewhat varied from each other for most of the characters studied showed, there is no environmental influence on these traits. Genotypic correlation coefficient were higher than strong relation to phenotypic correlation coefficient, indicated high relation among the studied character.
CMS lines, Genetic variability, Out crossing rate, Rice
