Physiological genetics of character associations in hybrid rice

Abstract

The studies were conducted at the College of Horticulture, Vellanikara, to analyse the "Physiological Genetics of character associations in Hybrid rice (Oryza Sativa L.) ". The study mainly aims to characterize the morpho- metabolic associations in plant attributes that contribute to higher productivity in hybrid rice. Three hybrids and their parental genotypes were evaluated to. understand how different genotypes may compliment one another physiologically and also to identify the stages at which the better physiological efficiency contribute heterosis. From this study, it was revealed that the heterotic advantages result in two ways VlZ., generalized morphologic improvement in growth and yield attributes and efficiency enhancement. The results also envisages the importance of heterotic functional efficiency over morphological efficiency. The stability of chlorophyll aJb ratio and the differential changes of Nrase enzyme activity, both at different phenophases shall serve as a better index for selection of genotypes in rice breeding programme. The pattern of biochemical character like soluble protein, enzymes like Peroxidase, catalase revealed that the magnitude of physiological expression is independent of genetic 'capabilities or genetic expressivity is conditioned by physiology of the plant. The soluble protein and enzyme activity at tillering phase appears to be the most critical in deciding the yield of the rice, in order to achieve a complete heterotic effect' in rice breeding. The biochemical as well as physiological aspects at different growing stages should be given due importance