Studies on Genetic Variability of Ratoon F1s for Grain Yield, Yield Traits and Quality Traits in Rice (Oryza sativa L.)

Abstract

Ratooning, the ability of the rice plant to regenerate new panicle-bearing tillers after harvest, could be a practical way to increase rice production per unit area and per unit time. The present investigation was conducted at Acharya N.G. Ranga Agricultural University – Regional Agricultural Research Station (RARS), Maruteru, Andhra Pradesh, to assess genetic variability, heritability and genetic advance for yield, ratoonability, physical and cooking quality traits in rice. The experimental material consisted of 28 ratoons of single cross F₁s developed from eight parents through diallel mating design in kharif season. The 28 F₁ ratoons, along with eight parents (MTU-1001, BPT-3291, MCM-100, MTU-1140, MTU-1121, MTU-1064, MUT-1061 and MTU-1064) were evaluated in a randomised complete block design (RCBD) with three replications during the summer season. The analysis of variance for the ratoon of 28 F1s along with 8 parentsshowed significant differences for all 27 traits in the study (viz., 10 yield-associated traits, 3 traits contributing for ratoonability, 6 physical grain quality traits and 8 cooking quality traits). The phenotypic coefficient of variation (PCV) values are higher than the genotypic coefficient of variation (GCV) values and the difference between them indicates the little role of environment in the expression of these traits. A wide range of PCV (1.86 - 30.73%) and GCV (1.56– 29.96%) was obtained for 27 traits. The presence of higher GCV and PCV observed in grain yield per plant (g) followed by gel consistency (mm) and alkali spreading value (mm), signifies the additive genetic control in the inheritance of that trait. High heritability along with high genetic advance as percentage of mean was recorded for the characters viz., number of ear bearing tillers per plant, number of grains per panicle, grain yield per plant, water uptake, gel consistency, alkali spreading value and amylose content, indicated the role of additive gene action in governing the inheritance of this traits and improvement of yield related and quality traits through simple selection may be rewarded. The study concludes that 28 ratoon F1s crosses, along with their 8 parents had adequate amounts of variability for yield-associated traits and physico-chemical quality traits.