Genetic parameters and correlations of yield attributing characteristics of weedy rice in Sri Lanka

Abstract

Weedy rice possesses a high diversity in yield attributing characteristics and is an important resource for rice improvement programmes. The present investigation was carried out to estimate the genetic parameters and the correlations of yield attributing characteristics of weedy rice using 370 weedy rice accessions in Sri Lanka. Analysis of variance revealed significant differences (p < 0.05) among the weedy rice accessions for all the characteristics studied, implying the presence of a substantial amount of genetic variability and scope for selection. Shattering percentage, total number of spikelets per plant and the number of filled seeds per panicle exhibited high genotypic and phenotypic coefficients of variation. The degree of difference between phenotypic and genotypic coefficients of variation was relatively low for all the characteristics, except for the total number of spikelets per panicle, indicating comparatively less environmental influence. Very high heritability values coupled with very high genetic advance were observed for the shattering percentage, total number of spikelets per plant and the number of filled seeds per panicle. High heritability values coupled with high genetic advance were recorded for height at the booting stage, number of panicles per plant and tiller number at the seedling and booting stages suggesting the prevalence of additive gene action in the expression of these characteristics and the possible selection for effective improvement based on their phenotypic performance. Correlation studies showed that simply selecting comparatively taller plants with long seeds would identify high yielding weedy rice plants, which may be used in rice improvement programmes.