Genetic variability and association studies for yield and floral traits in Temperature Sensitive Male Sterile lines (TGMS) of rice (Oryza sativa L)

Abstract

One hundred and nineteen rice TGMS lines were evaluated for ten morphological traits in fertility favouring environment and eight floral traits in sterility favouring environment respectively. The analysis of variance exhibited significant difference among the TGMS lines  for all the  traits studied except sterile lemma length indicates large amount of genetic variability was present in the experimental material. The morphological traits viz.,  pollen fertility, number of grains per panicle, single plant yield and floral traits namely anther length, anther breadth, stigma length, stigma breadth, glume opening angle, stigma exertion and pollen sterility were recorded high phenotypic and genotypic coefficient of variation.  High heritability with high genetic advance as per cent of mean was observed in morphological traits namely, days to 50 per cent flowering, pollen fertility, spikelet fertility, number of grains per panicle,  single plant yield and in floral traits viz., anther length, anther breadth, stigma length, stigma breadth, stigma exertion, glume opening angle and pollen sterility reveals presence of additive gene action and further genetic improvement through direct selection would be effective for these traits. The single plant yield observed significant and positive correlation with plant height, number of productive tillers per plant and spikelet fertility shows importance of these characters for yield improvement. In floral traits, stigma breadth and glume opening angle had non significant and positive correlation with pollen sterility. Path analysis showed that plant height and number of productive tillers had positive direct effect on single plant yield.  In floral traits, stigma breadth and glume opening angle had small positive effects on pollen sterility.