UNRAVELLING THE PHOTOPERIOD-DRIVEN PERFORMANCE OF KATARNI RICE LINES FOR YIELD AND QUALITY TRAITS

Abstract

Yield and quality characteristics were described for 60 lines derived from the Katarni variety across four different sowing dates. A univariate analysis of variance (ANOVA), which showed 14 traits to have statistically significant (p<0.01) genotypic variance, showed excellent genotypic divergence for the traits. Early sowing (29 May 2021) gave yields comparable to the optimal 15 June 2021 planting, but late sowing (15 July 2021) reduced yields in photoperiod‑insensitive lines. There was a yield decrease for the late plantings (15 July 2021) for lines that are photoperiod-insensitive, whereas several photoperiod-sensitive lines maintained comparatively higher grain yield under the same delayed sowing conditions. The Traditional Katarni lines were remarkable for their photoperiod sensitivity, as they did not flower until November regardless of sowing date. Across all environments, the number of grains, tillers, and 1000-g weight were positively correlated to yield which was true for the yield trait association analysis. of the traits that showed a non-significant positive direct effect on yield, the number of tillers.  was the most important, followed by 1000 grain weight. Flag leaf length and days to flowering were traits that had positive indirect effects, but their direct effects were different. There was a dependable set of traits that correlated to yield irrespective of length of photoperiod. Breeding lines for photoperiod insensitivity will likely stabilize flowering and yield. A balance of target traits such as number of grains, productive tillers, and 1000-g weight would provide excellent breeding scope for varying sowing dates.