Deciphering the genetic architecture of early flowering in the high yielding rice variety ‘KAU Manu Ratna’

Abstract

KAU Manu Ratna is a rice variety popular for its short duration and high yield. In the present study, the gene action of flowering genes of KAU Manu Ratna was studied in breeding populations obtained by crossing it with a long duration variety Swarna-Sub1. Studies in F₁, F₂, BC₁F₁, BC₁F₂ and BC₂F₁ populations revealed that the flowering duration in KAU Manu Ratna is controlled by two dominant genes with polymeric gene action. All the F₁, BC₁F₁ and BC₂F₁ plants flowered along with KAU Manu Ratna showed complete dominance for earliness, whereas F₂ plants segregated in a ratio of 9:6:1 for early, mid and late duration revealing its polymeric gene action. The segregation pattern of BC₁F₂ families also supports the polymeric gene action. In the F₂ population, days to flowering showed no strong correlation with yield-contributing traits. This suggests that the alleles responsible for earliness do not adversely impact the overall yield. Given these characteristics, KAU Manu Ratna is an ideal genetic resource for developing short duration climate-resilient rice varieties without compromising yield.