PHENOTYPIC AND GENOTYPIC ANALYSIS FOR EARLY MORNING FLOWERING TRAITS AT FLOWERING STAGE IN RICE (Oryza sativa L.)

The study focused on phenotypic and genetic factors underlying early morning flowering traits in rice in the hope that rice genetic improvement in the warming future will be made possible. Quantitative trait loci (QTL linked to early morning flowering (EMF) traits was analyzed by selective genotyping of phenotypic extremes among 684 BC1F2 lines (derived from the cross PSB Rc82 x WAB56-125) under glasshouse condition was undertaken using single marker analysis (SMA). Four parameters of flower opening time or start time (FOT), peak of flowering (POF), flower mostly closed (FMC), and flower closed (FC) time were recorded. Results of SMA revealed three markers possibly linked to FOT on chromosome 5, 7, and 9, while 6 markers were possibly linked to POF, FMC and FC time on chromosomes 5, 7, 8, 9, and 11. Generally, markers on chromosomes 5, 7 and 9 indicated QTLs controlling EMF during flowering stage in rice. While this needs to be confirmed using a larger population size and other mapping methodology, the results could already be useful for further fine mapping and eventually for marker-assisted selection of heat escape rice cultivars in the future.