Anthesis of spikelets in the panicle of a tall indica rice cultivar, Kajalghara, was completed within a period of 7 days. Development progressed in basipetal fashion from the spikelets of the uppermost primary branch of the panicle to the lowermost. According to the timing of onset of anthesis, spikelets of the panicle were segregated into seven groups. Dry mass accumulation and starch and assimilate (soluble carbohydrates and amino acids) contents of each group were studied from anthesis to grain maturity. Spikelets that anthesed earlier produced better quality grains and also had higher sink efficiency in converting soluble assimilates into reserve structural matter than those which anthesed later. These results rule out deficiency in supply of assimilates as a cause of partial filling of grains in the rice panicle. The study also emphasises the need for improving the percentage of high density grains in the rice panicle to maximise the use of available assimilates and enhance the grain yield potential of the plant.
Growth, spikelet number and assimilate contents of the panicle on the mainshoot of 20 indica rice varieties consisting of four duration groups were measured at intervals during the period between 2 weeks prior to anthesis and maturity. Panicle development was of longer duration in the late maturing varieties than in the early, and grain yield of the former was more than that of the latter due to difference in grain number. Shifting the cultivation of an early duration check variety to match the time of reproductive development in the medium duration group did not change its pattern of development. During development, the concentration of soluble carbohydrates, amino acids and phosphates changed significantly with time, and the pattern was the same in all varieties. Initially the concentration was low, but increased sharply a few days before anthesis to a peak level, then declined until anthesis. After anthesis it decreased to a minimum at maturity. Pre-anthesis metabolite concentration of the panicle was higher in the late varieties than in the early varieties, but not much difference was observed post-anthesis. Growth durations of the vegetative, reproductive and grain filling periods collectively influenced grain yield but, on the basis of partial correlation analysis, the vegetative duration was found most important for yield.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.