Analysis of Plant Characteristics Determining Ear Weight Increase during the Ripening Period in Rice (Oryza sativa L.). II. The role of the reserved carbohydrate at heading stage upon the receptive efficiency of assimilation products in spikelets.

Contribution of Biomass Partitioning and Translocation to Grain Yield under Sub-Optimum Growing Conditions in Irrigated Rice

“…This is because when the current supply of assimilates is limited by cloudy or rainy weather, the accumulated carbohydrates are easily translocated to the grains (Yoshida, 1981). Such a compensatory effect has been reported in instances where the supply of carbohydrate during grain filling is limited (Kobata and Takami, 1983;Sumi et al, 1996), as in cases of unfavorable conditions during grain filling, such as water deficits (Kobata and Takami, 1983), shaded conditions (Nagata et al, 2001), and low total solar radiation in our study. This was why T averaged across cultivars was 51 % higher in the WS than in the DS.…”

High night temperature stimulates photosynthesis, biomass production and growth during the vegetative stage of rice plants

“…Our preliminary experiments suggest that although biomass production was not different during the ripening stage, the ratio of filled spikelets to 1,000-grain weight was lower in the HNT plants than in the control plants. Sumi et al (1996) reported that the accumulation of carbohydrates in leaf sheaths before heading was a major determinant of the number of filled spikelets. Our present results indicate that the accumulation of sucrose and starch was lowest in the HNT plants (Fig.…”

Can Yields of Lowland Rice Resume the Increases that They Showed in the 1980s?

“…Generally, the contribution of NSC stored before heading for fi nal grain yield is about 30% (Cock and Yoshida, 1972;Akita, 1989). However, much evidence has been accumulated to indicate that NSC accumulated before the onset of grain-fi lling plays a more important role in rice grain-fi lling than merely compensation for a shortage of assimilates during the grain-fi lling (Takeda et al, 1980;Seo and Ota, 1983;Akita, 1989;Nakamura et al, 1992;Sumi et al, 1996;Tsukaguchi et al, 1996; Horie et al, 1997). It is reported for rice (Nakamura et al, 1992) and wheat (Radley, 1978;Signh and Jenner, 1984;Feught and Hofner, 1985) that fi nal grain size is closely related to endosperm cell number, which in turn is controlled by the supply of substrate during its formation.…”