Increased grain yield and biomass allocation in rice under cool night temperature
Article first published online: 16 JUL 2010
© 2010 Japanese Society of Soil Science and Plant Nutrition
Soil Science & Plant Nutrition
Volume 56, Issue 3, pages 412–417, June 2010
How to Cite
KANNO, K. and MAKINO, A. (2010), Increased grain yield and biomass allocation in rice under cool night temperature. Soil Science & Plant Nutrition, 56: 412–417. doi: 10.1111/j.1747-0765.2010.00473.x
- Issue published online: 16 JUL 2010
- Article first published online: 16 JUL 2010
- Received 28 July 2009. Accepted for publication 2 March 2010.
- grain yield;
- night temperature;
- Oryza sativa L;
The effects of different night temperatures on grain yield were examined in rice (Oryza sativa L. Akita-63) during the ripening period. Plants were grown under two different night temperatures (22 and 27°C) from anthesis to harvesting. The day temperature was maintained at 27°C in both treatments. Although the final biomass at harvest did not differ between the treatments, the dry weight of the panicles was significantly greater in the cool night temperature treatment. This increase in panicle weight was associated with increases in the 1000-kernel weight and the ratio of filled spikelets. Although panicle respiration in the high night temperature treatment decreased to almost zero just after the cessation of grain filling, the net CO2 fixation rate per day in the whole plant in this treatment tended to be higher, and this was associated with a higher level of starch accumulation. After grain filling, the starch content decreased and the final dry weight of other plant parts, including dead organs and new tillers, was greater in the high night temperature treatment. Thus, the noted decline in yield at the high night temperature led to changes in carbon allocation to new sinks for vegetative reproduction at the whole plant level. From these results, we considered the possibility that a cool night temperature tends to favor carbon allocation to panicles, resulting in higher yield.