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

Abstract

The effects of night temperature on biomass accumulation and plant morphology were examined in rice (Oryza sativa L.) during vegetative growth. Plants were grown under three different night temperatures (17, 22 and 27°C) for 63 days. The day temperature was maintained at 27°C in all treatments. The final biomass of the plants was greatest in the plants grown at the highest night temperature. Total leaf area and tiller number were also the greatest in this treatment. Growth analysis indicated that the relative growth rate in the 27°C night‐temperature treatment was maximal between days 21–42 and this was caused by increases in leaf area ratio, leaf weight ratio and specific leaf area. Plant total nitrogen contents did not differ among treatments. However, nitrogen allocation to the leaf blades was highest and the accumulation of sucrose and starch in the leaf blades and sheaths was the lowest in the 27°C night‐temperature treatment by day 42. Despite this, dark respiration was also highest, and both the gross and net rates of CO2 uptake at the level of the whole plant at day 63 were the highest in the 27°C night‐temperature treatment. Thus, high night temperature strongly stimulated the growth of leaf blades during the early stage of rice plant growth, leading to increased biomass during the vegetative stage of the rice plants. As the CO2 uptake rate per total leaf area was higher, photosynthesis at the level of the whole plant was also stimulated by a high night temperature.

Varietal Differences in Biomass Production of Rice Early After Transplanting at Low Temperatures

“…5), which would be an inherent characteristic of semi-dwarf highyielding indica genotypes. Carbohydrate accumulation in sink organs increases at low temperatures (Paul et al, 1991;Kanno et al, 2009). However, the decreased shoot elongation at the low temperatures in ET would mean a smaller volume of sink tissues (i.e.…”

“…Changes in temperature affect many traits that are responsible for biomass productivity in rice, including respiration, leaf photosynthesis (Makino et al, 1994;Maruyama and Nakamura, 1997), efficiency of nitrogen (N) use for leaf photosynthesis (Nagai and Makino, 2009), leaf emergence (Hiraoka et al, 1987), leaf elongation (Cutler et al, 1980), and the allocation of biomass and N to leaves (Kanno et al, 2009). However, understanding of the genotypic differences in biomass productivity of rice in response to temperature is limited, especially under fi eld conditions.…”

The Effects of Night-time Temperatures on Physiological and Biochemical Traits in Rice

“…In rice, higher plant respiration was observed in the vegetative stage due to HNT (Kanno et al, 2009).…”

Asymmetric warming effects on N dynamics and productivity in rice (Oryza sativaL.)

“…The warming treatment increases plant N accumulation, likely due to elevated soil N mineralization in the warming plots and/or the increased N uptake ability of plant roots (Tingey et al 2003). Although DW increased the C gain by photosynthesis and NW increased the C loss by night respiration, the higher-temperature treatment decreased the chlorophyll content of the rice, inhibited its photosynthesis and reduced its photosynthetic rate and photosynthetic product (Li 2003;Kanno et al 2009;Kanno and Makino 2010). The continuous daytime average temperature during 3 d, which was over 32°C/5 h, would affect the growth and development of conventional rice varieties, and Fig.…”