Agriculture Reference
In-Depth Information
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Fig. 19 Effect of low temperature on nutrient uptake in rice (Takahashi et al.
1954).
Color image of this figure appears in the color plate section at the end of the topic.
irradiance (1,500 Omolquanta m -2 s -1 ) decreases in quantum
effi ciencies in PS II (H PS II) and PSI (H PS I) and in the rate
of CO 2 assimilation were observed with a decrease in the
maximal quantum effi ciency of PS II (F v /Fm) by simultaneous
measurements of chlorophyll fl uorescence, P700 + absorbance
and gas exchange. The decreases in H PS II were most highly
correlated with those in CO 2 assimilation. Although the initial
and total activities of ribulose-1, 5-biphosphate carbocylase/
oxygenase decreased slightly, the maximal activity of Rubisco
remained almost constant (Hirotsu et al. 2005). Herath and
Ormrod (1965) reported that water temperature affected
the number and size of stomata of rice seedlings, at a lower
temperature (16°C), the number of stomata was smaller
and their size was larger than those at higher temperature
(24°C and 32°C). The temperature responses of photosynthetic
assimilation rate growth were examine in rice grown
hydroponically, under varying day/night temperature
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