Vergara - 1976 - Physiological and morphological adaptability of ri

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Climatic influence on photosynthesis
and respiration of rice
I. Tanaka
SUMMARY
were reviewed between climatic factors. photosynthesis. photorespiration,
and dark respiration of rice. as well as difference in Relationships climatic
response according to varieties and cultural management. The photosynthesis
of rice of tropical origin was seriously damaged by low temperature. even above
the freezing point. Chili injury of photosynthesis varied considerably" with rice
varieties. leaf nitrogen content. and root temperature for chilling period. The
temperattire-photosynthesis curve of nee was strikingly affected by photorespiration.
The wide temperature optimum for photsynthesis in normal air was
mainly attributable to increase in photorespiratitm at high temperature. Temperaturodark
respiration relations were well fitted by Aurhenius equation rather
than Q". The respiration of roots wuss more sensitive to high temperature injury
than that of leaves. The light-photosynthesis curve of rice leaves differed with leaf
position. nitrogen content. and thickness of leaves. The photosynthesis and
grain yield in a rice population were basically governed by leaf angle as well as by
leaf area index (LAI). The effect of atmospheric CO; enrichment on photosynthesis
was greater in C; species than in C. species. The lowering oft“), concentration
in an air was effective in increasing the dry matter production of rice. while
it brought about remarkable sterility‘. The submerged conditions resulting from
the monsoon rainfall greatly influenced photosynthesis of a rice population
by controlling C, weeds which compete seriously with rice plants.
INTRODUCTION
The differentiation and development of physiological functions have been
brought about by the complex interrelationships betvreen organism and environment
through a long process of evolution.
Rice. Oiyza sariva, is considered to have originated under a tropical rainy
climate which is characterized by high temperature. low light intensity, high
humidity. and abundant rainfall. The rice plant assimilates CO, through the
Calvin cycle (C1 species) and has a photorespiration z-n-"stem which releases a
large amount of CO, in light. On the other hand. tropical climate xvhich is
characterid by high temperature. high light intensity‘. and high evapotranspiratio11.
has brought about the differentiation of species with high photosynthetic
1'.
Tariaka. National Institute of Agricultural Sciences. Konosu. Saitama. Japan.