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Effect of age and carbon-dioxide concentration on assimilation by detached leaves of tea and sunflower*

Published online by Cambridge University Press:  27 March 2009

D. N. Barua
Affiliation:
The Botany School, University of Cambridge

Extract

A simple method has been described for measuring photosynthesis of detached leaves.

The reduced rate of photosynthesis of the tea leaf, immediately after excision, is due to stomatal closure. In mature detached leaves, kept well supplied with water in diffuse light or darkness and in a humid atmosphere, normal stomatal opening and maximum photosynthetic rates were obtained between 12 and 30 hr. from excision. Stomata on sunflower leaves do not close on excision.

Variation in the initial concentration of CO2 between 1·0 and 4·0% vol. with a final concentration not below 0·5% did not affect the rate of photosynthesis of sunflower leaves at 25° C. and under 32 klux light intensity. Under the same conditions of light and temperature, there was no change in the photosynthetic rates of tea leaves in 1 and 2% initial and 0·2% final CO2 concentrations. There were indications that CO2 concentrations below 1·0% might be rate-limiting for certain tea leaves, assimilating under low light (4 klux).

The development of photosynthetic capacity in the young leaves of tea and sunflower is a gradual process. In sunflower, the photosynthetic capacity develops fully before, and in tea after the leaf reaches half its final size.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1960

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References

REFERENCES

Barua, D. N. (1953). Effect of light intensity on the growth and assimilation of tea seedlings. Ph.D. Thesis Cambridge.Google Scholar
Briggs, G. E. (1920). Proc. Roy. Soc. B, 91, 249.Google Scholar
Briggs, G. E. (1923 a). Proc. Roy. Soc. B, 94, 12.Google Scholar
Briggs, G. E. (1923 b). Proc. Roy. Soc. B, 94, 20.Google Scholar
Brown, H. T. & Escombe, F. (1905). Proc. Roy. Soc. B, 76, 29.Google Scholar
Chibnau, A. C. (1939). Protein Metabolism in the Plant. New Haven: Yale University Press.Google Scholar
Clendenning, K. A. & Gorham, P. R. (1950). Canad. J. Res. C, 28, 114.CrossRefGoogle Scholar
Denny, F. E. (1932). Contrib. Boyce Thompson Inst. 4, 65.Google Scholar
Eden, T. (1944). Emp. J. Exp. Agric. 12, 177.Google Scholar
Freeland, R. O. (1952). Plant Physiol. 27, 685.CrossRefGoogle Scholar
Goodall, D. W. (1946). Ann. Bot., Lond., 10, 305.CrossRefGoogle Scholar
Irving, A. A. (1910). Ann. Bot., Lond., 24, 805.CrossRefGoogle Scholar
Kidd, F.West, C. & Briggs, G. E. (1921). Proc. Roy. Soc. B, 92, 386.Google Scholar
Mackinney, G. (1941). J. Biol. Chem. 140, 315.CrossRefGoogle Scholar
Maskell, E. J. (1928). Proc. Roy. Soc. B, 102, 467.Google Scholar
Petrie, A. H. K. & Arthur, J. I. (1943). Aust. J. Exp. Biol. 21, 191.Google Scholar
Singh, R. N. & Jha, J. D. (1939). Nature, Lond., 142, 161.CrossRefGoogle Scholar
Singh, R. N. & Lai, K. N. (1935). Ann. Bot., Lond., 49, 292.Google Scholar
Tubbs, F. R. (1936). Bull. Tea Res. Inst. Ceylon, 15.Google Scholar
Willstätter, R. & Stoll, A. (1918). Untersuchungen über die Assimilation der Kohlensäure. Berlin: Springer.Google Scholar