A preliminary investigation of assimilation, respiration and physico-chemical properties of zygophyllm coccineum in relation to soil moisture
| Autor: | Tadros, T. M. |
|---|---|
| Rok vydání: | 1947 |
| Zdroj: | Bulletin de l'institut égyptien. 30:163-181 |
| ISSN: | 1110-1938 |
| DOI: | 10.3406/bie.1947.3863 |
| Popis: | 1 . The rate of assimilation and respiration of Zygophyllum coccineum under different soil moistures were measured together with the changes in its physicochemical properties induced by dryness of the soil. 2. Apparent assimilation which represents the carbon balance in the plant was found to increase with dryness of the soil to a certain limit beyond which the balance was upset resulting in a big fall of the assimilation value associated with a rise in the-respiration value. 3. The tissue water content was not affected by changes in soil moisture until the plant reached the wilting stage. 4. Transpiration resistance increased with decrease of soil moisture. The transpiration rate was greater in the assimilating than in the respirating branches. 5. The osmotic concentration of the sap increased with dryness of the soil ; and this was associated with but not proportionate to a more defined increase in the bound water content of the tissues. 6. It was concluded that water binding takes place in the colloids of the protoplasm and in the osmotically inactive colloidal constituents of the cell sap, possibly as a result of drought. 7. Changes in the osmotic concentration after the processes of assimilation and respiration followed the changes in the carbon balance. Thus a decrease in the osmotic concentration took place when the katabolic balance predominated and an increase at the maximum assimilation stage. 8. Changes in the electrical conductivity of the sap were found to explain, with critical examination, the metabolic changes referred to above. Tadros T. M. A preliminary investigation of assimilation, respiration and physico-chemical properties of zygophyllm coccineum in relation to soil moisture. In: Bulletin de l'Institut d'Egypte, tome 30, 1947. pp. 163-181. |
| Databáze: | OpenAIRE |
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