Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-25T00:31:43.456Z Has data issue: false hasContentIssue false

Effect of leaf position and plant age on the translocation of 14C-assimilates in onion

Published online by Cambridge University Press:  27 March 2009

A. A. Khan
Affiliation:
Department of Biological Sciences, Ahmadu Bello University, Zaria, Kaduna State, Nigeria

Summary

Individual leaf blades of onion plants were treated with 14CO2 57, 71, 93 and 112 days after transplanting. The distribution of labelled translocates was determined 24 h after labelling. The older the plant the more of 14C-assimilate left the source leaf; 112 days after transplanting, leaves 1–7 all exported more than 70% with leaf 7 showing a maximum export of 93 % of the fixed carbon. In the early stages of the development, the leaves, pseudostem and the bulbs were the major sinks in decreasing order. But the bulbs became the dominant sink at 71 days and at 112 days the bulbs almost monopolized the import of the radiocarbon, with 90 % of the exported 14carbon being recovered from them. The bulbs received their 14carbon supply from all the leaves but particularly the basal and middle region leaves. Roots were a weak sink and received their 14carbon supply only from basal leaves. The stem and mature leaf blades were unimportant sinks throughout the life of the plant.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1981

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Ho, L. C. & Rees, A. R. (1976). Re-mobilization and redistribution of reserves in the tulip bulb in relation to new growth until anthesis. New Phytologiat 76, 5968.CrossRefGoogle Scholar
Ho, L. C. & Rees, A. R. (1977). The contribution of current photosynthesis to growth and development in the tulip during flowering. New Phytologiat 78, 6570.CrossRefGoogle Scholar
Jones, H. A. & Mann, L. K. (1963). Onions and their Allies: Botany, Cultivation and Utilization, pp. 1286. London: Leonard Hill. New York: Interscienco Publishers Ino.Google Scholar
Palmer, A. F. E., Heichel, G. H. & Musgrave, R. B. (1973). Patterns of translocation, respiratory loss, and redistribution of 14C in maize labelled after flowering. Crop Science 13, 371376.CrossRefGoogle Scholar
Wardlaw, I. F. (1968). The control and pattern of movement of carbohydrates in plants. Botanical Review 34, 79105.CrossRefGoogle Scholar
Wareing, P. F. & Patrick, J. (1975). Source-sink relations and the partition of assimilates in the plant. In Photosynthesis and Productivity in Different Environments (ed. Cooper, J. P.), pp. 481499. London: Cambridge University Press.Google Scholar
Warren Wilson, J. (1972). Control of crop processes. In Crop Processes in Controlled Environments (ed. Rees, A. R., Cockshull, K. E., Hand, D. W., and Hurd, R. G.), pp. 730. London and New York: Academic Press.Google Scholar