International Rice Research Institute, PO Box 933, 1099 Manila, The Philippines.
The involvement of the transpirational bypass flow in sodium uptake by high- and low-sodium-transporting lines of rice developed through intravarietal selection
Article first published online: 28 APR 2006
Plant, Cell & Environment
Volume 19, Issue 3, pages 329–336, March 1996
How to Cite
YADAV, R., FLOWERS, T. J. and YEO, A. R. (1996), The involvement of the transpirational bypass flow in sodium uptake by high- and low-sodium-transporting lines of rice developed through intravarietal selection. Plant, Cell & Environment, 19: 329–336. doi: 10.1111/j.1365-3040.1996.tb00255.x
- Issue published online: 28 APR 2006
- Article first published online: 28 APR 2006
- Received 12 April 1995, received in revised form 7 July 1995; accepted for publication 1 August 1995
- Oryza sativa;
- bypass flow;
- salt tolerance;
- sodium transport
We report the characterization of high- and low-sodium-transporting lines developed by intravarietal selection within a cultivar, IR36, of rice (Oryza sativa L.). The purpose was to investigate the mechanistic basis of sodium uptake in material in which differences in salt uptake could be isolated from the many other morphological and physiological characteristics that affect the phenotypic expression of salt tolerance. The lines differed in mean sodium transport by a factor of 2. They differed in vigour and water use efficiency, which are characters that modify the effects of salt transport, by only 12% or 13%. The lines did not differ significantly in other physiological traits that are components of salt resistance: compartmentalization at the leaf and cellular levels. There was a strong correlation between the transport of sodium and a tracer for apoplastic pathways (trisodium, 3-hydroxy-5,8,10-pyrene trisulphonic acid, PTS) in both lines. The regression coefficient for sodium transport on PTS transport was the same in both lines. The individual variation in PTS transport was similar to that in sodium transport, and the variation in the transport of both was very much greater than the variation in any other character studied. The high-sodium-transporting line took up proportionately more PTS than the low-sodium-transporting line. It is concluded that the transpirational bypass flow is of major importance in sodium uptake by rice and that selection for differences in sodium transport has been brought about by selection for heritable differences in the bypass flow.