Differential responses to Na+/K+ and Ca2+/Mg2+ in two edaphic races of the Lasthenia californica (Asteraceae) complex: A case for parallel evolution of physiological traits
Article first published online: 19 DEC 2002
Volume 157, Issue 1, pages 93–103, January 2003
How to Cite
Rajakaruna, N., Siddiqi, M. Y., Whitton, J., Bohm, B. A. and Glass, A. D. M. (2003), Differential responses to Na+/K+ and Ca2+/Mg2+ in two edaphic races of the Lasthenia californica (Asteraceae) complex: A case for parallel evolution of physiological traits. New Phytologist, 157: 93–103. doi: 10.1046/j.1469-8137.2003.00648.x
- Issue published online: 19 DEC 2002
- Article first published online: 19 DEC 2002
- Received: 27 August 2002 Accepted: 2 October 2002
- Lasthenia californica;
- Ca2+ : Mg2+ quotient;
- edaphic races;
- parallel evolution;
- salt tolerance;
- • Sodium, potassium, calcium, and magnesium ion uptake physiology and tolerance to sodium and magnesium were characterized in two edaphic races (A and C) of two closely related species in the Lasthenia californica complex.
- • Uptake rates of race A plants were 20-fold higher for Na + , and 2-fold higher for Ca 2+ and Mg 2+ than those of race C plants. Race A translocated c. 50% of absorbed Na + to the shoot compared with < 30% in race C. For Ca 2+ and Mg 2+ corresponding values for the two races were > 95% and ≤ 50%, respectively.
- • Germination, root growth and survivorship estimates indicated greater tolerance by race A to Na + and Mg 2+ . Significant genotype treatment interactions were observed, suggesting that these races are genetically differentiated in their tolerance responses.
- • The study suggests parallel evolution of physiological traits in populations belonging to the two species and points to intriguing correlations between the presence of sulfated flavonoids and the capacities for the uptake of and tolerance to specific ions.