Reversal of the inhibitory effect of light and high temperature on germination of Phacelia tanacetifolia seeds by melatonin
Article first published online: 8 JAN 2012
© 2011 John Wiley & Sons A/S
Journal of Pineal Research
Volume 52, Issue 3, pages 332–339, April 2012
How to Cite
Tiryaki, I. and Keles, H. (2012), Reversal of the inhibitory effect of light and high temperature on germination of Phacelia tanacetifolia seeds by melatonin. Journal of Pineal Research, 52: 332–339. doi: 10.1111/j.1600-079X.2011.00947.x
- Issue published online: 20 MAR 2012
- Article first published online: 8 JAN 2012
- Accepted manuscript online: 26 NOV 2011 02:34AM EST
- Received October 3, 2011; Accepted November 23, 2011.
- high temperature;
Abstract: Possible role of melatonin in the germination of negatively photoblastic and thermosensitive seeds of Phacelia tanacetifolia Benth was studied. Final germination percentage (FGP) was determined in the presence or absence of light at various temperatures, ranging from 0 to 40°C. The highest FGP was determined as 48.7% and 92% at temperature of 15°C in the presence and absence of light, respectively. Seeds were primed with 1% KNO3 containing various concentrations (0.3, 1, 6, 12, 30, 60, or 90 μm) of melatonin for 2 days at 15°C in darkness. Primed seeds were germinated at an inhibitory temperature of 30°C, and results were compared to those occurring at the optimum temperature of 15°C under both light and no light conditions. Melatonin incorporated into priming medium significantly reversed the inhibitory effects of light and high temperature. Germination was elevated from 2.5% to 52% of FGP for seeds primed in the presence of 6 μm melatonin in darkness at 30°C, while 1 μm melatonin had the highest FGP (21.0%) in the presence of light at 30°C. The highest FGP (47.5%) was obtained from seeds primed in the presence of 0.3 μm melatonin under the light condition at 15°C, while untreated seeds had 1.5% of FGP. The fastest seed germination was determined from seeds primed in the presence of 0.3 μm melatonin (G50 = 0.56 days) at 15°C in darkness. The possible roles of melatonin in promoting germination parameters of photo- and thermosensitive seed germination are discussed.