Rejili M.,Arid Area Institute IRA |
Rejili M.,Gabes University |
Vadel A.M.,Gabes University |
Guetet A.,Arid Area Institute |
And 4 more authors.
African Journal of Ecology | Year: 2010
Effects of salinity, temperature and their interactions on the rate and final percentage of germination were evaluated for two populations (Msarref, Oued dkouk) of the invasive glycophyte Lotus creticus Linné, grown under arid environmental conditions of the Tunisia. Seeds that were not treated with NaCl germinated well in a wide range of temperatures. For both populations, maximum germination occurred in distilled water at 25°C and lowest germination for all salinities was at 35°C. Germination was substantially delayed and significantly reduced with an increase in NaCl to levels above 300 m. m. Compared to the Oued dkouk population, final germination and germination rate of the Msarref population was completely inhibited at 300 m. m NaCl. The interactive effect of temperature and NaCl concentration on final germination and germination rate was significant (P < 0.01), indicating that the germination response to salinity depended on temperature. The inhibition of Oued dkouk population seed germination at high salt concentration was mostly due to osmotic effects while ionic effects were noted at Msarref population. The germination behaviour of the Oued dkouk population would therefore imply adaptive mechanisms to saline environments, while in the Msarref population such mechanisms seem to be absent. Since seed germination is more sensitive to salinity stress than the growth of established plants, the greater tolerance to salinity of Oued dkouk population would be an adaptive feature of this population to saline environment. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.
Zouaoui R.,National Water Research Institute |
Zouaoui R.,Arid Area Institute IRA |
Ksontini M.,National Water Research Institute |
Ferchichi A.,Arid Area Institute IRA
Pakistan Journal of Botany | Year: 2014
Ziziphus lotus (L.) Lam. is spontaneous plant (Rhamnaceae). It is of great ecological value and versatile, but it is endangered. To show the variability of phenological phases of this taxon, a study of phenology was conducted in arid Tunisia: ((Bou Hedma (BH); Matmata (MM); Medenine (Amra) (MD) and Oued Zes (OZ)) during two years (2010 and 2011). Our results show that the different phases, especially the flowering and fruiting coincide with the dry season. The observation of these shrubs in different phenological states shows a high variation between provenances (intersite) and between individual (intrasite). In 2011, the leafing out from BH presents a precocity and prolongation in time compared to others. The flowering is enough spread over time and present with fruiting phase at a given time. In 2010, the provenances of MD and MM are more precocious compared to other. By against, in 2011, all the provenances bloom at the same time. In BH, the fructification is the most precocious compared to others. These variations between provenances can be explained by the influence of temperature, soil moisture, photoperiod, exposure and soil texture. © 2014, Pakistan Botanical Society, All rights reserved.