Effects of Temperature, Water and Salt Stress on Seed Germination of Pinus Pinea L in the Saida Region, Algeria

Abstract

Pinus pinea (L) is one of the characteristic species of the Mediterranean flora, formerly introduced and naturalized in Algeria to stabilize and fix the western coastal dunes. The natural regeneration of Pinus pinea, like some other Mediterranean species, is facing serious problems. However, little or no research has been carried out on Pinus pinea in Algeria in terms of natural regeneration and the factors that determine it. Drought and salinity are abiotic constraints that can have a detrimental effect. In order to provide basic information for its multiplication, the effect of incubation temperature (15 ͦ C, 20 ͦ C,) and the impact of salt stress and water stress on seed germination were studied. Salinity treatments used were 2.92g/l, 5.84g/l, 11.68g/l, and under different osmotic potentials of Polyethylene glycol (PEG 6000) at 3g/l, 13g/l, 35g/l. Germination tests were carried out in Petri dishes. A maximum germination percentage (83%) was obtained under a temperature of 20 ͦ C. A negative correlation was obtained between NaCl concentration and seed germination, whereas in the concentration of 11.68g/l. germination was nil (0%), This suggests that Pinus pinea is moderately salt-tolerant at the germination stage. Pinus pinea seeds are moderately tolerant of water stress, with a germination capacity of 37% when exposed to a PEG 3 g/l solution, making this species a candidate for reforestation programs and consequently for extending its range.