Effect of Salt and Osmotic Stresses on the Germination of Pepper Seeds of Different Maturation Stages

Germination percentage, seedling fresh weight and sensitivity index of the pepper (Capsicum annuum L. cv. Sera Demre) seed lots harvested 50, 60 and 70 days after the anthesis (daa) in 2001 and 2002 were determined under the salt (NaCl) and osmotic (PEG) stresses at the same water potentials of -0.3, -0.6 and -0.9 MPa. The objective was to study whether the germination and seedling growth were inhibited by the salt toxicity or osmotic effect during the development. The higher the salt and osmotic stress concentrations the lower was the germination percentage and seedling fresh weight. The seed germination was higher and sensitivity index were lower in NaCl than in PEG at the same water potential and harvest in both the years. They were able to germinate at all the concentrations of NaCl but at-0.9 MPa of PEG, none of the seeds of any harvest germinated in both the years. The seeds harvested 70 daa showed the highest germination and seedling weight in all the NaCl and PEG concentrations in both the years. Results showed that the inhibition of the germination at the same water potential of NaCl and PEG resulted from the osmotic effect rather than the salt toxicity. Moreover; the seeds harvested 70 daa appeared to be more tolerant to the salt and osmotic water stress conditions than the other two lots.