Seed germination of Pinus halepensis provenances under NaCl stress.

Pinus halepensis seeds from nine European provenances were germinated in NaCl solutions. Inhibition of germination was not due solely to osmotic effects, but also to ion toxicity, as observed by comparing germination in NaCl to germination in isotonic solutions of polyethylene glycol. The negative ion effect did not vary among provenances. Parameters of germination kinetics (i.e., mean germination time and germination value), rather than final germination, were the most suitable for discriminating seed responses to NaCl among P. halepensis provenances. The order of NaCl tolerance of seed germination and drought tolerance in 24-week-old seedlings was similar.