GERMINATION IN STYLOSANTHES HUMILIS POPULATIONS IN THE PRESENCE OF NACL

The germination response to NaCl treatments (0, 67, 134, 201 and 268 m ol m(-3)) was investigated in six natural populations of Stylosanthes humilis H.B.K. from three ecogeographic regions of Pernambuco State, n orth-east Brazil. In general, salt tolerance was high, with percentage germination unaltered up to 67 mol m(-3) NaCl in two populations and unaltered up to 134 mol m(-3) NaCl in the remaining four. The estimate d concentrations which reduced percentage germination to 50% varied be tween populations from 200-295 mol m(-3) NaCl. Salt affected germinati on rate even more than it did the germination percentage, being altere d at 67 mol m(-3) NaCl. in all populations. The germination rate was r educed to 50% in the range of 131-176 mol m(-3) NaCl. There was a sign ificant variation in salt tolerance between these natural populations, and no relation was found between salt tolerance of the populations a nd the aridity of their provenance.