Respuesta de 20 variedades de caraota (Phaseolus vulgaris L.) ante el estrés por NaCl durante la germinación y en fase plantular

the response to nacl stress of twenty genotypes of bean (phaseolus vulgaris l.) was tested, in order to detect possible differences in their salt sensibility during germination and seedling stages. germination test was carried out in a growth chamber; the seeds were moistened with uniform amounts of nacl solution (40 or 80 mm nacl) or with distilled water (control) and after seven days the final germination percentage was recorded. for the evaluation in the seedling stage, the seeds were sown in inert substrate and daily irrigated with nutritive solution with nacl added in the concentrations indicated before; a control treatment was also included. ten days after sowing (das) the emergence percentage was determined, and fourteen das plant height, primary leaves area, shoot and root biomass and root biomass/shoot biomass were measured. all the evaluated genotypes tolerated the two nacl concentrations tested during germination; however, in the seedling stage, the emergence was totally inhibited at 80 mm nacl and the emergence percentage and growth variables were significantly reduced at 40 mm nacl. the results indicated an important genetic variation among the varieties of p. vulgaris and in their sensibility to nacl stress. the tolerance was diminished considerably in seedling stage, respect to the germination phase, being ？i-2591？, ？i-2687？, ？i-193？ e ？i-172？, the less affected varieties under salinization with 40 mm nacl during the establishment stage.