Impact of drought stress on germination and seedling growth of three forage legumes species (Fabaceae)

Drought causes major economic and ecological problems, such as reduced production of crops and fodder species. In the present study, using morpho-physiological approaches, we have characterised the response of three of the most widely grown forage legume species, cultivated in Algeria under water deficit conditions, with a goal of determining the species that is most tolerant to this constraint. The effect of drought stress induced by three concentrations of polyethylene glycol (PEG 6000), 5%, 10% and 15% corresponding respectively to three osmotic potentials-0.06 MPa,-0.17 MPa and-0.32 MPa on germination percentage (GP%), mean germination time (MGT), germination kinetics and seedling growth (assessed by seedling dry weight) were studied in vitro for vetch ( Vicia sativa L.), faba bean ( Vicia faba L. minor) and forage pea ( Pisum sativum arvense L.). The results show the influence of treatment and species factors on the three parameters studied. Our results showed that germination was not affected in V. sativa, but was significantly reduced from 10% PEG in V. faba and 15% in P. sativum. Seedling growth was significantly reduced at 5% PEG in V. sativa and P. sativum, whereas in V. faba it was only negatively affected at 15% PEG.