The Impact of PEG-induced Drought Stress on Seed Germination and Initial Seedling Growth of Lupinus albus L.

Drought is regarded as one of the most significant abiotic constraints to agricultural crop output worldwide. Drought in the spring and early summer, which coincides with important reproductive stages, severely limits lupin yield in Mediterranean climate zones. The purpose of this study was to determine how different drought treatments affected seed germination and initial seedling growth in Lupinus albus L. (white or field lupin). Seed germination parameters and initial seedling growth traits were tested against five levels of drought stress induced with Polyethylene glycol-6000 (PEG6000) at concentrations of 0, 4, 8, 12, and 16%. An experiment with four replications was conducted using a completely randomized design. The results revealed that the negative effect of drought stress started at 4% (-0.03 MPa or -0.3 bar) treatment for the initial seedling growth stage; whereas, it started at 12% (-0.2 MPa or -2 bar) treatment for the germination stage. Therefore, it was determined that L. albus was more sensitive to drought stress at the initial seedling growth stage than at the germination stage. However, it was observed that the growth parameters were more sensitive in shoot growth than in root growth to drought stress. There will be a sharp loss of yield in soils with levels of drought stress imposed by 12% PEG6000 (-0.2 MPa-moderate drought-) and beyond. Therefore, it is likely that L. albus has low drought tolerance.