Effects of Peg-Induced Drought Stress on Germination and Seedling Performance of Bread Wheat Genotypes

Abstract

This study was conducted to determine the response of some bread wheat genotypes to drought stress during germination and seedling growth stages. Two bread wheat cultivars (Karatopak and Sagittoria) and three advanced breeding lines (SERI.1B*2/3KAUZ*2BOW//KAUZ, 89N2090/WERAVER// SW91.4903 and STAR’S’KAUZ’S’s) were used as the seed material. Three different doses of Polyethylene Glycol (Control, -0.6 MPa and -1.2 MPa of PEG-6000) were used to generate drought stress in germination and seedling growth stages of bread wheat. Germination experiments were carried out in petri dishes placed into an incubator with 4 replications in completely randomized factorial design. Seedling emergence experiments were carried out in plastic containers filled with a mixture of sand and peat placed into a growth cabinet with 3 replications in factorial arrangement of CRD. Germination experiments showed that genotype, PEG and genotype x PEG interactions were significant for examined traits except for germination rate. In the seedling experiments, genotype, PEG and genotype x PEG interaction were significant for all parameters, except for mean emergence time. Generally, increased doses of PEG caused remarkable decreases in all examined traits, but increase in mean germination time and mean emergence time. As the PEG doses increased, genotypes responded differently with regard to examined traits in germination and seedling emergence of bread wheat genotypes. It can be concluded that PEG-6000 was useful agent to create drought stress in germination and seedling growth of bread wheat, but greater doses and osmotic potentials lower than -1.2 MPa could be applied to better determine the drought stress tolerance of bread wheat genotypes.