Priming techniques, germination and seedling emergence in two Papaver species (P. rhoeas L. and P. dubium L., Papaveraceae)

Abstract

Effect of priming methods including hydro-priming, hormonal priming, halo-priming and scarification techniques and environmental factors including constant temperature, light regimes, pH, salt and osmotic stresses on seed germination was studied in two species of Papaver (P. rhoeas L. and P. dubium L.) in a series of laboratory experiments. The effects of soil texture on seedling emergence were also tested in greenhouse trails. Hormonal priming of seeds with gibberellic acid (GA3) and potassium nitrate (KNO3) significantly increased germination. The maximum germination of P. rhoeas was obtained at seeds primed with 750 ppm of GA3 concentration for 48 h. The greatest seed germination of P. dubium was recorded in seed treated with 500 ppm GA3 for 48 h. Pre-treatment of seed with 0.5 g.L−1 KNO3 for 24 h increased germination in both species. The maximal germination of P. rhoeas (55.01%) and P. dubium (49.61%) was observed in temperatures 25 °C and 20 °C, respectively. The greatest germination of P. rhoeas (55.31%) and P. dubium (57.05%) was achieved when seeds were treated with pH 7. Increasing salt and osmotic stresses decreased seed germination of both species. Seed germination decreased linearly as NaCl concentration enhanced to 40 mM. Germination of both species was sensitive to osmotic stress and inhibited at the osmotic potential more than − 1 MPa. In all soil textures, seedling emergence decreased as planting depth increased. Seedling emergence of seed planted in the compost was higher than sandy loam and clay loam in all tested depths. Information gained from this study could be effective for a better understanding of germination and seedling emergence requirements that may be suitable for an integrative weed control program.