Effects of cold stratification and plant growth regulators on seed germination of Iranian horned poppy (Glaucium corniculatum)

Toward overcoming the seed germination problem of Iranian poppy, three experiments with a completely randomized design were conducted. The first experiment consisted of 5 ◦C cold stratification (10, 20, 30, 40, 50, 60, 70, 80, 90 & 100 days). The second experiment was composed of gibberellic acid (100, 150, 200, 250, 300, 350, 400, 450 & 500 mg/L), benzyl adenine (0, 25, 50, 100 & 200 mg/L) and strigolactones (0, 0.01, 0.1 & 1 mg/L). The third experiment was combined of the first and second experiments’ best treatments including 50 mg/L benzyl adenine 100 mg/L gibberellic acid, 200 mg/L benzyl adenine 400 mg/L gibberellic acid, 100 mg/L benzyl adenine cold stratification at 5 ◦C for 60 days and 100 mg/L gibberellic acid cold stratification at 5 ◦C for 60 days. Results of the first experiment showed that highest mean daily, rate and germination percentage was observed in 30, 60 and 70 days of cold stratification respectively, with amounts of 1.86, 3.4 and 81 percent. Results of the second experiment revealed that gibberellic acid had significant impacts on seed germination, in comparison with control, benzyl adenine and strigolactone. The maximum seed germination was observed using 100 mg/L of gibberellic acid. The third experiment demonstrated that combination of 100 mg/L gibberellic acid with cold stratification at 5 ◦C for 60 days increased germination percentage (81.25%), germination rate (5.23) and mean daily germination (1.35) for ten times, though its main effect could be attributed to 60 days of cold.