The effect of temperature on germination and emergence of wild wheat (Triticum boeoticum Boiss) and wild barley (Hordeum spontaneum C. Koch)

A series of laboratory tests were conducted on wild wheat and wild barely, collected from dryland wheat farms of Lorestan province to determine the effect of temperature on their germination and emergence. Treatments included tempereatures raging 0-40 °C. According to the two segments equations fitted to the trend of seed germination, different constant temperatures, base temperature, optimum temperature and maximum temperature for germination of wild wheat intact seed with seed coat (lemma and palea), were estimated at 0.79, 24 and 28 °C respectively, as for wild barley were estimated at 0.82, 30.6 and 36 °C respectively. Average emergence of wild wheat intact seeds planted in the soil at six fluctuating temperatures of day/night regimes was 71.3%. A average of wild wheat dehusked and intact seeds germination in Petri dish experiments for six fluctuating temperatures of day/night regimes, were 70.5 and 17.9 percent respectively. In the case of wild wheat, intact seeds for day/night regimes of 10/1, 30/10 and 35/15 °C seed germination did not happen, and maximum seed germination (79%) was achieved for the 15/10 °C temperature regime. Under these conditions, wild wheat intact seed germination mean of 20/5 and 25/10 °C temperature regimes were 14 percent. The lower mean germination of wild wheat intact seeds with lemma and palea in the testing germination in Petri dishes compared with the mean of dehusked seed germination without lemma and palea, and the emergence mean of intact seeds planted in the soil suggest existence of probable inhibitor substances in the seed coat, that under soil conditions are leached from the surrounding environment of the seed.