ﺑﺮرﺳﻲ ﺗﺎﺛﻴﺮ ﺗﻨﺶ ﮔﺮﻣﺎ ﺑﺮ روﻧﺪ ﺟﻮاﻧﻪزﻧﻲ داﻧﻪ ﮔﺮده 22 رﻗﻢ ﺗﺠﺎری ﮔﻨﺪم ﻧﺎن ( Triticum aestivum L )

Wheat (Triticum aestivum L.) provides more than 21% of the human food and is an important source of carbohydrates for human needs. Heat is a major factor limiting plant growth and making yield loss. Therefore, studying on this obstacle is essential to reduce wheat performance damage. This trial was conducted on 22 wheat commercial cultivars including Sepahan, Darya, Arg, Verinak, Aflak, Qods, Shiraz, Weebile, Babax, Atrak, Tajan, Bahar, Dez, Hirmand, Kavir, Arvand, Arta, Chamran ,Shirudi, Kauz, Montana and Pars. Pollen grains of these cultivars were cultured in a medium containing 18% sucrose, 9% polyethylene glycol, 2 g per litter of calcium nitrate and 60 mg per liter of boric acid. The pollen germination were evaluated at 25 (control), 30, 35, 40 and 50 °C for one hour. The in vitro experiments were arranged in a balanced completely randomized factorial design with three replications. Based on the results, with increasing temperature the pollen germination significantly reduced (P≤0.01) in all cultivars. The highest percentage of germination with 96% was observed at 25 °C in Weebile and the lowest percentage with 7% at 50 °C in Bahar. Finally, Kaus and Babax were distinguished as more tolerate and Monatana and Bahar as more sensitive cultivars.