Effect of temperature on vegetative and generative growth in five populations of range species of Festuca ovina

In this research project، some vegetative and generative taints were evaluated in 5 populations of Festuca ovina including: Kelack، Sirachal، Gorgan Kordestan، Zanjan، in greenhouse conditions. The seed samples of five populations were sown on the pots with temperatures (20±5) °C for day and (5-12) °C for night time. For cold treatment، some pots were transferred at 4°C on 15th of seedling growth stage for two weeks and again were returned to normal conditions of greenhouse. After a while، those pots were placed outdoor to complete the flowering stage. Vegetative and generative traits including: percent and speed of emergence، seedling length، vigor index، tiller number and leaf area، plant height، peduncle length، panicle length، panicle number and flag leaf length، seed yield، fresh and dry weigh were calculated for five populations. Results showed that the means of percent and speed of emergence، seedling length، vigor index، tiller number and leaf area in populations of Kelak، Sirachal، Goragan and Kordestan were increased by cold treatment compared to control. The mean values of generative traits in 5 populations by cold treatment were higher than that of control. Results also showed that populations subjected to cold treatment flowered earlier due to having lower values of growth degree days (GDD). Therefore، the emergence of flower in five populations was earlier with cold treatment than that of control. The mean of some generative traits including plant height، number of panicle، seed yield، fresh and dry weight were increased by cold treatment but this increasing was more for Kordestan and Gorgan than other populations.