Evaluation of cold tolerance in wheat (Triticum aestivum L.) cultivars under field conditions

Abstract

Cold tolerance of 14 wheat cultivars under field conditions was investigated. Cultivars including Anza, Bezostaja, Pishtaz, Tous, Zagros, Zarrin, Shahryar, Falat, Ghuds, Glenson, Maroon, Navid, Niknejad and MV-17 were planted in a complete randomized block design with 3 replications in the experimental station of college of agriculture , Ferdowsi University of Mashhad in autumn of 2004-2005. Growth stage of plants and chlorophyll content were measured before cold and winter survival, plant height, yield components and seed yield were measured at the end of growing season. Results showed that despite of a relatively extreme cold (-9.2 oC), most of the cultivars tolerated winter and only Zagros and Maroon with 93.3 and 73.3% winter survival, respectively, suffering winter damage. Toos cultivar had the highest seed yield and Maroon and Zagros cultivar had the lowest yield. Seed yield had the positive correlations with spikelet number per spike (r=0.85***), and 1000-seed weight (r=0.85***). Results of this experiment suggested that Glenson had the most level of cold tolerance and Maroon was the most cold sensitive cultivar. Key words: Cold tolerance, winter survival, yield, yield components, wheat.