Evaluation of low temperatures on germination and early growth and development in some corn inbred lines in laboratory and its relationship with farm phenological traits

The cold limits germination and growth of corn (Zea mays L.) but the varieties of corn significantly have differences with each other in reaction to temperatures. To determine the response of some phenological and agronomical traits affected by low and optimal temperatures in corn and to primary recognizing the cold tolerance corn inbred lines in early growth and development، an experiment was conducted، in two separately parts، in farm (in randomized complete block design with three replications) and the laboratory of Agriculture College، Shahrekord University، Shahrekord، Iran (in two completely randomized design in 12 and 25 oC temperatures with four replications) in 2007. Both experiments were done on ten corn inbred lines. The results showed that varieties on topic of germination and reaction ability to temperatures showed more variation in temperature 25 oC than in temperature 12 oC and with reducing temperature، the traits were strongly affected. Also varieties which had higher mean rate of germination (25 oC) and faster growth in the laboratorial conditions especially in the temperature of، 12 oC emerged sooner in the farm and reached to the establishment stage. At cold stress conditions، the early maturity lines and in favorite conditions، the late maturity varieties complete faster early growth and development stages until plant establishment. So with concerning the results of mean comparisons، the V5 inbred line was known as the best genotype tolerant to low temperature in this experiment.