Differential response to chilling injury of the group 6 chromosomes of cv. Chinese Spring wheat

Abstract

Winter wheat (Triticum aestivum L.) requires vernalization (exposure to temperatures between 1 and 10 °C) to induce heading. Vernalization also induces earlier heading of many spring wheat varieties. Studies of the spring wheat cv. Chinese Spring identified cytogenetic lines of the group 6 chromosomes that were susceptible to chilling injury when seedlings were grown at 6 °C for 8 weeks. Lines that were either ditelocentric for the long arm of chromosome 6D or nullisomic for 6D were susceptible, while those ditelocentric for the short arm of 6D were not. Neither cv. Chinese Spring nor ditelocentrics for either the long or short arms of chromosomes 6A or 6B were susceptible. Susceptible plants selected from F2 seedlings of plants monosomic for 6D were nullisomics. Doublemonotelocentric F1 hybrids from crosses between plants ditelocentric for 6DS or 6DL were resistant, but susceptible F2 seedlings from this cross were either nullisomic for 6D or telocentric for the long arm. The dominant gene(s) that prevents chilling injury at 6 °C appears to be on the short arm of chromosome 6D of cv. Chinese Spring wheat.Key words: chilling injury, wheat, telocentrics, nullisomics, vernalization.