A re-evaluation of controlled freeze-tests and controlled environment hardening conditions to estimate the winter survival potential of hardy winter wheats

摘要: To identify superior winter-hardy winter wheat genotypes it is essential to have a reliable screening method that can detect small differences in freezing tolerance. A highly significant correlation was obtained between the minimum temperature tolerated by fully cold-hardened seedlings and field survival index for 36 cultivars with tolerance varying from –13°C –23°C. On basis of their long-term under cold stress, these represent two separate genotypic groups, semi-cold-hardy (Group A) very cold-hardy B). The coefficient semi-hardy not significant, although hardy (coefficient determination 25.9%). However, freeze test did differentiate varied widely survival. In comparing (e.g., Norstar, Alabaskaja, Roughrider, etc.), no signi...