Abstract:

Developing crop cold-resistance is an important breeding target in cold areas. Although simulated experiments have been conducted in house for selecting cold-resistant varieties, it is not clear the performances of varieties in the field, especially the step-by-step cold exercise in simulated experiments is hardly consistent with that in natural condition. Dongnongdongmai 1 is winter wheat (Triticum aestivum L.) cultivar that can bear low temperature and grow normally in Heilongjiang Province. To provide basic data for cold-resistant breeding and cultivation in wheat, several physiological and biochemical characteristics related to cold resistance were compared using Dongnongdongmai 1 (winter greening rate more than 85% in spring) and Jimai 22 (cold sensitive, winter greening rate less than 1% in spring). Both cultivars were planted in field condition and sampled at different dates (different temperatures) before wintering. The samples were separated into leaves, tillering nodes, and roots, respectively. The results showed that soluble sugars, soluble protein, proline, chlorophyll content, superoxide dismutase (SOD) activity, and peroxidase (POD) activity of Dongnongdongmai 1 were higher than those of Jimai 22. Water contents in different organs and relative electric conductivity of Dongnongdongmai 1 were lower than those of Jimai 22, indicating Dongnongdongmai 1 had higher adaptability to coldness than Jimai 22. Tillering node was the most important organ for safely wintering because it contained more substances related to cold-resistance than leaf and root.

Key words: Dongnongdongmai 1, Cold resistance, Physiological and biochemical characteristics, Cold area