Abstract: This research utilised alfalfa varieties which are widely grown in Horqin sandy land of Inner Mongolia, and explored the rate of occurrence of crown desiccation under simulated overwintering and the effect of different soil water contents at different fall dormancy of alfalfa. The results showed that during simulated overwintering, the cold-resistant WL298 and WL168 varieties exhibited strong desiccation, while for Knight T and Gongnong No.1 varieties crown desiccation was medium. Variety WL363 also displayed medium crown desiccation, attributable to a high accumulation of protective sugar, which enhanced regrowth performance. However, the degree of desiccation of variety Magnum 4015 was low. When soil moisture content was maintained at 90% of field capacity during the winter, WL298, WL168, Knight T and Gongnong No.1 displayed better protective sugars and regrowth performance than Magnum 4015. When the moisture conditions were maintained below 40% of field capacity, the degree of crown contraction of all varieties increased significantly. In these conditions, varieties WL298, WL168, and WL363 had better regrowth performance, while Knight T and Magnum 4015 had poor regrowth.

Key words: alfalfa, crown, desiccation tolerance, cold tolerance physiology