关键词: 苜蓿, 秋眠级, 末次刈割, 抗寒性, 越冬率, 抗氧化酶

Abstract: In order to study the effects of last cutting time on the activities of winter survival ability and antioxidant enzymes in root neck of different fall dormancy alfalfa varieties in Horqin sandy land, three alfalfa varieties were selected as materials and conducted the lasting cutting on August 11 and October 13. Mowing was done at intervals of 15 days. The winter survival rate and the contents of POD, SOD, CAT and MDA of the root neck were measured. The results showed that the last cutting time and cultivars had interactive effects on the overwintering of alfalfa. The cold resistance of three alfalfa varieties was ‘WL168HQ’>‘Jiasheng’>‘WL298HQ’. Semi-fall dormancy alfalfa varieties showed an independent relationship between fall dormancy and cold resistance, and the effect of cutting on cold resistance of alfalfa varieties with strong cold resistance was lower than that of alfalfa cultivars with weak cold resistance. The last cutting time had significant effects on the activities of POD, SOD and MDA in root neck, but had no significant effect on the activities of CAT. Therefore, it suggested that the last cutting should be completed before the end of August for planting alfalfa in Horqin sandy land, and the cutting period of the alfalfa varieties with strong cold resistance could be extended to the middle of September.

Key words: Alfalfa, Fall dormancy rating, Last cutting, Cold resistance, Winter survival rate, Antioxidant enzymes