关键词: 苜蓿, 禾草, 混播, 根系, 可溶性糖

Abstract: Soluble sugar has positive influence on plant frost resistance. In order to study the effects of alfalfa and grass mixed sowing on soluble sugar content of their root system,  the legume-grass system, including alfalfa and 3 kinds of forage grasses (Bromus inermis Leyss, Elymus dahuricus Turcz and Phalaris arundinacea L.), were sowed at every other line proportion of 1∶1 (B1), 2∶2 (B2), 1∶2 (B3) and 2∶1 (B4). Then after the first frost, the soluble sugar contents in different mixed seeding grass root system were measured. Results showed that the contents of soluble sugars in alfalfa root  were not significantly affected by grass varieties, and the soluble sugar content of alfalfa root in the proportion of 2∶2 between legume and grass was significantly lower than that of 1∶2, 2∶1. There was no significant difference between proportions of 1∶1, 1∶2 and 2∶1. By mixing alfalfa with P. arundinacea, the soluble sugar content in  root  of P. arundinacea was higher than that in single planting of P. arundinacea. Among the 3 grasses, the soluble sugar content in P. arundinacea root  was significantly higher than those of the other two. To sum up, the soluble sugar contents in alfalfa and grass roots  were both higher than those of mixed sowing at proportion of 1∶1 and 1∶2. Considering the cold tolerance of alfalfa was usually weaker than those of the 3 grasses, the optimal choice would be the treatment with every other line proportion of 1∶2. The present reseach provided  theoretical reference for sustainable utilization of local legume-grass mixed grassland.

Key words: alfalfa, grass, mixed sowing, root system, soluble sugar