Effect of temperature in late autumn on free proline, soluble sugar and POD in alfalfa

The effect of temperature in late autumn on free proline, soluble sugar and POD in 9 alfalfa varieties with different fall dormancy was conducted. The result showed that the contents of free proline in 3 different fall dormancy types of alfalfa showed an increasing trend from 10th Sep. to 10 th Oct., and the contents increased with the temperature, in which, the variation extend of free proline in high fall dormancy alfalfa was the largest. The contents of soluble sugar in high and low fall dormancy alfalfa greatly fluctuated and the trends were opposite. This suggested that they were more sensitive to the storage nutrients. Meanwhile, the variation of moderate fall dormancy alfalfa was in the middle. The POD activity showed an increasing trend for different fall dormancy types of alfalfa and the fluctuation of the moderate and high fall dormancy types was greater than the low fall dormancy ones, this suggested that the varieties with moderate and high dormancy were more sensitive to the aboveground temperature.