Using 24 kale varieties as material,the effect of low temperature stress on cabbage leaf relative electrical conductivity,soluble protein content,soluble sugar content,proline content,malondialdehyde(MDA) content and super oxide dismutase(SOD) activity was determinated. The cold tolerance of kale was measured by cold resistant coefficient of each index and comprehensively evaluated by using principal component analysis and membership function analysis. The results showed that leaf relative electrical conduc...