Seasonal variation of foliar δ13C values as well as proline,silicon,MDA and relative water content in Sabina przewalskii Kom.and S.chinensis (Lin.) Ant.were measured.The results show that foliar δ13C values were significantly different at different seasons:lower in winter but higher in summer.δ13C values were positively correlated with air temperature and soil temperature.This demonstrates that foliar δ13C of Sabina is a successful empirical indictor of temperature.Furthermore,foliar δ13C values were positively related to proline and silicon content,and negatively related to relative water content and MDA content.Compared with S.chinensis,S.przewalskii has higher δ13C values,proline and silicon content as well as lower MDA and relative water content.All these results provided strong evidence that it is feasible for δ13C to be regarded as another index to evaluate freezing tolerance of Sabina.
Tuo ChenHuiJuan PeiYouFu ZhangLongYing WenHongGuan TangYuanQing He
