Many studies have shown that methanol(CH₃OH) application can promote growth of various plants.Among the mechanisms of CH₃OH stimulating plant growth,the carbon source hypothesis obtained the most supporting evidence.We attempted to verify the carbon source hypothesis by study the association between the effects on stimulating growth and CH₃OH metabolism in Petunia hybrida.The results showed that:(1)The addition of 2 and 6 mmol/L CH₃OH to MS agar medium all promoted the growth of P.hybrida,but the effect of the former (low concentration) was better than that of the latter (high concentration),and the latter induced stronger oxidative stress.(2)The analysis on ¹³CH₃OH metabolism in P.hybrida under different concentrations by ¹³C-NMR demonstrated that the amount of [U-¹³C]Fruc and [U-¹³C]Gluc produced from 6 mmol/L ¹³CH₃OH treatment was significantly greater than those from 2 mmol/L ¹³CH₃OH,which results indicated that the carbon source from methanol was assimilated to form carbohydrates through the Calvin cycle.However,this part of carbon source might have little contribution to stimulating growth of P.hybrida.These evidences suggested that there is not association between the effects on stimulating growth and methanol metabolism in P.hybrida,and this experiment do not support the carbon source hypothesis.