MTB GSL in the root was hydrolyzed to MTB ITC(4 methylthio 3 butenyl isothiocyanate) with the endogenous myrosinase by grating. MTB ITC was determined by gas chromatography, and MTB GSL was calculated from MTB ITC.

• 利用萝卜内部的芥子酶，使MTB?GSL水解脱去葡萄糖，测定水解生成的MTB?ITC（4?甲硫基?3?丁烯基芥子油），然后通过化学反应式计算得到MTB?GSL的含量。