RESUMO
To study the infection rate of leaf spot disease, the drying rate of root and volatile oil content of Asarum heterotropoides var. mandshuricum at the unwrapping stage, blooming stage, the initial fruit stage, fructescence and wither stage during the growth period under the different sunlight intensity of 100% (I), 50% (II), 28% (III), 12% (IV). The volatile oil content was measured according to the method of Chinese Pharmacopoeia and the oil composition was determined by GC-MS. The unwrapping stage, blooming stage and the early fruit stage postponed about 2 days with decrease of the sunlight intensity. The infection rate of leaf was 88.46%, 70.00%, 0.23%, 0.07% under light intensity of I, II, III and IV, respectively, the drying rate was 25.14%, 28.27%, 30.23%, 31.57% under light intensity of I, II, III and IV, respectively, and the volatile oil content was 18.1, 17.6, 16.3, 15.3 mL x kg(-1) under light intensity of I, II, III and IV, respectively. The composition of the oil determined by GC-MS was different between the groups, but the content did not changed significantly with the decrease of the light intensity.