Abstract:In order to investigate the impacts of different water contents in soil on life cycle forms and physiological metabolisms of Catharanthus roseus (L.) G. Don, four levels of water supply, including control (CK), light drought (LD), moderate drought (MD) and heavy drought (HD), were set up in the present paper. The cluster analysis was conducted to C. roseus seedlings upon water treatment according to their morphological characteristics. The results showed that 20 seedlings involved were dissected into two groups and the treatments of MD and HD led to significant morphological changes from that of CK and LD. Analysis of principal component analysis (PCA) on 15 kinds of phenotypic characteristics, separately being related to vegetative growth (V), sexual (S) and clone (C) reproduction, was conducted. The results showed that the life cycle forms under the conditions of CK, LD, MD and HD were V0.39S0.54C0.07, V0.36S0.50C0.14, V0.53S0.27C0.20 and V0.45S0.09C0.46. It suggested that MD and HD resulted in enhanced percentage of clone reproduction and decreased sexual reproduction. Alkaloid contents in C. roseus, including vindoline, catharanthine and anhydrovinblastine, were measured during stress. By the time of 16 d after treatment with HD, the contents of vindoline, catharanthine and anhydrovinblastine were significantly higher, being 1.5, 2.3 and 3.1 folds of the control, respectively. High level of anhydrovinblastine was proved to be induced by soil drought conditions, which offered theory for exploitation and utilization of drug plants.