Abstract:

A pot experiment in greenhouse was conducted to investigate the effect of drought stress on 1-year-old seedling growth of Camptotheca acuminata from 8 provenances. The camptothecin concentrations in leaves of the seedlings under drought stresses were determined by the ultra performance liquid chromatography (UPLC) and the yields of camptothecin per plant were subsequently calculated. Results showed that: The drought stress inhibited the seedling growth by decreasing the basal diameter and height increment, and decreasing total biomass of all seedlings from the 8 different provenances. The differences in the basal diameter and height increment, the total biomass, and the yield per plant were significant among different treatments and provenances (P<0.05). Variance analysis indicated that the contents of camptothecin had significant difference among provenances and levels of soil moisture (P<0.05),and the contents of camptothecin increased at first and then decreased in all the provenances with drought stress strengthening. Under drought stress, the yields of camptothecin per plant decreased in almost all provenances, but under light drought stress, the yields of camptothecin per plant increased in GL and NJ provenances, with the highest yield up to 27.904 mg per plant in GL provenance. The differences in the yields of camptothecin per plant were significant among different provenances. It is concluded that GL provenance had the highest content and yield of camptothecin per plant, and especially its yield was able to be improved under light drought stress. Thus this study would provide a theoretical basis for selective breeding as well as the establishment and management of leaf-producing plantation of C. acuminata.

Key words: Camptotheca acuminata, drought stress, growth, camptothecin