Provenance variation in camptothecin concentrations of Camptotheca acuminata grown in China

摘要

Camptotheca acuminata, a deciduous tree indigenous to southern China, contains camptothecin (CPT), an alkaloid of anti-cancer properties. Eighteen provenances were collected across its native range in 10 provinces south of the Yangtze River. A provenance test was performed for one growing season. Both growth characteristics and leaf CPT concentrations were determined. Seasonal height growth followed a typical “S”-shaped pattern, with a negligible height increment in the beginning of the season, a slow growth period from June 27 to August 11, a rapid growth period, and in the end a gradual decline in height increment with terminal bud set in mid-October. Final stem heights varied significantly among the 18 provenances. The difference was 43 cm or 38% between the tallest and the shortest. Significant differences were found among the 18 provenances in biomass production of whole-plant, shoot, leaf, root, and bark after one year of growth in nursery settings. Leaf CPT concentrations exhibited three-fold difference among the 18 provenances. Leaves are to be used as the target plant material for extracting CPT and the top five provenances were identified. These provenances warrant further field testing to determine the optimal growth conditions for accumulation of CPT.