Effect of planting density on plant growth and camptothecin content of Camptotheca acuminata seedlings

Effect of planting density on plant growth and camptothecin content ofCamptotheca acuminata seedlings

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25, 44 and 100 plants·m⁻²) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem, and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area ofC. acuminata seedlings all showed highest values at the planting density of 25 plants·m⁻². CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100 plants·m⁻², while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m⁻². It is concluded that for the purpose to get raw materials with more CPT fromC. acuminata, the optimal planting density ofC. acuminata seedlings should be designed as 25 plants·m⁻². Foundation item: This paper was supported by the National Natural Science Foundation of China (No. 3970086) and Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11) Biography: Wei Huan-yong (1978-), male, Graduate in College of Life Sciences, Northeast Forestry University, Harbin 150040, P. R. China. Responsible editor: Zhu Hong