Abstract: Taking four Saussurea species with different ecological breadth in the eastern QinghaiTibetan Plateau as test materials, their seedlings relative growth rate (RGR), root mass to shoot mass ratio (R/S), and specific leaf area (SLA) were determined under different nutrient and light treatments. The results showed that nutrient and light had significant effects on the seedlings RGR, R/S and SLA of the four Saussurea species, and there existed a certain interactive effect between nutrient and light. The plasticity of these morphological characteristics and their response patterns to the variation of nutrient and light conditions varied with species. Significant interactive effects (P<0.001) between light, nutrient, and species were observed on the R/S and SLA of Saussurea. For the four Saussureaspecies, the mean phenotypic plasticity index of their seedlings was positively correlated with their ecological distribution, being the highest (0.71) for S. japonica, the best widespread species in the four species. The morphological plasticity of Saussurea species was positively related to their distribution ecological breadth.

Key words: juvenile Apostichopus japonicus, light intensity, compound Chinese medicine preparation, microbial preparation, growth, digestive enzyme activity.