Variation in Growth and Secondary Phenolics Among Field-Cultivated Clones of Salix myrsinifolia.

Nine S. MYRSINIFOLIA clones were studied for secondary phenolics and phytomass production in an old, unfertilized hayfield after the second growing season. S. MYRSINIFOLIA is one of the most promising willow species for the production of herbal drug material. Its salicylate content is moderately high in all parts of the shoot. The leaf and stem phytomass varied significantly among clones, but more than 70% of the total variation could be explained by within-clonal phytomass variation. Similarly, the accumulation of salicin, salicortin, chlorogenic acid (+)-catechin, proanthocyanidins, and unknowns varied significantly according to source (tissue, individual, or clone), and in most cases the environmental (within-clonal) variation was nearly as high as the genetic variation (between-clones). In the selection of the best clones for the production of herbal drug material three main factors should be taken account: costs of cultivation, costs for transportation, and costs for production of extracts. A high phytomass clone may be a low-quality clone as far as salicylates are concerned.