Anatomical and histochemical characteristics of leaves and flowers of Tanacetum cinerariifolium and Tanacetum coccineum
The contents of pyrethrins in Tanacetum cinerariifolium and Tanacetum coccineum 'Robinson red' differ. In the present study, variations in the structures of the leaf and flower parts on the surface, mesophyll tissue, and oil glands were compared anatomically and histochemically between T. cinerariifolium and T. coccineum 'Robinson red'. In both species, oil glands were observed on the leaf and flower of epidermal tissues. Oil glands were located in the concave epidermis in the leaves of T. cinerariifolium only, while other oil glands were detected in the smooth epidermis. The structures of all oil glands comprised several head and stalk cells, with the number of cells differing between species. Furthermore, a T-type multicellular non-glandular trichome was found on the leaf surface. The mesophyll tissues of both species were composed of one epidermal layer, three layers of tightly packed palisade tissue, and six layers of spongy tissue. The palisade tissue of T. cinerariifolium comprised three tightly packed layers, whereas that of T. coccineum had only one layer. Histochemical staining using various dye reactions was darker in T. cinerariifolium than in T. coccineum. A significant difference was observed in the detection of terpenoids and sesquiterpene lactones. These results suggest that the histochemical techniques employed in the present study are applicable to initial selection in the breeding of pyrethrum strains with high pyrethrin contents.
Kobayashi, T. and Tabuchi, T. 2017. Anatomical and histochemical characteristics of leaves and flowers of Tanacetum cinerariifolium and Tanacetum coccineum. Acta Hort. (ISHS) 1169:157-164
lipids, oil gland, pyrethrum, sesquiterpene lactones, terpenoids