Comparative Anatomical Studies On Rabdosia Excise And R. Japonica (Burm.f.) Hara Var.glaucocalyx

Rabdosia excise(Maxim.)Hara and Rabdosia japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara are herbor of Rabdosia in Uabiatae.They are distributed mainly in the north area of China,Shanxi,Shandong and other povinces.A great deal of studies have been done on the chemical composition,pharmacological action,tissue culture and genetic diversity of the two species of plants.In this paper,a comparative anatomical study was made by paraffin section,free hand sectioning and Jeffery’s isolation method,in the vegetative organs of R.excise(Maxim.)Hara and R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara with the characteristic studies of biology and Phenology and habitat investigation.It provides a new data for taxonomy position of Rabdosia form the point of anatomical structure and,at the mean time,it gives a elementary study of the relationship between the structures and environment and also the study of domestication.The results are as follows:1.The primary root structures of R.excise(Maxim.)Hara and R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara:There were no obvious thick bands of cell wall in the inner cortex cells,all of which were actinostele.The developmental patterns of the primary xylem was all outside,the primary phloem arranged radially between the xylems.The primary xylem of R.excise(Maxim.)Hara is 4,and R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara is the 3 primary xylem.2.The secondary root structures of R.excise(Maxim.)Hara and R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara:The secongary root vessel of R.excise(Maxim.)Hara has array the diffuse porous shape;but The secongary root vessel of R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara has array the half-annular-porus shape.The vessel of the two secondary xylem were ringed vessel,and stubby shape.The tube wall was slightly thickened,the inclination of the end wall was small or flat,and the perforation plate types were single perforation plate.Both of them are ringed tracheid;wood parenchyma away from the vessel;most of them are the apotracheal parenchyma;the wood ray type R.excise(Maxim.)Hara is heteromorphic I.The wood ray types of R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara are heteromorphicI and heteromorphicⅡ.3.The stem structures of R.excise(Maxim.)Hara and R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara:The stem structures of the two are approximately the same,all of which are eustele.xylem is developed,and its development pattern is internal;and the pith parenchyma is developed or hollow;A large number of calcium oxalate crystal bundles were found in the parenchyma cells of the cortex and the pith.4.The leaf and petiole structures of R.excise(Maxim.)Hara and R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara:The two species are all heterophyll leaves;The stomata type are irregular and oval in shape;and the stomata are sunken and only in the lower epidermis of the leaves.The stomata number of R.excise(Maxim.)Hara is 372/mm~2,and the stomata number of R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara is 188/mm~2.All two plants have only one palisade tissue,but the palisade tissue cells are cylindrical in shape;The sponge tissue is well developed and the intercellular space is large;The ratio of palisade tissue and spongy tissue of R.excise(Maxim.)Hara is 80.9%.But the ratio of palisade tissue and spongy tissue of R.japonica(Burm.f.)Hara var.glaucocalyx(Maxim.)Hara is 52.81%.Large number of glandular hairs and non glandular hairs are found in the abaxial epidermis and petiole of the two leaves.The secretory ducts are distributed in the leaves and petioles of two plants.The petiole structures of the two species are basically similar.5.All of the two plants are mesophytes plants,which have strong resistance,such as shade resistance,cold resistance,insect resistance,and negative pressure resistance.In terms of anatomical structure and biological characteristics,two species are easy to be domesticated and propagated by means of vegetative propagation such as root division,seeding and tissue culture.