Drought tolerance of six Dendranthema×grandiflorum cultivars(Jinbeidahong,Tianxiayipin,Quanxiangchongtian,Ziyu,Guohuahuangzhuan and Junhedewu) under drought stress was evaluated with subordinative function,and the physiological and biochemical indexes such as exosmosis rate of cytoplasm,content of malondialdehyde(MDA),activities of superoxide dismutase(SOD) and peroxidase(POD),and the relative chlorophyll contents were measured.Comparing with control,with the degree of drought stress increase,the protoplasmic membrane penetrability of diferent species increased continually,while the chlorophyll contents were decreased gradually.The protective enzyme's(SOD and POD)activity of six cultivars presented to rise first and then drop,and reached its maximum on 18 days in the condition of drought stress.The MDA content of Guohuahuangzhuan and Ziyu kept increasing,whereas other cultivars showed the trend of declining firstly and then rising.The comprehensive evaluation of the six cultivars was handled by using the subordinative function method.The drought tolerance of six chrysanthemum cultivars is in the following order:Jinbeidahong,Tianxiayipin,Quanxiangchongtian,Ziyu,Guohuahuangzhuan and Junhedewu.

An anatomical study was conducted on the nutritive organs of Emmenopterys henryi.The results show that in the primary shoot and cortex of secondary shoot,pulp and root ′phloem of Emmenopterys henryi,many parenchyma cells are of obvious netted texture.Parenchyma cells of cortex and pulp are rich in primary structure of stem.The secondary xylem is diffuse-porous wood,vessel is simple perforation,end wall is slightly tilted,and there are few wood-parenchymatous cells.In old roots,there is no pulp in the center.The leaf is of dorsi-ventral leaf,wich developed palisade tissue,and stomata only scattering over the lower epidermis of leaf,which are the structural feature of mesophyte.

The results of structural botanical experiment on stem and leaf of Magnolia biloba(Rehd.et Wils.) Cheng show: there are secretory cavities distributed in the cortex and pith of the stem,of the rachis and the petiolule,and in the parenchyma under the main vein in the Magnolia biloba(Rehd.et Wils.) Cheng;in the walls of some cells there exist reticulate structures.The leaf is of dorsi-ventral leaf,and the stoma only scatter over the lower epidermis of the leaf,which belongs to anomocytic type.In the primare of the stem,the living thin-wall cells are very rich in the cortex and the pith.The secondary xylem is that of diffuse-porous wood.The vessel end wall,applanate and slopping is ladder-shaped compund fenestrated.The wood parenchyma is rare and has a star-scattering distribution.All these indicate that Magnolia biloba(Rehd.et Wils.) Cheng is a more primitive species in evolution.