The Biological Study Of Stellera Chamaejasme (Thymelaeaceae)

The seed biology, developmental morphology, artificial breeding, chromosome number and biological activity of Stellera chamaejasme were studied in this thesis. The wax section, karyotype analysis and other methods were used. The study results are as follows:1.Stellera chamaejasme seeds could germinate after dormancy in nature. The dormancy main reasons for the embryo physiological after-ripening, and seed coat for germination of a certain extent. After 4℃wet sand and GA treated, seed germination rate could be significantly enhanced. The germination rate of seeds, stored in nature for one and a half month, buried in wet sand at 4℃for one month and GA treated 24 h, could rise up to 62.0%.2.The transverse section of seedlings and adult plants stems' structures of Stellera chamaejasme are round, containing epidermis, cortex and central cylinder, limited secondary growth, collateral vascular bundle. Leaf contains epidermis, mesophyll and vein. Mesophyll tissue contains palisade tissue and spongy tissue, anomocytic stoma. Rootstock contains epidermis, cortex and central cylinder, collateral vascular bundle, and central cylinder is diarch, having secondary growth, ray homogeneous, spiral and reticulate vessels.3.The growing reason of Stellera chamaejasme is short, but the amount of annual growth of its root is large. Using transplanting plants after indoor propagation methods and direct seeding to breeding methods the small quantities of S. chamaejasme plants are obtained.4. The anther of Stellera chamaejasme has four locules. The microspore mother cell meiosis in the cytokinesis is simultaneous. The tetrads are usually arranged in tetrahedron. The mature pollens are subspheroidal or spherical in shape. The ovule erects, with two layers of integuments, thick nucellus. One of the four archeporial cells develops into a megaspore mother cell usually. The embryo sac is single spore, polygonum type. Endosperm is nuclear type.5.The chromosome number of Stellera chamaejasme is 18,which is consistent with the describtion of X=9 of Thymelaeaceae in "Taxonomy of plant cells" written by Hong Deyuan.6.The water extract of stem and root of Stellera chamaejasme inhibited the cabbage seed germination and radicle growth, being a role of allelopathy; after adding 50 ml ethanol extract of S. chamaejasme, the pupation rate and mortality of the yellow mealworm are highest; after adding 5 ml ethanol extract of S. chamaejasme, the 20 days' corrected mortality of the fruit fly is 58.62%, while for 20 ml, the 8 days' corrected mortality of the fruit fly reachs 100.00%.The morphology (nutrition body, gonopodium and chromosome number), reproduction and cultivation, insecticidal bioactivity of Stellera chamaejasme were studied in more detail in this thesis, providing the morphological basis for the use of S. chamaejasme as a traditional Chinese medicine and botanical insecticides, and also providing scientific basis for culture and genetic breeding of this species.