In order to find the odor characteristic of the essential oils from Cananga odorata and its three varieties were studied, one of them have been collected from Xishuangbanna, Yunnan, China, the others introduced from Thailand and Laos and cultivated in Xishuangbanna. The chemical components of three Yilan-Yilan oils were analysed qualitatively and quantitatively by means of capillary GC/MS/DS on Finnigan-4510, and 44 different constituents were identified. As the analysed result, the odor of Yilan-Yilan oils was related to the varieties and contents of the esters, alcohols and phenolic ethers. The more sesquiterpenes and its alcohols a Yilan-Yilan oil contains, the worse its odor is. The essential oil obtained from the flowers that changed colour from green to yellow was better than the essential oils obtained from the green flowers and the flower buds.

Rhododendron brevicaudatum R. C. Fang et S. S. Chang, sp. nov. (Subgen. Rhododendron, Sect. Rhododendron, Subsect. Micrantha) Species affinis R. micranthi Turcz., sed foliis multo majoribus ,9-12.5×2.5-3.3 cm, apice  breve caudato-acuminatis, basi subrotundatis, subtus indumento arachnoideo obsolete obtectis, corollis et capsulis majoribus differt.

Haec species nova spiculis ommino persistentibus numquam deciduis a congeneribus diversa.

Rhododendron atropunicum H. P. Yang, sp. nov. （Subgen,Rhododendron,Sect．Pogonanthum )Species affinis R.luhuoensis H．P．Yang，a quo differt calycis lobis lepidotis，secus marginem dense lepidotis,foliis majoribus,1-2 cm longis, 0.4-1 cm latis,subtus squamis atroferrugineis．

Camellia euphlebia Merr. ex Sealy var．yunnanensis C. J. Wang et G. S.Fan，var．nov．Subgen．Thea Chang，Sect．Chrysantha，Ser．Chrysanthae Chang.

An essential oil from leves of Murraya kwangsiensis (Huang) Huang,that was analyzed by GC-MS-DS technique. 24 compounds were isolated and .denied, and their content accounted for 97.03% of the essential oil. The major constituents were geranyl acetate (26.37%), geranial(21.79%),neral(20.77%), neryl acetate (20%),gelaniol (5.30%), γ-terpmene (2.39%), nerol (2.11%), linalool (1.78%), limonene (1.15%). The results indicate Murraya kwangsiensis is an unnoticed fragrant plant, the smell of which is alike to citranel oil, that is tit to be used.

The present paper reports on a new diterpenoid, weisiensin A (C28 H36O9, mp 298-300°C), which is isolated from the ethereal extract of the dry leaves of Rabdosia weisiensis C. Y. Wu, the chemical structure has been shown to be 1α, 6α, 7β-Triacetoxy-3β, llP-dihydroxy-ent-kaur-16-en-15-one( 1) on the basis of spectroscopic evidence and compared with known compounds. Trichorabdal A ( 2 ), a known component, is also isolated from this plant and its 12C NMR data are assigned.

Twelve species of epiphyllous liverworts, belonging to 10 genera and 5 families, were found at 650 m altitude on Daiwu (Tai Mo) Shan, Kowloon. Among them, 5 genera and 6 species are new records of epiphyllous liverworts to China, namely, Calypogeia tosana, Cephalozella microphylla, Drepanole-jeunea formosana, Heteroscy phus argutus, H. bescherellei, and Lepidozia fauriana.

Elatostema integrifolium（D．Don）Wedd．var．tomentosum（Hook．f．）W．T．Wang，comb．nov．-E．sesquifolum（Bl)Hassk．var．tomentosum Hook．f．Fl．Brit．Ind．5：565（1888）; W．T．Wang in Bull．Bot．Lab．North-East．Forest．Inst．7：34（1980）．

Michelia sphaerantha C. Y. Wu,sp.nov. Species M．foveolatae Merr．ex Dandy simillima，sed differt ramulis petio- lisque sparse pilosis，foliis subtus subglabris vel pubescentibus，floribus albis．

Eleven ditcrpenoid alkaloids were isolated from the fresh roots of Aconitnm austroyunnanense W. T. Wang, a famous folk herbal medicine with cura tivc effects of rheumatism, apoplexy palsy, fracture, etc. Alkaloid 1, a new compound, was determined to be 14-acetyl sachaconitine on the basis of its spectroscopic data and chemical method, and named austroconitine A( 1 ). Alkaloid 2 - 8, seven known compounds, were identified as vilmorrianine B (karakoline) (2), isotalatizidine (3), vilmorrianine D (sachaconitine) (4), vilmorrianine C(5), talatisamine (6), vilmorrianine A (7), 8 -deacetyl yunaconitine ( 8 ), respectively, through the direct comparison to those authentic samples. Alkaloids 9-11 are still under identification.

A new ent-spirokaurenc diterpene, guidongnin ( 1 ) , mp 235- 237°C,[α]22/D -160°(C = 1, pyridine), was isolated from the ether extract of dried leaves of Rabdosia rubescens (Hemsl.) Hara (Labiatae)that collected in Guizhou, China. Its structure has been shown to be ent-6 , 7 -spiroseco- 6 , 19 -γ-lactonic ring-7 , 20-δ-lactonic ring-16-kaurene-11β, 15α-diol ( 1 ) on the basis of spectroscopic and chemical evidence and compared with known compound, ludo-ngnin A. Two known spirokauranoids, ludongnin A ( 2 ) and B ( 3 ) were also isolated together with β-sitosterol, R-sitosterol-D-glucoside, 2α-hydroxyursolic acid and cirsiliol.

The causes threatening Pellacalyx yunnanensis Hu, a species endemic to Yunnan and a tree receiving priority protection in China, are discussed. The study focuses on its seed anatomy, the relations between different methods of seed storage and seed germination, and the effects of seed moisture content, tem-perature and ligh density on seed germination. It is concluded that the main causes of species decline involve the facts that seeds ripen during the dry season, short life-span prevents seeds from surviving until the rainy season, and most fail to germinate. Seeds require high temperatures and abundant moisture to germinate successfully. Reasons for the. species decline include long-term natural factors, such as climatic and geological changes, and human-related activity, particularly defo-restation. Thus, some measures for effectively preserving this species are proposed.

From 1983 to 1985, authors had made the field plot experiments on different doses of basal dressing with nitrogenous fertilizer (urea) of rice (Oryza saliva L.) in Yuanjiang (dry-heat river valley about 400 m altitude), Kunming (warm-cool plateau lake-shore about 1900 m altitude) and Lijiang (cold-cool plateau area about 2400 m altitude), Yunnan, respectively. The treatment of basal dressing was divided into three doses which the one was not applied with urea (CK), the other was applied with 20 kg/mu urea (middle dose) and the third was applied with 30 kg/mu urea (large dose). At the same time, each dose was rep-licated three times. The dry-matter production and partitioning in the aerial part had been made a comparison among the treatments of different doses.

The conditions for detecting tobacco mosaic virus (TMV) RNA in tobacco leave extract by RNA dot hybridization using a radioactive probe containing the cDNA of 3' terminal RNA of TMV strain OM have been studied. These conditions include the homology between the TMV strains isolated from Yunnan and Shanghai and the strain OM, the method for extracting viral RNA from tobacco leave and for adsorbing the extracted viral RNA onto nitrocellulose filter efficiently, the material interrupting the adsorption of viral RNA onto nitrocellulose filter and the hybridization of viral RNA with probe, and the speciality, sensiti-vity of the RNA dot hybridization method for detecting TMV-RNA in tobacco leave.

The embryo of Dendrobium candidum Wall ex Lindl. in different stages is globular. But embryos are different in shape,cell numbers,starch grains germination rate is 95% in vitro. Protocorms are dormed from embryo. The protocorm can directly form seedling or callus. The callus may differentiate into seedling again. During seed germination the starch is reduced gradually in the cells at the top of the embryo. The reduction of starch may be closely related to the meristem and the formation of the cotyledon.

The genus of Camellia consists of over 200 species, its distributing centre is in the south and southwest part of China. Morinaga firstly did the cytological studies of Camellia in 1929, who examined the chromosome number of C. sinensis and C. japonica and confirmed the basic number n = x = 15；then, C. sinensis var. macro phylla 2n=45, 2n = 60, to be polyploid were reported by Karasawa Simura in 1935；from 50th to 60th decade the research on chromosome number of Camellia had developed and 14 species were reported. Since 1970, a series works on cytological studies of Camellia either the wild species or the cultivated variaties had been done by K. Kondo.

1. The somatic embryogenesis is produced differently in the different cultivars of Sunflower. 2. The higher concentration of sucrose makes better somatic embryogenesis of Sunflower immature embryos. 3. The immature embryos of 2mm length among the embryos of different size have the highest percentage somatic embryogenesis in the same condition. 4. The higher concentration of Zeatin is, the more percentage of somatic embryogenesis in Nitsch medium supplemented with 0.5-l0.0ppm Zeatin and 17.5% sucrose in the immature embryo culture of Sunflower. 5. 2 , 4-D makes the embryos somatic embryogenesis, but does not make them differentiation. 6. In the slides show, the immature embryos produce the embryonic cell groups and embryoids, many of which are emerged in the cotyledon and hypocotyledonary axis. The surrounding cells of the embryonic cell groups degenerate, such there is the space between the groups of cell and the surrounding tissue.

The biosystcmatic relationships among Roegneria kamoji Ohwi, K. ciliaris (Trin.) Nevski and R. japonensis (Honda) Keng in the tribe Triticeae Dumortier were studied in the present paper by the methods of gcnome analysis and clectropherogram analysis of two kinds of isozymes. The three species were all sclf-pollinatcd plants. The Fi hybrids of R. kamoji x R. ciliaris, R. kamoji x R. japonensis and R. ciliaris y. R. kamoji showed an irregular chromosome pairing in mciosis and completely no seed set; the chromosome pairing pattern was nearly 7 I + 14II . The reciprocal Fi hybrids of R. ciliaris x R, japonensis presented a regular chromosome pairing in meiosis and very high seed set) chro-mosome pairing pattern was almost 7 I; and no reproductive isolation between the two species was observed. The three species shared two common genomes (II KK or SS YY). The zymograms of esterasc and acid-phosphatasc isozymes in R. kamoji were obviously different from those in R. ciliaris and R. japonensis; but no distinct difference was found between the latter two species. Large variations in estcras and almost no variation in acid-phosphatase were observed in different populations of the three species respectively.

This paper deals with the pollen grains of 32 species and varieties of Jasminum. A comparison was made among all these species and varieties,putting an emphasis on the shape and size of the pollen grains,the number and characteristics of the aperture and the ornamentation of the exine.