Tithonia diversifolia(Hemsl.) A. Gray (Compositae) is an American plant which has become naturalization in the south of China. In Yunnan, it is mainly distributed on small hills of torrid zone with an altitude from 500 to 1600 meters above sea level. The leaves have been used as an agent for subduing swelling, dissolving lumps and treating enteritis and gastritis in local folk medicine (云南省药材公司，1993). Previous report showed that T.diversifolia was rich in sesquiterpene lactones (Raghwendra et al, 1976). However, the plant distributed in Yunnan has not been studied yet......

From the aerial parts of Parana discifera, 10 phytoecdysones, β- ecdysterone (1) and its 2 -acetate (2) , 3 - acetate (3), 25 - acetate (4) ,2,3- acetonide (5) , 20, 22 - acetonide (6) , and 2 -deoxyecdysterone (7) and its 20, 22 - acetonide (8), 3-O-β-D- glucopyranoside (9) and posterone (10) were isolated. They have no anti - inflammatory, analgesic, sedative, anti - convulsant and anti -cerebra- hypoxic activities in animal testing with Kunming mice.

A new ent - kauranoid named laxiflorin D (1) was isolated from the leaves of Isodon eriocalyx var. hxifhra, whose structure was determined by the spectroscope methods. Six known ent - kaurane diterpenoids, laxiflorin A (2). maoecrystals A-C(3-5).Q(6)and eriocalyxin B (7). together with cirsimaritin (8) and 2a- hydroxyursolic acid (9), were also isolated.

Twenty phenolic compounds together with caffeine, were isolated from crude materials of Pu- Er tea produced in Yunnan Province, China. They were identified as ( - ) epicatechin, ( - ) epigallocate-chin, ( - ) epigallocatechin - 3 - 0 - gallate, ( - ) epicatechin - 3 - 0 - gallate, ( - ) epiafzelechin - 3 - 0 - gallate, ( + ) catechin, ( ± ) gallocatechin, quercetin, queroetin -3-0-β-D- glucopyra-noside, rutin, kaempferol, kaempferol -3-0-β-D- glucopyranoside, kaempferol - 3 - 0 - rutinoside, strictinin, 1, 6 - 0 - digalloyl -β- D - gluco - pyranose, theogaUin, chlorogenic acid, 3α, 5α - dihy-droxy - 4 - α - cafeoyl - quinic acid, coniferin, gallic acid by spectroscopic data.

The changes of protein components of plasma membranes and plasma - membrane - depleted vesicles from the roots of tomato seedlings under phosphate starvation were studied in this paper. Firstly, the results revealed that, under phosphate starvation for 7 days, the contents of proteins of plasma membranes and plasma - membrane - depleted vesicles from the roots of tomato seedlings approximated to those of their unstressed controls respectively. Secondly, the results from SDS- PAGE of proteins showed that there were four novel polypeptides (mw: 34 kD, 36 kD, 46 kD, 49 kD) which existed in the plasma membranes from the roots of tomato seedlings under phosphate starvation for 7 days but not in those of controls. The above -mentioned results of SDS - PAGE were further confirmed by CG - PAGE.

From PsammosUene tunicoides W. C. Wu et C. Y. Wu, two new natural cyclic dipeptides and two new cyclic octapeptides (named psammosilenins A and B) were isolated. Their structures were deter-mined as cycio (-Ala-Ala-), cycio (-Val-Ala-), cycio ( - Pro1, - Phe1 - Pro2 - Phe2 - Phe3 -Ala- Pro3 -Leu-) and cycle ( - Prol - Gly - Phe1- Val - Pro2 - Phe2 - Thr - Ile - ) by spectroscopic methods respectively.

Structure and species composition of degraded plant community, along a human - induced distur-bance gradient in Dagou watershed of the upper reaches of the Minjiang River, were investigated. In general, attributes of woody - layer structure (density, height, basal area, species diversity and biomass) were negatively related with increasing disturbance. Herbaceous layer attributes (coverage, biomass, diversity, e-cological dominance etc. ) responded positively. This may be common response of various plant communities on disturbance except their density attribute.

Using RT- PCR technique, we obtained a fragment of cDNA about 315bp from rice strains with different chilling- resistance. In amplification reactions, the used primers are degenerated primeis, which were designed according to the conserved amino acid sequences of glycerol - 3 - phosphate acyltransferase from several kinds of dicotyls. Sequences obtained show that the cDNAs fragments all have the parts of cD-NAs coding for Glycerol - 3 - phosphate acyltransferase, contain 315 nucleotides and encode 105 amino acids. While the cDNAs sequences and deduced amino acids sequences from the rice strains with different chilling- resistance were different from each other. The bigger difference of chilling - resistance between strains is, the bigger differences between their cDNAs sequences and the deduced amino acids sequences are. The difference of chilling-resistance is probably related to the subtitution of proline.

The outline of transverse section of the pedicel is more or less triangular in Strelitzia nicolai Regel & Koem. Vascular bundles of pedicel are scattered within the fundamental tissue, but those just beneath the locule region are arranged into an outer region consisted of two - ring bundles and a central region with dis-persed small bundles. The bundles from the outer region enter the ovary wall, while those from the central region extend into the axile and become placental bundles which fade away gradually in prolongation. The caipellary dorsal bundles (cdbs), the accompanying bundles of the dorsals (abds) and the parietal bundles of ovary wall could be easily distinguished. Three cdbs finally enter the style via prolongation. The abds sep-arately extend into three stamens of the outer whorl of androecium. Two abaxial parietal bundles run upwards into the two stamens of inner whorl, while the adaxial one divide into two branches. The inner one of these branches is gradually separated from the outer one and moves towards the central axile, and finally fades away just when the style appears. The outer one is arranged in a line with the other four bundles which final-ly enters the median petal.

The decomposition and its nutrient dynamics of leaf litters of Pinus yunnanensis, Cyclobanapsis glaucoides and Castanopsis orthacantha in pine forest stand and evergreen broad -leaved forest stand in cen-tral Yunnan had been investigated by using the litterbag method in a duration of 868 days. It was found that the decomposition rates of both broad - leaved leaf litters are greater than that of pine needles. There are ob-vious differences between pine forest stand and evergreen broad - leaved forest stand in decomposed mass loss of leaf litters of three species. The decomposition coefficients were 0.55 ~ 0.6 l a^-1 for three leaf litters in evergreen broad - leaved forest, and in pine forest they were 0.50 ~ 0.53 a^-l. The removal rates of nutrient elements in litter change with the quality of leaf litter and decomposing site. During decomposition process the N, Al, Fe and Zn release of three leaf litters in both forest stands showed increase in the first period in content, and thereafter showed decrease over rest of this trial.

Results of studies on the karyomorphology of three populations of the monotypic genus Di-chotomanthes Kurz are presented in this paper. The interphase nuclei and prophase chromosomes are catego-rized to be of simple chromocenter type and of proximal type respectively. The metaphase chromosomes range from 1.66{jm to O.SJpm in length. The karyotype is formulated as 2n = 34 = 28m + 6sm, and the kary-otypic asymmetry is of 1 A type. The same basic chromosome number and similar chromosome morphology of Dichotomanthes to those of members in the Maloideae support the point of view that Dichotomanthes belongs to Maloideae.

Nelumbo nudfera Gaertn. has a no - radicle seedling. The lower part of the cotyledon lamina fuses into a tube - shaped object, and comes into an integrity with the cotyledon node zone (CNZ) and the part below it. The lower part of CNZ has a χ - shape haplostele. The middle part has a haplostele with the xylem enclosed by the phloem. The six vascular bundles of the cotyledon trace extend into the cotyledon ra-diantly and evenly. The haplostele of the middle part of CNZ is separated into 4 ~ 6 big vascular bundles which were in the central part of the atacto - stele in the upper part of CNZ. Part of the small vascular bun-dles of the atacto - stele originals from the division of the cotyledon trace, and the other comes from rediffer-entiation of the surrounding parenchyma cells.

Musci include three Subclasses (Brotherus, 1924 ~ 1925): Sphagnidae, Andreaeidae and Bryidae, which are composed of about 100 families and 800 genera in the world. Our researches indicated that the types of spore dispersal has an important significance in the evolution of mosses. Based on the stud-ies of sporophyte, peristome teeth and the individual development of mosses, 5 types of spore dispersal can be inducted, that is decay dispersal, wind dispersal, vapour - wind dispersal, water dispersal and insect dispersal. Furthermore, the relationship between the spore dispersal and evolution is discussed in detail.

Spore characters of 23 acrocarpous moss taxa in China are reported. Observation results show that (1) there are two types of spore shape, namely spherical and ovoid; (2) the spore diameter can be divided into four groups, namely under 10 um, 11 ~ 20um , 21 ~ 30 um and over 31 um. There are three types of aperture, namely katalept, monolete and atreme. There are four kinds of exine ornamentation, namely bacu-late, tuberculate, verrucate and pilate. There are six of spore color, namely yellow brown, dark brown, yellowish green, golden yellow, grass green and purple.The size of moss spores are different from species, but the basic types are spherical and ovoid. Biyophyte spores have three types of aperture, the trilete is original one, the monolete is the evolutionary character and the katalept is mostly common one. The ornamentation of exosporium varies from species. The smooth exine is considered to be an evolutionary character.

A numerical taxonomy study of 24 populations of three dodders was studied by choosing 33 mor-phological characters and using the UPGMA. The result is shown as follows: (1) Cuscuta japonica Choisy is close to C. reflexa Roxb., while C. chinensis Lam. is alienated from them. (2) There are rich genetic both in C. japonica Choisy and in C. reflexa Roxb.. It is suggested that C. japonica Choisy could be di-vided into two varieties, and C. reflexa Roxb. into three varieties.

Species F. murierae (Gamble) Yi affinis, sed culmis junioribus praeter partem a vagina inclosum aliquantum farinosum nodis, vaginis culmorum (ca. 13 cm longis) brevioribus longitudine ca. 1/2 internodii partes aequantibus, glabris margine saepe non ciliatis, setis oralibus primo 3 in quoque latere demum caducis, laminis brevioribus, usque 5 cm longis, laminis foliorum minoribus ca. 4.5～8.5 × 0.7～0.9 (-1.1) cm basi cuneatis differt......

Based on the specimens at PYU, this paper gives some new contributions to pteridophyte of Yunnan. Three new species and two new varieties, three species new to China, one genus and two species new to Yunnan, a new combinative name of one species are described, illustrated or photographed. The phylogenetic position of another species is reviewed and its new combinative name is given in the present paper.

The region of Xinqing Mountains is situated between latitude 33°80′～35°50′,and longitude 100°10′～102°40′E. There are 711 species of seed plants that belong to 56 families and 257 genera in this region. The floristic characteristics in the area are as follows:(1) The Temperate elements has a percentage of 96.88%,it show the clear nature of the Temperate Zone that is the decisive factor of the floristic characteristics.(2)Most of the cosmopolitan elements and the endemic elements of China are developed from them relational genera that are wildly distributed. Shows the flora is a younf and derivative flora. (3)The main vegetation such as alpine meadows,alpine thickets and alpine moor meadows are all alpine type typical. Most of the constructivespecies of them are character species of ytpical alpine vegetation.Therefore ,in this flora,the alpine vegetaion are typical,and the characteristic species are typical ,and the feature of alpine and plateau flora is obvious.

A new genus of Opiliaceae,Yunnanopilia is described fromthe Red River Valley,South-Central Yunnan Plateau,China. This genus is a primitive one in the Opiliaceae by having hermaphrodite flowers in large panicles,and may be the ancestry type of both Lepionurus,Melientha and Champereia. It seems that this genus may be originated inthe Kam-Yunnania Ancient Landmass. This indicates that the Opiliaceae may also be orginated in the Kam-Yunnania.