Isolation and structural elucidation of four glycosides (A-D) from the aerial parts of Paris polyphylla var. yunnanensis (Fr.)H-M. On the basis of spectroscopic and chemical evidences, the structures of four glycosides were established as 25S-isonuatigenin-3-0-α-L-rhamnopyranosyl(l-2)[α-L-rhamnopyranosyl (l--4)]-β-D-glucopyranoside (A), 26-0-β-D-glucopyranosyl-nuatigenin-3-0-α-L-rhamnopyranosyl(l-2)[α-L-rhamnopyranosyl(l-4)]-β-D-glucopyranoside (B), kaempferol-3-O-β-D-glucopyranosyl (1-6)-β-D-gluco-pyranoside(C),7-O-α-L-rhamnopyranosyl-kaempferol-3-O-β-D-glucopyranosyl(1-6)-β-D-glucopyranoside (D).

Under the treatment of low temperature (2°C or 5°C ) in dark for 1-2 days, the activity of both superoxide dismutase (SOD) and peroxidase (POX) in the rice seedlings of these varieties of different cold-endurance in Yunnan Plateau were decreased with varying degress. The activity of both SOD and POX in these varieties with strong cold-endurance at light (28 °C, 2500 Ix) after chilling treatment are much higher than control. But the activity in these varieties with weak cold-endurance still are lower than control. The contents of ascorbic acid (ASA) and glutathione (GSH) were decreased gradually but the content of malondialdehyde (MDA) was increased with lenghthening time exposed to chilling temperature, strengthening chill-stress and recovery at light. Decrease of contents of ASA and GSH in these varieties with strong cold-endurance is smaller and increase of content of MDA is smaller, too.

Two new ursane glucosides, pruvuloside A and B, together with five known compounds, niga-ichigoside F2,sericoside,quercetin,quercetin-3-glucoside, kaempferol-3-0-glucoside, and a mixture of niga-ichigoside F1, and arjunglucoside I were isolated from the MeOH extract of Prunella vulgaris collected in France. Their structures were determined by means of spectral evidence.

A new cyclopeptide, annomuricatin A, has been isolated from the seeds of Annona muricata and the structure was elucidated by extensive 2D-NMR methods, pos. FAB-MS, and amino acid analysis.

In the previous papers, we have reported the isolation and structural elucidation of seven new cyclopeptides (stellarin A-G). Further chemical study on this plant resulted in the isolation of another new cyclopeptide, namely stellarin H(l). Its structure was established to be cycle (Phe-Ser-Leu-Val-Leu-Pro-Pro-Tyr-Ser) on the basis of the spectral and chemical methods. In adition, a known cyclic pentapeptide, pseudostellarin A, was isolated.

Cellularization of endosperm in peanut was observed with transmission electron microscopy. The free nuclei of endosperm at heart-shaped embryo stage are irregular in shape. Abundant mitochondria, plastids, Golgi bodies, vesicles and some endoplasmic reticulum are present in the cytoplasm of the free nuclear endosperm. The endosperm nodules are usually found at globular and heart-shaped embryo stage. There exist wall ingrowths on the embryo sac wall. Three patterns of endosperm cellularization were observed in different ovules: (1) The initial anticlinal walls arise from the embryo sac wall and grow predominantly by the coalescence of Golgi vesicles and endoplasmic reticulum cisternae. These freely growing walls which have middle lamellae branch and eventually meet to form the endosperm cells. (2) After the mitosis of the nuclei, the cell plates are formed between the sister nuclei. These cell plates grow continuously and branch. The cell plates are observed between the nonsister nuclei too.

The embryo culture was studied on interspecific and intergeneric hybrids from Genus Leymus species. The six species which were involved in this experiment were L. secalinus, L. angustus, L. aemulans, L. multicaulis, L. racemosus, and L. tianshanicus. Five interspecific crosses were formed from them, and ten intergeneric crosses were also formed from five of them with Psathyrostachys, Roegneria and Thinopyrum species. Their hybrid embryos were cultured in vitro by the means of embryo culture, and the interspecific and intergeneric hybrids were successfully rescued. The experimental results showed that embryo age of the hybrid embryos, nutrient compo-sition of media, and hybrid genotypes existed obvious influences on frequencies of seedling formed from hybrid embryos.

The ultrastructure and changes after hydration of pollen wall in Liriodendron chinense and L. tulipifera were observated by electron microscope. The results were shown follows: (1) The mature pollen wall consists of six layers which are exine sexine, nexine 1, nexine 2, inline 1, inline 2 and inline 3. (2) During hydration of pollen, new layer (pollen tube preparing layer) is formed be-tween intine 3 and vegetative cell plasma membrane by P-particles and coated vesicle. (3) When pollen germinates, pollen tube wall forms by protruding of part of intine 3 and new layer from germinating aperture. (4) Early stage of pollen tube differentiates into two layerspection outer lay-er which is dark and callose inner layer which is electron transparent.

Species affinis L.davidii (Franch.)H.S.Kung et L.B.Zhang, sed folliis margine ciliatis, follis lateralibus apice acuminatis vel caudatis differt.

Species habitu A.sinii(Ching)Holtt．similis、differt paleis rachidi et costae subulatis(non ovatis)nigris(non brunneis)，glandulis superficiebus ambabus laminae aureolinis cylindricis(non albidis lavatis)，pinnis infimis pinnatifidis(non pinnatis)．

In this paper Chingyungia scutellarioidea T. M. Ai of Verbenaceae is reduced to Melampyrum klebelsbergianum Soo of Scrophulariaceae, and Silvianthus bracteatus ssp. tonkinensis (Airy Shaw) H. W. Li is newly recombined.

This paper deals with the species diversity of pteridophytes from the Laojun Mountain Nature Reserve based on taxonomic and floristic studies. The results show: (1) Richness in pteridophytes species demonstrated by the following large species diversity indices, Dmg index 17.9, Dmn index 2.1, Dri index 41.1 and Dsi index 0.98; (2) High species density (0.02 species / m2) and high individual density (0.6 individual / m2) of pteridophytes; (3) The species occuring most frequently are Alsophila costularis (50.0), Egenolfia appendiculata (50.0) and Polypodiodes amoena (50.0); (4) The species with the largest relative abundance is Tricholepidium maculosum (5.2); (5) Great morphological diversity and variations in size of pteridophytes; (6) The taxa are relatively complete and diversified in phylogeny; (7) The geographical elements are complexity and outstanded by mountainous endemic species of Tonkin Gulf of SE. Yunnan; (8) Ecological diver-sity.

Nouelia Franchet is a monotype genus of Compositae. As rare and endangered as well as endemic species to China, Nouelia insignis Franchet is distributed in Sichuan-Yunnan region extending from 24' to 30' Nand 99'40' to 103'50' E.Some botanists have discussed the origin and floristic feature of Nouelia.

There are 3061 islands in Zhejiang, Which located in about 27 ° 05 / -30° 51/ N, 120 ° 09 / -123 ° 09 / E. It is quite rich in species and complex in composition of families and genera. On the basis of investigation in 1990-1993, there are about 1914 species, 12 subspecies, 175 varieties, 26 forms and 46 cultivarieties of vascular plant, which belonging to 195 families and 909 genera. The geographic element is complex and varied. According to statistics, 702 genera of wild seed plant can be divided into 15 areal-types. Dominant areal-types in the order, are the Pantropic, North Temperate, East Asia and Cosmopolitan. Besides, it has a very obvious zonal law.

The geographical distribution, the center of distribution and differentiation of Euclidieae, its system and evolutionary trends are discussed in this paper.

Subspecies haec a subsp. pectinata megasporophyllis intra glabris, inferne stipitato, stipitis 3-17.5 cm longis , ovulis 2-6 infra medium praeditis; seminibus (testa excussa) mimoribus, 3-3.5 cm longis, 2-2.7 cm diametribus; microsporphyllis emarcidis praeter apicem rhombiformem dense tomentosum glabris, ca. 4 cm longis; folia lobis costis prominentiis, ad centrum exsulcis; caule inferne lubrico, basi ramosodistinguenda.

Based on the comprehensive studies of most taxa in Adoxaceae dealing with the evi-dences of cytology, variation analysis of floral parts and basic numbers, the floral vasculature and morphology of inflorescence, the taxonomic system of Adoxaceae is reinstated and the phylogeny and distribution of Adoxaceae are discussed in detail.

Rhododendron is a largest genus which is now known at least 967 species in the family Ericaceae in the world and about 562 species in China (exclude the infraspecific taxa).