Five isoflavanoids had been isolated from the methanolic extract of Iris tectorrum . They were iristectorigenin A (l) , irisflorentin (2), irigenin (3), tectorigenin (4) and tectoridin (5) . Compound (l) and (2) were isolated from this plant for the first time. All of the compounds were identified on the basis of detailed spectroscopic analysis including two-dimensional NMR (1H-1H COSY;1H-13C COSY) data.

The embryonic callus induced from zygotic embryos of Picea wilsonii were used as initial culture and cultured on the modified 59 medium supplemented with 2.4 - D 1 mg/L and KT 1 mg/L. The effect of the semi- solid and the suspension culture on embryonic callus proliferation and their embryogenesis have been compared. The result showed that the method of suspension culture is better than that of semi solid culture , the growth rate of embryonic callus in suspension culture is 268.5%; as 12.4 times as that of the semi - solid medium; its frequency of embryogenesis is 93% , as 2.2 times as that of semi - solid medium. In order to get suitable condition for large scale propagation of somatic embryos, the factors affecting somatic embryogenesis in embryonic cell suspension culture were investigated.

An amide having Casium -antagonist activity was isolated from Aster tartaricus .Its structure was determined as N - ( N - benzoyl - L - phenylalanyl - ) - 0 - actyl - L - phenylalanol by spectral methods and synthesis.

The acid phosphatase activities from roots and both stems and leaves of tomato seedlings all in-creased markedly under phosphate starvation. Phosphate starvation also increased the activities of acid phos-phatase from cell surface of, and released by roots of tomato seedlings. The kinetic analysis of acid phos-phatase of roots of tomato seedlings revealed that phosphate starvation increased the affinity of the enzyme to its substrate. The results also revealed that phosphate starvation had no effect on the optimum pH (pH 4.93) of the acid phosphatase of roots of tomato seedlings. It was also found that molybdate strongly inhibited not only the activities of acid phosphatase but also Pi- uptake rates of tomato seedlings.

Antirrhinum majus seedlings hypocotyls, 20 mm in length, cut into three segments, which were cultured on MS medium and MS medium added with BA and NAA. The results indicated that adventi-tious buds and roots formation were higher in the basal hypocotyl segments than in the two upper hypocotyl segments. When the basal hypocotyl segments were cultured on the medium with different concentration of BA and NAA, the result was that the morphogenetic response was much better with BA and NAA supple-mented. The most optimum concentration was BA 1.Omg/L + NAA 0.15mg/L.

Very clear electrophoresis patterns have been gotten by isoelectric focusing (IEF) and microoper-ation of single pollen grains (d≈150um) from Cucurbita moschata . The results showed that there were different protein bands among pollen grains from one flower. This segregation occurred with a classical 1: 1 Mendelian ratio by statistics in all experiments. The technique of IEF of single pollen grains and micro-oper-ation provides a new and quick screening test applied to plant genetic breeding and developmental research.

The sequences of the ITS regions and 5.8S coding region of nuclear ribosomal DNA from the genus Tetrathyrium and the related genera of Hamamelidaceae were determined and analysed. Based on the ITS sequences, the phylogeny of Hamamelidoideae was reconstructed, which was similar to Endress' system of Hamamelidaceae in 1989. It was shown that all the species of the subfamily Hamamelidoideae formed a monophyletic group in this study. However within both Hamamelidoideae and the tribe Hamamelideae, the polyphyly was indicated in the MPTs. The monophyly of the tribe Eustigmateae was strongly supported (in-cluding Eustigma, Fortunearia and Sinowilsonia ). The ITS data supported Endress' treatment of merging the tribe Distylieae and Fothergilleae too. It was suggested that the genus Hamamelis was closely related to Fothergilleae in this study. Tetrathyrium and Loropetalum {armed a monophyletic group.

The sequence of rDNA Intergenic Spacer Region (ISR) was determined for the species Oscillatoria sp.(Cyanobacteria). The spacer sequences was 427bp in lengh exclusive of 16S and 23S rDNA coding regions, containing a Ile tRNA gene. Based on the analyses of the obtained sequences and the sequences from other three representative species of Oscillatoriaceae, and two species of Microcystis , the evolutionary affiliation among the genera of Oscillatoriaceae was discussed. In addition, the results showed that rDNA Intergenic Spacer Region can be served as a criteria for the identification or the classification of Cyanobacteria within the genus or intraspecies, which may be a useful genetic marker at the species or popu-lation level and may be one of the most suitable regions in the rRNA gene cistron for preparing DNA probes specific to Cyanobacteria species because of the high divergence of this region.

In present paper,The Karyotypes of nine specis and two varieties of the genus Camellia were re - ported The results were as following:Camellia henryana: 2n = 2x = 21m + 8sm + lst;C.furfuracea:2n = 2x = 30m + 20m + 10sm;C.leptophylla: 2n = 2x = 30 = 24m(lsat)4sm (lsat )+ 2st;C. yunnanensis:2n = 2x = 30 = 18m + 10sm +2st;C,pitardii: 2n = 2x = 30 = 18m + 12sm.Nine of them were reported for the first tine.Karyotypes were very sinilar each other among the above species, and comprision between sections was more important than rhat bitween species

The pteridophytic flora from the Big Bend at Yalu Tsangpo (River)comprises 108 gebara,45 families.The representative families are Dryopteridaceae(80/5,No.fo sp./No.of gen.),polypodiaceae (65/14),Athyriaceae(45/11),Aspleniaceae(23/3),Sinopteriddaceae (19/6).Thelyptedaceae (18/9),pteridaceae (13/2),Selaginellaceae (12/1) and Hymenophyllaceae(11/3).The main genera are polystichum ,Dryopteris,Asplenium,Athyrium, and some genera in polypodiaceae,which are some phy-logenically higher taxa;and in thos flora,there are on typical gernera which are endemic to this region It can de said that the pteriophytic flora of Yalu Tsangpo (River)Big Bend is a younger area one which devel-oped with the heaving of the Qingzang Plateau .It is rich that the families (62.2% to total )and genera (67.6% to total)are tropical taxa,but the top families and genera are cosmopolitan taxa This pteriophyti flora developed from an ancient one of tropical Asia.

Five new taxa of Basidiomycota are Previously undescribed from Gansu,Sichuan,yunnan of China.1.Macowanites yunnanensis Zang (Russulaceae),the genus Macowanites Kalchbr. is a new record to China. 2. Crepidotus Piceicola Zang (Crepidotaceae).3 Boletellus serpentipileus Zang et Yuan (Stro-dilomycetaceae).4.Xerocomus pinicola Zang et Yuan (Boleteceae).5.Lycoperdon longistipum Zang et M.S.Yuan (Lycoperdaceae).The morphological differences, habitats and similarities of these new taxa are compared with closely related species. The holotypes are deposited in the Crybarium Herbarium ,Kunming lnstitute of Botany(HKAS).

this paper reports 4 genera (Aindliaea,Hierochloe,Eremochia and Capillipedium),13 species and 1 naturalized species as new records in Henan province.

The genetic diversity in fifteen populations of Pinus, yunnanensis Franch. were studied by starch gel electrophoresis in the present work. Fourteen enzyme systems, presumably coded by 33 allozyme loci and their alleles were scored, and 32 were polymorphic with only one monomorphic locus (Dia - 4). The loci with three alleles are Lap-1, Lap-2, Aat-3, Skd-1, Skd-2, Adh-l, Adh-3, Gdh, Pgd-1, Pgm-1, Pgm-3, Pgi-l, P^-3, Mdh-l, Me, Idh-l, Idh-2, G6pd, Dia-1, Tpi-1,Tpi-2, Tpi -3 and Tpi-4, those with four alleles are Skd-3,Adh-2, Pgd-2, Mdh-2, Mdh -3, Mdh - 4 and Dia - 2, and those with five alleles are Aat - 1 and Dia -3.

An anatomical study on the stems of Vanilla planifolia and V.siamensis was made recently and the result showed that the arrangement and structure of stem tissues of these two species were different.In the cross section of the stem of V.planifolia,there is an annular sclerenchyma composed of some particular cells which are small and with sepcialized and thick walls between cortex and vascular tissue region.But in the stem of V.siamensis,this not only the important anatomical character to distinguish the two species,but also has potential value in the study of hybridization and breeding between the two species.

Micromorphological Characters of leaf epidermis of 12 species of Neottianthe Schltr.in China were examied by LW and SEM.It is found that the cells of both upper and lower epidermis are tetragonal,Pentagonal and hexagonal,anticlinal walls are stralght and arched;upper and lower epidermis are covered with cuticular membrance;stomatal apparatuses occur only on the lower surface and have just two guard cells without any accessory cells,there are "T"rod - like pieces at the polar region fo guard cells;outer stomatal ledge (or rim)are all unilayered .These characters are generally stable at genus level. Therefore the present anthors tend ot agree with Lang's (1997)view which 12 species combined Neottianthe.But it shows greatly diversity under LM and SEM that the size of epidermal cells, the inner mrgin of outer stomatal ledge and the cuticular ornamentaion.Besides,the anticlinal walls of eridermal cells in some spesies are significant pro-trusion.These dfferent micromorphological characters of leaf epidermis are usefull to identify some species in the genus Neottianthe .

Species affinis B. uniflorae F. N. Wei et Y. G. Wei, sed floribus pluribus 10~25 fasciculatis differt.

Species affinis S.alfredio Hance, sed stolone, ramoso, ramis sterilibus; foliis raorum florifro-rum et subter sterilium linearibus; squamis obtrapeziati- oblongis; folliculis lanceolati-cylindricis differt.

Haec species valde affinis P. lasiophrys Maxim. et P. lasiophrys var. sinicae Maxim., sed galea coroIlae purpurea reliquis luteis, fronte et lateribus glabra, dentibus calycis bogitudine dimidio calyci- tubum haud supermtibus differt.

ln order to furtner study the systematics and evolution of the family Hamamelidaceae,the five modern different classification systems of this family published by Harms (1930),chang Hung - ta (1937,1979),Bogle et al .(1980),Endress (1989) and Li Jianhua (Li,1997) are compared and discussed by the author based on the principie and method of stuody plant systematics. The taxonomic history and compar-isons of the classification systems of this family are also given in the present paper.As a result, the author considered that ahe classification system of Li Jianhua is more reasonable than the others,however, the au-thor still has different opinions in the classification trearment of some genera and tribes in this family.

Six new species and one oew variety of the genus Begonia from yunnan, China are described.They are Begonia lancangensis S,H,Huang,B.ceratocarpa S,H.Huang & Shui B.yingjiangensis S.H.Huang,B.subhouii S.H.Huang ,B. manhaoensis S.H.Huang et Shui,B.obliquefolia S.H.Huang et Shui,B.balansana Gagn. var,rubropilosa S.H.Huang & Shui .Eight species are describeb additionally and one species is named newkt,They are B.tetragona lrmsch., B.obsolescens lrmsch.,B. laminariae lrmsch .,B.truncatiloba lrmsch.,B. uillifolia lrmsch.,B.psilophylla lrmsch.,B.uersicolor lrmsch.,B.hekouensis S.H.Huang., B.pseudodryadis C.Y.Wu.