Abstract:Leaf ecoanatomical characteristics were studied of eight dominant species in three successional stages of forest community in Dinghushan，Guangdong,China．The trend of succession of the communities in Dinghushan was from coniferous forest dominated by Pinus massonianaa to coniferolls and broadleaved mixed forest dom inated by Pinus masssoniana, Schima superba, Castanopsis chinenis and Cryptocarya concinnca, and to monsoon evergreen broadleaved forest dominated by Cryptocarya concinna,C. chinensis，Castcmopsis chinensis，Schima snperba, Syzygium rehderianum， Aporosa yunncmensi and Blastus cochinchinensis．In this paper．the study of leaf an atomy included the ditermination of leaf thickness, adaxial and abaxial cuticular thickness， palisade and spongy tissues thickness,as well as tracheid and resin duct diameters. As compared to coniferous forest, the thickness of needles, and thickness of adaxial and abaxial cuticles of Pinus masssoniana in mixed forest were thinner, and the diameters of tracheids and resin ducts were smaller． As compared to mixed forest，lamina thickness and spongy,tissue thickness (S) of Castcampsis chinensis increased in monsoon evergrcen broadleaved forest． whereas palisade tissue thickness (P), and P/S reduced． As for Schima superba and Cryptocarya concinna， lamina thickness， P and S thickness， and P/S all decreased to a certain extent in monsoon evergreen broadleaved forest Significant difierences were observed in needle thickness, adaxial and abaxial cuticles thickness in Pinus masssoniana between coniferous forest and mixed forest．Such diferences were also seen in lamina thickness and P thickness in Castanopsis chinensis, Schima superba and Cryptocarya concinna between mixed forest and monsoon evergreen broadleaved forest.

Abstract:A bies yuambaoshanensis is an endangered species endemic to Guangxi in a limited area with less than 900 individuals， and is listed in the Plant Red Data Book of China． Field data were obtained from five 20 m × 30 m plots in Yuanbaoshan Nature Reserve by using tally with contiguous grid quadrat method for time-specific life table，and data from cultured seedlings in nursery, for dynamic life table An obvious periodic fluctuation in size structure of the population was showm． Expecting life ofindividuals larger than 18 cm DBH lowered obviously The survival curve of the population appeared to be a type of Deevey-Ⅲ．The mortality of one-year-old seedlings reached 48％.

Abstract:Population structure and spatial distribution pattern were investigated in a 3 600 m plot of forest community dominated by Castanopsis carlesii,C. fabri, Distylium myricoides and Adinandra millettii in Wuyishan State Nature Reserve．Fujian，China．Method ofTally with contiguous grid quadrats was used to analyze field data obtained．The results indicated that the populations ofth e four species had a great amount ofreserve seedlings． Spatial distribution pattern ofthese dominant populations appeared to have clumping distribution，but the clumping intensity showed diferences with K values (negative binomiaI distribution index) from O.2661 to 1.2877 Costanopsis carlesii population at different developmental stages all showed clumping distribution while D myricoides and C. fabri exhibited random distribution for large trees，and clumping distribution for saplings and median trees. As for A dimmdro millettii，population random distribution was shown in median trees,and clumping distribution in saplings． Such differences are due to the biological and ecological characteristics of the species and the competitive exclusion principle Varies plot sizes had also an effect on spatial distribution pattern.

Abstract:Micromorphological characteristics of lcaf epidemfis of 26 species of bamboos (Bmnbusa subgen. Dendrocalamopsis,9 species；subgen Bmnbusa，5 species；subgen Leleba．2 species；subgen．Lingrwmia, 4 species；subgenus uncertain，I species；Dendrocalamnus．5 species) were observed under SEM and LM．The results showed that the number and distribution of papillae in subsidiary cells of the stomata existed to some extent regular patterns which could be applied in the bamboo taxonomy Micromorphological characters of leaf epiderimis indicate that Bambusa subgen． Dendrocalamopsis is intermediate between genera Barnbusa and Dendrocalamus showing similarities to both ofthem ，but is closer to genus Bambusa. So it is more reasonable to treat Dendrocalampsis as a subgenus of Bambusa than as a separate genus.

Abstract:Outer ring (OR) and central region (CR) of vaseular bundles in pedicel of Alpinia henryi can be recognized . When OR and CR extend into sublocular region,the bundles of OR moves toward outside and increases in number from 13 to 40 scattered CR bundles are arranged into triangle and their number varies from 18 into 12．At the locular region,the CR bundles are arranged as 3 carpellary dorsal bundles, 3 parietal bundles，and 5-7 small placental bundles which fade away at the base ofprolongation．Outer large branches of the three carpellary dorsal bundles finally enter the calyx．At the base of the prolongation, three parietal bundles produce some transverse branches which become vascular plexus with branches of partial bundles and a few smalI branches originated from three carpellary bundles, but their bundles extend directly upwards．Finally，the adaxial parietal bundle splits up into 4 branches which runs up into a functional stamen while the two abaxial parietal bundles split up respectively into 2-3 branches going to the labellum ．The bundles of the vascular plexus finally enter petals，labellum and style．It suggested that the calyx contains not only bundles in three sepals but also in three absent stamens．The authors support the views that the labellum represents two absent stamens ofiilner whorI ofandroecium and the two glands are of modified gynoplural nectary.

Abstract:Six species of family Gesneriace aeare newly recorded to Guangdong Province,viz.Oreocharis magneidens Chun ex K.Y.Pan,Boeica stolonifera K.Y.Pan,Hemiboea subacaulis Hand.-Mazz.,Gyro choilos chorisepalum W.T.Wang and Opithandra sinohenryi (Chun) Burtt.A newvariety,Oreocharis nemoralis Chunvar.lanata Y.L.Zheng et N.H.Xia,is described.

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Abstract:Abstract：This paper records 1 7 species ofpteridophytes in Hong Kong．Nine ofthem are new records,i．e．Pteris finotii Christ, Aleuritopteris pseudofarinosa Ching et S. K. Wu, Ampelopteris prolifera (Retz.) Cop.，Asplenium fujianense Ching ex S．H. Wu，Dryopteris pacifica (Nakai) Tagawa, Oleandra imermedia Ching，Lephtogrammitis diversa (Ros．) Ching，and Pyrrosia martinii (Christ) Ching. Six species names are revised，viz．Pteris linearis Poir.，Cheilosoria mysurensis(Wall. ex Hook.) Ching et K．H．Shing，Cheilosoria chusana (Hook.) Ching et K．H Shing, Asplenium obscurum BI.，Asplenium pseudolaserpitiifolium Ching, and Polyctichum eximium (Mett. ex Kuhn) C. Chr. In addition，2 rare and endangered species，Doryopteris concolor (Langsd. et Fisch.) Kuhn and Phymatodes lonngisssima (B1.) J．Sm.，are also recorded.

Abstract:Endophytic mycorrhizaI fimgus P15 isolated from the roots of wild Cymbidium e nsifolium was used to infect the non-mycorrhizal rhizomes of C．sinense and C. ensifolium. A marked increase in respiratory rate，cytochrome C oxidase activity，and peroxidase activity was shown in the rhizomes of two infected species，while the change in IAA oxidase activity was slight．The levels of respiratory rate，activities of cytochrome C oxidase and peroxidase in the rhizomes of C. ensifolium, were all higher than those of C. sinense before or after infection, but the IAA oxidase activity showed the contrary．

Abstract:Hybrids F₁ from japonica variety Akihikari crossed with several wide compatibility varieties, and with some irwlica Varieties were used for anther culture on N₆and SK₃ media to compare callus induction rate， green and abbino shoots and the culture efficiency in these F₁S with those in Akihikari． The result showed that the anthers of variety Akihikari cultured on N₆ or SK₃ media had callusing rate 86.44％ and 66％ ,green shoot rate 23.1％ and 16.8％ ，and culture emciency 20.0％ and l1.1％ ， respectively, whereas anthers of hybrid F₁ from Akihikari crosses were more effective on SK₃ medium for induction and differentiation, suggesting that SK₃ was a suitable medium for anther culture 0f japonica with indica rices ． It is concluded that japonica Akihikari is a variety with high efficiency in anther culture． The culture efficiency was in the order：japonica(indica) WCV ×indica(japonica)WCV>japonica×WCV>japonica>japonica×japonica>japonica×indica. Callus velocity had no direct relation with callusing rate,green shoot rate, and anther culture efficiency. PCR analysis showed, albino or mixed albino shoots resulted from genetic varietion at first stage of callusing．

Abstract:Genetic transformation of Solanum photeinocarpum by Agrohacterium rhizogenes R1000 and R1601． the effects of some factors on transformation efficiency and the production of secondary metabolites by hairy root culture were studied. Hairy roots were induced from leaf and stern explants with A．rhizogenes strain R1000 and R1601 ca. 7 days after inoculation Hairy root frequencies obtained from leaf and stem explants inoculated by R1000 harboring the agropine-type Ri plasmid pRiA₄b were 90.2％ and 50.0％ , respectively, while those by R1601 with the agropine-type Ri plasmid pRi1500 and pTVK291 were 92.1％ and 49.2％, respectively． Opine analysis indicated that T-DNA genes of A. rhizogenes strain R1000 and R1601 were expressed in S．photeinoccapum hairy roots. Hairy root-inducing frequency of leaf explants from S．photeinocarpum grown on MS medium supplemented with PP₃₃₃ was remarkably increased， and that of leaf explants inoculated by doubled diluting agrobacterium liquid on MS liquid medium was also increased． Hairy roots grew rapidly and the dry weight increased by 420 times after culture for 4 weeks， and the dry weight contents of total glycoalkloids and saponins were 3l and 107 times higher than those of the original ones，respectively．

Abstract:Micropropagation was studied of four brometiad plants Aechmea fasciata，Vriesea poelmsnii, Cryptanthus zonatus and Neoregelia carolinae, cultured by stem explants．Induction medium of MS+NAA 0.5 mg L^-1+BA 5 mg L^-1 led to budding after one or two weeks of culture． MS+BA l mg L^-1 +NAA 0.l mg L^-1 was the optimum medium in subculture． The optimum concentration of NAA was 0.5 mg L^-1 in rooting. Plantlets transplanted oil media contained coconut-bant:sand=1：l or coconut-bant：turf：vermiculite (1：1：1) had better surviva1 rate up to 95％ ．

Abstract:A Vietnamese species of Bauhinia L.,B.carcinophylla Merr .,is newly recorded from China .

Abstract:Seven known compounds were jsolated from the leaves of w e um wall hi Hook．On the basis of spectroscopic analysis (UV，IR, ¹H-NMR,¹³C_NMR and MS), their structures were identified as β-sitosterol(I)，sitosteryl-3-O-β-glucoside (Ⅱ)，2-propenoicacid,3-[2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-(hydroxymethyl)-7-methoxy-5-benzofuranyl]-(Ⅲ)，pinoresinol(Ⅳ)，pinomsinol-4'-O-β-D- glucoside(V), benzoic acid, 2,5-dihydroxy-,methyl ester (Ⅵ)，quercetin 3-O-β-galactopyranoside (Ⅶ )．They were all isolated from the plant for the first time． The study of chemical constituents in this plant is useful for the delimitation of generic relationships in fern classification.

Abstract:To determine the effect of silver nitrate on genetic transformation, Agrobocrerium tumefaciens-mediated 1eaves of Morus alba cv. Shiniehinose were used as explants cultured on kanamycin-resistant screening medium (MS basal medium supplemented with 200-400 mg L^-1 carbenicillin and 30-40 mg L^-1 kanamycin)，to which 2 mg L^-1 silver nitrate was added．The results showed that the rate of browning leaf discs infected with Agrobacterium tumefaciens strain LBA4404 decreaced by 7.2％ ，regeneration frequency of kanamycin-resistant buds increased by 3.9％ , transformation frequency of Gly gene increased by 9.6％, and the false positive transformants as detected by PCR decreased by 42.5％．The experiments demonstrated that silver narrate had inhibiting effect on the growth of strain LBA4404，which might increase transfonnation frequency in white mulberry.

Abstract:Progress in studies on molecular mechanismof leaf senescence and on retarding senescence by introducing P_SAG12-ipt into plants are reviewed.

Abstract:This review contents a brief retrospection of physiological functions of plant hormone，ethylene The progresses concerned three important enzymes：SAMS，ACS and ACO in ethylene biosyn-thetic pathway are highlighted The possible methods to control endogenous ethylene’s productionin fruits or flowem by genetic engineering are outlined．