Abstract:Camellia changii Ye is a rare and endangered species endemic to China. It is confined to the E’huangzhang Nature Reserve at Yangchun City, southwestern Guangdong Province, South China. The genetic diversity was studied using Inter-Simple Sequence Repeat (ISSR) markers. A total of 60 individuals from two subpopulations were sampled. Ten primers with discernible DNA bands were applied. The percentage of polymorphic bands (PPB), Nei’s Index and Shannon’s Index were 55.29%, 0.2191 and 0.3215, respectively. The coefficient of gene differentiation (GST) was 0.0922. These results indicate that C. changii has low genetic diversity and low differentiation between the two subpopulations. Small population size and human disturbances are the main limiting factors for the extant population. Further studies on the factors limiting population development are urgently required.

Abstract:The 698 bp cytoplasmic copper/zinc-superoxide dismutase gene (OsCu/Zn-SOD) was cloned by RT-PCR from young panicles of rice Cpslo17, a wide-compatible rice cultivar (Oryza sativa). DNA sequence analysis indicated that the gene consisted of a full-open reading frame and encoded a protein of 152 amino acid residues. The nucleatide sequence of OsCu/Zn-SOD shares 88％ identity to maize Cu/Zn-SOD. No signal peptide was predicted by TargetP and ChloroP. Further analysis of encoding segment of OsCu/Zn-SOD revealed that it contained 8 exons and 7 introns. The putative three-dimensional structure of OsCu/Zn-SOD was predicted by the Swiss-Model server and Cu2+ and Zn2+ binding sites of OsCu/Zn-SOD were analyzed. RT-PCR results showed differential expression of OsCu/Zn-SOD in leavesof both japnica and indica rice. OsCu/Zn-SOD was expressed highly in panicles during young ear and the flowering stages or in immature seeds, however less in leaves and faintly in callus.

Abstract:The ultrastructure of microspore development in Jatropha curcas L. was observed under transmission electron microscopy. Many endoplasmic reticulums and plastids are present at microsporocyte stage. Organells including endoplasmic reticulum, mitochondria, plastids, dictyosome and sphaeroplassts are rich in microspore at meiosis and tetrad stages. And mitochondria and endoplasmic reticulum are still abundant during early and late microspore stages. The microspore divides into a large vegetative cell and a small generative cell. The vegetative cell abounds with starch grains and the generative one is rich in lipids. A great number of starch grains occur in epidermis, endothecium and middle layers at microsporocyte and tetrad stages, and are remarkably reduced at microspore stage. The tapetum is rich in organells from microsporocyte stage till late microspore stage, mainly including endoplasmic reticulum, plastids and mitochondria. Starch grains and lipids supply nutrients for the pollen development.

Abstract:The spores of Alsophila spinulosa (Wall. ex Hook.) R. M. Tryon, A. costularis Baker and Sphaeropteris brunoniana (Hook.)R. M. Tryon were cultivated in soil medium. The gametophyte development of the three species were observed under light microscope in spore germination, filament development, the formation and differentiation of prothallial plate and apical point, the rhizoid feature, and the development and differentiation of the antheridium and archegonium. We also reported ultrastructure of prothallus infected by fungi. The systematic significance of their gametophyte development in Cyatheaceae is discussed, as well as the causes of sexual generation endangerment.

Abstract:Armoracia rusticana leaves treated with lanthanum (Ⅲ) were determined in net photosynthetic rate (Pn) and chlorophyll (Chl) content. Changes in chloroplast ultrastructure were observed under transmission electronic microscopy. After 24-hour treatment with 30 mg/L La(Ⅲ), Pn and Chl content in leaves were increased by 0.82% and 3.69%, respectively, and the ultrastructure of chloroplast varied slightly. After 48-hour treatment with 30 mg L^-1 La(Ⅲ) , photosynthesis was inhibited and granum-thylakoid structure tended to be thinner and loose and incompact. After 24 or 48-hour treatment with 60 mg L^-1 La(Ⅲ) , Pn and Chl content were remarkably decreased and the chloroplast ultrastructure was effectively destroyed. Moreover, the ultrastructure got worse as the treatment time prolonged. The multifactors variance analysis showed that the length of treatment time had a slight effect on Chl content but a significant effect on Pn, whereas the lanthanum level singly or together with the treatment time significantly affected Chl content and Pn.

Abstract:The nucleic acid sequences and amino acid sequences of farnesyl diphosphate synthase (FPPS) from Lycopersicon esculentum, Hevea brasiliensis, Musa acuminata, Malus x domestica, Helianthus annuus and Vitis vinifera, which were registered in GenBank, were analyzed and predicted by the tools of bioinformatics in the following aspects: the composition of nucleic acid sequences and amino acid sequences, transit peptides, transmembrane topological structures, hydrophobicity or hydrophilicity, secondary and tertiary structure of protein, molecular phylogenetic evolution. The full-length gene of FPPS contains an opening reading frame, a 5’-untranslated region, and a 3’-untranslated region. FPPS is a hydrophilic and non-transmembrane protein without transit peptides at its N-terminal end. The amino acid sequences of FPPS include 5 conserved structural regions, out of which two are Asp-rich motifs. α-helix and random coil are the major motifs of predicted secondary structure of FPPS. β-turn and extended strands spread in the secondary structure of the protein. A large central cavity formed from the α-helices is present within the predicted tertiary structure of functional regions of FPPS. Five conserved amino acid sequences are on the surface of this cavity, two of which are conserved Asp-rich motifs on the inner walls of the cavity.

Abstract:We investigated influences of white light, UV-B, red light and blue light on phenylalanine ammonia-lyase (PAL) activity, baicalin content and cell growth in suspension culture of Scutellaria baicalensis Georgi. PAL activity and baicalin accumulation were promoted significantly by UV-B, moderately by white and blue lights. Red light had negative effects on PAL activity and baicalin accumulation. Baicalin content and PAL activity remarkably increased with UV-B intensity rising from 0 to 60 μmol m^-2 s^-1. The cell growth was promoted by red light, inhibited by UV-B, and unaffected by blue and white lights. Following treated with the alternation of 8 h UV-B of 60 μmol m^-2 s^-1 and 16 h red light of 50μmol m^-2 s^-1, fresh cell weight and baicalin content were 1.16- and 3.2-fold, respectively, higher than the controls. The yield of the total baicalin was 439 mg L^-1 which was 3.8-fold higher than controls.

Abstract:An effective protocol for plant generation was developed for Moringa oleifera and M.stenopetala. The colchicine induced tetraploid of drumstick was investigated. Plentiful plantlets were rapidly obtained using stem explants. Shoots were obtained on MS supplemented with BA 0.6 mg L^-1 and NAA 0.1 mg L^-1 for M.oleifera and MS with BA 0.5 mg L^-1 and NAA 0.2 mg L^-1 for M. stenopetala. Best rooting was observed on MS supplemented with IBA 0.2 mg L^-1. After 5-day treatment with colchicine, 40.0% of M. oleifera regenerants and 36.7% of M. stenopetala regenerants were found chromosome doubling. The tetraploids were characterized by their thick shoots and large thick green leaves.

Abstract:Five methods of genomic DNA extraction from D. loddigesii Rolfe were compared. DNA was detected by electrophoresis, UV and RAPD-PCR. DNA bands showed that the modified CTAB and carbamide methods are better than the other four methods including CTAB, carbamide, high salt and low pH, SDS and Chen methods.

Abstract:The seasonal fluctuation of cyanobacteria population in the through-flowing reservoirs of Shenzhen and Feilaixia in Guangdong Province was investigated in 2004. Seventeen genera of cyanobacteria composed mainly of filamentous ones were obtained. The common genera were Pseudanabaena, Microcystis and Dactylococcopsis. Cyanobacteria density ranged from 5 to 2 052 cells ml-1. The maximum cell density was found in Shenzhen Reservoir in June with filamentous species abundance of over 75%. The peak of cyanobacteria abundance was present in Feilaixia Reservoir in December with filamentous species occupying 90%. Cyanobacteria abundance and composition were changed mainly by hydraulic condition. The seasonal fluctuation of cyanobacteria population was more affected in Feilaixia Reservoir than in Shenzhen Reservoir since the hydraulic retention time of Feilaixia Reservoir had a greater variation than that of Shenzhen Reservoir. Filamentous cyanobacterias, especially Pseudanabaena, adapt to the reservoirs better than the other cyanobacteria species under high levels of nitrogen and phosphorus conditions. And their abundances will greatly increase when the retention time is prolonged.

Abstract:There are 114 species of invasive plants belonging to 80 genera, 36 families in Guangxi Province. The most abundant family is Compositae including 26 species. The plants all immigrated from aboard and 87 species (76.3%) are mainly from America. There are 90 species of Herbs amounting to 78.9% of the total species. The plants were introduced intentionally or unconsciously. They, especially poisonous or virulent weeds, have produced large negative effects on agriculture, forestry, human health and ecological environment in Guangxi. The effective approaches to defend against invasive plants are as follows: to investigate and evaluate invasive species, to recover native vegetation and species diversity, to implement risk analysis of invasive plants.

Abstract:Five Lasianthus Jack species that are new records for Hainan Province are reported. Their distinctive features are briefly mentioned. While Lasianthus austrosinensis H. S. Lo, L. filipes H. S. Lo, L. henryi Hutch. and L. formosensis Matsum. were recorded from the neighboring Guangdong and Guangxi Provinces, L. rigidus Miq. has distinct disjunct distribution in Tropical Asia.

Abstract:Dalbergia volubilis Roxb. (Leguminosae) is newly recorded from China.

Abstract:One newly recorded genus Tsaiorchis and five newly recorded species including Gastrochilus nanus, Liparis krameri, Malaxis microtatantha, Thrixspermum saruwatarii and Tsaiorchis neottianthoides of Orchidaceae are reported from Guangdong. All specimens are preserved in Herbarium of South China Botanical Garden, the Chinese Academy of Sciences (IBSC).

Abstract:The chemical structures and pharmacology of triterpenoid compounds in the genus Lysimachia L. are reviewed. Triterpenoid saponins in this genus, characterized by the oleanane-derived sapogenols, can be classified into two primary types of 13β, 28-oxide (Ⅰ) and Δ12-17-CH2OH (Ⅱ). The chemical transformations of the sapogenols in typesⅠ and Ⅱ are also described.