Abstract:A full-length cDNA of rice （Oryza sativa L.） glutathione synthetase （GS） gene was obtained by 5＇- RACE （rapid amplification of 5 ＇-complementary DNA ends）, and the gene was named as OsGS （GeneBank accession No.： AY453405）. The 1 892 bp cDNA contained an open reading flame （ORF） encoding a polypeptide of 540 amino acid residues with a predicted signal peptide of chloroplast. The alignment of OsGS cDNA with the mapped genome sequences office indicated that OsGS is located in the short arm office chromosome 12, and the transcript region （6 321 bp） of this gene consists of 12 extrons and 11 introns. The transcriptions of OsGS in rice under normal and stress conditions were studied by RT-PCR method. The results showed that, under normal conditions, the transcriptions of Os GS could be detected in roots, leaves of one-week old seedlings and roots of heading rice, but not in leaves, stems and spikes of heading rice. This result indicated that the expression of Os GS conforms to a spatio-temporal pattern. Under stress conditions, the expression of OsGS in the leaves of heading rice demonstrated that the transcription of OsGS was strongly induced by heat shock （40℃）, cadmium and drought; but not by salt, low temperature and wound. Further transcription analysis showed that OsGS expression was strongly induced by mild and medium drought stress for 4 hours. In addition, the exogenous ABA could induce the transcription of OsGS in the leaves of flowering rice, suggesting that the response of OsGS to drought might be mediated by ABA-dependent pathway.

Abstract:Nine lines of T₂ generation of marker-flee transgenic soybeans of Pudou 8008 with △⁶-fatty acid desaturase gene were characterized. PCR and Southern blot indicated that the selective marker gene （bar） had been removed from some transgenic soybean progenies, while △⁶-fatty acid desaturase gene was still in some progenies of these transgenic soybean lines. Northern blot showed that the △⁶-fatty acid desaturase gene could be transcribed in the marker-free transgenic soybean lines. Gas chromatographic analysis showed that six transgenic soybean lines could produce γ-linolenic acid.

Abstract:Photosynthesis-light response and growth feature were compared among 26 woody plants of over 4 years grown at the oil shale waste dump in Maonan district of Maoming city, Gnangdong Province. A remarkable difference was found in maximum net photosynthetic rate （Pmax）, apparent quantum yield （AQY）, instantaneous light utilization efficiency （ILUE）, plant height and diameter at breast height （DBH） among the tested species. According to growth and photosynthesis features, the trees were divided into 1） the fast-growing plants with the average DBH value of 9.44±2.23 cm, the average Pmax of 18.44± 1.38 μmol m^-2s^-1, ILUE of 1.11±0.68% and AQY of 0.0474±0.007 μmol CO₂ μmol^-1 quantum; 2） the moderate-growing plants with the above values of 5.09±0.90 cm, 11.54±1.01 μmol m^-2s^-1, 0.75±0.12% and 0.0406±0.004 μmol CO₂ μmol quantum, respectively; and 3） the slow-growing plants with above values dropping to 2.03 ±0.65 cm, 6.71 ±2.82 μmol m^-2s^-1 0.47±0.12 % and 0.0318±0.006 μmol CO₂ μmol^-1 quantum, respectively. The statistic analysis showed a very significantly positive relationship between ILUE and Pmax or DBH, and plant height also positively correlated with DBH and the total leaf area per plant. The results indicated that photosynthesis-light response curve and ILUE are useful to estimate the adaptation of plants to their habitat. Owning to higher ILUE, growth rates and water use efficiency, the woody species suitable for the restoration of the oil shade waste dump are as follows, Acacia auriculiformis, Bombax malabaricum, Erythrina indica, Terminalia bellirica, Tristania conferta, Ormosia pinnata, Cassia siamea, Samanea saman, Schima wallichii, Syzygium cumini.[

Abstract:Iris germanica ＇Royal touch＇ was used to investigate the effects of 5 different photoperiods on flower bud differentiation and photosynthesis. Short-day treatments accelerated the flower bud differentiation, whereas long-day treatments increased the numbers of the flower buds per inflorescence. The photosynthetic capacity per unit leaf area was higher in long-day treatments. Flower bud differentiation had a significantly positive correlation with leaf area, leaf dry weight, and the ratio of above： below ground biomass, respectively. These results suggested that effects of photoperiods on flower bud differentiation and numbers are related to plant biomass and photosynthesis.

Abstract:In order to evaluate the growth of A lexandrium tamarense, a toxic harmful algal bloom species, under nitrate and phosphate limitation, five test groups of both N and P limitation （N： 500-10 μg L^-1, P：74-1.5 μg L^-1, N：P=15：1） and nine test groups of only N or P limitation （N：500 μg· L^-1, P：74-0.74 μg L^-1 and P：74 μg L^-1, N: 500-5 μg L^-1 ） were set under laboratory conditions. Though cells ofA. tamarense multiplied exponentially just in the second day after inoculation in most test groups, the growth was obviously inhibited when both N and P limited simultaneously, and the cell densities did not show significant increase under N and P concentrations below 100 txg L^-1 N and 15 txg L^-1 P. However, cells grew significantly better in test groups of single nutrient element limitation than those under both N and P depletion. Furthermore, the growth of A. tamarense was affected less by moderate N or P limitation. The results suggested that the high ability of A. tamarense to adapt single nutrient limitation allows this harmful species to maintain constant growth rate and cell density in natural sea water, in which single nutrient limitation usually occurs, and thus helps shellfishes, feeding on A. tamarense, to accumulate paralytic shellfish poisoning （PSP）.

Abstract:The toxicities of the alga of Phaeocystis globosa and the red tide seawater collected from the seaport in Zhanjiang City in April 2005, were detected. The dispersed alga colony had certain impact on the survival of young Penaeus vannamei Boone shrimps with 24 h LC₅₀=1.0×10⁹ cells L^-1. The mortality of the young shrimps was as low as 10% exposed for 24 h to 1.00×10⁹ cells L^-1 of the alga colony removed of liquor. The red tide seawater had toxicity neither against the young shrimps nor against Epinephelus awoara （3 mm） fry. P. globosa exhibited no toxicity against the fry of Mugil cephalus and Latescal carifer. E. awoara fly were, however, sensitive to the alga, of which half died within 24 h in the presence of the alga colony liquor accounting for 10.9% of seawater volume．

Abstract:Based on a forest survey in Nanning city, this paper discusses the characteristics of the urban forest. Seventeen patches of the forest were selected for this survey, representing 4 functional areas of the city, i.e. education, living, transportation and commercial areas. There were 45 tree species and 24 shrub species as major components of the urban greening. Minority species were dominant in biomass. The pattern of the species distribution needs a rapid improvement. The average DBH of the community was significantly correlated with density, indicating the similarity between urban forest and natural forest. However, negative correlation between canopy coverage and density or modified importance value （mlV） suggested that the urban forest was special. Forest area had a significantly positive corelation with DBH, while importance index, indicating that spatial resources had negative with density, canopy coverage and synthetic same impact on community structure in urban forest as those in natural forest. The result of the classification of the urban forests by cluster and PCA analysis coincided with that based on the functional area, except a few patches of the forests. The patterns of the forest distribution in functional areas reflected that human cultural value had an impact on greening events. The vegetation community in the city still had large space to be improved and optimized.

Abstract:There were 514 species of seed plants belonging to 273 genera and 101 families in Jinzhongshan Nature Reserve. The deciduous oak forest was most widely spread. Four vegetation zones occurred along elevation, viz. deciduous broad-leaved forest, evergreen broad-leaved forest in the valley, mixed evergreendeciduous broad-leaved forest and deciduous broad-leaved forest, mossy dwarf shrub on mountainous tops and evergreen broad-leaved forest in the hilly land. Tropic was dominant accounting for 75.21% of the flora elements including cosmopolitan, temperate and endemic to China. The nature vegetation in Jinzhongshan Nature Reserve was divided into 5 vegetation type groups, 7 vegetation types （warm temperate conifer forest, warm temperate broad-leaved forest, mixed evergreen-deciduous broad-leaved forest, evergreen broad-leaved forest, bamboo forest and grass）, 2 vegetation subtypes （South Asia tropical evergreen broad-leaved forest in the hilly land and broadleaved dwarf forest on mountainous tops） and 33 formations.

Abstract:According to the inquisition for the fem in Chongqing near 10 years, including abundance field inquisition, specimen collection and authenticating, refering for literature and specimen, there are 604 species wild fern belonging to 120 genera and 47 families. The varient and subspecies obvious offamiliy and genera, for Athyriaceae, Thelypteridaceae, Dryopteridaceae and Polypodiaceae have 49 genera and 337 species and occupy 40.83% and 55.79% of the families and the genera of the fern in Chongqing. Endemism is notable and the endemic species to China and Chongqing are 164 and 33;The fern has characteristic of antiquity, survivable and originality and has tropical property or close affinity with tropical flora.

Abstract:The mega- and microsporogenesis and the development of male and female gametophytes in Lonicera mnackii （Rupr.） Maxim were observed. Young anther walls were composed of four layers including epidermis, fibrous layer, middle layer and amoeboid tapetum in early and middle April. Tetrahedral tetrads of microspores were present on about April 15. After the stage of tetrad, some microspores aborted and cytoplasms were absent. Three-celled mature pollen grains developed from April 23 to April 26 shortly before flowering. The ovary was trilocular with axile placentation and the ovules were anatropous, unitegrninous, and tenuinucellate. The mature embryo sacs occurred before flowering in late April, which were of the Polygonum type. Hypostase was at the chalazal end of the ovule. These results suggest that mega- and microspores and male and female gametophytes of L. maackii have normal development.

Abstract:The spore germination and the gametophyte development in Nephrolepis auriculata were observed by light microscope. The mature spores are yellow-brown, monolete, opaque, bean-shaped in equatorial view and elliptical in polar view with a smooth surface. The spore germination pattern is of the Vittaria-type. It occurs about 15 days after sowing and forms a filament of 5 -12 cells in length. The gametophyte development is of the Aspidiumtype, coming into being the prothallus cells about 30 days after sowing followed by young asymmetrical prothalli at the 45^th day. The mature prothalli are symmetrically heart-shaped. Unicellular hairs spread on the upper and lower surfaces and along the margin of the prothalli. The antheridium is visible 60 days after sowing, pelletlike, consisting of three cells. Within the following ten days, archegonium is available. The neck of mature archegonium is composed of 4 rows of cells and 3-5 layers of cells high. Young embryos are present within one month after fertilization.

Abstract:Callus was obtained from the terminal bud explants of Ficus robusta on Murashige and Skoog （MS） basel medium supplemented with 2.0 mg L^-1 BA and 0.1 mg L^-1 NAA. Following subculture on MS medium supplemented with 1.0 mg L^-1 BA and 0.05 mg L^-1 NAA, each explant produced 3 shoots. The frequency of rooting was over 96.67% on MS medium supplemented with 0.1 mg L^-1 IBA and 100 mg L^-1 AC. The survive rate after transplant reached above 98%.

Abstract:The essential oil from the leaves of Solarium verbascifolium L. was obtained by steam distillation, followed by solvent extraction, and analyzed by capillary GC-MS. The content of essential oil in fresh leaves was 0.0611% after steam distillation 8 hours. Eighteen peaks were detected and 17 compounds were identified, which accounted for 99.73% of the total oil. The main chemical components were germacrene D （37.07%）, copaene （26.29%）, 1β-（1-methylethyl）- 4,7-dimethyl-1α,2,4a（f3）,5,8,8a（α）-naphthalene （13.63%）, caryophyllene （8.03%）, 1 β-ethenyl- 1 or-methyl-2β,4β-bis （1 -methylethenyl）- cyclohexane （5.81%）,γ-elemene （2.16%）, α-cubebene （2.06%） and isoledene （0.98%）, respectively. The above eight compounds accounted for 90.22% of the total oil.

Abstract:Acanthus illicifolius Linn. var. xiamenensis （R. T. Zhang） Y. F. Deng, N. H. Xia ＆ H. B. Chen, a new combination of Acanthaceae, is proposed.

Abstract:Toreniafournieri （Scrophulariaceae） is a suitable experimental plant for studies of angiosperm fertilization since it has semi-naked embryo sac within which egg cell, two synergids and part of the central cell are clearly visible under the light microscope, which facilitates the in situ observation of egg cell before and after fertilization. Progress in researches on fertilization mechanism of T. fournieri is reviewed in the following aspects： how the pollen tubes get into the embryo sac, dynamics of calcium in fertilization process, changes in the cytoskeleton of embryo sacs before and after fertilization. The significance of T. fournieri in the studies of in vitro fertilization is briefly described.

Abstract:Elevated nitrogen deposition has the effects on the activities of enzymes responsible for decomposition of forest litter, which has attracted great attention worldwide. Progress in this field is reviewed in following aspects： the types of the enzymes, the factors affecting the enzymes, the ecological significance of the enzymes and the techniques for the studies on soil enzymes. According to the properties of litter substrate, the enzymes are classified into cellulolytic enzymes, ligninolytic enzymes, proteolytic enzymes and phosphatase. It is generally believed that elevated nitrogen deposition has a positive effect on activity for phosphatase, but irregular for other enzymes. The further researches on the relationship between elevated nitrogen deposition and soil enzymes are discussed.