Abstract:Interfamilial relationships of Santalales were investigated using chloroplast intron sequences. The lengths of trnL intron regions present considerable variation among the sampled Santalalean families, varying from 291 to 587 bp. The topology of strict consensus tree generated from parsimony analysis is largely congruent with trees previously published based on DNA sequences of other genes, which revealed the basal position of Schoepfia (Olacaceae), the monophyly of Loranthaceae and Viscaceae, and the paraphyly of Santalaceae．Loranthaceae are distinct from Viscaceae，the latter is derived from within Santalaceae．Our study also demonstrates the utility of the rapidly evolved chloroplast trnL intron for addressing relationships among the component taxa of San talales.

Abstract:This paper reports the cluster analysis of Euphorbiaceae by using Euclidean distance-UPGMA method according to 216 taxonomic characters. The result shows that the combinations of most tribes or subtribes are basically rational, but the position of tribes, such as Galearieae, and some subtribes, such as the subtribe of Antidesmeae, can not be clustered together. Furthermore, the result of cluster does not support Webster's system at subfamily level. According to the result, a new genus Archileptopus which was not included in Webster’s system，is closer to subtribe Pseudolachnostylidinae(Phyllantheae)than to Andrachaneae.

Abstract:Sampling techniques of vegetation study on tropical forest were examined with the help of table manipulation function and neighbourhood analysis function of GIS (geographic information system). An example was presented based on the survey data from a tropical ravine rain forest community at Bawangling National Nature Reserve on Hainan Island. The results indicated that the often-used species-area curve could not determine minimum area for the ravine forest, i.e. minimum area was much larger than 5 000 m²，while according to the importance value-area curve，minimal area for ravine forest was 4 000 m². Closest individual method was adopted to study plotless sampling．Results showed that the minimal point number for species-point number curve was 119， and that for importance value-point num ber curve was 280．Species-individual curve indicates that the individual number needed for investigation should be multiplied fourfold，if we want to obtain doubling species number．

Abstract:Based on the data obtained from background survey of vegetation in the field, the classification of vegetation in Piankou Nature Reserve, Sichuan Province, was made using geographic imformation system and remote sensing, as well as global positioning system in combination. As a result, six vegetation types (with fifteen formations) were classified, viz. 1. evergreen-and deciduous-broadleaved mixed forest, 2. deciduous broadleaved forest, 3. coniferous and broadleaved mixed forest, 4. subalpine coniferous forest，5. subalpine shrub，and 6．subalpine meadow．A map of vegetation types in the Reserve is given．

Abstract:Morphological indices of aboveground and underground organs of Plantago virginica were determined using Leaf Area Analysis System (FOCTA STD 1200P) and Root Analysis System (RHIZO STD 1600+) to investigate the influence of population density on the root morphology of the plant. The indices of aboveground organs included fresh weight, leaf number, leaf length, leaf breadth, leaf length-width ratio, leaf area, leaf perimeter, spike weight, spike number, spike length, inflorescence length and flower number.The indices of underground organs included root fresh weight,root length，project area,surface area，average diameter,root volume．The morphological indices of the root were divided into nine classes according to diameter size(O mm4.5 mm)．The relationships between the indices and the population density were regressively analyzed．The morphological indices which have obvious relationships with population density are leaf num ber,leaf area，leaf perimeter，individual flesh weight，spike weight，flower number,spike length，root flesh weight，root length，root surface area，and root volume．The results showed that the influence of population density on the indices of root morphology at different diameter classes were different，and the indices of root length，root surface area，root volume，and root project area of medium diameter size were more restricted by the population density.

Abstract:Ten plots were used to study the interception deposition, total canopy leaching, base cations from canopy leaching, and the H+ and NH4+ uptake by the canopy in subtropical coniferous-broadleaved mixed forest in Shaoshan, Hunan Province, from January 2001 to June 2002. The predominant elements in wet deposition in the forest were Ca²⁺, Mg²⁺ and K⁺. Ca²⁺ from canopy leaching was high, amounting to 155.34 mmol m^-2a^-1, followed by K⁺ (84.13 mmol m^-2a^-1) and Mg²⁺ (30.74 mmol m^-2a^-1). Large amount of Ca²⁺ leaching indicated that it was the main acidity bufering agent from can opy leaching，suggesting the potential harmfulness of acid rain to the forest．Seasonal changes in the amount of base cations from canopy leaching were in the order of winter> spring> summer>autumn，but the proportion of total leaching were summer(58.4％)>spring(54.1％)>winter(51.4％)>autumn (32.5％)．Seasonal uptake of NH₄⁺ by the canopy in the year observed varied from 30 to 100 mmol m^-2，and that of H⁺ from 30 to l80 mmol m^-2．

Abstract:Chalcone synthase (CHS) gene was cloned from the petals of Gerbera hybrida using RT-PCR method in our experiment. The sequence of the cDNA coding region was 1 197 bps, encoding a protein of 398 amino acids sharing 99% identical to CHS1 cDNA reported by Helariutta. The gene was fused in expression vector pET32a and was efficiently expressed by transforming into E. coli BL21(DE3) with IPTG induction.

Abstract:Based on the complete psaA gene sequence of Phaeocystis antarctica in GenBank, two primers psaAL and psaAR were designed to amplify psaA gene sequence fragment of Phaeocystis globosa. An unambiguous sequence of 629 bp was gained,which was aligned with the complete psaA gene of Phaeocystis antarctica in Clustal X. The corresponding nucleotide dissimilarity of the two sequences was only 3.34%, and no insertion/ deletion was found. The relative amino acid sequence and RNA secondary structure were concluded in DNAstar． The concluded amino acid sequence was also conservative，and there was only one distinct base among 209 amino acids，with the difference of 0.48％ ．However，the concluded RNA secondary structures were quite unlike，apart from a few conservative domains． Perhaps the secondary structure of RNA may benefit the study on taxonomy of Phaeocysitis．It is considered that the DNA sequences and amino acid sequences of psaA are conservative, which is unadvisable to use for molecular interspecific classification ofthe genus Phaeocysitis.

Abstract:Herbicide tertbutyl triazine was used for removal and control of red tide caused by Phaeocystis globosa and Alexandrium tamarense under laboratory condition. The results showed that the effective concentration of tertbutyl triazine for killing P. globosa and A. tamarense was 0.3 mg L^-1 and 0.2 mg L^-1, respectively, for 96 hours. Tertbutyl triazine might be a good algaecide with high efficiency and durative action.

Abstract:Specific leaf weight, photosynthetic rate, photorespiration rate, as well as N, P, K contents were measured in the leaves of Dendrocalamopsis vario-striata grown in Chishan Forest Farm in Fujian Province during shoot development. Results indicated that specific leaf weight (SLW) was higher at shoot abundant stage (in mid July) than that at early stage (on 12, June) and late stage (on 10, September). SLW decreased as the bamboo age increased, and increased with the ascending levels of leaf location on bamboo stems． Net photosyn thetic rate at shoot abundant stage was higher than that at early stage．whereas photorespiration rate and dark respiration rate were higher at early stage．The contents of N，P and K in bamboo leaves decreased gradually during shooting period．N content in leaves was in the order of 1-year-old>2-year-old>3-year-old bamboo, and being the highest in leaves on mid part of bamboo stems， whereas the contents of P and K decreased with the ascending levels of leaves on stems，an d increased with the increase of the bamboo age．The results would provide guidance for scientific management of D．vario-striata plan ting.

Abstract:Peroxidase(POD) from pericarp of litchi(Litchi chinensis Sonn.) was purified by 12.5-fold and a 1.9% yield using ammonium sulfate, DEAE-Sepharose and Sephadex G-75. The enzyme was determined to be homogenous by SDS-PAGE, which was relatively heat stable with a optimum temperature of 35℃, requiring a time of at least 30 min at 75℃ for 50% loss of the activity. Litchi POD had a optimum pH at 6.5, but it was stable within a range of pH 4.0-8.0. The apparent Km values with guaiacol, catechol and pyrogallol as substrates were 2.75, 12.4 and 12.8 mmol/L at 25oC and pH 7.0，respectively．The presence of Fe³⁺ and Cu²⁺ enhanced POD activity．L-cysteine，citrate acid,FeSO₄，SDS，GSH and ZnS0₄ partially inhibited POD activity,but it was completely inhibited by dithiothreitol and ascorbate.

Abstract:Effect of climatic factors on nitrogenase and hydrogenase activities in nodules of Acacia confusa, A. auriculaeformis and Dalbergia balansae were investigated. Hydrogen uptake activity was found in the nodules of all the three leguminous trees. In the presence of exogenous hydrogen, nitrogenase activity in nodules increased markedly, indicating that hydrogenase played an important role in increasing the efficiency of nitrogen-fixation in symbiotic system. Seasonal changes were obvious in nodulation and nitrogen fixation of leguminous species grown in Xiamen area． Results showed that more nodules produced and higher C₂H₂-reducing activity were observed in summer and autumn than in early spring and winter．The optimun temperature for both nitrogenase and hydrogenase activities in nodules was 25-30℃．Minor soil water deficit did not affect the C₂H₂-reducing activities，but serious soil drought markedly reduced the activities of nitrogen-fixation and hydrogen uptake．Shading reduced both nitrogenase and hydrogenase activities in nodules.

Abstract:New cross combinations were subjected to regional test during 2000-2002 in Guangdong Province by using fuzzy comprehensive evaluation method. The evaluation factors included fresh spike yield, plant type traits, growth duration, resistance and quality. The results showed that the fuzzy comprehensive indexes for the combinations could well reflect the practical quality levels of the corn varieties. This method is more accurate in quantifying the factors evaluated in comparison with the weighted aggregative index method． The evaluation values finally obtained could reflect both the relative grades between evaluation factors and the absolute grades directly.

Abstract:Buckwheat (Fagopyrum esculentum Moench) seedlings in Hoagland solution were fed with different substances, and oxalate contents in the roots and leaves were determined after 36 hours. The results showed that ascorbate and its precursors as well as isocitrate decreased to some extent the oxalate content in roots and leaves, whereas glycolate and glyoxylate significantly increased oxalate content, suggesting that oxalate in the leaves was synthesized mainly from glycolate pathway. Oxalate content in leaves of

Abstract:Germinated maize (Zea mays) seeds were used for desiccation tolerance experiment. The seeds started to lose desiccation tolerance at 25℃ after germination for 24 hours. The loss of desiccation tolerance reached 50% and 100% after 33 and 58 hours, respectively. Ultrastructure observation showed that the reserve substances especially lipids in radicle cells decomposed gradually during treatment, while organelles such as mitochondria were well differentiated.

Abstract:The leaves of Senecio cineraria cv. Silver Dust were used to study the callus induction, shoots induction and rooting. It was shown that MS medium supplemented with 2 mg L^-1 2,4-D+1 mg L^-1 BA+0.1 mg L^-1 NAA was good for callus induction, while MS medium containing 0.5 mg L^-1 BA+0.1 mg L^-1 NAA, half-strength MS medium containing 0.01 mg L^-1 NAA gave best results for shoot induction and for rooting, respectively.

Abstract:

Abstract:Based on the examination of specimen in the Herbarium of Royal Botanic Gardens, Kew, visited by the first author in 2000, two new combinations of Viola (Violaceae) are presented. Viola curvistylis Boiss. ex Gagnep is treated as a synonym of V. yunnanensis W. Beck., and V. hossei W. Beck. is treated as a synonym of V. sumatrana Miq.

Abstract:A new variety of Mussaenda, M. pubescens Ait. f. var. alba X. F. Deng et D. X. Zhang, is reported.

Abstract:Apomixis provides a unique opportunity to fix and utilize hybrid vigor. A number of research programs around the world have tried to use apomixis as an important plant-breeding tool. This paper presents a brief review of the current status of knowledge in the main fields of apomixis research. New apomictic plants are enumerated. Genetic mechanism is summarized. The problems in this field and development prospects are discussed.

Abstract:During the past several decades， nitrogen deposition has brought a series of environmental and ecological problems．The subjects included in this literature review are：(1) elevated nitrogen deposition changes nitrogen metabolism in plants due to the increasing nitrogen concentration in plant tissues；(2) it influences photosynthesis including photosynthetic rate，photosynthetic pigments and Rubisco concentrations；(3) elevated nitrogen deposition increases plant respiration；and (4) increases the susceptibility of plant resistance to coldness，pests and diseases．

Abstract:Botanical gardens are scientific and educational institutions holding documented collections and conservations of rich living plants through simulating nature． It is also an important base combining conservation of biodiversity，public education，storing and utilizing plant resources．Digital botanical gardens appear with the development of information technology which is practically utilized in botanical gardens． Here we give the broad and narrow definition of digital botanical gardens based on the research on its history．We also discussed the information technology systems，virtual plants，and intelligent management of special plant sections based on the case in South China Botanical Garden．