Abstract:PSII photochemical activity and electron transport rate of whole chain (PSII+PSI) in spinach chloroplasts were measured under photooxidation (MV plus strong light) with or without addition of various exogenousphotosynthetic carbon metabolic intermediates, Na-glycolate and inhibitors of photosynthetic electron transport. The results indicated that under photooxidation condition, the addition of "RuBP regeneration system" and sodium glycolate increased qP and Φ_PSⅡ, while R5P, DHAP and HCO₃^- increased qN,compared to nonphoto-oxidative contro1．Other chemicals，3-PGA，3-GAP，HPMS，DCMU，DBMm， Ant A and gramicidin D all showed an inhibitory efect on PSII photochemical activity (expressed by chlorophyll fluorescence parameters)and electron transport rate of PSII+PSI(determined by oxygen electrode)． It is proposed that carbon metabolic intermediate could act as a physiological regulator to modulate PSII photochemical activity. Alteration or blocking the flux / direction of photosynthetic electron transport，and changing the concentration of metabolites in Calvin cycle and photorespiratoy C₂ acid cycle would cause a direct or indirect efect on PSII activity under photooxidation condition．The effect varied with diferent chemicals．

Abstract:Pulp of litchi (cv. Baila) was used to investigate the changes of membrane lipid peroxidation and the activities of cell protective enzymes during storage at low temperatures. The results showed that the litchi pulp could be maintained well for 40 days at 3℃ or 50 days at -1℃ without symptoms of chilling injury. The cellmembrane electrolyte leakage and malondialdehyde (MDA) content of the pulp stored at 3℃ or -1℃ increasedgradually with time of storage, and showed no marked difference between the two temperature treatments within 30 d of storage．However．the treatm ent at -1℃ significantly delayed the increase of cell membrane electrolyte leakage and MDA content after 30 days of storage．The activities of superoxide (SOD)，ascorbic acid-peroxidase (ASA—POD)，catalase(CAT)in the pulp stored at 3℃reached their peaks at the 20th day and peroxidase(POD)at the 30th day． Storage at -1℃ inhibited the activities of these protective enzymes and reduced their peak values, thereby，significantly slowed down pulp senescence．

Abstract:UV-B absorbing capacities of methanol and cell-bound alkali extractable phenolics were measured in leaves of potted one-year-old seedlings of Pinus massoniana, Schima superba, Cryptocarya concinna, Castanopsis fissa and Castanopsis chinensis to investigate the UV-B protecting strategy in plants exposed to full sunlight. The results indicated that the UV-absorbing capacity of methanolic extracts was higher in plants grown under full sunlight than under shade regime. UV-B absorbing capacity of methanolic extracts in leaves of C．fissa, C. chinensis and P. massoniana under full sunlight was by 42．6％，32．6％ and 4．2％ higher than that under shade, respectively． The UV-B absorption ofcell wall-boun d alkali extractable phenolics in leaves ofC concinna and S．superba grown under full sunlight was by 35％and l1.7％higher than that under shade． respectively． But it was lower in leaves of P．massoniana, C．chinensis and C. fissa. grown under full sun light than that un der shade．It is likely that part ofphenolics moved from cell wall into cytoplasm to enhance the protective effect of palisade tissue against UV-B．Besides， massoniana and the broad-leaved trees had lower chlorophyll content and higher specific leaf area under full sunlight as compared to shading condition，which may have protective role for organelles in inner tissues.

Abstract:The two-year-old scion from Satsuma mandarine (Citrus unshiu Marc. cv. Guoqing No.4) was grafted onto 5 kinds of rootstocks: Poncirus trifoliata (I) for control, two somatic hybrids of C. reticulata with P. trifoliata (II) and with C. jambhiri (III), and two sexual hybrids C. sinensis × P. trifoliata (IV), C. maxima × P. trifoliata (V). The experiments showed that the trees growing from all the four kinds of rootstocks were vigorous compared to the control. Treatment II had more flowers than the control，but the treatment III，IV and V less．Highest content of photosynthetic pigments was observed in treatm ent IV and lowest in the control． Diferent treatm ents obviously influenced the tendency of the annual changes in the contents of soluble sugar and starch in leaves．The contents of soluble sugar and starch in leaves in different treatments changed obviously in various periods． The use value of somatic hybrids as a rootstock is discussed．

Abstract:Effects of water temperature, nitrogen, phosphorus, vitamin and antibiotic on the growth of toxic Alexandrium tamarense (Hong Kong strainⅡ) were studied under experimental conditions. Optimum growthtemperature, N and P concentrations were 21-25℃, 882-1 765 μmol/L and 18-72 μmol/L, respectively. Complex vitamin B was found to be beneficial for the algae growth, whereas over 50 U ml^-1 antibiotic showed obviousinhibition effect.

Abstract:The extraction of haemolytic toxin from Phaeocystis globosa was studied under laboratorial condition at various algal growth phases. Optimal conditions for breaking algal cell wall by ultrasonic was 600 W of power treated for 30 minutes at 4℃, the maximum volume of cultures being 3 000, 2 000 and 1 000 ml at logarithmic, stationary and senescent phases, respectively. High haemolytic activity was observed in stationary and senescent phases, but low or even nil in logarithmic phase. At least four haemolytic substances were found in this alga.

Abstract:Morphological studies of the pollens of 21 species in four sections of genus Osmanthus from China are reported in this paper. The pollen grains are spheroidal or subprolate in shape. The sculptures of the pollen exine are unexceptionally reticulate. Most species are 3-colporate, and few are 4-colporate or with 6 apertures. The ora are obvious or not obvious. Especially, pollens of each of the nine species are 3-colpate and 3-colporate; O.hainanensis is 3 and 4-colporoidate. Transitional types of the apertur also exist in these species．Some characters indicate that the pollen aperture of genus Osrnarahus is on the transitional stage from simple to compound apertures in Oleaceae．Two types ofpollens can be divided based on whether or not the lumen become small from the center of the mesocolpium toward the colpi．Th e sculpture characters show correspondence to the sectional division of Osmanthus，and to some extents the comprehensive characters of pollen morphology have corelation with that of the structural morphology ．In general，pollen morphology presents a systematic significance in the genus Osmanthus．

Abstract:Pollen morphology of 6 species in the Sect. Theopsis of Camellia were observed under SEM. Pollen grains of the species studied are prolate in shape, elongated-elliptical in equatorial view and trilete rounded (trilete obtuse-triangular for C. euryoides and C. parvicaudata) in polar view, ca. 92.3-106.8 μm × 45.2-58.6 μm in size with apecture 3-colpate, furrow membrane absent or not obvious. Four types of sculptures can be recognized: (1) exine rugulate (Camellia subacutissima Chang and C. handelii Sealy), (2) exine irregularly reticulate(C. fraternal Hance and C. septempetala Chang et L．L．Qi)，(3) exine cerebroid(C. euryoides Lindl.)and (4) exine foveolate(C. parvicaudata Chang)．The features in species studied will serve as good taxonomic characters.

Abstract:Megasporogenesis in Doritis pulcherrima collected from Hainan Province was observed undertransmission electron microscope. The megasporocyte is elliptical before the initiation of meiosis with its nucleus migrating toward the micropylar end and polarization being seen. The megasporocyte undergoes the first meiotic division, giving rise to two dyad cells. After meiosis Ⅰ, the chalazal dyad cell expands in size and differentiates into functional megaspore at the expense of the micropylar dyad cell. The functional megaspore undergoes the second meiotic division resulting in the formation of a binucleate embryo sac．The developmental pattem of the megasporogenesis in Doritis pulcherrima is ofbisporic Allium type．Some characters ofthe programmed cell death such as integrated plasma membrane， increasing amount of vacuoles， and hi dy compressed chromatin appears during the degeneration of the micropylar dyad cell， while the organelles distribute uniformity and the chromatin diffuses in the functional megasp qore．Some plasmodesmata occur on the chalazal cell wall of the functional megaspore but they disappear at the stage of binucleate embryo sac． Phagosomes wi th degenerated organelles are visible in functional megaspore at chalazal side.

Abstract:The length, width and the chloroplast numbers in stomatal apparatus, and the pollen sizes weremeasured of three species of genus Hibiscus (H. schizopetalus, H. mutabilis, H. rosa-sinensis) and three cultivars (H. rosa-sinensis L. cv. Double Rainbow, cv. Flavo-plenus, and cv. Carminatus). The characters of stomatal and pollen size are positively related with the chromosomal number and ploidy of these plants, which could be helpful for the ploidy determination of Hibiscus plants. However, the pollen size of these species and cultivars diverse greatly. The chromosome numbers and ploidy of hibiscus are discussed.

Abstract:Genetic variation of gliadin from endosperm were examined of 40 individuals of Pinus thunbergiipopulation in an area of 7.1 hm2 Fuqing natural forest in Fujian Province. Forty patterns of gliadin diversity and 9 loci were obtained by using polycrylamide gel electrophoresis. The results indicate that the proportion ofpolymorphic loci (P) was 55.56, mean number of alleles per locus (A) was 3.00, mean effective number of alleles per locus (Ae) was 2.28, mean expected proportion of heterozygous loci (He) was 0.533, mean observed proportion of heterozygous loci (Ho) was 0.402，and the fixation index (F) 0.246>0．The population exhibits high genetic diversity，which deviates from Hardy-Weinberg’s equilibrium law．This is probably due to sampling error，or unevenness of stand or poor growth of the individuals， resulting in ineficiency of radom mating and genetic drift.

Abstract:Based on nine climatic factors which affect the growth of Alnus formosana, the adaptive regions forintroduction of the species were investigated using the fussy resemble priority ratio method (FRPR). The nineclimatic factors are mean annual temperature, mean temperature of the coldest months, mean temperature of the hottest months, extreme minimum temperature, extreme maximum temperature, mean annual cumulativetemperature ≥10℃, mean annual precipitation, the number of months with monthly precipitation <50 mm in a year，and mean annual sunshine hours．The results show that the adaptive regions cover over 1 0 provinces along the Yangtze River and its southern areas．The most adaptive regions are in southern subtropical and tropical zones, and followed by middle subtropical zones．The conditions that suitable for the growth ofA．formos are：mean anual temperature above 15℃ ，extreme minimum temperature above -10℃，mean an ual precipitation exceeds 1 000 mm ， and the number of months with precipitation less than 50 mm not exceed 5 months． Climatic factor analysis indicates that the temperature is the first principal component afecting the survival and the distribution of this species， while comprehensive efects of temperature and precipitation are the second and third components which afect the growth of the plant.

Abstract:Fifteen medicinal Bulbophyllum species in China are presented. The local names, distribution, habitat, and folk medicinal uses are given. Bulbophyllum species used as folk herbs are mostly distributed in south and south-west China, in particular, in Yunnan Province. Some species such as B. kwangtungense, B. odoratissimum and B. ambrosia are common in Guangdong and Guangxi. Some suggestions for the conservation and reasonableutilization of the plant resources are made.

Abstract:A new variety from the progenies of combination Alpinia oxyphylla Miq. × A. henryi K. Schum. was bred. The new variety has some good horticultural characters, such as big and beautiful flower, erect inflorescences, large bracts and red lip, long blooming period, etc., which is suitable for gardening and cut flowers.

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Abstract:Merremia boisiana (Convolvulaceae), a liana species of the family Convolvulaceae that imperilssecondary forests in Guangzhou, is newly recorded from Guangdong Province.

Abstract:Four species and one variety are newly recorded from Hainan Province, namely Amaranthusroxburghianus, Phyllagathis asarifolia, Phyllagathis ternata, Grewia angustisepala, and Quisqualis indica var.villosa.

Abstract:Strategies to achieve high-level expression of foreign genes in plants are mainly introduced in thispaper. The authors summarize general ways to improve amounts of foreign proteins in plants in respect ofoptimization, integration, transcript, translation, transport and interaction of genes.

Abstract:The term of ecological models refers to a wide variety of types of models which simulate variousecosystem phenomena on different scales. Ecological models could be classified into various types according to different criterion. In this review ecosystem simulation models are summarized in four aspects. 1) Individual and population dynamics models describe the simulation of germination, growth and mortality of individual plants in an ecosystem, and the intraspecific and interspecific competition as well. The Gap model and Soil-Plant-Atmosphere model are included here．2)Community and ecosystem models simulate the replacement of plant species through the succession of ecosystems， including the transform ation of vegetation types and the corresponding changes (influences)in biogeochemical cycling．The ecosystem productivity model，biogeochemical cycling and succession models are applied to the community responses to global climate changes．3) The study of landscape ecosystem models consist of stochastic model and process-based landscape model，including temporal and spatial dynamic changes．The former is to simulate dynamic changes of comunity pattern in succession process，while the latter to spatial configuration of each ecosystem of which the landscape is made up．4) Biosphere and global ecosystem are related with the atm osphere and climate principally through the exchanges of energy， water and elements．Because of the limitations of equilibrium terestrial biosphere models， new generation models，such as TEM, CENTURY，FBM，Biome-BGC，CASA and so on，are critically needed for assessing and predicting the primary production and biogeochemical cycles of the biosphere in changing global environments． The goal of dynamic biosphere modeling is to model dynamics of terrestrial ecosystems caused by natural and anthropogenic disturbances，as well as the interactions of energy，water and the atmosphere． At last， in combination with the practice the prospect of the development of ecosystem simulation models in all aspects is given.