Abstract:When detached leaves of four rice cultivars, IR72, Guichao 2, Tesanai 2 and II You 4480, growing under 350 μl L^-1 (ambient) and 600 μl L^-1 (enrichment) CO₂ concentrations, were treated by different temperatures (30, 35, 40, 45, 50 ℃ ) for 30 min. Results showed that the cell membrane leakage increased with increasing temperature. There was a breakpoint with significant rise in 40-45 ℃ treatments in IR 72 and Guichao 2, whereas that in Tesanai 2 and II You 4480 were between 45-50 ℃. With increasing

Abstract:Electron leakage rate and respiratory rate were studied with mung beau mitochondria. Succinate, NADH, a-ketoglutarate, malate and NADH were strongly effective in supporting mitochondrial respiratory rate and electron leakage rate. The ratio of electron leakage rate and respiratory rate (O₂^-./O₂) were not markedly different when different substrates were utilized in mung beau mitochondria. Electron leakage rate was promoted and respiratory rate was inhibited by antimycin-A when succinate, a-ketoglutarate and

Abstract:Treatment with 0.1 mmol/L spermine (Spm) could maintain high contents of reduced sugars and soluble proteins at early stage in cut rose flowers during vase-holding period, in the meantime, the increase in membrane permeability in petals and leaves, the accumulation of MDA in petals, and the ethylene evolution were inhibited. However, spermidine (Spd) did not show remarkable effect.

Abstract:A tissue culture system for obtaining high frequency shoot regeneration of Brassica campestris was studied. Shoots could be induced directly from cotyledons cultured on MS medium supplemented with 2.0 mg L^-1 BA and 0.5 mg L^-1 NAA, the shoot regeneration rate being 31.6%. Addition of 2.0 mg L^-1 AgNO₃ in the medium could greatly increase the frequency of shoot regeneration, and the shoot regeneration rate reached to 86.5%.

Abstract:The soil nutrients, the contents and seasonal dynamics of mineral elements as well as the relationship among the elements in leaves of fruit-bearing trees of Citrus grandis Osbeck cv. Shatianyou in Meizhou were studied. Results show that there was no obvious difference in rhizospheric soil nutrients between normal trees and retrogressive trees, but the coments of various elements in leaves in different fruiting period were different. The change in various elements in the retrogressive trees in fruiting

Abstract:Acacia mangium trees planted in 1993 in Xiamen region, Fujian, showed that the growth rate and aboveground biomass were higher than those of A. cunninghamia and A. auriculaeformis. The annual litter-fall of 4-year-old trees of A. mangium and A. auriculaeformis were 1 150 g m^-2 and 668 g m^-2, respectively. Seasonal variation of nitrogenase activity in nodules of A. mangium and A. cunninghamia was obvious and was in the order August>October>May>February. The phyllodes of A. mangium were found to contain

Abstract:An investigation of stand biomass and productivity was undertaken of Eucalyptus urophylla planted at spacing of 2 mx3 m in 1990 on Dongmen State Forest Farm, Guangxi Province, China. Stands in 27 plots with 20 m x 24 m each were measured, and 9 individual sampling stands from each diameter class were chosen. Regression equations for predicting biomass production were developed using functional dependence of biomass in different plant components on D²H. Mean biomass production of 10-year-old single tree and

Abstract:对薇甘菊(Mikania micrantha H.B.K.)在不同生境下生长状况及其对其它植物的危害程度的研究表明,这种热带杂草是喜光、好湿的。薇甘菊伴生物种以藤本植物居多,其中葛藤和五爪金龙出现的频度最大。薇甘菊及其伴生种通过攀爬树冠,形成盖幕作用而对其它植物造成危害。在森林内薇甘菊危害的对象主要是低矮的乔木,对高大乔木影响不大。

Abstract:Mikania micrantha, a harmful exotic weed in southern China, likes to grow in humid soil under high light intensity. This climber commonly grows together with other vines such as Pueraria lobata and Ipomoea cairica. They climb to tree crown and cause damage by forming a cover on the canopy. Fifteen sites in Guangdong Province where M. micrantha is distributed were investigated from October 1998, and some plots were sampled in March 2000. The habitat and the growth of M. micrantha, soil moisture,

Abstract:Gas exchange in leaves of selected plants was measured by using LCA-4 portable photosynthesis and transpiration system (ADC, England). Analysis of the difference in net photosynthetic rate (Pn) between Mikania micrantha and its companion species was also made. Results were as follows : (1) Mikania micrantha, a herbaceous vine, had a strong capacity for CO2 fixation, the Pn being 21.56 μmol CO₂ m^-2S^-1, which was higher than that in the accompanying somewhat woody twiner Pueraria lobata (16.97) and climbing herb

Abstract:Investigation of the vegetation of Heishiding Nature Reserve in Guangdong was carried out from June 1998 to May 1999 by means of global position system. The classification of vegetation types and plant formations was issued in Acta Scientiarum Naturalium Universitatis Sunyatseni Vol. 39, No. 2. In this paper thirty plant associations under 5 vegetation types with 10 formations were classified. A distribution map of plant associations on the scale of 1: 10000 completed with the aid of geographic information

Abstract:Two rare species of Triuridaceae, Sciaphila megastyla Fukuyama & Suzuki and S. ramosa Fukuyama & Suzuki, are first reported in mainland of China. The two species were collected by Mr. Lain in Damaoshan of Kowloon, Hong Kong, on 18 Sept, 1999 and S. megastyla Fukuyama & Suzuki was also collected by Mr. Williams (without collection number and date) in Maanshan.

Abstract:Four species of genus Smilax Linn. are reported as new records to Guangdong and Hainan provinces, viz. S. astrosperma Wang & Tang, S. scobinicaulis C. H. Wright and S. tetraptera Gagnep. for Guangdong, and S. kwangsiensis Wang & Tang for Hainan. S. kwangsiensis Wang & Tang var. setulosa Wang & Tang is regarded as a new synonym of S. kwangsiensis Wang & Tang, while S. lanceifolia Roxb. var. opaca DC., S. microphylla C. H. Wright var. elongata Warb. and S. lanceifolia Roxb. var. elongata (Warb.) Wang & Tang

Abstract:

Abstract:Pollen morphology of 36 species in 34 genera belonging to 8 subtribes of the tribe Andropogoneae was examined and compared by means of light microscope and scanning electron microscope. Results reveal that the morphology of pollen grains in this tribe is mostly unanimous. The pollen grains are sub-spherical or ellipsoidal with a single operculate aperture surrounded by a raised rim. The surface of exine is interspersed with granules. All these show that it is a natural group. Except for some differences in exine ornamentation and pollen size，there is no great evolutionary divergence among genera in pollen morphology．Based on the ornam entation，the pollen grains in the tribe can be divided into 3 types，namely scabrous，obscurely verrucate and obviously verrucate，which is useful in the research of systematic evolution．

Abstract:Plants from Litsea contain several chemical constituents such as alkaloids, volatile oils, fatty acids and others. In this paper chemical constituents from Litsea plants are reviewed to provide an information for the research of plant resources.

Abstract:Lectin was extracted from leaves of Aloe vera L. var. chinensis (Haw.) Berger in a dilute NaCI solution. After centrifugation, the collected supernatant was dialysed. Pure lectin of Aloe (ACL) was isolated by N-acetylglucosandne-Sepharose 4B affinity chromatography and purified by Sephadex G-100 gel filtration chromatography. The apparent molecular weight of ACL was 35 kD. It consisted of two subunits, 15 kD and 20 kD. ACL could agglutinate rabbit erythrocytes and the human erythrocytes with groups A and O specifically, except those with groups B and AB．The activity of ACL was inhibited by D-mannose and N-acetylglucosamine．Neutral sugar content in ACL was 4.8％.

Abstract:Three crystalline compounds were isolated from the bark of Taxus chinensis (Pilger) Rehd. Their structures were identified to be rutaecarpine, kaempferol-4'-methyl ether and sitosteryl-3-O-β-glucoside by spectroscopic methods. Rutaecarpine is first found from the plant of Taxus.