Abstract:O₂ and NO₂^- photoreduction in chloroplasts isolated from the leaves of Castanopsis fissa (tree) and Psychotria rubra (shrub) seedlings grown under three light intensities were compared in the presence of glyceraldehyde (an inhibitor of PCR and PCO cycle activity) and NH₄Cl (uncoupler of photophosphorylation). The highest rate of O₂ photoreduction (Mehler reaction) was observed in chloroplasts from full sun-exposed leaves of both plants,which was 66%-68% of total electron transport. NO₂^- photoreduction showed a similar trend， but it was only l1％-15％ of total electron transport activity．Shade leaves exposed to 36％ and 16％ of full sun light significantly decreased the photoreduction rates of 0₂ and NO₂^- and the percentage of 0₂ photoreduction to total electron transport，but had no effect on the percentage of electron transport partitioning to NO₂^- photoreduction． The activities of nitrite reductase(NiR)，nitrate reductase (NR)in leaves and the ratio of NiR／NR activity were also afFected by light intensity．As the light intensity was reduced，NiR activity decreased in C. fissa，and NR activity increased in P．rubra， whereas the changes in NR activity in C. fissa or NiR activity in P. rubra were not significant．The ratio of NiR/NR activity in two sun leaves reached more than 3，and it was just 1.7—2.2 in shade 1eaves．

Abstract:The systematic analytical method of grey theory was used to study the relationships between chlorophyll-b and 10 environmental factors (temperature, plankton biomass, salinity, dissolved oxygen (Do), pH, phosphate, nitrate, nitrite, Fe, and Mn) in seawater. Samples were collected from Dapeng Bay of the South China Sea, near Yan-tian area of the Shenzhen City. The resulting grey relative values and their permutation indicated that nitrate, phosphate, nitrite and pH had more influence on the chlorophyll-b concentration in seawater than any other factors．A grey model{GM(l，n)｝was established to relate chlorophyn-b concentration with four factors among the ten．

Abstract:By using ammonium sulfate fractionation, Sephadex G-25, DEAE-Cellulose, and Sepharose-6B chromatographies, glycolate oxidase isozyme GO I was purified from spinach green leaves which showed only one band with molecular weight (M_r) of 40 000± 2 000 in SDS-PAGE. The specific activity of purified GO I was 8.4 U min^-1mg^-1 protein. GO I showed its M_r of 470 000 in 4%-20% ND-PAGE and could catalyze both oxidations of glycolate and glyoxylate simultaneously. The isoelectric point (PI) of GO I was about PH 7.4. There was a immunity precipitate line determined by immunity double-difusion reaction between the antibody raised against GO I and crude protein from spinach green leaves．The specitic G0 I antibody was purified by protein A-Sepharose CL-4B column and specific antigen affinity elution．Only the 40 000± 2 000 band could immunity cross-react with Go I antibody，and different Go I polvmers of 470 000，280 000，and 80000 were found when crude protein were conduced to SDS-PAGE Ⅵ stern blot or ND-PAGE Western blot using this speciftc GO I antibody.

Abstract:Sterculiaceous plants in the world are estimated to be 1 546 species in 60 genera, which distribute mainly in the tropics and subtropics with a few in temperate regions. Sterculiaceae is a large and multiform family, and the attribution of some genera has still no identical views. Based on J. Hutchinson's system and some references, an adjustment of the position of some genera in the family has been made, and 12 tribes in the family are classified. The distribution of Sterculiaceae plants in the world is included in 6 kingdoms with 23 regions，based on Takhtajan’s floristic regions．In this paper 99 species with 7 varieties in 25 genera of Stercul iaceae in China， including 85 wild species with 7 varieties in 18 genera and 14 cultivated species in 8 genera are considered． Main characters of the l2 tribes and the distribution of genera are described．The authers suggest that Stercnllaceae originated before Cretaceus period，i.e．before the separation of Gondwana， because fossil plants had been found in Africa ，Europe ，Asia and America．According to the modern distribution pattern of Stercnliaceae，many genera till now distribute in Madagascar and tropical Africa which are endemic，and the mole primitive tribe ，Dembeyeae，mainly distributes here．It is suggested that Madagascar and tropical Africa might be the origin of Sterculiaceae from where expanded to Eurasia，Australia and America． A distribution map of Sterculiaceae in the world is given The genera with the number of species grown in 23 provinces and regions of China are tabulated．

Abstract:Orchid flora in the mountains of Guangdong ranged from 22° to 25°31°' N, 109.5° to 117°E was studied. Special attention was paid to the growth environment of orchids including horizonal and vertical distributions, and temperature and habitat factors. An analysis of areal types of Guangdong orchids in relation to the areal pattern of world distribution is given. A list of Guangdong orchids containing 204 species and some varieties in 70 genera is presented.

Abstract:

Abstract:Fire synonyms in species of Sabia distributed in China are proposed. S. campanulata Wall. ex Roxb. var. kingiana Nayar et Majumder is treated as S. campanulata Wall. ex Roxb., S. metcalfiana L. Chen as S. leptandra Hook. f. et Thoms., S. longruiensis X. X. Chen et D. R. Liang and S. swinhoei Hemsl. ex Forb. et Hemsl. var. parvifolia Y. H. Xiang et Q. H. Chen ex Ying et al. as S. swinhoei Hemsl. ex Forb. et Hemsl., and S. nervosa Chun ex Y. F. Wu is proposed as a synonym of S. coriacea Rehd. et Wils. S. burmania L．Chen was erroneously recorded from China, which is distributed in Myanmar．

Abstract:Leaf anatomical variations between species of Boesenbergia (B. curtisii, B. prainiana B. rotunda and B. plicata) and Kaempferia (K. pulchra, K. galanga, K. gilbertii, K. rotunda, K. parviflora and K. angustifolia) were studied in order to investigate anatomical variations which could be used to distinguish species. Results show that there are variations in the type of stomata, the structure of the midrib, the outlines of the leaf margin and petiole in transverse section, and the presence or absence of abaxial or adaxial hypoderm is and trichomes in the lamina．The results suggest that a combination of these characters is useful in distinguishing the species studied．

Abstract:Allozyme variation was examined in 48 pomelo cultivars from the collection nursery of the Chinese Academy of Agricultural Sciences. Ten loci observed in 5 enzyme systems, Esterase (EST), Phosphoglucoisomerase (PGI), Phosphoglucomutase (PGM), Shikimate dehydrogenase (SKD), and Superoxide dismutase (SOD) were encoded by 25 alleles. Except for 2 loci of PGI, all other 8 loci were polymorphic. Effective number of alleles per locus was l.55, and the expected heterozygosity was 0.2805, Which were comparatively low． Pomelo culfivars are rich in aUozymic genetic diversity．Lower level of total germplasm diversity is probably due to a long history of artificial sdeetion and gene loss．

Abstract:An analysis was made on expression of sesquiterpene cyclase gene, glutathione reduced and oxidized forms (GSH, GSSG), and lipid peroxidation and their corelationship in the detached leaves of Capsicum annuum treated with CuCl₂. The results showed that sesquiterpene cyclase gene was induced to express by elicitation of CuCl₂. The content of phytochaletin and GSSG increased, whereas GSH decreased in leaves under the elicitation of CuCl₂, and accumulation of lipid peroxidation products increased accordingly. It is speculated that solue kind of lipid peroxidatiou products or oxidation products of GSH might involved in the signal cascades in the elicitation of sesquiterpene cyclase gene expression under CuC1₂ treatment．

Abstract:Orthogonal experimental design was adopted to tissue culture in banana (Musa acuminata Colla cv. Williams). Effects of BAP, NAA, IBA and different explants on explant direct budding were investigated in banana by using orthogonal design [L₂₇ (3¹³)]. Statistic analyses indicated that the main factor which mostly influenced the results was explants. BAP was the second factor, and both NAA and IBA the third. The results showed that the optimal medium was MS basal medium supplemented without the three growth regulators，and the best explant for the medium was the apical meristem of shoots．

Abstract:Eight cultivars of sweet maize (Zea mays var. rugosa), which attended Guangdong provincial supersweet maize regional experiment in autumn cropping season in 1999, were evaluated by using the relation degree of grey system theory. They were analyzed from 17 traits including high-yielding, early-maturing, good-quality, plant height and green ear morphological characters. The comprehensive evaluation results showed that Supersweet 711 ranked first, which gave high yield, having strong stems and big green ears;Suitian 2 ranked second， having traits of early maturing， good quality and a appropriate plant height with medium ear height．The unweighted relation degree of other tested varieties ranked in descending order being Jingfeng 3，Jinyin 2，Yuetian 3，Supersweet 28，Suitian 1 and Yuetian 2． The weighted relation degree was in the order：Supersweet 711> Jinfeng 3>Suitian 2>Yuetian 3>Supersweet 28>Yuetian 2>Jinyin 2>Suitian 1．

Abstract:Twenty-seven constituents in essential oil from the leaves of Litsea rotundifolia var. oblongifolia were identified by means of GC-MS-DS. The content of these compounds amounted to 88.75% of the essential oil. The main compounds are dodecanoic acid (43.68%), myristic acid (14.61%), n-undecanoic acid (4.70%) and palmitic acid (4.15%).

Abstract:Gramineae is one of the largest families with widest distribution on the globe. It contains most important crops in the world including a great number of apomictic species. Apomixis has great potentialities for utilization of crop hybrid vigor. However, apomixis as a reproductive way of diversity in plant revolution is very comprehensive. In this paper, the distribution of apomictic species in Gramineae is reviewed. Advance in studies on apomixes in aspects of cytology, genetics and molecular biology are also summarized.