Abstract:Pollen grains of 58 species of Artemisia were observed under LM and SEM to verify the reliability of the classification of Artemisia species. The tricolporate pollen grains with reduced exine ornamentation of Artemisia species make them easy to be distinguished from species of other genera of Compositae. Based on exine ornamentation, the pollen grains of Artemisia can be divided into two types: type Ⅰ, the hasal part of spinule corrugate and extend, type Ⅱ, the hasal part of spinule nearly rounded. There are 4 subtypes in type Ⅱ. i.e. Ⅱ-1, with spinules arranged sparsely, interspinule granular, Ⅱ-2, with spinules arranged sparsely, but interspinules smooth, Ⅱ-3, with spinules arranged densely, interspinule granular; Ⅱ-4, with spinules arranged densely, but interspinule smooth. The results observed have proved useful in the study of systematics in Artemisia. The evolution trends and the affinity of sections in Artemisia are also discussed.

Abstract:Based on an examination of specimens now available from China and Japan, Lysimachia tashiroi Makino was reduced to L. patungensis Hand-Mazz. as synonym; L.tanakae Maxim. was treated as a subspecies of L. christinae Hance. The distribution and geographical vicariism of this genus between China and Japan were also discussed.

Abstract:This paper discusses how to use the similarity coefficients, i.e. associationcoefficients, to analyse the floristic resemblance and to resolve problems in comparative study of numerous floras being short of disirable comparison, and in floristic affinity tending to 'phenology" similarity by using improper formula, or neglecting the negative matching shared numbers and so on. The authors take flora similarity in two separate circumstances, narrow and broad similarities, the former points to the normal matching shared numbers of any two floras, and the later, to both the negative and normal matching shared numbers of any two floras. The floristic resemblances, similar relationships and the substance of similarity coefficients from the angle of Set-Theory are discussed. It is considered that the formula of similarity coefficient set up by P. F. Russell and T. R. Rao(1940) is suitable for discussion and determination of narrow similarity, but the simple matching coefficient put forward by R. R. Sokal and C. D. Michener(1958) is suitable for broad similarity. Among them, the formula of similarity coefficient by P. F. Russell and T. R. Rao (1940) is a special form i.e d=0 of the formula of simple matching coefficient by R. R. Sokal and C, D. Michener(1958). The authors suggest two new concepts, one is the similarity in population, and the other, similarity in areal-type, so as to have a unified study of the noristic similarity in different regions separately according to the study of flora in china by Prof. C. Y. wu. In this paper, six floras are used as examples.

Abstract:Pollen morphology of 31 species in 9 genera, belonging to subfadrily Hydrangeoideae, was examined by means of microscope and scanning electron microscope. The shapes of pollen grains of most species are subspheroidal and subprolate. Apertures basically with tricolporate, in Deinanthe caerelea it shows a reduced non-meridional furrow. Omamentaion of exine ranges from perforate with or without granules to apparent reticulate. Xirengeshoma shows similarity to the remainder of the subfamily. A particularly close relationship of Pileostegia and Schizophragma is indicated. Hydrangea shows great variation, and is closely linked to other genera, suggesting its central place of evolution in Hydrangeoideae. The present observation also indicates that generally, there is no clear cut discrimination of groups in Hydrangeoideae and they overlap each other complexly.

Abstract:The origin and the whole development stage of the juice sac of Citrus sinensis (L.) Obs. "Jincheng" were investigated. Results indicated that the juice sac originates from a single cell of the carpellary endoepiderdris. After the anticlinal and periclinal divisions of the initial cell, a multicellular globular-structure is produced. The globular-structure developes into a column6tructure with the differentiation of a cluster of meristem cells at its apex. As result of the active divisions and growth of the meristem cells, the column-structure expands and widens. At last the column-struCture developes into an expanding sac with a slender stalk that is the juice sac.

Abstract:Restoration ecology theories are very useful for revegetation in degradation ecosystem.In this paper, the application of restoration theories to revegetation in low-subtropics are discussed. It is a best way for revegetation in degradation ecosystem following vegetation succession law. The theories, which relate to spatial, matter, energy and biodiversity, should be used for the construction of revegetation in degradation ecosystem.

Abstract:The garlic bulbs (Allium sativum L.) after harvest were stored at low temperature (1 - 5 ℃), ambient temperature and high temperature (35 ℃), and the subsequent effects of storage on physiological and biocheAncal changes were examined. Respiratory rate, protein and vitadrin C contents gradually increased as the storage period of garlic bulbs progressed at ambient temperature, while sugar and dry matter contents decreased markedly after 2 months of storage, and the germs of garlic bulbs began to sprout. Controlled atmosphere storage (O2 2 - 5%, CO2 8 --10%) at low temperature(1 - 5 ℃) obviously inhibited the germination of garlic bulbs which did not sprout after 8 months of storage, and about 95% of garlic bulbs observed were in good condition. The storage at high temperatue in combination with polyethylene packaging also showed a similar effect.

Abstract:Two thermoperiod-sensitive genie male sterile(TGMS) lines of rice, Pei-ai 64s and GD-2s, were grown in greenhouse for multiplication by means of heating from January to May, 1995. When the TGMS lines were in the sensitivity stage of fertility alteration, the mean daily temperature in the greenhouse was controlled at 23 ℃. After heading, their pollen fertility was monitored by dricroscope and the seed setting rates were checked. The results showed that the seed setting rate of Pei-ai 64s reached 50.7%, its individual plant yield was averagely 3.5g. The multiplication of pedigree seeds for Pei-al 64s grown in the greenhouse in winter was successful. It is proved that seed being multiplied in the greenhouse in the winter is a better way to expedite the reproduction of TGMS lines at low critical temperature.

Abstract:The rhizomes of Cymbidium sinense were incubated in the medium of 1/2MS +BA (1mg L-1) +NAA (1mg L-1) +La3+ (10mg L-1). After incubation for 30d, the rhizomes were used for observating the ultrastructure and development of the chloroplast, ndtochondria and nucleus. The results showed; 1. The development of the chloroplast of the rhizome treated by La3+ was enhanced. There were much more lamellae and osdriophilic granules in chloroplast stroma, and the development of the chloroplast was faster than that of the control. There were little lamellae and larger starch grains in the chloroplast stroma of the control. 2. After treatment with lanthanum, the development of Antochondria was enhanced, and their volume was larger than that of the control. There were more ergastic material in mitochondria stroma of rhizome which was treated with La3+. 3. After treated by La3+, the chromatin in nucleus was increased. The above results showed that there was good effect of La3+ on the development of chloroplast, mitochondria and nucleus in the rhizome of Cymbidium sinense.

Abstract:Cupper and zinc-containing superoxide dismutase from broad beau(Vicia faba) seeds was purified to homogeneity by the steps of crude extract, chloroform-ethanol treatment, aceton precipitation, DEAE-cellulose chromatography and Sepharose 6B chromatography. The purified enzyme had a specific activity of 2852 units mg-1 protein. Its activity was strongly inhibited by KCN and H2O2. Its molecular weight and subunit molecular weight were 31000 and 14400 respectively, which indicated that the enzyme was composed of two identical subunits. The enzyme was stable to heat below 70 ℃ and to pH at range of 5 -9, and exhibited maximum ultraviolet absorption at 273.5um.

Abstract:The NaCl-induced inhibition of nitrogen-fixing activity of blue-green algae Anabaena 7120 was removed to a certain degree by the. introduction of appropriaternannitol into the test system. When the preincubation of algae cells was done in dark before experiment for 24 hours or in the presence of photosynthetic inhibitors, such as DNP or CCCP, the enhancing effect of mannitol on the nitrogen-fixing activity of Anabaena 7120 supressed by NaCl weakened or disappeared. In the addition of O2 together with H2 the enhancing effect of mannitol on nitrogen-fixing activity of Anabaena 7120 was reinforced under NaCl stress. A marked inaction in nitrogen-fixing activity of Anabaena 7120 occurred under NaCl stress when O2 was introduced into the test system alone. When algae cells inactivited by NaCl were incubated in the aerobic condition the accelerated action of mannitol upon the nitrogen-fixing activity was higher than that in anaerobic condition. The mannitol-supported nitrogen-fixing activity of Anabaena 7120 under NaCl stress was accelerated in the addition of N2 together with CO2 or addition of CO2 alone, while it was depressed by adding N2 alone.

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