Abstract:

Abstract:A new combination, Champereia manillana var. longistaminea (W. Z. Li) H. S. Kiu ,and two new records, Phyllanthus amarus Schumacher (a naturalized weed in South China)and Drypetes formosana (Kanehire & Sasaki) Kanehira grown in Guangdong and Hong Kong, arereported.

Abstract:Pollen morphology of the 2 species (Orchidantha chinensis and O. longisepala) inLowiacae from China was examined under SEM and LM. Their pollen grains are bean-shaped,bilaterally symmetric, heteropolar and inaperturate. The sculpture on the surface of middle part ofpollen grains is densely striate and that on surfaces of both ends of those is rugulate. Slight differ ences of sculpture exist between the 2 spedes. The features of pollen morphology of the 2 speciesshow that the pollen of Lowiaceae can be considered as a peculiar pollen type which is observed inthe order Zingiberales for the first time.

Abstract:The species and distribution of the cysts of dinonagellates and other organisms inDapeng Bay, the South China Sea, was investigated in March 1992 at 12 sites bycollecting the sediments on sea-bed. From cysts of 30 species found, Scrippsiella trochoideawas the most dominant one at all sites investigated, and Gonyaulax polyedra, Protoperidiniumavellana and Alexandrium tamarense were common species. It was found that highest cystabundance was in sediment at site under deep water and in sediment at site where waterflow was stable. Most of the living cysts accumulated in sediment layer at 0-5 cmwith high phospate concentration and low N/P value. On the basis of the distributionof cysts of different species, the possible outbreak of red tide is disccussed.

Abstract:An artificially bared plot of 1 600 m2 in Heishiding, Guangdong Province, was establishedin 1986 by clear cutting conifer and broadleaf mixed forest, removing all the trees, and all theground vegetation was cleared and burnt in the plot. In 1990, the natural regeneration of the vegetation in the plot was shown to be restored fast. The restoring process was started to develop fromPinus massonian- Schima superba-Cunninghamia lanceolata community, and the forest communityhad been basically restored within 4 years. There were 42 tree species in the plot. The species similari coefficient between the plot and the previous plot was 0.6250, and the the species diversity andevenness were higher than those in community of the original plot due to the influence from theneighbouring communities. Compared to other near-by plots set in 1986, the communities of Whichhaving different ages up to more than 50 years were suggested as a successional series, the numbersof tree species and individuals developed in the bared plot tended to increase rapidly in thebeginning, then decrease, and then increase again slowly.

Abstract:The characteristics of transpiration in leaves of Liriodendron chinense seedlings measured by a CI-30lPS Portable Photosynthesis System showed that the highest transpiration rate in soil withsufficient water appeared in the afternoon of sunny summer. The leaf/air temperature difference,stomatal conductance, reactive humidity and other factors markedly affected the transpiration rate.The daily average water use effidency of L. chinense sablings was 4.142 mmol CO2 mol-1 H2O.

Abstract:The increase of the differential absorbance at 505 nm(△A505) induced by highlight was measured in leaves of Aloe vera, Mangifera indica, Brassica chinensis, Sonchusoleraceus and unicellular green alga Dunaliella salina 1009. Absorbances of leaf discs andalga solution were measured directly by using a spectrophotometer after high light treatment. The differential absorbance was obtained from absorbent difference between thesamples under high light and in the dark. Leaves were collected at 8 a.m. and reservedin the dark to ensure the high content of violaxanthin. During the high lightl 500 μmol m-2S-1) exposure period, △A505, increased gradually in all tested plant species andDunaliella salina. The obvious increase of △505 could be found after short time exposure(5-10 min). The maximum of △A505 was observed during the time of exposure for 50 min depending on the species tested, then it slightly decreased. The presence of ascorbicacid stimulated the light-induced △A505 increment in Aloe leaves and Dunaliella cells. Theincrease of △A505 in illuminated leaves of Aloe and Sonchus disappeared during thesubsequent 5h-recovery in the dark. The result supported that △A505 is an useful and simpleindicator of in vivo violaxanthin de-epoxidation, and the xanthophyll cycle operates activelyin both higher and lower plants under high light condition. Red and white lights at thelevel of 1850 μmol m-2s-1 were chosen to irradiate the sample for comparing their effects on△A505 △A540 (light scattering, an indicator of energy state of chloroplast) as well as pigmentsand chlorophyll fluorescence of Dunaliella salina. These two light sources led to thedecrease of Fv/Fm, Fv/Fo and Fo, showing the characteristics of reversible photoinhibitionduring light exposure from 5 min to 90 min. No difference in pigment content or the ratiobetween chlorophyll and carotenoid was found under the two light sources. However, redlight showed less effect on PS II primary photochemical efficiency and △A505, but moreeffect on energy state as compared with white light.

Abstract:The activities of fructose 1,6-bisphosphatase, NAD-dspendent glyceraldehyde-3-phosphatedehydrogenase, phosphoenolpyruvate carboxylase, phosphoenolpyruvate phosphatase and pyruvate kinase isolated from peanut leaves were inhibited by 5 mmol/L of Ca2+. When peanut sablings weregrown in Hoagland solution containing 0, 5 or 15 mmol/L of Ca2+, fructose 1,6-bisphosphalase(FBPase) and phosphoenolpyruvate carboxylase (PEPCase) showed the highest aedvity at 5 mmol/Lof Ca2+, but the highest aCtivity of pyruvate kinase (PK) was found at 0 mmol/L Ca2+.Photosynthetic and respiratory rates showed a similar changing trend as the activities of FBPase,PEPCase and PK. The high concentration of Ca2+ (15 mmol/L) enhance the chlorophyll content.

Abstract:Physiological fruit drop of longan (Dimocarpus longan Lour. cv. Shuizhang) wasstudied by measuring the cellulase and pectinase activities and ABA content in juvenile fruitscollected from 5 trees of 15 years old in Fujian Province in May 1993. The results showedthat there was a significant relationship between cellulase activity and fruit dropping.Cellulase activity in drop fruits was significantly higher than that in normal ones. No obvi- ous difference in pectinase activity' between normal and drop fruits was found, and thepectinase activity was slightly enhanced in drop fruits only at middle stage of fruitdropping. The content of ABA in drop fruits was higher than that in normal fruits. It wasshown that higher content of ABA and higher cellulase activity promote-d physiological dropof longan juvenile fruits.

Abstract:Effects of polarity and concentration of NAA on the ability of producing hairy roots incucumber cotyledon explants infected by Agrobacterium rhizogenes R1000 and R1601 were studied.The results showed that hairy roots appeared only at the hasal part of cucumber cotyledon explantsinfected with A. rhizogenes R1000 and R1601. If 0.1mg L-1 and 5.0 mg L-1 NAA were added to MSmedium, the rooting ability of the basal part of cotyledon infected with A. rhizogenes R1000 andR1601 was enhanced. However, in treatment only with 5.0 m L-1 NAA in precureandcocultivation on MS medium, the hairy roots could be incited in the apical part of cucumbercotyledon infected with A. rhizognes R1000 and R1601. Opine analysis evidenced the intergraionand expression of TR-DNA.

Abstract:The cut flowers of Chinese rose (Rosa chinensis Jacq. cv. shenzhenhong) treatedwith epibrassinolide(epiBR, basic preservative+0.1 mg L-1 epiBR) prolonged the flower lifein vase by 1- 1.5 times, and markedly improved the quality of cut flowers as compared tothe control (distilled water) or basic preservative only (2% sucrose +500 mg L-1citric acid+250 mg L-1 8-hydroxyquinoline +25 mg L-1 AgNO3). Further studies showed that epiBRcould increase the fresh weight of cut flowers and promoted the increase of reduc...

Abstract:Hypocotyls and epicotyls from sterile seedling of Citrus microcarpa Bunge were examined for direct shoot formation, callus induction and plant regeneration. The ability ofshoot induction from epicotyl was much higher than that from hypocotyl, with the highestshoot production frequency of 96.9%. Epicotyl segments oriented with their apical endsprotruding from the medium (t ) produced more shoots than that when they were placedwith their hasal end upwards (4 ) or placed horizontally (--). Optimal callus inductionmedium was MT+IBA 0.5 mg L-1 +BA I mg L-1. MT media with BA 4 mg La for epicotylcallus, and BA 2 mg L-l for hypocotyl callus, gave higher plant regeneration frequencies.When individual shoot was rooted on a rooting medium supplemented with IBA I mg L-',a root induction rate of 84.4% was observed.

Abstract:Five diterpenoid alkaloids were isolated from the tubers of Aconitum karakolicum Rap. col-lected in Yili, Xinjing, the structures of which were identified as aconitine, deoxyaconitine, ncoline,songorine and 12-epi-napelline on the basis of speCtral data. The last constituent was obtained in thisplant for the first time.

Abstract:A simple method to create chromosome region specific library in plant materials,including microdissection, amplification, characterization and cloning, is described. A singleNOR region of chromosome I from Vicia faba was microdissected and directly amplified bySUP-PCR in a magnified system. The sizes of the PCR products ranged from 200 to 900bp. Southern hybridization with total genomic DNA demonstrated the reliability of themethod. Part of the products were cloned into plasmid PUC 18. The inserts ranged between0.25 and 0.9 kb.

Abstract:

Abstract:

Abstract: