Abstract:The pteridophyte flora of Guangdong consists of 56 families, 139 genera and 464 species, among them primitive taxa or relic species are abundant. A detailed floristic analysis shows: ① The pteridophyte flora of Guangdons has 3 monotypic familiar, 9 monotypic genera and 4 woody genera. ② The tropical and subtropical families are dominant, which constitute 39. 3% of the total families, and the pantropic, the cosmopolitan and the temperate families being 33. 9%, 21. 4%, and 7. 1%, respectively. ③ The percentages of cosmopolitan, Pantropic, tropic-subtropic, subtropic and temperate genera in fern flora of Guangdong are 6. 5%, 29. 5%, 29. 5%, 25. 9 % and 8. 6%, respectively. Most genera are monotypic and oligotypic (77%). The above distribution pattern reveals the transitiveness of the elements from tropical to subtropical. ④ The pteridophyte flora of Guangdong is closely related to that of Guangxi (esp. in SE Guangxi), the index of genus similarity being 0. 84. and is also related to that of Hainan, S Hunan, Fujian and S Jiangxi, Showing an integrality of pteridophyte flora of S China.

Abstract:The Genus Pueraria DC. belonging to Phaseoleae (Papilionaceae),contains 18species.Nine species and 2 varieties are distributed in southwestern, southeastern and middle southern perts of China. Some species of Pueraria are economically important for its edible tubers or the use for fodder, green manure and medcinal herbs in Asian countries.This paper deals with the histoly of the genus. A key and a brief description of each Chinese species are given. It is confirmed that the bole chromosome number of Pueraria is X=11.

Abstract:A taxonomic reunion reveals that four spevies of the genus, P. ambigua, P. anacamptolepis, P. intralimbataand P. makincli two species of Caduciella, C. guangdongensis and C. mariei occur in South China. P. ambigua in Guangdong, Guizhou and Hainan Island, P. anacamplolepis in mainland China (Guangdong, Guagnxi) and Hainan Island,P. nakinci in Fujian, Guangxi and Hainan Island, C. guangdongensis in Hainan Island are reported for the first time.P. alopecuroides is treated as a doubtful species. Diagnostic charaders, distributions, laslitiot, habitsts and a key to the studied species are provided.

Abstract:Ligustrum lucidum and Fraxinus chinensis are two species of the major host trees for wax insect (Ericerus pela). From external to internal pets, the bark structure of both species includes periderm, cortex, fibre bundles of primary phloem and secondary phloem. Their sieve tube members eaist with compound or simple sieve plates, and they all contain P-protein and sieve tube scorch. Companion cells arranse in a row or single cell as long as the sieve tube member. The longevity of sieve tube in Ligustrum lucidum lasts 12 months, while in Fraxinus chinensis 8 months at the most. Obvious division of cambia in both species begins in mid to late March, but euds in mid November in Ligustrum lucidum and in late Novembe in Fraxinus chinensis. The differentiation of xylem and phloem of both species begins in mid March,but ends in mid November and late December in Lingustrum lucidum, and in late September and late November in Fraxinus chinensis. In winter, there are partially differentiated sieve elements in phloem of both species. Thais partinlly differentiated sieve elements in Fraxinus chinensis appear in autumn, mature in mid March of next year, and collapse during September and October. In branches of Ligustrum lucidum there is a overwintering and functional zone with average thickness of 170. 2μm in phloem, while the zone in Fraxinus Chinensis only several cell rows thick.

Abstract:An abnormal Phenomenon of meiosis in Potion mother cell of ghana is reported for the first time. The principal character of the meiosis is that the two chromatids of some univalents separate early in metaphase. The authors suggest that this might be caused by the allogenic genomes which can not synchronize in meiosis. The origin of banana Gaozhouai is also discussed

Abstract:The useful part of sandal tree (Santalum album) is the fragrant heartwood, which usually starts its formation in about 10-year-old plants and increases slowly in size with the aging of the plant. In natural condition, it will take 30-40 years for the formation o f commercially valuable hastwood in a sandal tree. In this study, 2-yeal-old seedlings of Santalum album were treated by 1% of a plant growth inhibitor (PGI-1) with different dosases (1ml, 3ml) and different frequencies (once, twice and four times per year). Plants treated with the same quantity of water and that not being treated were used as control. After three years of treatment, the plants were dug up, the stems and roots were ground into powder and distillated by steam separately. The obtained oil were measured and analysed by using gas chromatography. The results show that PGI1 has distinct effects on forcing the heartwood formation in Santalum album. The average oil contents in stems and roots, as well as the sandalol content in the oil of the plants treated by PGI-1, with very few exceptions, are much higher than that treated by water. On the other hand, the differences of oil and sandalol contents are inconspicuous between the plants treated by water and that not being treated. It shows that mechanical injury alone during treatment has little influence on the formation of heartwood in sandal tree.

Abstract:Cymbidium sinense (Andr ) Willd. plants were cultured hydroponically in nutrient solution at different K levels following K starvation in order to compare their growth,development, disease resistance and some Physiological characters. In normal culture condition, the content of K was more than that of N and P, the ratio of N, P, K was 6: 1: 9. Therefore,attention Should be Paid to K fertilizer in cultivated C. sinense. Plant grown at K deficient (0 mmol/L) or low K (0. 1 mmol/L) medium showed inferior growth, fewer flower number and much brown spot disease. If plant grew at normal K supplied conditions (1, 5 or 10 mmol/L), higher rates of Photosynthesis, respiration and stronger activity of root system occurred. Those plants grew rapidly in leaf, existed a considerable number in flower and low rate in leaf brown spot disease. Authors suggest that 5 mmol/L of K is suibole for C. sinense gtowth.

Abstract:Seedlings of three subtropical forest species, Schima supeba, Cryptocarya concinna,and Castanopsis fissa, were grown under varied light conditions at 100%, 40% and 16% of nature sunlight intensity. During the winter time, the fully exmpding leaves in the top of the Plants were collected for determination of chlorophyll fluorescence,contents of chlorophyll, carotenoid, soluble protein and soluble sugar, as well as the permeability of cell membrane.All of the species exhibited acclimation to different irradiances and low temperature in winter. No considerable leakness of leaf electrolyte was observed, but the toeal electrolyte of leaf was declined at low irradiance.Chlorophyll fluorescence Fv/Fm ratio was slightly decreased (Scheime superba and Castanopsis fissa) or markedly decreased (Cryptocarya concinna) in leaves at 100% of irradinnce. Same trend of decreasing Fv/Fm value was found in three species after treatment for 9 hours with leaf discs at 5℃ and light intensity of 100μmol m-2s-1. The ratios of Chl a/b and soluble sub/protein and Fv/Fm were lower in Cryptocarya concinnathan in Schima superba and Schima superba and the former was susceptible to high light and low temperature, but the latter two species showed a higher ability of environmental acclimation.In comparision with 100% and 16% of irradiance, however, the similar ratio of soluble protein/Chl in three species, and more soluble sugar and plotein in leaves at 40% of irradiance showed that this light level favoured the normal synthesis of organic compounds durins winter season.

Abstract:The changes of anther proteins in a typical Hubei Photoperiod-sensitive genie male -sterile rice (HPGMR) Nongken 58s under the induction of long day (14/10h, light/dark) and short day (9/15h, lisht/dark) were analysed by two-dimensional polyacrylamide gel electrophoresis. Proteins from anthers were resolved into 180 components.The protein electrophoretogram showed that there were evident difference between sterile anthers and fertile anthers at diffent stages of pollen development. Four of the protein spots, namely P1 (70KD, pI6. 2), P2 (68KD,pI6. 2), P3 (37KD, pI7. 4) and P7 (38KD, pI6. 2) were oborved in sterile anthers from early uninucleate stage to trinucleate stage of pollen. These proteins were considered as the specific proteins related to sterility formation under iong day induction.Free histone was also analysed by SDS-PAGE in anthers. It showed that the histone patterns were chansed with the development of pollen, and the relative contentS of free histone in sterile anther were lower than that in fertile anther by 19. 6% and 7. 4% at the uni- and dinucleate stages of pollen. The decrease of Part of flee histone content may be caused by the effects of decreasing amount of synthetic DNA in the sterile anthers.

Abstract:Cymbidium sinense(Anar)Willd. plants were cultured hydloponically in culture solution at different K levels following K starvation. The contents of Carbohydrate and protein as well as some enzymes activities in various growth periods had been measured. With increasing K concentration, the contents of soluble suber, starch, cellulose and protein in plants treated with 5 mrnol/L KC1 were inerased by 125, 117, 127 and 41% respectively than those of the control. However, these KC1 treated plants had reduced by 44 and 24% in the contents of reducing sugar and free amino acid respectively than those in the control. Pseudocorm was the major organ for storing reducing sugar, soluble sugar, starch,protein and free amino acid, but cellulose mainly diStributed in leaf. When K was sufficient to plant requirement, the activity of pyruvate kinase in leaf iucreased by 15 times as against the control, and nitrate reductase was also about 1. 8 times the activity of the control. The possible reason for K promoting growth, development and disease resistance in C. sinense was discussed. And, three methods of Preliminary physiological diagnosis for K nutrition in this Plant were also suggested.

Abstract:The effects of three exogenous hormones on germination of the seed of Chinese fir (Cunninghamia lanceolata) were studied. The results showed that the seed germination was actively stimulated by Gibberellin (GA), and significantly inhibited by 6-benzylaminopurine (6-BA) and Abscisic acid (ABA). When the three exogenous hormones were used together, it was shown that GA at 50-100 ppm had an active role in promoting seed germination, while 6-BA at concentration not exceed 50 ppm exhibited disinhibition effect. The inhibition effect of ABA could be antagonized by 6-BA and GA.