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2004  Vol. 22  No. 4

Abstract:
Differential display method was used to identify novel genes regulated by the ethylene generator,ethephon in tobacco plants.A full length cDNA of S-Adenosyl-L-Methionine synthase (SAMS2) which contains 1350 bp was isolated by this way combined with RACE technology.Sequence analysis revealed that this gene shared 90% similarity in gene sequence and 96% similarity in protein sequence with a known SAMS (SAMS1) gene though they have low homologous in the 5’ and 3’ uncoden region.RT-PCR analysis indicated that the expression of SAMS1 was induced by the treatment of high temperature but has no response to oxidative stress induced by methyl viologen (MV) and NaCl stress,while SAMS2 was up-regulated by all the three stress treatment.
Abstract:
Three transgenic wheat lines have been evaluated under field conditions during 2 years continuously, together with 4 non-transgenic lines of wheat. Two of the non-transgenic lines are donor plants of the transgenic lines and the other two are local region cultivars used as control materials. The plant growth and development of all transgenic lines were normal under the conditions tested. But their morphological and major agronomic traits were different from the donor plants, especially when comparing with 2 local cultivars. In the yield and 1000 grains weight, there was difference of major agronomic traits between transgenic lines and its donor lines. Results of the histochemical and SDS-PAGE analysis showed that the target genes were stably inherited.
Abstract:
The phylogenetic relationships of three species of Glycyrrhiza (G.uralensis,G.infleta,G.glebra) were analyzed by RAPD.Nine random primers of high stable quality were screened from 50 primers.The cluster analysis results of 961 amplified DNA fragments were indicated as follows:the average genetic distance among the fifteen groups of Glycyrrhiza was 0.41,of which the max genetic distance was 0.63 while the min 0.26.The results show that there is some difference between RAPD cluster analysis and the original species.
Abstract:
In the present paper 37 species and 14 varieties of Clematis from Hubei Province are recognized based on extensive identification of specimens and review of literature. The genus Clematis is widespread throughout the world and its distribution center is situated in the subtropical regions of China. The Clematis species are richest in Yunnan and Sichuan from where the total species numbers of Clematis in other provinces decrease gradually in all directions in China. Most of the species of Clematis from Hubei concentrate in the west montane region of Hubei. The geographical elements of the flora of Clematis are rather simple, of which Chinese endemic elements are dominant, amounting to 68.6% of the total species from Hubei. Therefore its nature is temperate. According to the distribution of the primitive groups of Clematis and the conjecture of the origination center of the primitive taxa of Ranunculaceae Subfam. Helleboroideae, it is assumed that Clematis originated from Southwest China. And in the light of this assumption we explain the relations between the flora of Clematis from Hubei and those from neighbouring provinces.
Abstract:
The internationally important wetland,Poyang Lake Nature Reserve has several small lakes relatively independent from Poyang Lake.The aquatic plants in these lakes were destroyed by a catastrophic flooding occurred in 1998.The restoration of the aquatic vegetation following the high water stress was analysed by comparing the results of vegetation investigation in 1999 and 2001,as well as the historical data.The species number and the biomass in 1999 were lower than those before the flooding.However,species had restored by 2001,and the biomass of Vallisneria spp.and Hydrialla verticillata had exceeded that before the stress,but the biomass of the rest plants were still low.It was suggested the different restoration of plants were mainly related with their different vegetation propagation methods.The vegetation restoration in lakes of Poyang Lake Nature Reserve was different from that in temperate and other subtropical lakes in that no pioneer stage when Chara dominated occurred.The reason was that the frequent severe fluctuation of water levels in Poyang Lake affected the settlement of Chara.In the paper,we think that the decline of biomass of aquatic plants and the species number was just a short-term effect;and it will spend several years to restore the lake vegetation.
Abstract:
Based on field survey for plant community by quadrates, both quantitative and ordination analyses of plant communities in water-level-fluctuation zone within Three Gorges Reservoir Area of Changjiang River were performed using TWINSPAN (Two Way Indicator Species Analysis) and DCA (Detrended Correspondence Analysis) methods. One hundred and twenty-two quadrates collected from the study area were classified into nineteen types by TWINSPAN, and four vegetation types were identified. The result revealed a relationship between the plant communities and environmental gradients, which is also confirmed in the chart of DCA. Diagonal line of the two-dimensional ordination diagram of DCA indicated that soil water content is highly correlated to submersed duration in the areas, suggesting that the major factors restricting distribution and composition of plant communities are submersed duration and edaphic humidity. Analysis of the composition and distribution of those communities provides a baseline data for selecting plants for reconstructing water-level-fluctuation of Three Gorges Reservoir in the future.
Abstract:
The diversity of phenotypic characters of Myricaria laxiflora and its patterns, as well as the divergence of characters and its relationship with habitats were studied in this paper, using 11 anatomical parameters of stem as phenotypic characters and partially sampling the populations covering whole distribution area of the species. The results indicated that each character among populations and general characters in various populations have significant or extremely significant differences. 63% divergences of characters belong to inner-population variation, while 37% belong to geographical variation. The character variation measure in populations correspond to that of the environment. The 5 pre-populations above Fengjie, Sichuan Province are more similar with each other, while the 5 post-populations from Fengjie are otherwise, which showed that the diversity center of phenotypic characters is located in the valley between Three Gorges rather than the valley beyond them.
Abstract:
Cymbidium aestivum Z.J.Liu et S.C.Chen,a new species of Orchidaceae from southern Yunnan,is described and illustrated.The new species is akin to Cymbidium dayanum Rchb.f.,from which it differs by the larger flowers with sepals 4.2-4.8 cm long,pale purple-brown sepals and petals,lanceolate bracts 1-1.5 cm long and a long mid-lobe equaling 3/5 the length of the lip.
Abstract:
A new variety,Yulania denudata(Desr)D. L. Fu var. pubescens D. L. Fu,T. B. Zhao et G. H. Tian,was described in this paper. The variety can be distinguished from Y. denudata(Desr.)D. L. Fu var. denudata by follow characters. The single pistil is pubescent and the follicetum is verrucose of var. pubescens. But the single pistil is glabrous and the follicetum is lenticellate of var. denudata.
Abstract:
A new strain of Spirulina sp. was separated from sewage, and the suitable medium was selected. This Spirulina sp. was as long as 1750 μm, it waves and rotates actively under optimal living conditions. The water in which this Spirulina sp. lived was slightly acid or hypereutrophic, the salinity was low,and the temperature was 534℃,the concentration of total nitrogen and total phosphate were 4.534.96 mg/L and 0.390.48 mg/L respectively. Culture experiments revealed it grew only under low light intensity, which is quite different from the Spirulina’s common characteristics of adaptation to high light intensity, high temperature, high salinity and high alkaline. NH+4 is helpful for this Spirulina sp. to grow. The Spirulina sp. adapted well to sewage, thus it may be applied in purification of sewage.
Abstract:
The callus of barnyard grass (Echinochloa crusgalli)was treated with compound 5 (1-phenyl-4-(3,4-methylenedioxy)-phenyl-diacetylene) under UV-A irradiation for 3 h, which forms an inner environment of oxidizing stress in the cells. Exploiting the method of bioche-mistry, we assay the activity of several protective enzymes in the oxidizing stress. The results showed that compound 5 can stimulate the activity of glutathione-S-transferase(GST), glutathione peroxidase (GSH-Px) and peroxidase(POD) and inhibited the activity of superoxide dismutase (SOD) under UV-A. The activities of GST, GSH-Px, and POD under light were higher than those under non-light. The enhanced percentages of GST, GSH-Px, and POD at the concentration of 10 mg/L under light were 10.47%, 113.68% and 166.68%, but SOD was inhibited at 1 mg/L and 10 mg/L, the inhibiting percentage was 50.25% and 76.46%, respectively. The relationship between compound 5 oxidization and anti-oxidization was discussed in the paper.
Abstract:
The changes of leaf morphology, structure and photosynthetic characteristics of Gynostemma pentaphyllum under different shading treatment were studied through the experiment in the field and the basin containers. The results revealed that the leaf morphology, structure and photosynthetic characteristics of this plant cultivated in above two ways appeared similarity. The leaf morphology and structure were largely affected by light intensity. Under shading treatments, it presented shade leaf features with large size, dark green, thin thickness of leaf blade, palisade tissue and spongy tissue, and undeveloped vascular bundles compared with those under full sunlight. Meanwhile, the contents of chlorophyll and net photosynthetic rate under shading treatment were higher than those under full sunlight. Available data indicated that G. pentaphyllum is of sciophiles, and shading treatment benefited the growth and development of this plant.
Abstract:
Seeds of rape (Brassica napus L.) were cultured in the presence of exogenous salicylic acid ranging from 0.08 to 10.00 μmol/L (0、 0.08、 0.40、 2.00 and 10.00 μmol/L)to see the effect of salicylic acid on the formation of lateral roots in rape. The results show that 0.40 μmol/L salicylic acid treatment enhanced the formation of lateral roots significantly, in which the number of lateral roots was increased by 47.8% compared with the control. More auxin and lower abscisic acid were detected both in leafs and roots of the treatment of 0.40 μmol/L salicylic acid. It showed that salicylic acid might be involved in the regulation of lateral root formation through influencing the content of endogenous auxin and abscisic acid in rape.
Abstract:
The correlativity between agronomic characters and yield per plant and between biochemical matter contents in flower buds and leaves and agronomic characters of CMS hybrids were estimated in pepper by using the method of grey correlation degree. Results showed that the magnitude on grey correlation degree between various agronomic characters and yield per plant was plant spread, plant height, fruit length, fruits per plant, weight per fruit, the first flower node, fruit width and branches per plant. The magnitude on grey correlation degree between various biochemical matter contents in flower buds and agronomic characters was soluble sugar, soluble protein, POD activity, ABA, IAA, free proline and ZRs. The order in leaves was soluble sugar, POD activity, free proline, ABA, IAA, ZRs and soluble protein.
Abstract:
It was conducted with ’Nice’ navel orange (Citrus sinensis Osbeck) two-year-old young tree whose rootstocks were Red tangerine +Trifoliate and Red tangerine +Rough lemon somatic hybrid, Troyer Citrange and Swingle Citrumelo sexual hybrid. Study on the effects of rootstocks on the growth and the annual changes in the contents of carbohydrates in leaves through potted experiment. The results are the following. Red tangerine + Trifoliate grew more vigorously than the other three. The number of blossoms of Red tangerine +Trifoliate was larger than the other three too. Difference in chlorophyll a/b and carotenoid content showed insignificance among all rootstocks. Different rootstocks remarkably influenced all contents of chlorophyll. Rootstocks obviously influenced the tendencies of the annual changes in the contents of the soluble sugar and the starch in leaves. During the dormant period, Red tangerine+ Trifoliate had higher content of the soluble sugar and the starch in leaves, and Red tangerine+ Rough lemon was to the contrary. During the growing period, Red tangerine+ Rough lemon had the lowest contents of the soluble sugar and the starch in leaves, and Red tangerine+ Trifoliate was between 2 sexual hybrids. The utilizations potential of these two somatic hybrids were discussed intensively.
Abstract:
The effects of medium concentration on callus growth and the accumulation of chlorogenic acid and flavonoids of Eucommia ulmoides were investigated. The treatments were designed in B5 medium supplemented with 0.5 mg/L NAA + 0.5 mg/L BA.The results showed that the callus growth was increased when KNO3 content was increased,whereas chlorogenic acid and flavonoids contents were highest when KNO3 concentration was 2/3 of original amount in B5 medium.The 4/3 content of (NH4)2SO4 in B5 medium were best for the callus growth and flavonoids content and yield, whereas chlorogenic acid content was highest when (NH4)2SO4 content was 1/3 of original amount in B5 medium.The callus growth was highest when MgSO4 concentration was 2/3,whereas chlorogenic acid and flavonoids contents were highest when MgSO4 content was 1/3 in B5 medium. The original content of NaH2PO4,CaCl2 and MnSO4 in B5 medium were best for the callus growth and the accumulation of chlorogenic acid and flavonoids. The contents of ZnSO4 and FeSO4 in B5 medium was best for the callus growth but chlorogenic acid and flavonoids contents was highest when ZnSO4 and FeSO4 concentration was 1/3 in B5 medium.
Abstract:
The preparation of mataphase chromosomes and DNA fibres of rice is the key technique in the research of rice genome structure. However these techniques are still in deficiency at present. In this study, a method to prepare metaphase chromosomes with high efficiency was deve-lopped in rice. In the chromosome slides prepared using this method, there were mass of metaphase cells, less impurity, clear background, well dispersed chromosomes and well presered chromosome morphologies. The mitotic index of root cells is up to 25%. We also established a DNA fibres preparing method. Since cell wall is a main abstacle in the preparation of DNA fibres, thus nuclei ware isolated by chopping first, then lysed by SDS to release DNA, and DNA fibers were prepared by drawing DNA using a cover side. DNA fibres prepared by this method showed equally spread parallel thread with clear background, and were suitable for in situ hybridization analysis. The highly efficient methods to prepare rice metaphase chromosomes and DNA fibres will surely accelerate rice genome mapping and organization analysis.
Abstract:
The spore germination and gametophyte development of 21 ferns are studied. It indicates that:①the development period of prothallium and young sporophyte of the same species is different due to seeding time of spores; ②the optimal temperatures of spores germination and gametophyte development of 21 ferns are about 15-24℃; ③the rate of spore germination of rare ferns is much lower than the ferns which occur large populations in nature; ④the treatment with GA3 can accelerate the germination of the spores; ⑤the prothallium changes from large to small, green to yellow when young sporophyte comes out. The prothalliums of all 21 ferns die away after the appear of the 3rd leaf of sporophytes; ⑥shapes of the 1st and 2nd leaves of the young sporophyte are different from those emerged later; ⑦spores cultured in dark can not germinate; ⑧a prothallium can develop only one young sporophyte though it has many archegoniums, and the spore propagation with leaf mould substrate is an economical method.