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2000  Vol. 18  No. 1

Abstract:
This paper deals with anatomical characteristics and microscopic constant numbers of 11 species and one variety of folk medicinal Swertia, which distribute in the regions from Hubei and Tibet of China to Toyama and Tokyo of Japan through Nepal.The waviness of the anticlinal walls and the ratio of the Feret′s diameter of the epidermal cells in the leaves are detected with the Image Analyze System (Olympus Optical Co. Ltd and Nippon Avionics, SP-500 SET) through the treatment of binarization.These taxa could be distinguished from each other by the characteristics such as types of vascular bundles, number of palisade cell layers, distribution of needle crystals and stomata, stomatal index, palisade ratio, ratio of Feret′s diameter and waviness of the anticlinal walls of the adaxial epidermal cells in leaves, etc.The results, especially application of Image Analyze System, provide a new method for identifying the botanical origin of crude leaf and herb drugs.
Abstract:
The functional leaves of in vitro screened somaclonal variants (Jing 3037Rand Jing 105R) resistant to Xanthomonas oryzae were inoculated with X.oryzae strain Zhe173.The observation of the leaves after72 h inoculation by means of scanning electronic microscopy(SEM) showed that Jing 30 37Rand Jing 1 05Rhad far fewer bacterial numbers around the water pores than Jing 3037Sand Jing 105S. This resultsupported that the infection path of X.oryzae to rice leaves was through the water pores into the vascular tissues and also confirmed that in vitro screened somaclonal variants(Jing 3037Rand Jing 105R) had stable resistance in plantlet level to X.oryzae.
Abstract:
The distribution of oil cells in the leaves of14species of Magnoliaceae was studied with tissue clearing and paraffin sectioning.The results are as follows:oil cells are round or elliptical in shape, their diameters are from30 μm to50 μm.From leaves cleared, oil cells are distributed in areole in most species and on the vein in some species.The oil cells in 5 species are in contact with veinlet termini.From the cross sections of leaves, there are three types of distribution of oil cells.First, oil cells are dispersed in the whole mesophyll in 8 species.Second, oil cells consist in palisade tissues between palisade tissue and spongy tissue in 3 species.Third, oil cells are distributed in spongy tissues, between palisade tissue and spongy tissue in other3species.Furthermore, some oil cells in the leaves of4species are in contact with epidermis.The lysigenous cavities from oil cells are found in the leaves of4species.
Abstract:
The tapetum- promoter(CA55) was amplified from the total DNAof Zea mays L.by polymerase chain reaction, and was fused with barnase(BN) and barstar(BS) genes, respectively.The male sterile gene.CA55BNNOSand its fertility restoration gene CA55BSNOSwere construced.They were cloned into p CAMBIA3300, respectively.The expression vectors for cereal male sterility and its fertility restoration were obtained.
Abstract:
The resultsofthe experimentwhich the differentconcentrationsofcalmodulin antagonist—— CPZwere supplied to 1/2 Hoagland cultural solution showed that CPZinhibited the uptake of nitrate and its transformation into organic nitrogen in wheat seedlings, and the root was more sensitive to CPZthan the leaf.This coincided with the variations of nitrate reductase and glutamine synthetase activities in the same organ in wheatseedlings under the treatmentof CPZ.Finally, CPZresulted in the decrease of dry weight of root and upground parts of wheat seedlings.CPZcaused the increase of total calcium content in wheat seedlings.The results indicated thatcalmodulin, as a memberofthe second messengersystem, probably plays an important role in regulation of nitrogen assimilation in plants.
Abstract:
The floral composition and the higher plant species diversity of the Heptacodium miconioides community in the Tiantai Mountain of Zhejiang Province were analyzed.According to the statistics of nine plots, there are altogether69families of seed plants(including varieties) which can be subdivided into 186species, 143genus.Most of them are distributed in the temperate zone in terms of the geographic composition of seed plant genera.In the vertical structure of community, both the species richness and species diversity index of the second sublayer of tree layer are much greater than those of the first sublayer, and their evenness is of slight different significance.The various indexes of diversity between the tree layer and the shrub layer have slight differences.The species richness and species diversity index of the tree layer and shrub layer are obviously bigger than those of the herb layer.The Heptacodium miconioides community has a high composition diversity of species, genus and family, the community has a great variety of plants whose composition is complex.
Abstract:
Amethod for constructing a community for ex situ conservation of the rare and endangered plants in the Three Gorge Reservoir Area was proposed.The principles and methods of choosing habitat and determining area, species component and community structure were discussed.According to the results of investigation of the archaic and relict communities of the rare and endangered plants in the Three Gorge Reservoir Area and its adjacent area, a community for ex situ conservation in a unique habitat of Jiugongshan Nature Reserve was designed.The community area was about 300 0 m2 and dominant species were Davidia involucrata, Dipteronia sinensis, Tetracentron sinensis and Tapiscia sinensis.There were35species of the rare and endangered plants of the Three Gorge Reservoir Area and more than 70 species of other plants in the community.The community structure and the patterns of plants populations will be developed step by step with the growth of the plants in the community.
Abstract:
According to incomplete statistics, there are about 52 rare and endangered species in Chongqing, comparing to China, the proportion is13%.According to different principles, there are3 pteridophyte species and14gymnosperm species and35angiosperm species;5first- protection species and 23second- protection species and 24 third- protection species;5endangered species and 22 rare species and25threatened species among 52 species.Comparing to China, there proportion are23.1%, 19.7%, 11.5%, 62.5%, 14.5%, 10.8% ;4.1%, 20.0%, 15.9%, respectively.Chongqing also owns 28 rare and endangered species that will be published in a short time.
Abstract:
Field expeditions of Rubusresources were carried out in Yunnan Province from 1996 to 1997. One new species, 5new varieties and6species, 5varieties of new distribution have been found in the wild.According to our collections and the information by predecessors as well, it is totally about 107 species and 45varieties of Rubusfound here, among them 30 species and 16varieties endemic to Yunnan Province, 28species and 10 varieties endemic to SW China.It was also found that the Rubus species are more concentrated in the SEand Wparts of the province.The distribution and diversity of Rubus resources were reported and some valuable germplasms such as Rubus ellipticus var.obcordatus were recommanded.