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1993  Vol. 11  No. 4

Abstract:
In the present paper, the chromosome numbers and karyotypes of 12 species of 6 genera berry plants, including Rubus, Ribes, Vaccinium, Hippophae, Sambucus and Schisandra were reported. The chromosome numbers of R. cragaegifolius, R. komarovii and R. burejense were reported for the first time.
Abstract:
The wild Echinochloa plants are representative weeds in rice field, agronomists have tried to elucidate their morphological and ecological characteristics. But the cytological study is still lacking. This paper deals with the chromosome morphology of 7 spcies and varieties of this genus.This study showed that the chromosome numbers of root tip cells in the analysed species of Echinoloa were 2n=36 or 54. The karyotypes in the analysed 6 species were as follows:E. crus var. crusgailli 2n=54=48m+6sm; E. crus var. zelayensis (H. B. K.) Hitchc 2n=54=42m(2SAT)+12sm(4SAT); E. crus var. mitis (Pursh) Peterm 2n=36=24m+12sm(2SAT); E. cruspavonis (H. B. K.) Schult 2n=36=34m+2sm(2SAT); E. caudata Roshev 2n=54=42m+12sm(4SAT); E. hispidula (Retz.) Nees 2n=36=24m(2SAT)+10sm; E. glabrescens Munro ex Hook. f. 2n=54=44m(4SAT)+10sm(2SAT); E. oryzoides (Ard) Fritsch 2n=54=48m+6sm(2SAT). The chromosome numbers and the karyotypes of these species and varieties were reported in China for the first time.
Abstract:
In this paper the methods of quantitative description and treatment of six kinds fundamental characteristics of flora was establishedas follows:1. Floristic abundance Aiq=niq/Mq (1)2. Floristic resemblance Riq=a(iq)/Mq (2)3. Floristic acientness Oiq=(niqu/niq)/(mqu/Mq) (3)4. Floristic growth of speciation Siq=(niq-1/niq)/(Mq-1/Mq) (4)5. Complex of floristic elements Fiqp=(niqp/niq)/(Mqp/Mq) (5)6. Endemicity of floristie elements Eiq=(eiq/niq/(eq/Mq) (6)Secondary, the fuzzy mathematical methods of comprehensive judgement which had been used for the integrative comparison and evaluation of six kinds quantitative targets on the fundamental characteristics of flora was introduced. The integrative expressive formula of parameter on the fundamental characteristics of flora was established as follows:di=f(d1i, d2i, d3i) (i≤t) (7)Last, based on the analysising of the spermatophyte floristic fundamental characteristics of 3 single flora, the applied circumstance of the integrative expressive formula of parameter on the fundamental characteristics of flora was discussed. The results was in correspondence with the paracticable circumstances.
Abstract:
Based on our studies, some results about the flora geography in Mount Bei of Jinhua in Zhejiang Province are summaries as follows: 1. There are 140 families, 519 genera and 1052 species of seed plants; 2. The floristic elements are very complex and varied, originating 14 geographical elements, the temperate, tropical and subtropical elements comprise the greatest proportion of the flora; 3. Fuzzy cluster analysis can be used to compare the floristic relationship among different regions.
Abstract:
Zhuxi is in the west part of Huhei, situatcd at 31°31′—32°29′N, 109°29′—110°08′E. It belongs to evergreen and deciduous broadleaved mixed forest. There are 863 taxa (including subspecies and varieties) in 483 genera, 127 families of seed plants (in which 42.59% are woody plants) in this area. The floristic geographical elements of the flora in Zhuxi are very complex and interlacked. They are widely in connection with the flora of the world, with an ancient floritic origion as well as the majority of temperate elements and a lot of tropical elements. The decisive elements of the flora in this area belong to the subtrapics various in types of vegetation. The chief vegetation-types in Zhuxi can be divided into 7 vegetation-type groups, 10 vegetation-types and 49 formations.Yunwuxi is located in the central South of Zhuxi. The data of the investigation indicated that Yunwuxi was a typical and representative place in the vegetation of Zhuxi, and one of the best and complete conservative areas of the Northern subtropical zone. There are many rare and threatened plants and endemic species in which some relatively gather into one formation in Yunwuxi. Yunwuxi is a comprehersive and valuable place to be protected and an ideal place to set up natural protective area.
Abstract:
The stratal species diversity of the secondary serial communities of the evergreen broadleaved forests in Jinyun Mountain is measured by the method of a grid contiguous quadrat along a transection. From the stratal diversity-area curves it is illustrated that the species richness (S) is higher, but the equitability and individual density are lower, and the minium diversity area size is also larger, and that the HA and HN-area curves are similar to S-curve and relatively flatten, while the HC and HD-area curves somewhat fluctuate. HN and HA in terms of individuals and abandance of species could express the information content of diversity for communities. It is statistically shown that the variability of diversity for communities with higher J is lower, while those with smaller J is higher. During succession, S of each stratum increases constantly; J is higher and H is associated positively with S at the initial phase of the shrub and herb strata, and later J decreases and H relates to J positively. However, H of tree stratum is always not negatively correlated to J. Mainly the variation in the life form composition are characterized by the decreasing of herbs, particularly of annuals, and by the decreasing of tree species, both in tha amount and in the role played in the communities. The diversity of climax communities situated in diffrent sites differenetiates according to the reducing sequence from herb to shrub to tree strata. The dominance-diversity curves based on Ⅳ could be represented from a straight line with no steep slope p ogressively to a typical sigmoid curve. Two questions, on the measurement of diversity and on the stability-diversity during succession, are also discussed in detail.
Abstract:
In this paper, the forest community in Huoshan mountain, Shanxi was studied using the method of Principal Component Analysis (PCA) ordination. 105 plots used in the sequencing regularity of the community was analysed with the environmental gradient. It was proved that PCA method was applicable to the study of the aestatisilvaes.
Abstract:
This paper reported the changes of cell membrane permeability, process of cell physiological metabolism and some macromolecules and enzymes.The determined results of conductance and K+ consistency of leaky solution from leaves indicated that great quantity of electrolyte in leaf cells had leaked and the membrane permeability had dramatically increased under 0℃. When electrolyte greatly leaked, serious injury symptoms had occured outside of plants.After treatment with low temperature, the content of soluble sugar and free proline accumulated in leaf cells of Eichhorina crassipes as the protective matter of the chilling injury, but no obvious changes were determined about soluble protein content.The peroxidase activity decreased and its isoenzme electrophoretograms increased 1—4 bands, CAT activity inereased clearly and its isoenzyme electrophoretograms increased 1—2 bands, and SOD activity decreased slightly and its isoenzyme electrophoretograms increased 1 band after treatment under 0℃ for 36 hours. The dehydrogenase activity in plant roots decreased.
Abstract:
Experimental matcrial used was jackfruit (Artocarpus heterophgllus Lam.) seed collected in Xinyi County in Guangdong. The moisture content of newly harvested jackfruit seed was around 58.6%. As water content of seeds declined, germination percentage and germination index decreased. Jackfruit seed is very sensitive to desiccation and is defined as a typical recalcitrant seed. When seeds were naturally desiccated, the activity of superoxide dismutase (SOD) in embryonic axes and cotyledons first incresed, and then rapidly decreased. The contents of malonaldehyde (MDA) and lipid hydroperoxide rose dramatically. The reason why jackfruit Seeds were sensitive to desiccation could be that activity of SOD which is a protective enzyme in plant dropped, and that the peroxidation of membrane-lipid was accelerated. Therefore, the structure and function of membrane were damaged, and then seed viability lost.
Abstract:
In the present report, we studied the organogenesis in culture in vitro of hypocotyl and cotyledon explants and cotyledon protolasts of Medicago hispida and also studied transformation of the cotyledon explants and protoplasts of M. hispida mediated by Agrobacterium tumefaciens. When the explants were cultured on MS medium supplemented with IAA 0.5—1mg/L and cytokinin (BA or ZT) 0.5—2mg/L, the shoots differentiated from the explant-derived calli in condition of light (25℃; 12h/day) at 30—40 days of culture and further developed to form intact plantlets after they were subcultured on the same medium composition. The purified protoplasts isolated from cotyledons of M. hispida were cultured in B5 liquid medium containing 2,4-D 0.5mg/L and KT 0.2mg/L. It was observed that the division frequency of the cells was about 30—41%. The shoots were induced from protoplast-derived calli after they were transferred and subcultured onto MSB medium. Using the method of co-cultivation, cotyledon explants and protoplast-derived cells of M. hispida were transformed by Agrobacterium tumefaciens strains PGV 2260 (pBI 121) or C58Cl (pBZ 6111), and transformants were abtained. Enzyme activity of GUS and NOS assay demonstrated that foreign genes expressed in the transformed plants and calli.
Abstract:
The trichome of the blue-green alge Anabaena azotica was suspended in 0.5mol K3PO4, 7% or 36—38% Formalin, 70% or 95%alcohol, glacial acetic acid, or the trichome suspension boiled or passed a autoclave (in 15 pounds for 15 minutes). The treated trichome discoloured immidiarely and became inactive, However, the inactive trichome could move and aggregate to the direction from light irradiation. But in 1mol NaOH or HCl they lost its moving ability. Inactive trichome or cells of Spirulina Platensis, Anabaenopsis elenkini and Anacystis nidulans have also had phototaxis.
Abstract:
This paper reports the fundamental information about the natural condition, flora plant resources, precious and rare protective plants, old tree resources and the specific plants in the three gorges region, and indicates the necessity and probility to construct the botanical garden in the three gorges reservoir region. In the same time, the task, feature, plan and design of the botanical garden are given.