Effect of Osmotic Stress with PEG6000 on Osmotic Adjustment Solute in Seedling Leaves of Chenopodium album L.

[ Objective] The purpose was to discuss drought resistance mechanism of Chenopodium album L. and supply theoretical basis and practical guidance for artificial cultivation and popularization of C. album. [ Method] C. album seedlings grown to 6th leaf stage were conducted osmotic stress treatment with PEG6000 osmotic whose concentration was set up as 0, 5%, 10% and 20% and the various physiological indices of the 3rd -5th function leaves in upper plant were determined after being treated for 0, 1,3, 5, 7 and 9 d. [ Result] Under osmotic stress with 5% PGE, the relative water content （RWC） of C. album reduced less. Under osmotic stress with 10%, the RWC in seedling leaves of C. album decreased to 62% on the fifth day and the leaves began to wither. Under osmotic stress with 20%, the RWC in seedling leaves of C. album decreased to 61.9% on the third day and the leaves appeared withering, and the RWC decreased to 48.6% on the 7th day and the leaves were dry and yellow. Proline contents in seedling leaves of C. album under osmotic stress with 5%, 10% and 20% PEG were 7.64, 10.9 and 29.4 times of CK on the 7th day. [ Conclusion] C. album hed some adaptability to moderate osmotic stress, but the PEG osmotic stress with high concentration and long time might lead to severe damage on C. album.

Risk Communication： Survey on Quality of Safety Data Sheets of Agricultural Substances

Manufacturers of chemicals are responsible for setting up a list of tools, including labels and safety data sheets, in order to provide adequate information about dangerous properties being labels and safety data sheets the main instruments for the immediate advice about dangerous substances and preparations for general public and workers. While correct labelling gives the possibility to general public to recognise the risks arising from handling and use of dangerous chemicals, safety data sheets are provided for professionals in order to allow safe handling and storage of dangerous chemicals in work places. Information contained in safety data sheets are also designed to suggest safety measures to be taken for the protection of workers as well as precaution measures and adequate actions to be taken in the case of accident. This project has critically revised the information contained in a list of safety data sheets of active ingredients provided for plant protection products, in order to assess the quality and the consistency of the data contained. Reported data have been then compared to published data. Considerable deficiencies/mistakes/inconsistencies have been found in the data reported along the safety data sheets of the examined substances, showing an urgent need of improving the enforcement related to a systematic recognition in this field as well as training of people involved in compilation of safety data sheets by producer side.

XU Xiaohui,CHEN Hui'e and WANG Gangcheng College of Construction Engineering,Jilin University,Changchun 130026,China

On the basis of geological investigating work and experimental studies on slide zone soil of one landslide in Tibet,the authors analyzed granulometric composition,clay mineral composition and physical and mechanical properties for the soil in the slide zone.The soil samples are gravel containing fine particle.Particles larger than 2 mm occupy the main proportion with the content 51.5%--68.5%.The relative content of clay minerals is low.The clay minerals are illite smectite mixed layer and kaolinite,and their relative contents are 6%--13% and 4%-11%,respectively.The main mineral ingredient is quartz and the relative content is over 30%.Therefore,the soil’s hydrophily is poor.The cohesion and internal friction angle are high,causing preferable physical-mechanical features of slide zone soil.On the basis of the obtained data,the landslide stability is evaluated by means of limit equilibrium method.The safety factors are 3.191 and 1.92 respectively under both natural and normal water level conditions.The study results show that the landslide is stable.It can provide the appropriate basis and reference for landslide stability evaluation and landslide control in Tibet.