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以小流域为单元进行水土流失综合治理,是具有中国特色的水土保持治理技术。利用3S技术建立小流域管理数字化信息系统,是以遥感影像为背景,确定集水区域,以山脊为界,面积控制在10～20km~2,同时考虑行政边界,在计算机上,以地理信息软件为技术平台,绘制小流域边界,并输入18位小流域编码。根据管理需要,按市、县、乡、按流域、按水库上游等各种管理方式绘制成若干种小流域图,为各级水土保持管理部门提供服务,提高水保工作的管理水平,为领导决策提供重要的依据。 相似文献
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Action of atrazine, chlortoluron and MCPA on the pyrovate, oxalacetate, cetoglutarate, glutamate and glutamine content in the leaves and roots of cucumber (Cucumis sativus) Lethal rates of atrazine, chlortoluron and MCPA were administered to 17-day old cucumber seedlings growing in a nutrient solution. The ketonic acid, glutamate and glutamine composition of the leaves and roots was determined after intervals of 1–4 days. Two days after application of photosynthesis-inhibiting herbicides, the ketoglutarate, oxaloacetate, pyruvate, glutamate and glutamine content of the leaves was 11–20%; 30–54%; 43–50%; 101–112% and 49–65% respectively, compared with the controls. After 4 days it was 16–22%; 31–56%; 26–42%; 71–75% and 180–205%. In the roots, the glutamate decreased in the same proportion as the ketoglutarate while the glutamine increased the first 2 days and decreased on the fourth day. The MCPA treatment did not modify the cetoglutarate concentration in the leaves but increased it from 300 to 800% in the roots. Simultaneous analysis of ketoglutarate and glutamate can be used to identify the nature of a herbicide treatment. 相似文献
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Modification of the content of ATP. glucose, fructose and saccharose in cucumber plants (Cucumis sativus) under the action of various herbicides. Lethal doses of atrazine, MCPA, diehlobenil, alachlor and paraquat, applied over 3 days through the roots and/or through the leaves showed that the phytotoxicity of herbicides is not necessarily linked with a decrease in ATP. Atrazine, administered through the roots, led to a decrease of 57–88% in the glucose and fructose and from 70 to 97% in the saccharose in the leaves. In the roots the losses were 14–60% and 33–96%, respectively. The glucoside losses were even more markeu when atrazine was applied through the leaves. After treatment with MCPA, the glucose in the leaves increased by 150 to 420%, fructose by 160 to 450%, while saccharose fell by 20–39%. Alachlor decreased the reducing sugars in the leaves and increased them in the roots. Diehlobenil caused a drop in leaf glucides the first two days and a rise on the third day. The authors suggest some formulae by which the nature of the herbicides could be expressed in terms of their relationship to the content of these constituents. 相似文献
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稻瘟病菌在水稻CO39近等基因系上的生命表和繁殖表 总被引：1，自引：0，他引：1
本文选用以CO39为背景的水稻近等基因系与广东省稻瘟病菌3个优势生理小种(ZC13、ZB1和ZB5)构成12个亲和性和非亲和性互作组合,组建各组合稻瘟病菌的生命表和繁殖表,分析在亲和性互作中稻瘟病菌的生存和繁殖状况对寄主发病的影响,并探讨在非亲和性互作中抗性基因在抵御病菌侵染过程中的作用。结果表明,在亲和性和非亲和性互作中,稻瘟病菌生长繁殖各阶段均参与了感抗反应并发挥了一定的作用:在CO39近等基因系上,同一小种的孢子萌发率或菌丝形成率无明显差别,而小种间则表现一定差异;病菌的定殖和繁殖是亲和与非亲和互作的关键阶段,定殖率、病斑形成率低,则寄主表现抗病,反之则表现感病。在繁殖表众多表示种群增长的参数中,世代平均产孢量F'、净增殖率R0、最大相对增长率rmax和种群趋势指数Ⅰ等4个指标适合于反映稻瘟病菌繁殖状况与感抗病反应的关系。 相似文献
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