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在本实验室前期工作中,发现生长于青藏高原的有毒植物瑞香狼毒对菜青虫具有较好的防治效果.采用微量点滴法研究瑞香狼毒素对菜青虫的触杀活性,以叶片夹毒法和灌喂法研究胃毒活性.在触杀活性试验中,72h的致死中量(LD50)为0.96μg/头,以6.25×103mg·L-1浓度的样品液2μL点滴试虫,即1.25×10μg/头处理组的72h校正死亡率为92.2%.在胃毒活性试验中,72h叶片夹毒法的致死中浓度(LC50)为3.82×103mg·L-1,5.00×104 mg·L-1浓度处理组校正死亡率为91.2%;72h灌喂法的LD50为3.80μg/头,以5.00×104mg·L-1浓度的样品液2μL灌喂试虫,即1.00×102μg/头的处理组的72h校正死亡率为96.8%.结果表明,瑞香狼毒素对菜青虫具有较好的触杀活性和一定的胃毒活性. 相似文献
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The relationship between plant species diversity and functional diversity in grassland will change with environmental changes. The plateau pika (Ochotona curzoniae) has an effect on the hydrothermal process of alpine meadow in its nesting area. However,it is not clear whether the disturbance of plateau pika effects the relationship between plant species diversity and functional diversity in alpine meadow. A random stratified and paired design was used to select plots in Luqu county in Gansu Province,and Qilian and Gonghe Counties in Qinghai Province and a field survey was conducted to investigate the effects of plateau pika disturbance on the relationship between plant species diversity and functional diversity of the alpine meadow. It was found that plateau pika disturbance significantly increased the plant species richness index and the species diversity index but did not significantly affect the species evenness index. Plateau pika disturbance significantly increased plant functional richness index (P< 0.05) but had no significant effect on the plant functional evenness index or the functional divergence index. With plateau pika disturbance effects,the relationship between plant functional richness index and species richness index changed from a logarithmic function to a quadratic function,and the relationship between plant functional evenness index and species evenness index changed from non-significant to significantly positive. In addition, positive correlations between functional richness index and species richness index,and functional richness index and species diversity index were significantly decreased,as were negative correlations between functional divergence index and species richness index,and functional divergence index and species diversity index were significantly decreased. The findings of this study provide basic information for understanding the mechanism of species coexistence of plant communities under plateau pika disturbance and help understanding of how plant diversity effects in an alpine meadow ecosystem function under plateau pika disturbance. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
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四川省天然草原生产力监测方法研究 总被引:1,自引:0,他引:1
采用定点监测与路线监测、地面调查与遥感监测相结合的方法,对四川全省范围内2006-2009年连续4年的地面调查数据进行统计分析;结合MODIS植被指数(EVI)进行相关性分析,按主要的草原类型(组)分别建立草原产量的估测模型。经过反复修正和验证,应用估产模型分组、分区域对2007-2009年3年的草原产量进行测算,全省3年平均可食鲜草单产为4 752 kg/hm2,总可食鲜草产量8.39×1010 kg,折合干草2.53×1010 kg,理论载畜量29.69×106羊单位。分析表明,采用该技术和估测模型进行草原监测,监测结果基本符合各地实际,适用于省、州级草原部门开展较大范围的草原监测工作。 相似文献
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5种杀菌剂对青贮玉米3种病害的田间防治效果 总被引:1,自引:0,他引:1
为有效防治青贮玉米Zea mays Linn.锈病、小斑病和大斑病, 筛选出低毒、无公害的高效防治杀菌剂, 选用哈茨木霉水分散粒剂(1亿cfu/g)、枯草芽孢杆菌可湿性粉剂(1 000亿孢子/g)、37%苯醚甲环唑水分散粒剂、15%三唑酮可湿性粉剂和80%代森锰锌可湿性粉剂5种杀菌剂进行田间药效试验。结果表明, 1亿cfu/g哈茨木霉WG对青贮玉米3种病害的田间防效最优, 37%苯醚甲环唑WG对小斑病的防效最好, 15%三唑酮WP对锈病的防效最理想, 80%代森锰锌WP对大斑病的防效最优。 相似文献
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为探讨混播比例和刈割时期对禾豆混播草地地上生物量和营养品质的影响,本研究设多花黑麦草100%(H)、75%多花黑麦草+25%箭筈豌豆(HJ1)、50%多花黑麦草+50%箭筈豌豆(HJ2)、25%多花黑麦草+75%箭筈豌豆(HJ3)与100%箭筈豌豆(J)5个处理,结果表明,混播比例可显著(P<0.05)影响分蘖/分枝数、粗蛋白含量、单茬/累计干物质产量、粗蛋白产量和可消化干物质产量,对株高、茎叶比、干物质含量、中性洗涤纤维含量、酸性洗涤纤维含量和可消化干物质含量无显著影响;刈割时期只对黑麦草分蘖数和单茬干物质产量无显著性影响,对其余指标有显著影响(P<0.05);混播比例与刈割时期对箭筈豌豆分枝数、茎叶比、粗蛋白含量、可消化干物质含量和累计干物质产量有交互效应(P<0.05)。混播组合HJ2累计干物质产量19 030.44kg·hm-2、累计粗蛋白产量3 130.66 kg·hm-2、累计可消化干物质产量13 214.14 kg·hm-2,为最佳混播组合。 相似文献
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