在甘肃省玉米生产中存在长期过量施用氮肥的问题,导致农产品品质下降、地下水污染、耕地土壤质量退化等问题,土壤线虫作为指示生物能在一定程度上反映出土壤生态系统的质量状况.在甘肃省榆中县玉米田进行了0(CK)、5、10、15 g N/(m2·a)4个不同施氮水平的处理,分析了各处理对土壤线虫群落的多度、属丰富度、成熟度指数、富集指数、结构指数等生态指数及复合代谢足迹的影响.采用非度量多维尺度法分析了土壤线虫的群落组成情况,并采用置换多元方差分析检验了不同施氮处理间土壤线虫群落组成的差异.结果表明,适量施氮使线虫的总多度、食细菌线虫和植食线虫的多度显著增加,使食真菌线虫和杂食捕食线虫多度显著减少,进而导致线虫群落的组成发生了显著性变化,同时也使线虫群落的属丰富度显著降低.此外,随着施氮水平的逐渐增加,线虫的体型呈逐渐减小趋势,基础指数显著升高,结构指数、成熟度指数、复合代谢足迹显著降低,反映出施氮后线虫群落逐渐不稳定,施氮导致土壤食物网的连通性降低、食物链变短,食物网分解途径由以真菌途径为主转变为以细菌途径为主,食物网能量流动总体变慢.

基于云班课的SPOC课程在高职院校植物保护教学实践中开展了教学资源库的建设,构建了基于蓝墨云班课的植物保护课程的教学模式,通过签到、授课、测试等线上线下混合式教学活动,并对教学效果进行了分析.结果 表明:蓝墨云班课为学生搭建了学习平台,激发了学习兴趣,有效地提高了学生的综合学习能力,提高了植物保护技术课程的教学效果.

The application of Koch's postulates confirms the pathogenicity of A. alternata(Fr.)Keissler in Trifolium repens Linn of which leaves are used as test materials in the experiment. In PDA medium,at six different treatment temperature of 15、20、25、30、35、40℃,under the pH value of 5、6、7、8、9,A. alternate (Fr.)Keissler have been cultured for seven days at constant temperature. The result shows that under the treatment of 25 ℃,colony growth is the fastest and average diameter is 7.1 cm;and at pH 6 colony growth is the fastest and average diameter is 9.0 cm.

近年来，随着人们生活水平的不断提高，人们对吃的食物也有了更高的要求。蔬菜作为一种生活必需品也逐渐向绿色无污染、有机蔬菜等方向发展，现代化的蔬菜大棚种植技术在我国农业生产中也得到了广泛的应用和发展。基于此，通过介绍大棚蔬菜种植技术的含义及相关优势，提出大棚蔬菜种植技术对人们的生活所产生的重要影响。

The experiment researches into the influence of the different proportion of furfural residue and vermiculite mixture as cultivation matrix on potato minituber.The results showed that compared with CK,vermiculite（25∶1） makes roor length increase by 0.9 cm and makes stolons number increase by one,so it is the most useful way for the development of potato minituber.

The growth dynamics of Sophora flavescens from different sources which were Chengde City,Hebei Province,Lushi County,Henan Province,Min County and Cheng County,Gansu Province,were studied.The results showed a similar growth dynamics of stem,leaves and root for different source germplasms.The highest number of leaf and leaf dry weight were observed in late August,and for the roots,it appeared in the late October.However,significant differences in terms of biomass among five source germplasms were observed.S.flavescens from Chengde City attained the lowest stem height but the highest root dry weight compared with the others.A relative higher leaf growth rate in the earlier stage and earlier defoliation in the late stage was also observed in Chengde City germplasm,which indicated its early-maturing characteristics.The germplasms from Gansu provience attained the highest plant height with plenty leaves,intermediate production,later defoliation which indicated its late-maturing characteritics.The germplasm from Lushi County,Henan Province attained the lowest production.

<正>苦参(Sophora flavescensAi)t为豆科槐属植物,是我国传统药用植物。苦参的根为常用中药材,有明显的抗菌、消炎、杀虫作用。除在医药上被广泛应用外,近年来又被广泛用于生物农药的开发,随着对苦参中提取的苦参碱应用研究的突破,苦参用量逐渐加大。但是苦参种子一般于10月中下旬成熟,

The experiment was conducted to study the effect of potassium(K) on growth,total alkaloids concentration and total alkaloids yield of Sophora flavescens.The four levels of K applied were K2O 0(Control),15,60,240 mg /kg using potassium sulfate(K2O 50%) fertilizer in pot experiment.Statistical analysis showed that stem height,root fresh weight,root dry weight,chlorophyll(Chl) concentration,total alkaloids concentration and total alkaloids yield of Sophora flavescens were increased significantly with K applied.The root fresh weight was increased by 14%with 60 mg/kg K2O applied compared with the control.The root dry weight was increased by 8.6%with 60 mg/kg K2O applied compared with the control.Chl concentration,total alkaloids concentration were increased with K applied.Chl concentration was the highest with 60 mg/kg K applied,increased by 5.6% compared with the control.Total alkaloids concentration was the highest also with 60 mg/kg K2O applied,increased by 38.7% compared with the control.The total alkaloids yield per plant was the highest with 60 mg/kg K2O applied,increased by 50.5% compared with the control.It was considered that the positive effect of potassium on root dry weight was due to the positive effect on main root dry weight,and total alkaloids concentration was increased with K applied by improving Chl concentration.

本文通过对距枸杞树不同距离和不同深度的土壤的可溶性盐分及盐离子的研究,结果表明:3年生枸杞地土壤可溶性盐分较荒地土壤可溶性盐分有较明显的降幅,0～10cm土层中,距枸杞树干30cm、60cm、90cm处分别比荒地的1.30%下降0.72,0.77和0.84个百分点。随土壤深度的增加,Cl-含量呈下降趋势。显然,栽植枸杞对改良盐碱地具有重要的意义。