施钾对苜蓿苗期根冠生长及其抗蓟马的影响  

Effects of potassium application on root crown growth of alfalfa and its resistance to thrips at seedling stage

作　　者：周生英 刘艳君 刘宁云 温雅洁 胡桂馨[1] ZHOU Shengying;LIU Yanjun;LIU Ningyun;WEN Yajie;HU Guixin(Paracultural College,Gansu Agricultural University,Engineering and Technology Research Center for Alpine Ro-dent Pest Control National Forestry and Grassland,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院,国家林业和草原局高寒草地鼠害防控工程技术研究中心,甘肃兰州730070

出　　处：《甘肃农业大学学报》2023年第1期173-181,共9页Journal of Gansu Agricultural University

基　　金：国家自然科学基金项目(31960350);甘肃省自然科学基金项目(20JR5RA021)。

摘　　要：【目的】探索施钾对苜蓿根冠生长与苜蓿抗蓟马的影响。【方法】选用甘农3号紫花苜蓿(Medicago sativa Gannong No.3)(G3)和甘农9号紫花苜蓿(M.sativa Gannong No.9)(G9)为材料,以牛角花齿蓟马(Odontothrips loti)为研究对象,在网室盆栽条件下,设置0.4、0.6、0.8、1.2 g(K_(2)O)/10 kg土4个钾处理,以不施钾为对照,评价了不同钾处理下苜蓿的受害程度,并测定了两个苜蓿品种的根冠植物学特性和生物量变化。【结果】施钾后,苜蓿的受害指数显著下降,苜蓿的叶面积增大、株高升高、分枝数和侧根数增多,茎粗、根颈直径和主根直径增粗,根、茎和叶的生物量显著增加。受害14 d,G3和G9叶生物量在K_(2)处理最大,分别为0.1129 g和0.1186 g;茎和根生物量在K_(3)处理最大,分别为0.1197 g、0.1048 g和0.1217 g、0.1084 g;叶、茎和根生物量的增加率大小依次为根>茎>叶,根冠比随施钾量的增加而增加。受害21 d,G3和G9茎生物量在K_(3)处理最大,分别为0.1571 g和0.1595 g;叶和根的生物量在K_(2)处理下最大,分别为0.1461 g、0.1597 g和0.1512 g、0.1699 g;叶、茎和根生物量的增加率为根>叶>茎,根冠比随施钾量的增加呈先上升后下降的趋势,在K_(2)处理最大。【结论】在受害程度中等情况下,钾元素促进苜蓿的干物质向贮藏器官(根和茎)分配,以产生补偿生长,而随着受害加重,钾元素调控干物质更多向贮藏器官和光合器官(根和叶)分配,以维持苜蓿的生存并增强了苜蓿对蓟马的耐害性。施钾后,抗蓟马苜蓿甘农9号对蓟马的耐害表现较好,但感蓟马苜蓿甘农3号的施钾效应高于甘农9号。本试验中,K_(2)(0.6g(K_(2)O)/10 kg土)是最佳施钾处理。【Objective】The study was conducted to explore the effect of potassium application on alfalfa root crown growth and its tolerance to thrips.【Method】Medicago sativa Gannong No.3 and M.sativa Gannong No.9 alfalfa varieties were chosen as experimental materials,and Odontothrips loti was selected as research object,four levels of potassium application were set,i.e.,0.4 g,0.6,0.8 g and 1.2(K_(2)O)g/10 kg soil,with no-potassium application as the control.The damage indexes of alfalfa were evaluated,and the botanical characteristics and biomass were measured under different potassium application levels.【Result】The damage indexes of two alfalfa varieties decreased significantly with potassium application amount increasing,meanwhile the leaf area,plant height,the number of branch and primary lateral root all increased,and the diameter of stem,root collar and taproot were thickened and the biomass of roots,stems and leaves of both varieties increased significantly.The leave’s biomass of K_(2) treatment was the highest 14 days after infestation by O.loti,which of G3 and G9 were 0.1129 g and 0.1186 g,respectively.The total biomass of stems and roots were the highest for K_(3) treatment,which were 0.1197 g,0.1048 g for G3 and 0.1217 g,0.1084 g for G9,respectively.The rate of increase in leaves,stems and roots biomass ranked as following:root>stem>leaf,and the ratio of root to shoot increased with increased potassium application.Twentyone days after infestation by O.loti,the stem biomass was the highest for K_(3) treatment,which of G3 and G9 were 0.1571 g and 0.1595 g,respectively;and the biomass of leaves and roots were the highest for K_(2) treatment,which were 0.1461 g and 0.1597 g for G3,and 0.1512 g and 0.1699 g for G9,respectively.The rate of increase in leaves,stems and roots biomass ranked as following:root>leaf>stem,and the ratio of root to shoot increased firstly and then decreased with increased potassium application,which for K_(2) treatment reached the maximum.【Conclusion】Potassium application pro

关 键 词：钾 牛角花齿蓟马 苜蓿 植物学特性 生物量分配 耐害性 

分 类 号：S431.14[农业科学—农业昆虫与害虫防治]