Germination pretreatment and storage behavior of Terminalia laxiflora seed     

Befkadu Mewded  Debissa Lemessa  Hailu Negussie  Abiyot Berhanu 《林业研究》2019,(4):1337-1342

Terminalia laxiflora Engl.&Diels.is an important indigenous and multi-purpose species in Ethiopia.However threatened due to low germination and its storage behavior is unknown.In this study,we aimed to(1)test pretreatments for breaking the dormancy of T.laxiflora seed and(2)determine its storage behavior.Seeds were subjected to four pretreatments such as soaking,scarification,high-temperature,and control.Experiments were done before storage and after 2 years of dry storage at cold temperature(-10℃)based on randomized design with four replicates.The first round of experimental results showed that T.laxiflora seeds with high temperature treatments at 78℃for 10 min showed significantly higher germination percentage(80%).In the second round experiment,high-temperature treatment at 78℃for15 min,cold water soaking,high-temperature treatment at78℃for 10 min,hot water soaking,and high-temperature treatment at 78℃for 5 min showed significantly higher germination percentage from the remaining treatments(75,64,58,56,and 53%,respectively).To break the dormancy of T.laxiflora seed and attain good germination result,seeds should be pretreated with high-temperature at 78℃for 10 min to test the initial germination before storage and should be pretreated with high-temperature(at 78℃for15,10,or 5 min),soaked in cold,or hot water for 24 h to monitor the germination after storage.The two experiments show that T.laxiflora produces orthodox seed.  相似文献   

苎麻单纤维断裂强力统计特征研究     

冷鹃  肖爱平  杨喜爱  程毅  廖丽萍  聂晴岚 《中国麻业》2014,(3):151-155

为了研究苎麻单纤维断裂强力的全貌与分布规律,通过采用等速伸长法测得其断裂强力,根据断裂强力的频数直方图的分布趋势,用正态分布的偏度、峰度等参数对其进行分析,用Q-Q图与Kolmogorov-Smirnov（以下简称K-S）检验法检验苎麻单纤维强力的正态性,总体上服从正态分布规律,但有一定偏差,不对称,为右偏尖峰态。同时提出了建立在统计基础上的苎麻单纤维断裂强力指标体系,即运用主体断裂强力、品质断裂强力、平均断裂强力、弱强纤维断裂强力和超强纤维强断裂力五个指标来表征单纤维断裂强力。  相似文献   

基于嵌入式电子监控器的马铃薯收获机开发     

付昱 《农机化研究》2022,44(5):83-87

为了实现马铃薯收获和地膜回收同时进行,基于嵌入式技术,设计了马铃薯收获机.在马铃薯挖掘和地膜回收过程,测试地膜厚度、工作速度、挖掘深度和铺放时间4个因素影响程度,进行四因素五水平试验.试验结果表明:地膜回收率影响主要因素为地膜厚度及工作速度;对伤薯率影响由大到小分别为挖掘深度、工作速度.同时,建立伤薯率和地膜回收率模型...  相似文献   

土壤表土中植物根系影响其抗蚀性的模拟降雨试验研究——以张家口试验区为例   总被引：9，自引：0，他引：9  

吴淑安  蔡强国 《干旱区资源与环境》1999,13(3):35-43

土壤中植物根系的存在可以增强土壤的抗蚀性,溅蚀量、贯入深度和被崩解的情况等都是土壤抗蚀性的反映。通过对人工添加根系、固有根系和缺少根系三种不同土壤类型,进行的溅蚀、贯入和崩解试验,发现具有植物根系的土壤,其崩解速率远比少根系或缺少根系的土壤为慢,而根系的多少则似乎与溅蚀、贯入不存在明显的关系,后者更多地取决于土壤的颗粒组成特性。  相似文献   

Type and time of autumn tillage with and without herbicides at reduced rates in southern Sweden: 2. Weed flora and diversity     

Ullalena Bostrm  Hkan Fogelfors 《Soil & Tillage Research》1999,50(3-4)

The design of integrated weed management (IWM) systems is essential in order to reduce the use of herbicides for crop production. By combining different weed management practices, herbicides may be used at lower doses than normally recommended, while still maintaining acceptable weed population levels. The purpose of this study was to develop tillage strategies, with and without herbicides at reduced rates, appropriate for different weed populations. The influences of type and time of stubble cultivation, harrowing and mouldboard ploughing on the weed flora were followed during 1988–1994 in eight long-term field trials situated in southern Sweden. Spring-sown barley (Hordeum distichon L.) and oats (Avena sativa L.) dominated the crop rotations. Herbicides were either omitted or used at ca. 50% of a full dose. The perennial species Sonchus arvensis L. was favoured by omittance of ploughing but was better controlled by late ploughing not preceded by stubble cultivation; the reduction in the latter treatment being 74%. Stubble cultivation succeeded by ploughing reduced biomass of Elymus repens (L.) Gould. by 90% compared with ploughing solely. Early ploughing reduced the biomass of the species by 50% compared with late ploughing. The species Cirsium arvense (L.) Scop. was highly favoured by early ploughing followed by late autumn harrowing, the biomass of the species being six-fold higher than in other treatments. Compared with other treatments, stubble cultivation favoured four annuals but efficiently controlled three others, while omittance of ploughing favoured six annual and two perennial weed species. Late ploughing not preceded by stubble cultivation favoured four annual and one perennial species, while early ploughing was more efficient than late ploughing in controlling two of the annual species. Influences of treatments on weed species were frequently moderated by interspecific competition resulting in inconsistent response at different sites. Herbicides reduced the number of species by three, from 11 to eight species, averaged across sites and tillage systems. Influences of treatments on diversity were not consistent, since weed floras differed between sites and since some of the species responded inconsistently to tillage and herbicides. This study shows that by utilizing appropriate tillage strategies it is possible at many sites to maintain acceptable weed population levels, although herbicides are used at 50% lower doses than is normally recommended. The timing and type of tillage have to be chosen for being as efficient as possible to the most troublesome weed species at a site.  相似文献   

超高分子量聚乙烯渔网线捻回角与强力的初探   总被引：1，自引：1，他引：0  

茅利生  郭亦萍  马海有 《海洋渔业》2004,26(3):243-246

本文叙述了采用 8种网线复捻捻回角的超高分子量聚乙烯渔网线强力性能的试验结果。经分析可见 ,网线的断裂强力、单线结强力均与捻回角的余弦呈回归关系。以网线的断裂强力性能为主 ,兼顾网线的单线结强力、断裂伸长率等性能参数 ,比较UHMWPE、普通聚乙烯和聚酰胺三种纤维制成网线后 ,它们的强力利用率均应 >6 5 % ,由此得出制作超高分子量聚乙烯渔网线合理的捻回角区间为 18°～ 2 1°  相似文献   

基于有限元分析的核桃脱壳技术研究   总被引：21，自引：7，他引：14  

史建新  赵海军  辛动军 《农业工程学报》2005,21(3):185-188

核桃破壳是核桃深加工的第一步,必须首先解决。经实测发现核桃形状不规则、壳仁间隙小。试验证明核桃壳完全破裂所需的变形量大于壳仁间隙,用一般的机械挤压方法破壳必将造成大量的碎仁。该文采用结构静力分析的有限单元法,通过所建核桃的几何模型和破壳的有限元模型,对核桃在几种载荷作用下的应力分布规律进行了分析,找出了核桃壳变形量不大且产生局部裂纹点多、裂纹点易扩展的最佳的施力方式。设计了导向机构。试验表明,核桃导向装置基本实现了使核桃的椭圆长轴与破壳辊轴线平行,使核桃以滚动方式挤压扩展裂纹提高了露仁率。  相似文献   

化学物质打破桃休眠的效应初探   总被引：4，自引：0，他引：4  

田莉莉  方金豹  陈锦永  顾红 《落叶果树》2003,35(2):4-6

以油桃品种华光和寿星桃为试材，应用石灰氮、氰胺、苯基噻二唑基脲、赤霉素、6－苄基腺嘌呤、硝酸钾进行打破桃休眠的试验。结果表明，石灰氮破眠效果最佳，可使中芽提早萌发13－14天，花芽提早7天萌芽，提早开花7－13天，且萌芽率显著提高，其余供试药剂也有不同程度的破眠效应，只是效率较低，使用破眠剂的时期和浓度不同，效果也异。休眠芽中可溶性糖含量增加，淀粉含量下降，是解除休眠的标志。  相似文献   

辅助和正常出壳鸭胚肝脏差异蛋白质组学分析     

刘雅丽  曾涛  杜雪  宋美娥  章晓伟  马敏彪  刘晶  卢立志 《农业生物技术学报》2016,(9):1337-1345

本研究应用同位素标记相对和绝对定量(isobaric tags for relative and absolute quantitation,iTRAQ)技术结合质谱鉴定与生物信息学方法,研究鸭(Anas platyrhynchos domestica)胚胎(鸭胚)孵化过程中出现弱胚现象的分子调控机理,筛选辅助出壳鸭胚肝脏组织差异表达的蛋白.结果表明,共鉴定获得136个差异蛋白,与正常出壳组相比,辅助出壳组有76个蛋白表达上调,60个蛋白表达下调.基因本体(Gene Ontology,GO)注释和通路富集分析表明,这些差异蛋白主要与糖代谢、氧气运输、细胞骨架、应激反应以及氧化还原代谢等生物过程相关,其中辅助出壳组糖酵解通路中的4种酶和细胞呼吸通路中的3种酶表达均显著上调(P＜0.05),参与肌动蛋白丝生物过程的7种蛋白也均表达上调,而参与氧气运输的3种血红蛋白和应激保护的3种热休克蛋白表达显著下调(P＜0.05).利用qRT-PCR检测顺乌头酸酶1(cytoplasmic aconitate hydratase 1,ACO1)、醛缩酶B(fructose-bisphosphate aldolase B,ALDOB)、甘油醛-3-磷酸脱氢酶1 (glyceraldehyde-3-phosphate dehydrogenase 1,G3P1)和热休克71 kD同源蛋白(heat shock cognate 71 kD protein,HSPA8)4个基因mRNA水平的表达,结果仅ACO1 mRNA和蛋白质水平表达模式一致.结果表明,弱胚可能与糖代谢和呼吸代谢等生物过程变化有关,辅助出壳组能量和代谢率较低.研究结果为更好理解鸭胚孵化过程中出现弱胚现象的分子调控机理提供了蛋白质组学信息.  相似文献   

矿用高压开关电器短路开断与关合试验电源     

陈钊 《保鲜与加工》2016,(2):58-63,106

针对国内冲击发电机性能参数不足,以国外冲击发电机作为试验电源,建立基于直接试验法的矿用高压开关电器短路开断与关合试验系统,提出了一种新的技术解决方案。仿真试验结果表明,该方案满足综合性煤矿高压电气实验室建设项目技术指标和试验标准要求,为大容量开断与关合试验系统设计和建造提供一种技术思路。  相似文献