不同种植密度对机采辣椒品种性状和产量的影响     

王岩  牟玉梅  张爱民  邢丹  郭涛 《热带作物学报》2021,42(5):1342-1347

为明确不同种植密度对机采辣椒品种性状、产量的影响,以适宜机采的辣椒‘辣研102’为研究对象,设置4个种植密度（P0:38 480株/hm²、P1:51 307株/hm²、P2:76 961株/hm²、P3:102 615株/hm²）,分别于贵阳、遵义两地开展田间小区试验。结果表明,随着种植密度的增加,辣椒株高呈增加趋势,茎粗呈下降趋势。辣椒根部、地上部生物量均在高密植条件下（P3）时达到最小。辣椒的发病率与病情指数均随种植密度的增加而显著提高,高密植处理条件下（P3）达到最大,发病率分别为41.67%（贵阳）、43.33%（遵义）,病情指数分别为31.05%（贵阳）、29.86%（遵义）。过高的种植密度导致单株辣椒光合作用大幅下降:P1、P2、P3处理条件下光合速率分别较P0处理显著降低13.94%、24.73%、29.66%（遵义）;P1、P2、P3处理条件下辣椒叶片蒸腾速率较P0降低10.02%、19.81%、42.12%（贵阳）。辣椒总产量随种植密度增加而显著提高,而商品果产量随种植密度的增加呈先增加后降低的趋势。商品果产量在P1条件下获得最大值,相对于P0、P2、P3贵阳辣椒商品果产量显著提高了16.43%、32.81%、41.67%,遵义提高了20.25%、26.67%、61.02%。综合辣椒生长与商品果产量,贵州机采辣椒‘辣研102’最佳种植密度为51307株/hm²。  相似文献   

海贝柱自动晾晒设备设计     

刘晓  侯加林  张观山  周伟 《渔业现代化》2017,44(5)

针对当前传统人工晾晒海贝柱效率低下、容易造成污染等问题。设计了海贝柱自动晾晒机械,采用阶梯式晾晒生产线对湿海贝柱分级晾晒,多条晾晒生产线分时、高效的工作,机器上方设有遮板以保证晾晒作业不被污染而且不受天气条件的影响。整机采用stm32单片机、传感器等技术实现自动化作业,机器控制系统监测到生产线发生故障或海贝柱出现堆积时会立即停止工作以便于检查故障、减少损失。试验结果表明:机械晾晒不会造成海贝柱内的营养成分的流失,机械晾晒海贝柱的干基含水率达到30%仅需12h,机械晾晒海贝柱能节省大量的干燥时间,显著的提高了晾晒效率,避免了人工晾晒过程导致的二次污染和损失。该研究为海贝柱自动晾晒机械的研制提供了技术参考。  相似文献   

计算机犬病诊断原理   总被引：1，自引：0，他引：1  

刘孟强  何保荣  刘桂荣  杨宝拴 《农业网络信息》2004,(7):11-13,31

本研究模拟人类专家的诊断过程,对常见犬病用计算机进行诊断模拟,试验建立了犬病诊断的计算机处理系统(QBZD)。本文主要阐述了QBZD系统的结构构成、诊断机理及操作应用  相似文献   

烤烟适宜施氮量试验初报   总被引：9，自引：3，他引：6  

刘诚  王振飞 《江西农业学报》2005,17(3):95-96

试验结果表明,烤烟施氮量以90.0~112.5kg/hm2为佳,在此条件下,烤烟的产量和产值最高。  相似文献   

跑车带锯机列的电气改造     

鲁艳玲  李云峰 《森林工程》2002,18(3):28-28,30

本文通过对木工跑车带锯机列摇尺制动和摇尺操纵的电器改造，实现了摇尺自控和跑车摇控。提高了木材出材率，改善了工人的劳动条件。  相似文献   

关于水稻机插秧技术在泰和县试验示范的探讨     

尹国庆  梁景晟 《中国农机化》2004,(3):58-60

介绍了江西省泰和县进行水稻机插秧技术与手工插秧对比试验。对不同农艺的经济效益和不同育秧方式的适应性进行了分析，并指出了目前技术措施存在的不足之处。  相似文献   

植树挖坑机钻头主轴扭转振动数学建模与求解     

于建国  孟庆华 《林业科学》2006,42(11):101-105

介绍国内外机械化植树造林机械发展状况,指出国内植树用挖坑机研究重点,利用空间运动学和机械振动理论以及弹性动力学原理着重分析建立钻头主轴扭转振动模型并用数值方法进行求解,同时系统地分析钻头主轴下端部件与土壤的相互作用力、钻头主轴重力及惯性力等因素的影响,给出动态的准随机边界条件和初始条件.为下一步的钻头动力学特性仿真及整机动态特性研究,合理预测和控制钻头的运动规律,改善钻头的动力学特性,提高钻头工作效率及改进设计方法提供新的理论依据.  相似文献   

Biochemical properties of the pathogenesis-related proteins from tobacco     

J. F. Antoniw  R. F. White 《European journal of plant pathology / European Foundation for Plant Pathology》1983,89(6):255-264

This review describes the discovery and identification of the pathogenesis-related proteins (PRs) from tobacco. In crude leaf extracts the PRs are distinguished from the proteins in uninfected plants by their solubility at pH 3, resistance to a range of proteases, and mobility in polyacrylamide gels upon electrophoresis (PAGE) in non-denaturing conditions. PAGE has been used as a qualitative and semi-quantitative assay for PRs, and their migration in gels made from different acrylamide concentrations has been used to identify charge and size isomers and electrophoretically identical PRs in different tobacco cultivars. The subunit composition and molecular weight (mol. wt) of the four PRs identified first in Xanthi-nc were determined by SDS-PAGE; staining the gels has shown that these same four proteins in Samsun NN did not contain carbohydrate, lipid or nucleic acid, nor were they isozymic forms of twenty five enzymes known to increase in activity following infection with TMV. Evidence suggests that most of the PRs in Xanthi-nc and Samsun NN are extracellular.The purification of several PRs from Xanthi-nc, Samsun NN and other tobaccos is described, as well as their mol. wt, subunit and amino acid composition. PRs 1a, b and c consist of a single polypeptide and have similar mol. wt and amino acid compositions. Antisera prepared against purified Xanthi-nc b₁ protein have been used to determine serological relationships between PRs and form the basis of a very sensitive quantitative assay using ELISA. The regulation of synthesis of some PRs has been shown to involve translational control.  相似文献   

Some coat protein constituents from strawberry latent ringspot virus expressed in transgenic tobacco protect plants against systematic invasion following root inoculation by nematode vectors     

S. Kreiah  M. L. Edwards  W. S. Hawes  A. T. Jones  D. J. F. Brown  W. J. McGavin  J. I. Cooper 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(3):297-303

The coding sequences in RNA2 for the coat proteins (CP) of strawberry latent ringspot virus (SLRSV) were modified and amplified using polymerase chain amplification reactions (PCR) to facilitate their expression inAgrobacterium tumefaciens-transformedNicotiana tabacum Xanthi-nc. The coding sequences for the smaller capsid protein (S, 29kDa) and that for the theoretical precursor of L and S (P, 73kDa) had ATG initiation codon sequences added at the 5-proximal Ser/Gly (S/G) cleavage site in the unmodified sequence. The sequence coding for the larger of the two proteins of mature SLRSV capsids (L, 44kDa) had an ATG codon added at its 5 S/G site and a TAG stop codon sequence added at the 3-proximal S/G site. The P, L and S proteins were expressedin planta to a maximum concentration of 0.01 % of total extractable proteins but did not assemble into virus-like particles. When challenged by mechanical inoculation with virus particles or viral RNA, and compared with control plants, tobacco plants (primary transgenic clones or S1 and S2, kanamycin-resistant seedlings) expressing the virus capsid subunits separately, or their precursor, decreased the accumulation of SLRSV particles in inoculated leaves and fewer plants became invaded systemically. In experiments in which the roots of seedlings were exposed to SLRSV-carrying vector nematodes (Xiphinema diversicaudatum), SLRSV was detected in the roots of non-transformed control tobacco plants (6/20) and in transgenic tobacco expressing the L protein (7/40), but not in any of 25 tobacco plants expressing the S protein or in 35 expressing the P protein. This is the second example of CP-mediated resistance to virus inoculation by nematode vectors.  相似文献   

Comparison of the effects of salicylic acid and ethephon with virus-induced hypersensitivity and acquired resistance in tobacco   总被引：4，自引：0，他引：4  

L. C. Van Loon  J. F. Antoniw 《European journal of plant pathology / European Foundation for Plant Pathology》1982,88(6):237-256

The induction of a hypersensitive reaction in Samsun NN tobacco by tobacco mosaic virus (TMV) at 20°C leads to the development of both localized and systemic acquired resistance, and is associated with the appearance of pathogenesis-related proteins (PR's) and large increases in peroxidase activity and ethylene production. Salicylic acid (SA) induced a similar resistance in treated plant parts and occasionally also in untreated upper leaves of plants of which three lower leaves had been injected. SA also induced the same four PR's, but these were confined to the treated leaves. Thus, the connection between the presence of PR's and the reduction of TMV multiplication and spread may not be direct.In contrast to TMV, SA did not stimulate ethylene production and hardly increased peroxidase activity. Induction of acquired resistance and PR's by SA developed equally well at 20°C and at 32°C. However, pricking leaves with needles moistened with the ethylene-releasing compound ethephon mimicked TMV infection in inducing acquired resistance and PR's in both treated and untreated leaves at 20°C, but not at 32°C. Ethephon increased peroxidase activity at both temperatures, but only at 20°C dit it induce changes in both the anodic and the cathodic isoenzymes that were similar to those induced as a result of TMV infection. SA induced PR's and reduced TMV multiplication in Samsun tobacco, and inhibited virus spread in Samsun NN at 32°C.These observation indicate that neither the induction of PR's, nor the development of acquired resistance is temperature-sensitive. On the other hand, the effects of ethephon are temperature-sensitive in the same way as the hypersensitive response to TMV. It can thus be hypothesized that ethylene, produced naturally during the hypersensitive reaction of tobacco to TMV, leads to the temperature-sensitive synthesis or release of a presumably benzoic acid-type compound that functions as the natural inducer of PR's and acquired resistance. Although vanillic acid has been shown to accumulate in hypersensitively reacting tobacco leaves, it produced none of the effects of SA, and thus cannot be the natural inducer.Samenvatting Inductie van een overgevoeligheidsreactie in Samsun NN-tabak door tabaksmozaïekvirus (TMV) bij 20°C leidt tot de ontwikkeling van een verworven resistentie die zowel lokaal als systemisch werkzaam is, en gaat samen met het verschijnen van pathogenesis-related proteins (PR's) en sterke toename in de activitieit van peroxidase en de produktie van ethyleen. Salicylzuur (SA) induceerde een vergelijkbare resistentie in behandelde plantedelen en af en toe ook in niet behandelde bovenbladeren van planten waarvan drie onderbladeren waren ingespoten. SA induceerde ook dezelfde vier PR's, maar deze waren beperkt tot de behandelde bladeren. Er bestaat dus geen directe samenhang tussen de aanwezigheid van PR's en de remming van de vermeerdering en uitbreiding van TMV in de plant.In tegenstelling tot TMV stimuleerde SA de ethyleenproduktie niet en verhoogde het de peroxidaseactiviteit nauwelijks. Inductie van verworven resistentie en PR's door SA trad even goed op bij 32°C als bij 20°C. Net als infectie met TMV leidde aanprikken van bladeren met naalden die gedoopt waren in een oplossing van ethefon — waaruit in het blad ethyleen vrijkomt — echter tot inductie van verworven resistentie en PR's in zowel behandelde als onbehandelde bladeren bij 20°C, maar niet bij 32°C. Ethefon verhoogde de peroxidaseactiviteit bij beide temperaturen, maar alleen bij 20°C induceerde het veranderingen in zowel de anodische als de kathodische isoënzymen die vergelijkbaar waren met die welke geïnduceerd werden als gevolg van infectie met TMV. SA induceerde PR's en verminderde de vermenigvuldiging van TMV in Samsun tabak, en remde de uitbreiding van het virus in Samsun NN bij 32°C.Deze waarnemingen tonen dat noch de inductie van PR's, noch de ontwikkeling van verworven resistentie een temperatuurgevoelig proces is. Daarentegen zijn de effecten van ethefon op dezelfde wijze temperatuurgevoelig als de overgevoeligheidsreactie op TMV. Men kan daarom veronderstellen dat ethyleen, dat op natuurlijke wijze geproduceerd wordt tijdens de overgevoeligheidsreactie van tabak op TMV, aanleiding geeft tot een temperatuurgevoelig proces, namelijk de synthese of het vrijkomen van een verbinding, vermoedelijk een benzoëzuurderivaat, dat fungeert als de natuurlijke inductor van PR's en verworven resistentie. Hoewel is aangetoond dat vanillinezuur zich ophoopt in overgevoelig reagerende tabaksbladeren, veroorzaakte deze verbinding geen enkel van de effecten van SA. Vanillinezuur kan dus niet de natuurlijke inductor zijn.  相似文献