专家系统在果树中的应用及研究进展

专家系统是一种模拟人类专家解决领域问题的计算机系统,它主要分为知识库、综合数据库、推理机、解释器、接口等几部分。现今,国内果树专家系统的应用类型主要分为果树栽培生产专家系统和果树营养、病虫害诊断防治决策系统两类;在果树专家系统上的应用研究最多的计算机理论主要是：人工神经网络、模糊神经网络、多媒体技术、Web技术等;果树专家系统的开发手段主要是利用现成的农业专家系统平台直接进行二次开发,还有少数是直接利用程序语言进行原型系统开发。今后随着信息技术的不断发展,利用果树学的特点结合先进的计算机理论和技术,将开发出动态的、更具智能化的果树专家系统。     

基于知识模型的作物适应性评价专家系统设计

系统引入了知识模型概念,建立了以知识模型为特征的知识系统,将知识工程、数据库有机结合,采用正向与反向相结合的推理控制策略,建立了基于知识模型的作物适应性评价专家系统,实现了作物适应性评价的计算机辅助决策,具有较强的跟踪解释能力。用本系统对江苏省地区小麦适应性还进行了实例分析。     

基于几何语义知识的冬小麦自动分类

【研究目的】为了实现遥感影像的作物自动分类,并探索空间信息在分类中作用,【方法】本文提出结合光谱和空间信息的作物分类方法。首先,借助光谱信息实现地物初始分割,然后以目标作物历史空间分布为语义约束,根据隶属度提取目标作物。最后,在多时相遥感影像条件下,以冬小麦为目标作物进行了方法的验证,【结果】结果显示,本文方法可实现冬小麦自动提取与识别,总体精度为95.33%,Kappa系数为0.90,可满足农情监测的实际需求。另外,在单时相遥感影像条件下,本文结合几何语义知识的作物分类精度也达到了较高水平。【结论】相对于遥感影像单一光谱信息的分类方法,本文方法利用了作物空间信息,不仅能满足精度要求,还实现了分类的自动化,对工程化应用具有一定的参考价值。     

棉花早衰程度诊断数码图像数字化指标的研究

应用计算机数字图像技术研究了诊断棉花早衰程度的方法。在光照条件下采集了棉田群体图像,然后分别提取了红绿蓝(RGB)三色分量和色度、饱和度和亮度指标(HSI)。在RGB和HSI颜色模型下分析了各分量与棉花早衰程度的相关特性。然后得出诊断棉花早衰程度的指标。分析结果表明:颜色分量G/(R B)和色度H分量与棉花早衰程度线性相关,可用作利用数字图像技术快速诊断作物长势的指标,而其它分量与棉花早衰程度没有明显的相关性;诊断模型G/(R B)分量比色度H分量有更好的拟合优度。     

河北省又取得一批农药植保类科研成果

<正>(接上期)4.蔬菜病虫害诊断专家系统的开发与应用单位名称:邢台职业技术学院评价单位名称:河北省科技成果转化服务中心针对蔬菜病虫害诊断与防治问题,基于神经网络、人工智能等技术,研发了蔬菜病虫害诊断专家系统,系统可在领域专家的知识和经验的基础上,有效指导农民及时诊断防治病虫害的发生,避免或降低农民的经济损失。其关键技术与创新点为:(1)融合了神经网络自适应学习能力强和专家系统知识表     

棉花计算机模拟模型的现状及展望

本文在阐明计算机模拟与专家系统基本概念的基础上，着重综述了国内外关于棉花的生育期、叶龄、光合与呼吸作用等６个方面的模拟模型，提出了现有模型存在的问题以及今后的发展方向与前景。     

冬小麦叶片生长特征的动态模拟

叶片形态生长特征是作物群体发育动态的重要内容,在很大程度上决定了作物冠层内的光分布、CO₂传输及光合生产等^[1,2],同时也是作物生长诊断及遗传育种等多个研究领域的重要生理指标^[2]。近年来,随着农业信息技术的飞速发展和虚拟现实技术在农业上的应用,使得建立作物形态建成模拟模型和虚拟作物生长系统成为可能,其中前者是后者的基础,也是当前数字化可视化农作系统研究的关键技术。迄今为止,关于作物叶片形态生长特征的模拟虽有报道^[3~10],但由于禾谷类作物的叶片形态的复杂性、可变性以及形态指标的难获取性,准确描述禾其变化特征仍是有待研究解决的一个难点^[1]。在其描述中,叶长、叶形、叶面积是最主要的决定因素,对作物的个体和群体形态建成产生直接的影响^[1,3]。为此,本研究以冬小麦为试材,通过对不同株型冬小麦品种不同叶位叶片生长特征的连续观察和定量分析,构建冬小麦叶片生长特征的动态模拟模型,包括叶长、叶形和叶面积生长动态,以期为虚拟小麦生长系统的建立提供技术基础。     

遥感技术在植物氮营养诊断和推荐施肥中的应用之研究进展

·通过对遥感技术在作物氮营养诊断方面的研究与最新进展进行了综述，系统评价了高光谱遥感技术、可见光数字图像技术和卫星遥感技术在作物氮营养诊断与氮肥推荐方面的原理、优缺点以及目前的研究现状。认为遥感技术在作物氮营养诊断方面仍然存在技术复杂与设备昂贵等方面的问题，但随着技术的发展，遥感技术在未来精确养分管理方面有广阔的应用前景。     

光质对作物生长发育影响研究进展

作物的生长是光形态建成的过程,光质在作物生长发育过程起重要的调节作用。该文综述了光质对作物形态建成、光合作用、物质代谢、基因表达的影响及其通过光受体和激素调节等方面作用机理的研究现状,展望了光质在作物方面的研究方向和途径,提出了光质对作物生长发育研究的意义和目的,以期为光质对作物生长发育影响的进一步研究提供参考。     

计算机自动化控制系统在棉田滴灌中的应用

通过计算机控制系统，利用各种传感器，自动采集、监测农田土壤水分、土壤温度、大气温度、大气相对湿度、田间水分蒸发量和土壤全盐含量等农田环境参数，根据这些参数结合数学模型可预报需灌时日和需灌水量，显示有关农田温度、湿度变化状况，为自动化灌溉系统提供控制信息、传递控制信号，并结合作物需水规律实施灌溉，为棉花的生长提供科学合理的灌溉方案，实现降低劳动强度，增加棉花生产效益的目的。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...