共查询到20条相似文献,搜索用时 93 毫秒
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首先论述概论,其中包括:1)阐述了害虫综合管理(IPM)技术,明确了水稻害虫综合管理的现状及存在的问题,并指出;人的因素是IPM成败的关键.2)首先提出了害虫防治经历了定性研究、定量研究以及定性和定量综合一体研究3个阶段的观点.因此,能够综合利用定性信息(包括专家知识)和定量信息的专家系统(系统中包含模型)的研制和应用,有助于作出更高层次的决策.可以认为,这将是IPM,特别是生态系统综合管理的发展方向. 相似文献
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昆虫性信息素微胶囊的研究进展 总被引:8,自引:0,他引:8
微胶囊是应用昆虫性信息素进行害虫治理的主要剂型之一。文章对昆虫性信息素微胶囊常用的制备方法进行总结,并介绍其在害虫控制方面的应用进展,探讨昆虫性信息素微胶囊制备及其田间应用效果的影响因子,并对今后昆虫性信息素微胶囊的发展作了展望。 相似文献
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为更准确地对性信息素监测下田间害虫的发生量进行测报并指导有效防治,建立了基于性信息诱捕下种群的Logistic增长模型,并与通常诱捕模式进行了比较分析。在性信息素诱捕环境下利用种群增长平衡点获得诱捕强度(E)与害虫的自然增长率(r)的数学关系,建立了诱捕量与田间害虫发生虫量的数学模型,明确了性信息素诱捕与害虫自然增长平衡时的各变量间的关系,同时根据害虫发生规律研究了性信息素诱捕时的防治害虫的经济阈值(Es)模型。以性信息素诱捕梨小食心虫为实例,通过田间调查梨小食心虫成虫的发生,拟合Logistic模型并测定3种性信息诱捕强度下梨小食心虫的自然增长率,据模型求解不同性信息素诱捕下的诱捕强度(E),确定了防控梨小食心虫的经济阈值(Es),明确达到经济阈值时的持续诱捕数量。本模型为有效测报和诱捕防治害虫提供了基础理论与依据。 相似文献
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通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一. 相似文献
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真菌类遗传学分析的知识结构教学 总被引:5,自引:2,他引:3
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。
Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching. 相似文献
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The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth. 相似文献
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Time of detection of recessive genes: effects of system of mating and number of examined individuals
E. Santiago 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(6):867-872
Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed. 相似文献
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龙胆科药用植物化学成分的研究现状 总被引:16,自引:0,他引:16
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。 相似文献
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Scales of spatial patterns of distribution of intertidal invertebrates 总被引:15,自引:0,他引:15
Few comparative studies of spatial patterns at different scales have examined several species in the same habitat or the same species over a range of habitats. Therefore, variability in patterns among species or among habitats has seldom been documented. This study quantifies spatial patterns of a suite of intertidal snails and a species of barnacle using a range of statistical techniques. Variability in densities was quantified from the scale of adjacent quadrats (over a distance of centimeters) to tens of kilometers. Significant differences in abundances occurred primarily at two spatial scales. Small-scale differences were found at the scales of centimeters or 1–2 m and, for many species on many shores, these accounted for most of the variability in abundances from place to place. These are likely to be determined by behavioural responses to small-scale patches of microhabitat. Large-scale differences in abundance were also found in most species at the scale of hundreds of meters alongshore. These are likely to be due to variation in recruitment (and/or mortality) because of limited dispersal by adults of these species. There was little or no additional variation among shores, separated by tens of kilometers, than was shown among patches of shore separated by hundreds of meters. Identification of the scale(s) at which significant differences in abundance are found focus attention on the processes (and the scales at which these processes operate) that influence patterns of distribution and abundance. Some of the advantages and disadvantages of various procedures are discussed. 相似文献
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Finbarr P.M. O'Harte Peter Højrup Christopher R. Barnett Peter R. Flatt 《Peptides》1996,17(8):1323-1330
This study evaluates the nature of glycated human insulin formed following exposure to hyperglycemic conditions in vitro. Glycated insulin was purified by RP-HPLC and its molecular mass (5971.3 Da) determined by plasma desorption mass spectrometry (MS). The difference in mass (163.7 Da) from nonglycated insulin (5807.6 Da) corresponds to a single reduced glucose (glucitol) residue. Following reduction of insulin disulfide bridges, MS confirmed that the B-chain was glycated. Enzymatic digestions with trypsin, endoproteinase Glu-C, and thermolysin, followed by RP-HPLC and identification of fragments by MS, localized glycation to the B-chain (1–5) region. Electrospray tandem MS identified the site of glycation as the B-chain NH2-terminal Phe1 residue. This was confirmed by automated Edman degradation with glycated human insulin. 相似文献