共查询到20条相似文献，搜索用时 923 毫秒
1.
异色瓢虫十九斑变型对豆黄蓟马成虫的捕食功能反应 总被引：1，自引：0，他引：1
异色瓢虫十九斑变型是长春地区大豆田中重要的捕食性天敌昆虫之一,为明确这种天敌昆虫对豆黄蓟马成虫的控制作用,在实验室条件下测定了其捕食作用以及密度和种内干扰对其捕食能力的影响。结果表明:异色瓢虫十九斑变型成虫对豆黄蓟马成虫的捕食功能反应符合HollingⅡ方程,回归模型为Na=0.934 6N/(1+0.0339N);异色瓢虫捕食作用受自身密度制约,平均捕食量随自身密度增大而减少,回归模型为A=13.534P~(-0.702 9);异色瓢虫成虫间存在种内干扰,干扰反应回归模型为E=57.218P~(-1.246)。异色瓢虫十九斑变型对豆黄蓟马成虫有较好的捕食作用和控制潜能。 相似文献
2.
不同温度下鞍形花蟹蛛亚成蛛对茶尺蠖3日龄幼虫的捕食功能 总被引：2，自引：1，他引：1
鞍形花蟹蛛（Xysticus ephippiatus Simon）是茶园害虫的重要捕食性天敌,为了明确它对茶尺蠖（Ectropis obliqua Prout）的控制能力,在20、25、30℃ 3种不同温度条件下,研究了鞍形花蟹蛛亚成蛛对茶尺蠖3日龄（1龄末2龄初）幼虫的捕食反应。结果表明,鞍形花蟹蛛雌蛛和雄蛛对茶尺蠖3日龄幼虫的捕食功能反应均符合HollingⅡ型方程,在相同温度下,捕食量随着猎物密度的增大而增加。在25℃和30℃时,雌虫的捕食上限均为68头;雄虫的捕食上限以30℃时最大,为67头。相同条件下雌、雄蛛之间的捕食量没有明显差别,而温度对鞍形花蟹蛛的捕食量有明显影响。 相似文献
3.
白斑猎蛛对假眼小绿叶蝉的捕食作用 总被引：5，自引：0，他引：5
假眼小绿叶蝉是茶园的重大害虫之一,白斑猎蛛是假眼小绿叶蝉的重要捕食性天敌之一。室内条件下,白斑猎蛛对假眼小绿叶蝉的捕食作用的研究结果表明,白斑猎蛛对假眼小绿叶蝉具有一定的捕食作用。白斑猎蛛雌、雄蛛对假眼小绿叶蝉成、若虫的功能反应均为Holling型反应,白斑猎蛛对假眼小绿叶蝉控制能力(a/Th)的大小比较关系为:雌蛛对若虫>雄蛛对若虫>雌蛛对成虫>雄蛛对成虫。白斑猎蛛对自身密度的干扰反应可用E=Na/(NP)和E=QP-m拟合,表明白斑猎蛛个体之间具有极显著的相互干扰作用。 相似文献
4.
草间小黑蛛对假眼小绿叶蝉捕食作用的研究 总被引：5，自引：0，他引：5
在实验室条件下，研究了草间小黑蛛成蛛对不同密度的假眼小绿叶蝉的捕食功能及温度对捕食功能的影响和捕食者自身密度对捕食作用的影响。其功能反应的类型属于ＨｏｌｌｉｎｇⅡ型反应。温度对寻找产应有一定影响，２４℃条件下，处置时间短，捕食率较高。草间小黑蛛对自身密度的寻找效应可用Ｗｅｔｔ型模拟。 相似文献
5.
测定5种杀虫剂亚致死剂量对龟纹瓢虫捕食作用的影响效应,在龙眼角颊木虱同一猎物密度条件下,亚致死剂量处理的龟纹瓢虫对猎物的捕食量显著低于对照组,但是其捕食功能反应模型结构没有改变,均属于HollingⅡ型,只是功能反应模型参数发生了明显的变化,即捕食者对猎物的瞬间攻击率a下降,处理时间Th延长,最大理论捕食量下降。结果表明:杀虫剂亚致死剂量处理对龟纹瓢虫的捕食作用存在明显的不良影响,5种杀虫剂中以吡虫啉对龟纹瓢虫的捕食作用影响最小,氰戊菊酯的影响程度最大。 相似文献
6.
《大豆科学》2015,(3)
采用室内试验与田间罩笼试验的方法分别测定了草皮逍遥蛛对大豆蚜的捕食功能与田间控害作用。结果表明:草皮逍遥蛛在室内条件下对大豆蚜的捕食功能反应符合Holling-Ⅱ型方程,当蚜蛛比小于100时,草皮逍遥蛛的捕食量随着大豆蚜密度增加而上升,日均最大捕食量为49.2头。在田间罩笼条件下,草皮逍遥蛛的日均最大捕食量为84.4头,当蚜蛛比小于50时,草皮逍遥蛛可以对大豆蚜起到较好的控制作用,当蚜蛛比大于50时,草皮逍遥蛛可以将大豆蚜发生高峰期推迟约3 d。草皮逍遥蛛可以对大豆蚜起到较好的生态调控作用,但是当大豆蚜处于"窝子蜜"阶段和之后的上升期和盛期时,需要有瓢虫等其它天敌存在时才能有效控制蚜虫危害。 相似文献
7.
六斑月瓢虫成虫对几种蚜虫捕食作用的研究 总被引：2，自引：0，他引：2
六斑月瓢虫是华中、华南地区栖息于蔬菜、果树等作物上的一种重要的食蚜天敌.其成虫能捕食豆蚜、玉米蚜、桃蚜、高售指管蚜和桔二叉蚜等.当5种蚜虫同时存在时,其较喜食桃蚜.在一定的猎物密度范围内,随着猎物密度的增大,其捕食量逐渐增加,两者之间存着密切的相互性.单头成虫对豆蚜、玉米蚜、桃蚜、莴苣指管蚜和桔二叉蚜的日捕食量上限分别为127、141、256、111和233头.当猎物密度不变时,随着捕食者自身密度的增加,其个体日捕食量减小,因而六斑月瓢虫成虫各个体之间在捕食蚜虫的过程中存在相互干扰效应. 相似文献
8.
拟小食螨瓢虫成虫对朱砂叶螨捕食作用的研究 总被引：4，自引：2，他引：2
拟小食螨瓢虫是一种栖息于木薯上的朱砂叶螨的重要天敌。其成虫能捕食朱砂叶螨的各个虫态,随着猎物密度的增加其捕食量逐渐上升,对朱砂叶螨卵、幼螨、若螨和成螨的日捕食量上限分别为146粒,87、91和11头。当猎物密度不变时,随着拟小食螨瓢虫成虫密度的增加,其捕食量下降。 相似文献
9.
以转Bt基因棉和常规棉为材料,通过室内测定,研究了以转Bt基因棉为食的扶桑绵粉蚧（Phenacoccus solenopsis）对异色瓢虫（Harmonia axyridis）成虫功能反应的影响。结果表明,异色瓢虫对用转Bt基因棉处理的扶桑绵粉蚧的捕食量与常规棉无显著差异,捕食量均随着密度的增加而逐渐增大,捕食功能反应符合Holling-Ⅱ模型。异色瓢虫对用转Bt基因棉处理的扶桑绵粉蚧的日最大捕食量明显大于常规棉,所用处置时间短于常规棉,瞬间攻击率无显著差异。 相似文献
10.
为明确条纹蝇虎（Plexippus setipes）对灰茶尺蠖（Ectropis grisescens）的防控效果,在室内条件下,开展了条纹蝇虎对灰茶尺蠖幼虫的捕食量、捕食功能反应、捕食选择性和种内干扰效应的研究。结果显示,条纹蝇虎偏好捕食灰茶尺蠖低龄幼虫,不同发育阶段捕食能力存在显著差异;其中成蛛捕食能力最强,日均可捕食灰茶尺蠖1龄幼虫17.44头,幼蛛捕食能力相对较弱,日均捕食1龄幼虫2.33头。条纹蝇虎捕食功能反应符合Holling Ⅱ模型,捕食量随灰茶尺蠖幼虫密度的增加而增加,而搜寻效应逐渐降低。捕食选择性试验表明,条纹蝇虎对灰茶尺蠖1龄幼虫和2龄幼虫表现为正喜好性（Ci>0）,对3龄幼虫表现为负喜好性（Ci<0）。条纹蝇虎对灰茶尺蠖幼虫的捕食作用同时受自身密度的影响,存在较强的种内干扰反应,该反应符合Hasse Ⅱ模型。研究表明,条纹蝇虎对灰茶尺蠖幼虫具有较强的捕食能力和良好的防控潜能,这为利用茶园蜘蛛天敌资源提供理论依据。 相似文献
11.
12.
《Journal of Crop Improvement》2013,27(2):81-114
Summary The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices. 相似文献
13.
Novel food and non-food uses for sorghum and millets 总被引：4，自引：3，他引：4
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity. 相似文献
14.
Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.
The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).
The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors. 相似文献
15.
Yanhua Lu Chongwei Zhang Peter Bucheli Dongzhi Wei 《Plant foods for human nutrition (Dordrecht, Netherlands)》2006,61(2):55-63
Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China. 相似文献
16.
Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive.
Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated
seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk.
Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than
in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d. 相似文献
17.
《Journal of Crop Improvement》2013,27(2):379-400
Summary Heterocyclic 1,4-benzoxazin-3-ones and related benzox-azolinones are important natural products of the cereal crops maize, wheat and rye. Much research has focused on the role of these compounds as defensive agents against plant diseases and pests. Studies of a wide variety of biological effects on herbivores and nematodes, plant pathogenic fungi and bacteria are reviewed in this article. Phytotoxic activity of the compounds is also considered with respect to allelopathic interaction with higher plants. Recent investigations of molecular aspects of interactions of cyclic hydroxamic acids and related benzoxazo-linones with acceptor organisms have demonstrated different effective detoxification strategies and tolerance mechanisms. This research has greatly advanced our knowledge about the multiple roles that these allelochemicals play in ecological systems. 相似文献
18.
Potential of dry fractionation of wheat bran for the development of food ingredients,part I: Influence of ultra-fine grinding 总被引：1，自引：0，他引：1
Youna Hemery Marc Chaurand Ulla Holopainen Anna-Maija Lampi Pekka Lehtinen Vieno Piironen Abdelkrim Sadoudi Xavier Rouau 《Journal of Cereal Science》2011
Wheat bran is an undervalued by-product of white flour and has great nutritional potential due to its high content in fibres and bioactive compounds. Micronized bran could be used as a food ingredient to improve the nutritional potential of cereal products, or be used as a starting material for other processes (bioactive compound extraction or bran fractionation). The aim of this work was to find a way to efficiently decrease the particle size of bran. The influence of the grinding temperature (ambient or cryogenic grinding) on the granulometric distribution of particles, their composition, and their microstructure was studied, at lab-scale and pilot-scale. It showed that the intrinsic characteristics of bran (glass transition within intermediate layers at −46 °C) had more influence on its grinding behaviour than the type of grinding device used: the particles size distributions obtained after grinding at lab-scale and pilot-scale were very similar. At both scales, the granulometric curves were narrow for cryogenic grinding, while for ambient grinding they were spread over the whole particle size range. Ultrafine particles were obtained in both ambient and cryogenic conditions. Negative temperatures, by increasing the material’s brittleness, favoured a fast fragmentation of bran: one step of cryogenic grinding allowed a median particle size of nearly 50 μm to be reached, whereas three successive steps of ambient grinding were needed for the same result. On the other hand, ambient temperature favoured the dissociation of the different constituent layers of wheat bran, and produced less composite particles than cryogenic grinding. 相似文献
19.
Multiple use of plants: Studies on selenium incorporation in some agricultural species for the production of organic selenium compounds 总被引：3，自引：0，他引：3
The technique of spraying plants with inorganic forms of selenium can be employed for phytochemical production of organic selenium compounds. Fractionation of the plant material makes it possible to produce a highly concentrated and well defined selenium supplement with potential use in animal and human nutrition. The fractionation also gives opportunities to combine production of organic selenium compounds with other products, for example plant fibres. Multiple use of plants can contribute to a more efficient utilization of land area (in comparison to monocultures solely adapted to food production). It also gives the opportunity to develop systems suitable for long term fixation of carbon, as long as the plant material is not reoxidised to carbon dioxide. Plant fibres could provide raw material for the production of paper or building materials in combination with the production of organic selenium compounds preferentially accumulated in another fraction of the processed plant. 相似文献
20.
Summary
Macrosiphum euphorbiae, collected in the field from potato plants infected with potato leafroll virus (PLRV), transmitted the virus to fewer potato
plants in a field trial than did laboratory-rearedMyzus persicae. In the laboratory,M. persicae was the only efficient vector of PLRV fromPhysalis floridana seedlings, potato sprouts or excised leaves toP. floridana. Two clones ofM. euphorbiae and one clone ofAulacorthum solani transmitted PLRV from infected potato plants toNicotiana clevelandii as effeciently asM. persicae but a clone ofAphis gossypii was an inefficient PLRV vector. An isolate of PLRV, whichM. persicae transmitted inefficiently from potato toN. clevelandii, was also transmitted inefficiently byM. euphorbiae andA. solani. 相似文献