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1.
在不同温度条件下(24、26、28、30、32℃),建立丽草蛉(Chrysopa formosa Brauer)实验种群生命表,研究温度对丽草蛉实验种群生长发育及繁殖的影响。结果表明:丽草蛉卵期、幼虫期、蛹期、产卵前期和世代发育起点温度和有效积温分别为9.22、7.47、8.69、7.04、7.52℃和72.40、302.21、240.86、140.49、793.16日度。丽草蛉各虫态发育历期随着温度的升高而缩短;丽草蛉发育速率与温度为显著相关性;内禀增长率(rm)均大于零,种群趋势指数(I)均大于1,丽草蛉实验种群呈增长状态;在26、28、30℃时,丽草蛉内禀增长率(rm)及种群趋势指数(I)分别为0.095 0、0.116 3、0.113 9及48.363 5、66.610 0、48.069 3。26~30℃为丽草蛉种群生长的适宜温度。 相似文献
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基于均匀设计优化的大螟实用饲料配方及继代饲养 总被引：3，自引：1，他引：2
通过均匀设计对大螟人工饲料配方进行了优化,获得的实用饲料优化配方如下:琼脂3g,大豆粉8g,茭白粉11g,酵母16g,蔗糖6g,稻茎粉3g,玉米粉11g,麦芽粉5g,干酪素7g,维生素C 0.8g,山梨酸0.64g,金霉素0.54g,胆固醇0.04g,无机盐1.5g,蒸馏水200g。该配方对大螟已连续饲养超过10个世代,优于以往报道的饲料。该配方饲养的大螟第1代初孵化幼虫发育至蛹的比例(化蛹率87.5%)较原配方(CK,40.8%)提高46.7个百分点。从第1代到第10代的连续饲养过程中,大螟的化蛹率、羽化率、卵孵化率和单雌产卵量等指标没有明显退化趋势,平均分别为42.5%～87.5%、79.7%～95.8%、90.0～94.9%和95～252粒/雌。第10代除雄幼虫历期显著较长外,其余各指标均与第1代无显著差异。 相似文献
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莲草直胸跳甲成虫产卵选择性及叶位与幼虫发育适合度的关系 总被引：2，自引：0，他引：2
采用室内自由选择法和发育测定法研究莲草直胸跳甲(Agasicles hygrophila)成虫对喜旱莲子草(Alternanthera philoxeroides)叶位的产卵选择性及后代发育与不同叶位叶片的适合度.结果表明:(1)莲草直胸跳甲成虫嗜好在中部叶片的叶背产卵,以在第2对叶上的选择系数最高,选择率为35.18%,与第1对叶上的28.03%差异不显著,但显著高于对其他叶位的选择系数;(2)相对于在叶表进行取食,初孵幼虫显著趋向在叶背,且这样取食的1龄幼虫存活率高、发育历期显著缩短,这与雌虫选择在叶背产卵的习性相符,说明其选择有一定生物学意义,即有利于后代发育;(3)叶龄对莲草直胸跳甲各龄幼虫发育有显著影响,叶位越低,各龄幼虫的发育历期越长,但存活率上以取食第1叶位的为最高. 相似文献
5.
温度对豆天蛾发育历期及取食量的影响 总被引：2，自引：0，他引：2
近年来豆天蛾作为一种昆虫源食品受到人们的关注,研究了温度对豆天蛾幼虫发育历期及取食量的影响。结果表明:3~5龄幼虫在5个温度条件下发育速率随温度的升高先增加后降低,(28±1)℃为发育速率的顶点;3~5龄幼虫在5个温度下的总取食量分别为10.7、10.4、10.8、11.1和10.7 g。总取食量、日取食量和日增重随温度的升高而先升高后下降,且均在(28±1)℃条件下出现最大值。为探索人工饲养豆天蛾的最适温度条件提供一定的理论基础。 相似文献
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防治眼菌蚊Bt.菌株的筛选与培养条件优化 总被引：1，自引：1，他引：0
通过11株Bt.菌株对平菇厉眼蕈蚊3龄幼虫的室内毒力测定试验,得出91019菌株对平菇厉眼蕈蚊3龄幼虫有较高的毒力效果,其发酵原液和250倍稀释液对平菇厉眼蕈蚊3龄幼虫的校正死亡率分别达到93.10%和82.76%。通过正交试验对91019菌株的各培养条件进行优化,得出理论最佳培养基组分及培养条件为:玉米粉1.0%、黄豆饼粉2.5%、酵母粉2.0%、鱼粉2.0%、蛋白胨0.4%,KH2PO4 0.5 g/L,CaCO3 4.0 g/L,MgSO4.7H2O0.5 g/L,ZnSO4.7H2O 0.02 g/L;接种量2.0%、pH7.0、装液量25 mL、培养温度25℃。 相似文献
7.
本研究通过对人工饲料加豆蚜及纯豆蚜饲养的七星瓢虫对茶蚜的捕食能力进行评价,以倒数法拟合Holling圆盘方程,明确不同饲养方式七星瓢虫对茶蚜的捕食能力.研究结果表明,当N→∞时,每头豆蚜饲养的七星瓢虫成虫的后代1～4龄幼虫以及雄雌成虫在1 d内对茶蚜的最大捕食量分别为30.7692、94.3396、303.0303、588.2353、222.2222、500.0000头.当N→∞时,每头混合饲养的七星瓢虫成虫的后代1～4龄幼虫以及雄雌成虫在1d内对茶蚜的最大捕食量分别为29.6736、112.3596、277.7778、555.5556、120.4819、188.6793头.豆蚜饲养七星瓢虫和混合饲养七星瓢虫成虫两种方式饲养的七星瓢虫第1代各龄幼虫对茶蚜的捕食量之间没有显著性差异(P>0.05,n=6),混合饲养七星瓢虫幼虫羽化的成虫对茶蚜的捕食量极显著低于豆蚜饲养七星瓢虫幼虫羽化的成虫对茶蚜的捕食量(P<0.01,n=6).本研究表明,混合饲养的七星瓢虫对茶蚜具有较强的捕食能力,在七星瓢虫对茶蚜的防治应用中具有广泛前景. 相似文献
8.
稻纵卷叶螟对不同植物的产卵趋性与取食选择 总被引：1，自引：0，他引：1
【目的】稻纵卷叶螟是我国水稻上的一种重要害虫,在田间除水稻之外还可取食多种禾本科植物并完成生活史,但在大发生年份该虫几乎只在水稻上发生。本研究旨在明确该虫在水稻及其他寄主植物上的产卵选择及后代取食趋性的机制。【方法】采用室内笼罩选择实验比较了稻纵卷叶螟在水稻、玉米、稗草、狗尾草上的产卵与取食选择性以及取食经历对产卵、取食选择的影响。【结果】在笼罩条件下稻纵卷叶螟成虫在水稻叶片上的着卵量占总卵量的49.08%,显著高于其他三种植物;幼虫取食水稻后发育历期为17.29 d,显著短于取食玉米和狗尾草,同时取食水稻后蛹重最重;幼虫期分别取食水稻和玉米的稻纵卷叶螟成虫对四种植物的产卵选择无变化,仍显著偏好选择水稻产卵;低龄幼虫的取食选择性在几种植物之间无显著差异,低龄期取食水稻的幼虫发育到3龄、4龄后对寄主的取食选择顺序为狗尾草水稻、稗草玉米;低龄期取食玉米的幼虫发育到3龄、4龄后对寄主的取食选择为狗尾草玉米水稻、稗草。【结论】稻纵卷叶螟成虫显著偏好在水稻上产卵,产卵选择性不受幼虫取食经历影响,产卵选择性与幼虫的取食选择性并不一致。幼虫取食水稻的发育历期最短,蛹重最高。高龄幼虫显著偏好取食狗尾草,同时,低龄期的取食经历改变了高龄幼虫对水稻和玉米的取食偏好。 相似文献
9.
分别用番茄果实、辣椒果实和人工饲料饲养斜纹夜蛾,观察不同食料对斜纹夜蛾(Spodoptera litura Fabricius)的生长发育、存活、不同龄期幼虫的粪便重量、成虫产卵量的影响,组建相应食料下的斜纹夜蛾实验种群生命表.结果表明:喂饲辣椒果实的斜纹夜蛾幼虫发育历期和全世代显著长于喂饲番茄和人工饲料,喂饲人工饲料的斜纹夜蛾不同龄期幼虫的粪便重量显著重于喂饲辣椒果实;种群趋势指数(Ⅰ)均大于1, 内禀增长力(rm)均大于0,斜纹夜蛾种群呈增长趋势. 相似文献
10.
大造桥虫幼虫生长发育及其取食规律的初步研究 总被引：1，自引：0，他引：1
大造桥虫是危害大豆的主要食叶性害虫之一.为了明确大造桥虫幼虫发育龄期及各龄期对大豆叶片的取食量,深入研究其取食危害规律,采用离体叶片单头饲养法,系统观测幼虫生长发育及各龄期取食量.结果显示,大造桥虫幼虫共6龄,在27 ～ 28℃条件下,幼虫发育历期平均需要19.05 d,其中1龄3.07 d,2龄2.00 d,3龄1.86 d,4龄2.24 d,5龄3.33 d,6龄6.38 d.各龄幼虫的头宽与体长均随着龄期的增长而增大,头宽与体长的生长模型分别为n =0.178e0.489x(R2 =0.997)和y2=1.671e0.519x(R2=0.994);大造桥虫幼虫发育阶段与取食量的关系模型为:叶面积,y1=6.387e1.202x(R2=0.976),鲜叶重,y2=0.467e1.319x(R2=0.949).整个幼虫期可累计取食大豆叶片面积为17 218.88 mm2,重量为2 669.50 mg.其中4～6龄幼虫的取食量占整个幼虫期取食量的98％以上.因此,从有效控制大造桥虫幼虫危害的角度出发,防治宜在3龄前进行. 相似文献
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《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