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橘小实蝇是一种毁灭性果蔬害虫,本文研究了高能电子束对香蕉中橘小实蝇的致死效果,探索其用于防治和口岸检疫诊断的可行性。通过AB5.0~20x型电子直线加速器对香蕉中橘小实蝇的卵和幼虫、沙土中蛹辐照,辐照剂量为0、500、1000、1500、2000、3000Gy,结果显示高能电子束辐照对橘小实蝇卵、幼虫、蛹的LD50分别为879.8、2839.1、868.5Gy,表明幼虫对高能电子束的耐受能力较强。3000Gy能有效抑制卵的孵化(孵化率1.05%)、蛹的羽化(羽化率0),而幼虫致死率仅62.22%。高能电子束辐照效应还有待进一步研究优化。 相似文献
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为简化辐照工艺制定方法,以10Me V电子直线加速器为研究对象,利用铝片叠层法测定电子束单双面辐照时铝片中的剂量分布情况,并以此为基础推算、建立并验证不同密度产品10Me V电子束单双面辐照的深度剂量分布曲线,得出10Me V电子束辐照时各射程深度与材料密度的关系公式。根据深度剂量分布曲线,明确了双面辐照时均一密度产品在不同辐照深度情况下对应的剂量不均匀度(U)。以U≤2.5为标准,将产品按不同厚度分类,建立相应的辐照加工工艺,且实际生产应用效果良好。本研究对10 Me V电子直线加速器辐射加工工艺制定具有一定的指导意义。 相似文献
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为探究高能电子束辐照对大黄的影响,以川产道地大黄饮片为试验材料,以未处理组及硫磺熏蒸组为对照,研究不同剂量(2、3、5、7、10、13、15、25 kGy)电子束辐照对大黄微生物数量、理化性质、活性成分、抗氧化活性的影响。结果表明,高能电子束辐照能降低大黄饮片中的微生物数量,3~5 kGy及以上剂量辐照使大黄微生物数量降至检测限以下,在360 d的贮藏期内微生物数量均控制在药典规定以下,保持较高的卫生标准,而经7 kGy及以上剂量辐照可完全灭菌。辐照对大黄干燥失重、总灰分含量无显著影响,水浸物含量显著增加,其5种蒽醌类成分含量略有增加。贮藏期内,大黄水浸物、蒽醌类活性成分含量明显下降,辐照处理能较好地保持大黄的质量。综合评价表明,3~5 kGy辐照剂量范围能有效杀灭大黄中的微生物,同时大黄水浸物含量明显增加,活性成分含量略有增加,适用于辐照后短期(约180 d)贮藏。7~10 kGy辐照处理能使微生物含量在一年贮藏期内处于较低水平,且对其活性成分含量具有较好的保持作用,适用于辐照后长期(约360 d)贮藏。本研究结果为高能电子束辐照技术在大黄及其制剂的加工与贮藏中的应用提供了一定的理论参考。 相似文献
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辐照处理在防治储粮害虫方面有重要意义,为了缓解储粮害虫的磷化氢抗性问题,采用电子加速器对磷化氢抗性品系和敏感品系赤拟谷盗成虫进行辐照处理,研究了0~1 000Gy电子束辐照对两品系赤拟谷盗的生物效应,并分析了二者对辐照的敏感性。结果表明,电子束处理对赤拟谷盗的致死效应与辐照剂量有关,两品系赤拟谷盗的致死规律大致相同。两品系赤拟谷盗成虫对电子束的敏感性存在差异,但差异不显著。两品系赤拟谷盗成虫经200Gy剂量辐照后不能产生下一代,因此,200Gy可以作为辐照防治赤拟谷盗的参考剂量。本试验为电子束防治储粮害虫提供了技术支持,对促进辐照技术在绿色储粮中的应用提供理论基础。 相似文献
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为探讨高能电子束辐照对麦冬的影响,以川产道地药材麦冬为研究对象,研究不同剂量0 (CK)、2、4、6 kGy电子束辐照对其微生物数量、感官品质、理化品质、活性成分含量及抗氧化活性的影响。结果表明,电子束辐照能明显降低麦冬中需氧菌、酵母及霉菌总数;此外,所有样品中均未检出大肠埃希氏菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)及沙门氏菌(Salmonella)。电子束辐照有利于提高麦冬总皂苷含量,对水分、总灰分、水溶性浸出物、总黄酮、总多糖、总酚含量及抗氧化活性均无显著影响(P>0.05)。电子束辐照后麦冬颜色变暗,主要表现为a*值增加。主成分分析(PCA)及线性判别分析(LDA)结果表明,2 kGy电子束辐照剂量对麦冬风味影响较小。综上,2 kGy辐照处理能有效降低麦冬中微生物数量,对其活性成分含量及抗氧化活性无显著影响,能保持麦冬的色泽及风味品质。本研究为电子束辐照技术在麦冬及其制剂的加工应用提供了一定的理论依据。 相似文献
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电子束辐照对不同虫态的嗜卷书虱的辐照作用 总被引：3，自引：1，他引：2
采用HJIY-6M2高频单枪电子辐照加速器产生的电子束辐照处理嗜卷书虱,研究了0、25、50、100、200、300、400、500、1000Gy的剂量对混于饲料中的嗜卷书虱成虫、若虫和卵等不同虫态的影响。结果表明：嗜卷书虱各虫态对电子束辐照的敏感性由高至低依次为卵、若虫、成虫;经50Gy辐照后嗜卷书虱的卵不能孵化;成虫和若虫辐照后4周的半致死剂量LD50分别为186.1Gy和122.0Gy,经300 Gy辐照后的成虫和若虫分别在8周和6周内完全死亡。考虑到辐照不应对粮食营养品质和加工特性造成明显影响,300Gy剂量电子束可作为有效防治嗜卷书虱的参考剂量。 相似文献
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辐照处理在农产品检疫除害、杀菌保鲜方面具有重要意义。以智利进口甜樱桃为对象,研究了电子加速器辐照处理对果实花青素、色泽及保鲜效果的影响。甜樱桃经过0.00、0.41、1.06、1.88 kGy剂量电子束辐照处理后分别于室温(13~17℃)贮藏7 d、低温(4±1℃)下储藏15 d。结果表明,电子束处理对果实花青素含量的影响与贮藏温度和剂量有关,0.41kGy电子束处理的总花青素和单体花青素含量高于对照和其它剂量电子束处理。电子束处理可影响花青素的聚合和降解,4℃贮藏15 d时,电子束处理花青素聚合色素比均小于对照。硬度下降是甜樱桃贮藏的主要问题,适宜剂量电子束处理结合低温贮藏可减缓果实硬度的下降幅度。电子束辐照对甜樱桃的色泽、总可溶性固形物含量影响不大,其果实的失重率和霉变率均低于未辐照果实,保鲜效果良好。 相似文献
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低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响 总被引：2，自引：2，他引：0
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
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Aleš Lebeda Ivana Doležalová Eva Křístková Barbora Mieslerová 《Genetic Resources and Crop Evolution》2001,48(2):153-164
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions. 相似文献
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Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
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Thomas Larsen Jesper Luxhøi Jakob Magid Lars Stoumann Jensen Paul Henning Krogh 《Biology and Fertility of Soils》2007,44(1):59-68
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization
and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition
with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the
decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots
with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass,
soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration,
N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially
(<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation
in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils,
indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but
the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation
for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community
performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea. 相似文献
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《中国生态农业学报》2014,(6)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
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《中国生态农业学报》2014,(7)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
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I.L. Boyd 《Biological conservation》2010,143(7):1664-1674
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options. 相似文献
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Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage 总被引：1，自引：0，他引：1
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate. 相似文献
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《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
20.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献