海南哈密瓜简易设施栽培覆盖模式研究初报

利用海南冬春季节的热带气候资源，采用设施园艺栽培技术能够反季节生产原产新疆的哈密瓜。该文采用不同覆盖模式的简易竹木结构设施大棚，种植反季节哈密瓜的试验研究初步结果。     

吐鲁番哈密瓜土壤养分及酶活性对连作年限的响应

哈密瓜(Cucumis melo var.saccharinus)连作障碍已经成为制约其产业发展的重要因素,为探明哈密瓜连作年限对土壤养分及酶活性的影响,以吐鲁番鄯善县不同连作年限哈密瓜田为研究对象,分析了不同连作年限哈密瓜农田根际土壤及非根际土壤的养分含量及酶活性特征.结果表明:1)随连作年限的递增,哈密瓜根际土壤和...     

不同微生物菌剂处理对哈密瓜品质及土壤养分和酶活性的影响

针对哈密瓜长期连作引起的产量低、品质差问题,研究微生物菌剂对土壤肥力和哈密瓜品质的影响.试验以哈密瓜为研究对象,对连续种植3年哈密瓜土壤设置对照、12#菌剂、D74菌剂、1#菌剂、12#和D74菌剂混合菌剂共5种施肥处理,对比不同处理的哈密瓜品质、土壤养分特征和酶活性的变化,并对哈密瓜品质、土壤养分和酶活性相关性进行分...     

北海市大棚设施农业现状与发展对策

设施农业属于高投入高产出,资金、技术、劳动力密集型的产业。它是利用人工建造的设施,使传统农业逐步摆脱自然的束缚,实现农产品的反季节上市,进一步满足多元化、多层次的消费需求。本文以北海大棚设施农业为研究对象,通过分析北海大棚设施农业现状,主要成效及存在问题,针对如何推进北海大棚设施农业提出对策。     

热水结合果蜡处理抑制振动引起哈密瓜衰老的机理

远距离运销是哈密瓜流通过程中的重要过程,其中运输过程中的振动是影响哈密瓜衰老的重要逆境。为了减少运输振动导致的哈密瓜的成熟衰老。该文以哈密瓜为原料,利用模拟振动台对哈密瓜进行振动处理,并利用热水结合果蜡对哈密瓜进行保鲜。随后在模拟销售条件的室温条件下（23℃）对哈密瓜的细胞膜完整性及相关的指标进行了检验,同时还利用透射电镜对新鲜和贮藏结束后哈密瓜组织细胞微观结构变化进行了检测。结果表明,运输振动胁迫加速了哈密瓜细胞的微观变化及细胞膜完整性丧失,在经过28 d的模拟销售条件的室温条件下,对照组（未经处理）的相对电导率分别是振动处理组的95%和热水果蜡处理组的1.15倍,且三者间区别显著（P<0.05）。这主要是由于运输振动增加了哈密瓜果实的呼吸作用,伴随较高的丙二醛产生,较低的超氧化物歧化酶,过氧化氢酶和过氧化物酶等抗氧化酶活性。而热水结合果蜡处理抑制了运输振动引起的哈密瓜细胞膜脂质的氧化及与相关的变化,延缓了哈密瓜的衰老,保持了贮藏过程中哈密瓜的品质。研究结果可以为提高采后哈密瓜的运销品质和保鲜效果提供一定的参考。     

哈密瓜常温保鲜贮运技术研究

该研究旨在解决新疆哈密瓜采后低温贮运费用高,常温贮运腐烂率高,损失严重的问题。针对哈密瓜采后腐烂的主要病原菌匍枝根霉(R.stolonifer)、链格孢霉(A.Alternata)、半裸镰刀菌(F.semitectum)、脂状青霉(P.digitatum),筛选出对症的抑菌剂,并研究其最适使用浓度;以常温贮藏哈密的瓜失重率、呼吸强度、过氧化氢酶(CAT)、纤维素酶、果胶甲酯酶(PE)、多聚半乳糖醛酸酶(PG)活性等为指标,研究云南虫胶作为被膜对哈密瓜采后生理的影响及其最适使用浓度。含有0.60g/L扑海因、0.8g/L氯硝胺、0.6g/L特克多、0.8g/L施宝功和1∶24(V.V-1)虫胶的混合溶液浸泡哈密瓜10s,于28℃,85%RH,贮藏30d,腐烂率1.87%,同期对照腐烂率49.54%。处理后的哈密瓜在室外温度28～34℃、棚车内温度30～38℃的条件下,经过12～15d由新疆哈密运抵苏州、上海、广州的腐烂率分别为3.37%、4.12%和4.86%。哈密瓜表皮以内0.8cm几乎无抑菌剂残留。用上述配方的虫胶与抑菌剂的混合溶液浸泡哈密瓜,可有效降低哈密瓜采后常温贮运中的腐烂率,保持良好风味和商品质量,大量节省运输费用     

基于深度学习与图像处理的哈密瓜表面缺陷检测

针对传统人工检测哈密瓜表面缺陷效率低等问题,提出利用卷积神经网络(Convolutional Neural Networks,CNN)对哈密瓜表面缺陷进行快速检测.对原始图像进行主成分分析(Principal Components Analysis,PCA)、奇异值分解(Singular Value Decomposi...     

新疆吐鲁番地区哈密瓜复种关键栽培技术分析

新疆吐鲁番地区具有土层平坦、土壤营养充足及光照时间较长的优势,适宜哈密瓜生长,因此当地的种植户将哈密瓜作为长期栽培的重要作物。目前,哈密瓜复种关键栽培技术得到了普及与推广,农业种植人员应当正确运用复种栽培技术,确保哈密瓜的栽培产能显著提高,且果实达到优质的作物栽培标准。在哈密瓜的复种实践过程中,技术人员需要重点探索关键性的复种栽培处理手段与措施,结合因地制宜的栽培种植方式提升哈密瓜的品质与产量。基于此,分析新疆吐鲁番地区哈密瓜复种关键栽培技术。     

高能电子束辐照对鲜切哈密瓜生理生化品质的影响

通过0．5、1．0、1．5和2．0kGy剂量的电子柬辐照处理鲜切哈密瓜,采用聚丙烯（PP）材质托盘和聚乙烯（PE）保鲜膜包装,置于5℃,相对湿度85％-95％的冷库中贮藏,研究高能电子束辐照对鲜切哈密瓜生理生化品质的影响。结果表明,电子束辐照能显著降低呼吸速率,显著抑制Vc、可溶性固形物的含量的下降,减少丙二醛积累,降低多酚氧化酶和过氧化物酶活性,并提高苯丙氨酸解氨酶活性。1．5kGv辐照处理的鲜切哈密瓜在贮藏至第13天时,感官品质保持良好。综合电子束辐照对鲜切哈密瓜的保鲜效果,确定最佳处理剂量为1．5kGy。     

我国无土栽培的新技术,新成果,新动向

简介中国自１９８６年至１９９５年无土栽培的发展情况。主要包括高效，节能，实用的无土栽培设施与配套技术；反季节的蔬菜无土栽培技术和一些应用研究成果；以及这些成果的推广情况和今后发展动向。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【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。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

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.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

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.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.     

Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater

Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

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.     

Increase in auxiliary photoprotective photosynthetic pigments in wheat seedlings induced by Azospirillum brasilense

Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.     

Responses of native legume desert trees used for reforestation in the Sonoran Desert to plant growth-promoting microorganisms in screen house

Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria (Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation. Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured as transpiration and diffusive resistance, when these trees were cultivated without water restrictions.