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1.
利用人工催产、授精和孵化技术,对50组白鲫(♀)和禾花鲤(♂)亲鱼成功地进行杂交繁殖试验。在注射催产剂10 h后,白鲫亲鱼开始产卵,5.5 h后产卵结束,共产卵42尾,产卵率84%,产卵约285.6万粒,受精卵约201.9万粒,受精率约70.7%。经60~72 h的孵化,出苗149.2万尾,孵化率73.9%。培育获得3~5 cm苗种98.2万尾,成活率65.8%。  相似文献   

2.
鱼类工厂化循环水人工繁育设施装备应用研究进展   总被引:1,自引:0,他引:1  
水产种业的高质量发展是推动养殖业发展的基础,现阶段中国鱼类人工繁育生产方式设施装备化程度低,产业大而不强,转型升级的需求迫在眉睫。该研究在文献调研整理的基础上,首先就循环水人工繁育设施装备在亲鱼产卵、鱼卵孵化、鱼苗培育等方面的研究和应用情况展开论述。相对于常规培育方式,循环水系统能够最大程度上构建出符合亲鱼交配和产卵的环境条件,养殖密度0.01~4.5 kg/m3,系统循环率9~76%/h,换水率0.7~3%/d;针对不同性质的鱼卵,介绍了国内外目前常用的孵化器主要有瓶式孵化罐、平列式孵化槽、漏斗式孵化器等,阐明了其适用对象、工作原理和主要性能表现;针对育苗和养殖系统构建需求的差异,综述了目前在循环水育苗设施装备应用研究中关注的重点和难点。其次,概述了中国鱼类人工繁育发展现状和问题,分析了循环水人工繁育技术的优势和面临的挑战。最后提出,鱼类工厂化循环水人工繁育具有较高的可行性和引领性,但是要实现产业化应用仍需要进一步开展基于品种对象的人工繁育环境构建及循环水处理、繁育过程鱼类对环境应激源的生物学响应、智能繁育装备等方面技术攻关和装备研发。  相似文献   

3.
京津冀区域面积21.7万km2,具有良好的自然和农业生产条件,2013年耕地面积699万hm2,蔬菜播种面积90.4万hm2,其中设施栽培42.0万hm2,在我国农业生产中具有重要地位。发展都市型现代农业是京津冀地区的必然趋势。该区设施农业复种指数高,产出强度大,化肥、有机肥使用量大,造成土壤氮磷超量累积,淋失严重,重金属超标,面源和重金属污染形势严峻,危及土壤及地下水安全,生态环境质量下降。此外,随着集约化程度的提升,尾菜等设施农业废弃物不断增加,给环境带来巨大压力。所有这些环境污染问题已成为阻碍经济、社会可持续发展的重要瓶颈,严重制约着京津冀协同发展。  相似文献   

4.
生态农业是将农业生态系统同农业经济系统综合统一起来,以取得最大的生态经济整体效益的一个农业生态经济复合系统。农业养殖园是生态农业的重要模式之一。规模化、集约化畜禽养殖产生的污染已经成为我国农村面源污染的主要来源。以位于重庆市南川区的鑫宜居生态农业特种养殖园为例,分析其废水、废气及固体废物污染排放情况,针对这些污染,提出"合理的污水处理工艺和配套储存设施,粪便堆肥处置要点,大气污染防治对策,环境风险对策,政策措施建议"等环境保护对策及建议。  相似文献   

5.
鳜鱼是一种适应性很强的淡水名贵鱼类,因肉质细嫩、外形美观、养殖性状优良而深受消费者和养殖者的青睐。但鳜鱼系肉食性鱼类,以活饵为食,拒绝摄食配合饲料,因而不少单位及个人往往因活饵料未能配套或未能驯食人工饲料而达不到应有的养殖效益,从而丧失养殖信心,在一定程度上影响了该鱼的推广养殖。由此可见,解决鳜鱼养殖的饵料配套问题,尤其是解决养殖中鳜鱼食性驯化的技术问题,已成为发展鳜鱼人工养殖急需解决的一大现实问题。基于此,分析池塘网箱鳜鱼苗种人工饲喂驯化技术要点。  相似文献   

6.
上海都市型生态农业模式及对策   总被引:2,自引:0,他引:2  
利用文献资料调查、统计分析和实地调研的方法, 分析总结了上海生态农业发展的现状, 研究提出了设施化+生态技术为主、集约化+生态技术为主、科技化+生态技术为主、市场化+生态技术为主、产业化+生态技术为主、观光休闲+生态技术为主等6个上海都市型生态农业发展的主要模式.重点分析整理了上海都市型生态农业的不同实践模式及其发展过程中存在的问题, 进而提出上海发展都市型生态农业的对策措施.  相似文献   

7.
LED在植物设施栽培中的应用和前景   总被引:33,自引:6,他引:27  
该文综述了近年来发光二极管(LED)在植物设施栽培中的研究与应用,内容包括:应用于植物设施栽培的LED特征,LED在植物组织培养、设施园艺和航天生态生保系统等方面的研究,以及LED应用于植物设施栽培领域的前景分析.  相似文献   

8.
日本产温室设施的性能测定   总被引:2,自引:1,他引:2  
通过对日本产温室的测试研究,对其结构特性,覆盖材料及配套设施包括室内外遮阴帘,双层保温幕,通风及降温系统,自动控制系统的性能等进行了分析,提出了改进意见。  相似文献   

9.
西藏涅如藏布流域可分为自然生态保护区、草地农业系统建设区和高效农林复合系统建设区进行综合治理开发。在自然生态保护区应以封禁为主,并进行必要的生态移民;在草地农业系统区应通过合理调整畜种结构,大力发展畜牧业生产;在高效农林复合系统区应强化水利配套设施建设,建立合理的灌溉制度、土地用养制度和灌木防护林体系。预测了涅如藏布流域的治理开发前景。  相似文献   

10.
生态农业景观与生物多样性保护及生态服务维持*   总被引:5,自引:3,他引:2  
现代集约化的农业生产极大地改变农业景观生物多样性状况及生态系统服务功能,进而影响到农业可持续发展。大量研究显示,农业生态系统中物种多样性维持、害虫控制、传花授粉等生态系统服务功能受到景观结构的影响,仅仅改变集约化的生产方式,并不足以促进生物多样性的恢复及生态系统服务的维持,尚需考虑景观结构的调整和管理。从不同尺度上优化景观要素的空间配置和景观管理方式、建设生态农业景观成为促进农业景观生态系统服务功能维持、保护生物多样性和农业可持续发展的重要措施,具体包括:1)在区域和景观尺度上合理规划和配置种植区域和非种植区域以确保生态安全与稳定性;2)在地块间尺度保护、建设和管理甲虫带、野花带等生态设施,为农业生产提供必要生态系统服务;3)在地块内尺度通过多样化的种植和优化管理措施以获取农业生产和自然保护之间的平衡;4)整合景观规划设计与生态循环工程以促进农业景观资源的高效利用。  相似文献   

11.
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   

12.
“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   

13.
To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.  相似文献   

14.
Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.  相似文献   

15.
Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.  相似文献   

16.
Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P500 und P501 verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P500 and P501 were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.  相似文献   

17.
Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×105 viable propagules g-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.  相似文献   

18.
细菌、真菌及植物氮营养信号研究进展   总被引:1,自引:0,他引:1  
氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外(生长介质中)氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。  相似文献   

19.
Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.  相似文献   

20.
李聃枫  朱春梧 《土壤》2020,52(3):561-566
自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。  相似文献   

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