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51.
我国草坪业研究概况及现状分析 总被引:7,自引:1,他引:6
我国草坪开发利用通过近十多年的研究,已由小规模的试验转入大规模的生产经营,形成具有独立性的新兴产业。本文就草坪种质资源、草坪草引种、草坪建植(观赏与运动草坪)与管理技术(施肥、除杂、病虫害防治)及草坪生态研究进行综述,并简要概括了我国草坪业目前取得的成就及亟待解决的主要问题。 相似文献
52.
中国水资源面临危机,通过对中国水资源现状、特点及存在问题的分析,指出了实现水资源可持续利用的出路是建立节水型社会。并从制度、经济、科技、文化及具体措施几个方面分析了建设节水型社会的基本思路。 相似文献
53.
就合作社的设立原则、设立人和出资形式3个主要问题展开论述,以期对农民专业合作社的规范化发展作出有益探索。 相似文献
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55.
将HACCP体系应用于出口浓缩苹果清汁的生产过程中,对浓缩苹果清汁的生产过程进行了危害分析,并确立了原料验收、拣选、后巴氏杀菌、灌装前过滤、发运前检查签封五个关键控制点,并根据生产的实际情况及实验确立了每个关键控制点的关键限值,监控和纠偏措施。同时,对HACCP体系的有效运行做了说明和分析。 相似文献
56.
We assessed the growth and survival of a willow clone (Salix matsudana × Salix alba ‘A 13/44’) growing under different vegetation management in the flooded area of the Parana River Delta (Argentina) during
the first 2 years after planting. Treatments consisted in a combination of practices applied in the row and in the inter-row.
In the row (1-m wide) vegetation was manually cut with machete (r-M), treated with glyphosate at 3% (r-H) or maintained undisturbed
(r-U); in the inter-row vegetation was crushed with a roller (I-R), treated with glyphosate at 3% (I-H) or maintained undisturbed
(I-U). Height, diameter and relative growth rate of the dominant sprout were evaluated. Tree survival was high (96%) and not
affected by treatments. Growth was modified by the vegetation control at early stages. Height and diameter were higher in
r-H plots compared to r-U plots; both were similar in the I-U and I-H plots but greater than in I-R plots. Early differences
in diameter relative growth rate among row treatments were found. Possible mechanisms associated with willow growth responses
such as plastic responses under resource limited conditions and amelioration of the microenvironment by the native vegetation
are discussed. 相似文献
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58.
为探讨高品质实蝇基因组DNA提取,研究模板DNA浓度、引物浓度、Taq DNA聚合酶用量、dNTP浓度、退火温度及时间对ISSR-PCR扩增结果的影响,以3种实蝇为材料,建立通用且稳定的实蝇ISSR-PCR反应体系。结果表明:获得了高品质实蝇基因组DNA;确立了通用且稳定的实蝇ISSR-PCR反应体系:10×PCR Buffer 2.5 μL,模板DNA 50 ng,引物0.25 μmol/L,Taq DNA聚合酶0.50 U,dNTP 200 μmol/L,最后加ddH2O至25 μL;明确了ISSR-PCR扩增程序:94℃预变性5 min,94℃变性30 s,52.4℃退火45 s,72℃延伸90 s,循环36次,最后72℃延伸7 min,4℃保存。体系的建立弥补了实蝇传统形态检测的不足,为快速准确鉴定、种群异质性及遗传多样性分析奠定了基础。 相似文献
59.
Dugald C. Close Neil J. Davidson Keith C. Churchill Ross Corkrey 《Forest Ecology and Management》2010
Many regions of southern Australia exposed to broad-acre grazing are denuded of trees. Re-establishing trees in these landscapes is important for both environmental and economic reasons. We investigated whether climate at the site of origin of the seed can inform species selection for tree establishment on ex-pasture sites within agricultural landscapes. We established trials at four sites in the sheep and cattle grazing region of the Midlands of Tasmania at: ‘Woodland Park’; ‘Sorrel Springs’; ‘Inverel’ and ‘Glen Morey’ farms (long-term average rainfalls of 584, 520, 520, and 479 mm, respectively). Eucalypt species were selected, based on high tolerance to frost and drought inferred from climate at the sites of origin and based on the limited scientific literature available, from across Tasmania and mainland Australia. We investigated the mortality, health and height growth of 18 eucalypt species three months, one and six years after planting. Climatic data from the site of origin of the seed of these species was used to group species into categories of mean annual temperature and mean annual rainfall at seed-source. Sensitivity of species to environment was investigated and compared using modified joint regression. At three planting sites, Woodland Park, Sorrel Springs (except health of the temperature category comparison at six years) and Inverel, we found significantly greater height and health one and six years after planting for local (Tasmanian) compared to non-local (Australian mainland) species, and for species where the site of origin of seed was categorised as low or medium mean annual temperature compared with those categorised as high mean annual temperature. There were no significant differences in mortality for these comparisons. At Glen Morey, height was significantly greater at six years after planting of local compared to non-local species and of species from low and medium mean annual temperature categories compared with the high mean annual temperature category. Mortality was significantly greater in local than non-local species six years after planting. Health was not significantly different for these comparisons. Differences in height, health or mortality of species categorised into mean annual rainfall at seed-source were largely non-significant at all sites one and six years after planting. A study of the sensitivity of species to environment of planting indicated that Tasmanian species were less sensitive than mainland species when height data was compared. When health data was compared, species with a site of origin of seed categorised as low rainfall were less sensitive to environment than species categorised as medium and high-mean rainfall. When mortality data was used significant differences were identified in the sensitivity of species to planting environment but this was not related to locality, mean annual temperature or rainfall at seed-source. Species that attained above average height and low mortality across three or more sites included Eucalyptus pulchella, Eucalyptus perineana (Tasmanian species), and Eucalyptus microcarpa, Eucalyptus benthamii and Eucalyptus melliodora (mainland species). Whilst temperature (and to a lesser extent rainfall) at seed-source is a good indicator of the success of tree establishment, high variability between sites points to the need to consider climate, browsing pressure and farm management at the paddock-scale when planning revegetation plantings. This has important implications for carbon sequestration plantings. 相似文献
60.
本文根据对博白县33个乡镇进行抽样调查的情况,分析博白县乡镇农技推广体系的现状。提出了加强乡镇农技推广体系建设的5条意见和建议。 相似文献