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61.
[目的]研究超级稻Ⅱ优602植株对N素水平和配置方式的动态反应。[方法]试验以II优602为材料,分析不同施N量及配置方式下功能叶、叶鞘、茎秆全N含量的动态变化。[结果]不同N素水平下功能叶的最高全N含量出现的时期不同,其中A3水平下以复水期最高。齐穗期、成熟期植株各部位的全N含量均表现为施肥处理>CK,功能叶>叶鞘>茎秆,而不同处理下,植株不同部位的全N含量表现出明显的差异。Ⅱ优602在成都平原种植,适宜的施N水平和配置方式为:N素165kg/hm2,底肥:追肥=6:4。[结论]该研究为超级杂交稻的高产栽培提供N素调控的理论依据。  相似文献   
62.
目的探讨糖尿病前期(IGR)中医体质及与相关指标的关系。方法用前瞻性研究方法,采集517例IGR患者信息,进行中医体质辨识和相关指标的分析。结果①517例IGR人群中,单一体质类型者、二种体质类型相兼者、三种体质类型相兼者分别占25.8%、66.5%、7.7%;前3位的体质类型分别是痰湿兼湿热质、痰湿兼气虚质、湿热质,共占64.8%。②痰湿兼湿热质、痰湿兼气虚质、湿热质体质量指数(BMI)、腰臀比(WHR)、血脂TC、TG、LDL-C显著高于其他体质组,差异有统计学意义(P<0.01)。结论①IGR人群体质可表现为单一体质,也可表现为复合型体质,其中以痰湿兼湿热质、痰湿兼气虚质、湿热质为主,提示痰湿和湿热是IGR人群的重要因素。②BMI、WHR、血脂TC、TG、LDL-C是IGR痰湿和湿热体质的辨识和疗效判断的参考指标。  相似文献   
63.
The risk for damage associated with spruce bark beetle attacks on living trees was estimated in 12 forest districts in the Nordic countries during three years. Pheromone‐baited traps and trees were used. Five groups of three traps were deployed annually on fresh spruce clear‐fellings in each district. The mean catches within districts and years ranged from 950 to 46000 beetles per trap group. The standard error averaged 15 % of the mean catch. One tree was baited annually at each of five other sites in each district. The mean number of trees colonized by Ips typographus in each district and year ranged from 0 to 5 per site. The standard error was high, averaging 44% of the mean. Inventories of tree mortality within the districts yielded values ranging from 0 to 150 killed trees per km of spruce forest edge. There was a strong linear correlation between mean catches in traps and log‐transformed tree mortality (r=0.82). The correlation between colonization success at tree‐baiting sites and tree mortality was weaker (r=0.59), owing to one deviant observation. The results indicate that pheromone traps and baited trees may be used to assess the risk for damage caused by Ips typographus.  相似文献   
64.
受体牛同期发情多因素影响的研究   总被引:1,自引:1,他引:0  
在进行牛胚胎移植时,为了使移植工作能够集中进行,需要对大批受体牛进行同期发情处理。试验一中,比较了PG法和CIDR+PG法处理同期发情的2种不同处理方法对同期发情效果的影响;试验二中,用PG法进行同期发情试验研究不同繁殖状况下同期发情的效果;试验三中,同期发情处理方法采用CIDR+PG法,研究不同营养水平、不同带犊情况因素对受体牛同期发情效果的影响。结果表明:2种不同同期发情处理方法使受体牛同期发情率差异不显著(P〉0.05);使用PG法进行同期发情试验中不同繁育情况之间同期发情率比较后,显示选择育成牛作为受体牛处理最佳;在同期发情处理方法采用CIDR+PG法试验中,典型放牧条件下不同营养水平产犊超过3个月同期发情率都显著高于产犊不足3个月的牛。本研究显示不同繁殖状况、营养水平高低、不同带犊情况对受体牛同期发情效果的影响各有差异。  相似文献   
65.
为建立一种能够快速、灵敏和特异地检测J亚群禽白血病病毒(ALV-J)的SYBR Green Ⅰ荧光定量PCR方法,本研究以ALV-J原型病毒株HPRS-103的pol基因3′端与gp85编码基因之间的保守区域(5 258 bp~5 802 bp)为检测目的片段,构建重组质粒并作为靶基因,通过对其浓度、引物浓度和退火温度的优化,建立了ALV-J SYBR Green Ⅰ荧光定量PCR方法.结果显示该方法的最低检测限度为2.36×102拷贝/μL,比普通PCR高100倍;与其他禽源病毒无交叉反应;批内和批间变异系数均小于5%.表明本研究建立的方法具有良好的特异性、稳定性和灵敏性.采用该方法对100只临床病鸡进行检测,ALV的检出率为44%.随机选择10只感染阳性鸡,检测病毒基因在心脏、肝脏、脾脏、肺脏和肾脏中的分布与表达水平,结果表明ALV-J在各主要脏器中均有分布,但以肾脏中的病毒表达量最高.  相似文献   
66.
Abstract

Maize grain yields have increased dramatically over the past fifty years, and concurrently end-uses have proliferated requiring special quality characteristics. Plant breeders have developed many specialty types of maize, all of which are influenced by the agronomic practices used to produce the crop. Grain yield increases have resulted in lower protein concentration except when the yield increase resulted from nitrogen fertilizer application. Irrigation improves the biological value of protein, while higher nitrogen application rates alter the amino acid balance thereby reducing the nutritional value. Kernel breakage susceptibility and kernel density increase with higher nitrogen fertilizer application rates, and are reduced by irrigation. Extractable starch and oil concentration are largely influenced by hybrid choice, but small production practice effects have been documented. Essential mineral nutrient levels are often influenced by soil or foliar fertilizer application. The production of aflatoxin can be reduced by irrigation or other strategies to avoid water stress during grain fill. Although genetics usually exerts the largest effect on maize grain quality, agronomic practices are also important.  相似文献   
67.
董展展  黄杰 《安徽农业科学》2013,(12):5572-5575
选取了17项指标构建一个可以充分反映县域综合发展水平的评价指标体系,采用因子分析法、分异指数评价法与GIS空间分析工具相结合,对浙江省县域综合发展水平空间分异进行研究。结果表明,浙江省综合发展水平在数值上呈强者偏强,弱者偏弱,中低水平和低水平相对集中的"金字塔型"分布特征;空间分异较大,全局空间分异ID指数为0.223 4,空间分异特征表现为发展水平较高的县域集中分布于环杭州湾地区,发展水平低的县域集中分布于浙西南地区。据此提出了平衡区域发展的对策建议。  相似文献   
68.
【目的】通过控制施肥量来模拟夏玉米不同产量水平,了解不同产量下夏玉米光合及耗水特性变化,为田间用水管理、区域农业高效用水发展战略的制定提供理论依据。【方法】设置4个产量水平分别为9 000 kg/hm~2(C0),9 750 kg/hm~2(C5),10 500 kg/hm~2(C10),11 250 kg/hm~2(C15),以不施肥为对照(CK),研究不同产量下夏玉米穗位叶光合性能、叶绿素荧光及耗水量和水分利用效率变化。【结果】夏玉米拔节期、花前和花后的株高、叶面积指数、净光合速率、气孔导度和蒸腾速率均随目标产量的提高而增加,花前胞间CO2摩尔分数随产量的提高而增加,C15处理株高、叶面积指数、净光合速率、气孔导度、蒸腾速率和胞间CO2摩尔分数分别较CK平均增加25.5%、39.1%、42.1%、97.9%、79.8%、32.0%;夏玉米拔节期、花前和花后SPAD随目标产量提高,C15处理SPAD较CK平均增加17.9%,qP、ETR、Y(Ⅱ)在不同光照强度下为CKC0处理>C5处理>C10处理>C15处理;耗水量和水分利用效率随产量的提高而增加,土壤体积含水率降低,C15处理耗水量和水分利用效率较CK分别提高15.2%、14.1%,土壤体积含水率较C0处理降低11.0%。【结论】夏玉米较高的叶面积指数、生物量和耗水量是形成高产的重要原因,其中后期干物质的合成是产量形成的主要原因,因此应加强夏玉米生育后期田间用水管理。  相似文献   
69.
Plants have evolved different mechanisms to survive under stress conditions. This field study was conducted to evaluate the influence of nitrogen (N) application on dry biomass allocation and translocation in two maize varieties under short pre-anthesis and prolonged bracketing flowering period of drought. Two maize varieties, ‘Pioneer 30B80? and ‘Suwan 4452? receiving N at 0 (control), 160 (optimal) and 320 (supra-optimal) kg ha?1 were subjected to short pre-anthesis and prolonged bracketing flowering periods of drought. Prolonged bracketing flowering period of drought had more suppressive effect on anthesis-silking interval, dry matter allocation and translocation, leaf greenness, contribution of current assimilates to grain (CCAG), kernel number, kernel weight and kernel yield of two maize varieties than a short pre-anthesis drought. Nitrogen application at optimal level was the best for all traits, except CCAG. The maize variety ‘Pioneer 30B80? performed better under both drought types due to more root xylem vessels of large size and more accumulation of dry matter in leaves and roots than the variety ‘Suwan 4452?. Therefore, the variety ‘Pioneer 30B80? may be planted in drought prone environments and may be used in breeding program aimed at developing drought-tolerant cultivars.  相似文献   
70.
A field experiment has been conducted to determine the effects of different irrigation water and AMF (Arbuscular Mycorrhizal Fungi) biofertilizer, photosynthesis activator and traditional fertilizer dry bean (Phaseolus vulgaris L.) on yield and growth parameters in Nevsehir Province of Turkey in 2015. The experiment has been carried out using three replications in a split plot design with three different irrigation types as main plots and AMF biofertilizer (ERS), photosynthesis activator (Multigreen-Mg), traditional fertilization (TF-Control), ERS + Mg, ERS + TF and TF + Mg applied as subplots. The number of pods per plant, the length of pods, the number of grains per pod, the weight of grains per plant, the yield of grains, 1000 seed weight, the number of grains per plant, protein yield, arbuscular mycorrhizal fungi rate have been evaluated as yield and growth criteria in the study. In the experiment, as well as the treatment x irrigation interaction, the plant height, pod number per plant, pod lenght, grain number per pod, grain weight per plant, grain yield, 1000 seed weight, grain number per plant, protein rate/grain, protein yield, root weight and AMF colonization parameters, were the other studied properties that were found to be significant. The results obtained were 877.6 mm for I100 irrigation treatment, 512.2 mm for I50 irrigation treatment and 40.19 mm water for I30 irrigation treatment. Regarding the growth parameters of dry bean, the highest PH was in ERS + Mg (67.66 cm), the lowest PH was in ERS (54.33 cm); In I50, the highest Plant Height (PH) was in ERS + Mg (65.66 cm), the lowest PH was in TF-Control (53.00 cm); and in I30, the highest PH was in TF-Control (50.66 cm), and the lowest PH was again in ERS + Mg (44.33 cm). For protein yield (PY) value, ERS + Mg, ERS + TF, TF + Mg have been placed in the same group, in I100 and I50 irrigation treatment. The highest value was ERS + TF (34.90 kg da?1) in I100, The lowest value was TF-control (19.90 kg da?1) in I30 irrigation treatment. In terms of mycorrhiza colonization ratio, ERS has been ranked first in all irrigation treatments, while the highest mycorrhiza colonization has been observed in I30 irrigation treatment (26.30%). ERS was followed by ERS + Mg (23.33%). As expected, the lowest mycorrhiza colonization ratio in all irrigation treatments have been observed in TF-control treatment, while the highest mycorrhiza colonization ratio has been respectively observed in I30 and I50 irrigation topics. The highest root weight (RW) in I100 irrigation treatment was observed in ERS (15.06 g plant?1) and it was observed in ERS (19.05 g plant?1; 26.30 g plant?1) in I50 and I30 irrigation treatments. The lowest RW in all irrigation treatments has been observed in TF + Mg (4.43 g plant?1, 6.40 g plant?1, 10.26 g plant?1), respectively.  相似文献   
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