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1.
研究了不同颜色色板对假眼小绿叶蝉诱集效果和对天敌缨小蜂的引诱作用，结果表明黄色板诱集的小绿叶蝉数量最多为68.33头·板-1，紫色板最低5.28头·板-1，黄色板诱集数量极显著高于其他色板（F=10.50，P＜0.01），不同色板的诱集效果为黄色＞绿色＞黑色＞灰色＞红色＞蓝色＞白色＞紫色。不同色板诱集缨小蜂的数量差异极显著（F=16.82，P＜0.01），黄色板诱集缨小蜂数量最多19.00头·板-1，色板引诱缨小蜂的数量为黄色＞绿色＞蓝色＞白色＞红色＞紫色＞灰色＞黑色。黄色板对寄生蜂的引诱力最强，平均每板30.89头，不同色板诱集的缨小蜂与假眼小绿叶蝉的益害比差异不显著（F=1.20， P＞0.05）。 相似文献
2.
CO2浓度升高对春小麦光合作用和籽粒产量的影响 总被引：5，自引：1，他引：4
为给在大气CO2浓度升高条件下农作物栽培和农业可持续发展的科学管理决策提供依据,利用开顶式气室(OTC)研究了大气CO2浓度升高对春小麦辽春15生长发育过程中净光合速率、田间气体交换特性、光合酶活性等光合生理生态指标的变化规律以及对籽粒产量的影响.结果表明,CO2浓度增加到550 μmol·mol-1条件下,小麦叶片Pn升高,在孕穗期、灌浆期增幅达到显著水平(P＜0.05);叶片Ci提高,在灌浆期Ci增加达到极显著的水平(P＜0.01);而小麦叶片Gs、Tr呈下降趋势,均在灌浆期与CK差异显著(P＜0.05);各生育时期小麦叶片Hill反应活力都增强,孕穗期升高达到显著水平(P＜0.05);叶绿体Ca2 /Mg2 -ATPase活性均高于对照,但未达到显著水平.高CO2浓度使得小麦生物量积累有所增加,在拔节期、孕穗期小麦植株干重极显著增加(P＜0.01);提高了小麦籽粒产量,表现为穗粒重极显著增加(P＜0.01).在光合作用的整个过程中CO2浓度升高都起到了促进作用,并且最终表现在植株生物量和籽粒产量上. 相似文献
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为探索GDF-8基因在山羊不同生长阶段的肝脏、心脏、肾脏、脂肪和骨骼肌中mRNA表达发育性变换规律，采用SYBR Green实时荧光定量PCR技术对2月龄、3月龄和4月龄的海南本地山羊进行检测。结果显示，GDF-8基因在3月龄的心脏组织中mRNA表达量最高，其次是肾脏和骨骼肌；在2月龄和4月龄时5种组织中GDF-8基因表达量较低，尤其是在心脏组织中几乎不表达；在肝脏和脂肪中的表达依次为4月龄＞2月龄＞3月龄，且各月龄之间表达差异极显著(p＜0.01)；心脏、肾脏和骨骼肌的表达依次为3月龄＞4月龄＞2月龄，其中，肾脏在不同月龄段表达差异极显著(p＜0.01)，而心脏和骨骼肌在2月龄和4月龄之间表达差异不显著(p＞0.05)。 相似文献
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乙烯、6-BA对大豆幼苗生长、生化成分及细胞组织结构的效应 总被引：1，自引：0，他引：1
采用人工培养箱技术,研究ETH、6-BA及其复配处理对大豆幼苗的形态特征、生物量、生化成分、内源激素以及细胞组织结构的调节效应,为大豆芽菜的安全生产提供理论和技术支持.结果表明:不同处理之间大豆幼苗形态存在差异(P＜0.05).ETH、6-BA及复配处理,均抑制了大豆幼苗的根和下胚轴的生长,促进下胚轴的增粗,三者处理后的根长分别比对照减少了24.1%(P＜0.01),44.7%(P＜0.01)和51.7%(P＜0.01);下胚轴长分别比对照减少39.2%(P＜0.01),4.1%(P＞0.05)和26.2%(P＜0.05);下胚轴粗分别比对照增加18.5%(P＜0.01),9.2%(P＜0.05)和32.3%(P＜0.01).大豆幼苗形态上的差异可以通过其下胚轴细胞组织结构的变化来解释,ETH促进了细胞的横向分裂与皮层细胞的扩大,促进下胚轴的增粗,抑制了细胞的径向分裂;6.BA促进了皮层细胞的横向分裂与扩大,抑制了细胞径向的伸长;ETH-6-BA复配处理促进了皮层薄壁细胞的分裂与扩大.不同处理之间大豆幼苗的维生素C含量存在差异(P＜0.05);与对照相比,处理组大豆幼苗的GA含量降低,ABA含量增高(P＜0.01). 相似文献
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黑河地区55份大豆品种资源农艺性状和营养成分的聚类分析 总被引：7，自引：0，他引：7
收集黑河地区55份大豆品种资源材料,以豆芽厂原料大豆S135为对照.采用SPSS15.0软件对大豆品种的15个农艺性状及营养成分进行相关分析、主成分分析和非系统聚类分析.结果表明:单株产量与生育期和单株荚数呈极显著正相关(P＜0.01),与营养生长期和百粒重呈显著正相关(P＜0.05),与底荚高呈极显著负相关(P＜0.01);粗脂肪与粗蛋白呈极显著负相关(P＜0.01),与粗纤维、营养生长期呈显著负相关(P＜0.05).在主成分分析中,选取方差累计贡献率为84.49%的前5个主成分来评价黑河地区大豆品种资源.进一步通过非系统聚类分析,将参试的55份晶种资源分为5类,其中5个品种与对照晶种S135为第一类群,从农艺性状和大豆的营养成分来考虑,第一类适合作芽用大豆晶种;且5个类群性状之间的差异较明显,这有利于育种亲本材料的选择,同时为进一步选育和筛选优良的芽用大豆品种提供理论依据. 相似文献
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为探讨不同钠替代钾条件下椰子叶片叶绿素、丙二醛及Na+、K+含量的变化，在沙培环境中对椰子苗进行钠替代钾试验。结果显示：在Na+、K+总浓度为4 mmol/L的情况下，与100%钾的对照相比，25%的钠替代钾处理中叶绿素a、叶绿素b、总叶绿素含量上升；50%、75%处理明显下降，100%处理略有下降；各处理Chla/Chlb比值变化趋势基本一致，总体趋于平稳且各处理间差异不显著(P＞0.01)。随时间的推移，25%、50%处理丙二醛(MDA)含量与对照相当，趋于平稳，而75%、100%处理丙二醛(MDA)含量呈上升变化。80 d后，各处理的Na+含量随着钠替代钾比例的上升而逐渐增加，较之对照均达到了极显著水平(P＜0.01)；而25%、50%、75%的K+含量略低于对照但差异不显著(P＞0.01)，且各处理间差异也不显著(P＞0.01)，100%处理K+含量明显低于其他各处理且均达到了极显著水平(P＜0.01)。结果表明：部分钠替代钾处理对椰子苗的叶片光合色素及K+含量没有影响甚至有促进作用，表现出一定的耐盐能力。 相似文献
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不同地区不同裸燕麦品种淀粉品质分析 总被引：2，自引：0，他引：2
为研究不同生长环境对燕麦淀粉品质的影响,分别选取同时在我国两大燕麦主产区内蒙古和河北省种植的10个裸燕麦品种,测定其抗性淀粉含量、总淀粉含量、糊化特性和淀粉水解率,通过多重比较分析品种的变异性和地区之间的差异性。结果表明,两地区内参试样品间的抗性淀粉、总淀粉、峰值黏度、破损值和回生值的差异均较大;两地区之间,抗性淀粉和总淀粉含量存在显著差异(P<0.05),淀粉水解率以及大部分糊化特性存在极显著差异(P<0.01);内蒙古地区种植的燕麦样品淀粉水解率、糊化温度极显著(P<0.01)高于河北地区种植的燕麦样品,而峰值黏度、破损值、回生值极显著(P<0.01)低于河北地区的样品。 相似文献
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运用野外实地测量和室内浸提法对4种套种雷公藤人工林凋落物持水量、持水率和吸水速率进行了研究。结果表明：4种林分的凋落物最大持水量大小为杉木林(11.66 t/hm2)＞马尾松林(6.81 t/hm2)＞厚朴林(5.90 t/hm2)＞纯林 (4.28 t/hm2);在不同浸泡时间段,林分的凋落物持水率大小为厚朴林＞纯林＞马尾松林＞杉木林;凋落物最大持水率为厚朴林(205.12%)＞纯林(163.33%)＞马尾松林(139.33%)＞杉木林(120.96%);4种不同种植模式雷公藤林分的凋落物吸水速率大小为厚朴林＞纯林＞马尾松＞杉木,浸泡0.5 h后的吸水速率分别为2 630.05、2 407.32、2 035.09和1 592.14 g/kg/h。凋落物持水量与浸泡时间、凋落物持水率与浸泡时间呈现极显著的(P＜0.01)对数递增函数关系,凋落物吸水速率与浸泡时间呈现出极显著的(P＜0.01)递减幂数函数关系。 相似文献
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为了解小麦种质资源的品质状况,并给小麦品质改良提供参考,以来源于国外及国内不同麦区的230个小麦品种(系)为材料,研究小麦面团揉混特性参数的变异和分布特点及与其他品质性状的相关性.结果表明,参试品种(系)面团揉混参数间均存在极显著差异(P＜0.01),除峰值高度、尾高和8 min尾高外,其他揉混参数的变异系数均在30％以上.同时,在本试验中,国外引进品种的面团揉混参数均高于国内品种,多数参数的差异达到显著水平(P＜0.05);来源于北方春麦区的品种(系)面团揉混参数值较高,来源于华南冬麦区的品种(系)各揉混参数均最低,且部分参数达显著差异(P＜0.05).同时筛选出一批揉混参数值极高或极低的材料,可作为小麦品质育种的优选亲本.相关性分析结果表明,多数揉混参数与籽粒硬度、蛋白含量、吸水率、形成时间、稳定时间、粉质质量指数和干、湿面筋含量呈显著或极显著相关. 相似文献
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优质籼型旱稻光温敏核不育系GHS的光温反应特性 总被引：1，自引：0，他引：1
通过9种人控光温组合处理,结合分期播种试验,研究了早稻光温敏核不育系GHS育性的光温反应特性.结果表明,日长对GHS的育性有一定的影响,在日长15.0 h条件下,其不育起点温度低于23.0℃;在13.0 h条件下,不育起点温度为24.0℃以下;在11.0 h条件下,不育起点温度上升到24℃以上.GHS光敏性较强,可育花粉率的光长影响率达72.53%,比对照培矮64S高出7.12个百分点.对GHS可育花粉率的方差分析表明,GHS的温度效应不显著(P＞0.05),光长效应显著(0.01＜P＜0.05),光温互作效应极显著(P＜0.01),属不育起点温度较低、不育临界光长较短的光温互作型两川核不育系.在湛江自然条件下,GHS有2个育性转换期,连续稳定不育期达145 d以上,正常年份可进行晚季安全制种,但没有适合GHS繁殖的光温条件. 相似文献
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为探讨保健砂在蛋鸡生产中的合理应用,将450只文昌鸡（24周龄蛋鸡）随机分为5组,每组90只。对照组饲喂基础日粮和添加剂,试验组饲喂基础日粮、添加剂和保健砂,各试验组添加比例分别为2％、4％、6％和8％。同期对照组与试验组Ⅳ的产蛋率、料蛋比差异均显著（P<0.05）,对照组与试验组Ⅰ、Ⅱ、Ⅲ的产蛋率、料蛋比差异不显著（P>0.05）,平均蛋重、蛋壳厚度以及破损率各试验组与对照组对比差异均不显著（P>0.05）。试验结果说明饲料中添加4％～6％保健砂,有助于提高文昌鸡的产蛋率、减少饲料消耗,提高养鸡生产经济 相似文献
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Two contrasting Gremie perennial ryegrass and Blanca white clover seeds mixtures were established. Each sward type was either continuously or rotationally (four paddocks) grazed at two stocking rates by lambs of 26–28 kg initial mean live weight in two 12-week experiments. Dry matter production, assessed by the cage method, was lower on the high-clover sward during the first experiment but overall was similar between seeds mixtures. Clover content, and differences between sward types, declined with time and was lowered by continuous grazing in both experiments and by the higher stocking rate in the first experiment. Animal performance was related to intake and both were increased by lowering stocking rate, increasing clover content and adopting a continuous grazing system. The results are discussed in relation to the experimental methods used and to other published findings. 相似文献
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海南假臭草地理群遗传多样性RAPD分析 总被引：2，自引：0，他引：2
对海南省18个市(县)的假臭草地理种群进行RAPD-PCR聚类分析,将海南假臭草地理群分为5个类群:其中澄迈、海口、文昌、临高、儋州、昌江为一类群,东方、乐东、三亚、保亭、五指山、琼海、万宁、陵水、定安为一类群,屯昌、白沙、琼中各为一个类群。通过NTsys-pc2.10数据处理,分析各假臭草地理群的遗传相似系数,其遗传相似系数范围在0.539 682 5~0.904 761 9之间,说明快速进化是假臭草生物入侵的一种手段。 相似文献
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A. D. H. Joblin 《Grass and Forage Science》1963,18(1):69-73
A sixteen-month trial is described where strip grazing was compared with a 3-paddock system of rotational grazing. 71 /2 acres of grazing was allotted to each group, but the strip-grazed cattle were limited to half an acre of grazing while the paddock-grazed beasts had access to 24 acres at a time. The pasture was rested for 6 weeks after strip grazing and 2 weeks after paddock grazing.
Treatment effects were found to vary with the pasture conditions. The paddock-grazed cattle benefited most when average grass quality was declining following the onset of drying conditions. The strip-grazed group showed to advantage when drying conditions persisted for several months and the usefulness of a rationed system of grazing management became apparent. There was an overall trend in favour of paddock grazing which is interpreted as suggesting that, under the conditions of the experiment, pasture quality was more frequently limiting animal production than was pasture quantity.
After one year's grazing the liveweight gains per acre were 221 lb from strip grazing and 251 lb from paddock grazing. 相似文献
Treatment effects were found to vary with the pasture conditions. The paddock-grazed cattle benefited most when average grass quality was declining following the onset of drying conditions. The strip-grazed group showed to advantage when drying conditions persisted for several months and the usefulness of a rationed system of grazing management became apparent. There was an overall trend in favour of paddock grazing which is interpreted as suggesting that, under the conditions of the experiment, pasture quality was more frequently limiting animal production than was pasture quantity.
After one year's grazing the liveweight gains per acre were 221 lb from strip grazing and 251 lb from paddock grazing. 相似文献
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Seventeen grass or oats swards, displaying a wide and largely independent variation in surface height and bulk density, were produced using different seed rates at sowing and different cutting or grazing pre-treatments. Four sheep confined in cages were allowed to take twenty bites from small patches of each sward, and measurements of bite weight and the physical dimensions of the average bite in the sward (bite depth, area and volume) were related to a range of sward structural characteristics.
Mean bite weight per sward ranged from 40 to 330 mg dry matter (DM). It was positively related to surface height (range 6–55 cm), which acted primarily upon bite depth and hence bite volume, and to the bulk density of the grazed stratum (range 0·1–2·0 mg DM cm−3 ) which influenced bite weight directly. The effects of surface height and grazed stratum bulk density were independent and additive, resulting in a planar response surface.
The influence of sward variables on bite area was less clear than on bite depth, but within a given grass species the effect of surface height appeared to be positive and that of the population density of grazed leaves and stems negative. These findings are considered in relation to a theory concerning grazing mechanics.
The merits of the grazing cage technique are discussed and suggestions made for further work. 相似文献
Mean bite weight per sward ranged from 40 to 330 mg dry matter (DM). It was positively related to surface height (range 6–55 cm), which acted primarily upon bite depth and hence bite volume, and to the bulk density of the grazed stratum (range 0·1–2·0 mg DM cm
The influence of sward variables on bite area was less clear than on bite depth, but within a given grass species the effect of surface height appeared to be positive and that of the population density of grazed leaves and stems negative. These findings are considered in relation to a theory concerning grazing mechanics.
The merits of the grazing cage technique are discussed and suggestions made for further work. 相似文献