We thank Kent J. Bradford and his students at the UC Davis Seed Biotechnology Center for recording seedling emergence data.

1.循环水浴和表的研制<ol><li>取得两个循环浴与泵至少为10升/分钟到在thermogradient表的每一端控制温度油藏。 注意:一个循环浴必须冷藏储存，而另一只需要加热的。 </li><li>检查循环水浴，以确保他们的过滤器和蓄水池清洁。 </li><li>标识为表和浴室的位置。只要泵可通过表流体循环上表下方的缸的位置。将梯度表在方便的高度，除去盖子，达到表面上的所有位置。 注:表和浴室的位置必须通风良好，无极端温度，相对自由的灰尘，并有机会获得电路，以充分权力的浴室和照明系统。 </li><li>填充每个浴到储存罐的顶部的水和防冻剂的混合物（1:1比），以提高热交换，防止结冰。 注:防冻剂的浓度取决于浴的规格和温度的溶液中。不需要高防冻液浓度除非产生冰点温度以下。纯防冻液可能损害某些水浴泵。 </li><li>连接缸的入口和出口分别与柔性管到出口和入口管在桌子上，在表中的两个相对的暖端和冷端，以创建一个连续流动的模式。 </li><li>使用具有弹性的墙壁弯曲的时候不会压力或纠结下扩大厚壁软塑料管。使用领螺杆，软管夹在管工会当系统被加压以保持无滴漏连接。包装用泡沫保温管流通管道，以减少热交换的包围。 </li><li>随着管道阀门开启，瞬间打开循环泵检查泄漏和管道坍塌这可能会降低流动。如果泄漏发生调整螺丝夹。检查照明灯具，确保其正常运行。 </li></ol> 2.表实验的准备<ol><li>行与亲水性材料褶子之间thermogradient表的底部，如温室毛细管垫，纸巾，或无光泽报纸更均匀地分配水。 </li><li>与生长介质均匀地填表格下面或者甚至与角板的顶部。包装的生长介质得足够紧删除与温度平衡干扰气泡。 注:也可以用乡土。 </li><li>用表的入口和出口管阀打开，激活一个浴设定为温度5℃以下，并在相对浴的温度5℃的最小和最大期望的温度（5-40℃）以上的循环浴，分别在流通占热量损失和增益。 Monitor是储层浴和添加水和防冻剂（乙二醇）的混合物作为需要时水平下降的循环溶液填充在表中的管道。 </li><li>调整浴温，直到所需的生长介质的温度（5至40℃或其它所需的实验的温度）上的梯度表中实现。 注:确切温度通过测量生长介质温度和调整浴直至所需生长介质的温度在整个表达的迭代过程来实现的。 </li><li>桌子上的不同位置处的温度数据记录器，以在实验中记录不断发展的媒体或土壤的温度。推荐使用数据采集器在尺寸上的微型圆形晶圆电池相似。包裹在数据记录器封口膜，以防止在不断增长的媒体实验位置水渍和地点。 </li><li>均匀润湿日益媒体的最大持水量70％-80％媒体。湿润的土壤更有效地传导热量角撑板之间。 注:水倾向于从表的温端更快速地蒸发，所以更频繁的应用程序可能需要更换蒸发损失。最大持水量是水通过容器保持在生长介质饱和和重力水2天排水后，用穿孔的底部的量。含水量之前和在105℃下72小时烘箱干燥后重量分析测定。 </li><li>允许该表中平衡24小时，以确保（5至40℃）遍及在达到所需的温度在开始实验之前。 </li><li>通过在每个角调整脚直到表斜坡非常轻微朝向与漏的角倾斜表。这消除多余的水分，防止在桌子上湿点，并鼓励媒体均匀的水分含量。放置一个容器漏下方赶上径流。 </li><li&gt;在每天或以保持湿润媒体越来越需要媒体和水厂种子。 注:由于发芽测试可能会如何进行一个例子，我们种植的番茄种子25（ 白毛lycopersicum L. CV传奇），甜瓜（ 甜瓜品种海尔斯最佳珍宝），生菜（ 莴苣 L. CV黑色种子。辛普森），和燕麦（ 燕麦 L. CV天鹅）2厘米深。 </li><li>计数出现苗数每日根据公式计算平均时间出现: &#160; Σ（N I XT I） MTE = ------------- Σ（N I） 注:其中n <suB&gt; i是时刻t i时出现种子数; t是出现的开始天数;和ΣN I是出现种子总数。 </li></ol> 3.操作Thermogradient表<ol><li>调整浴到所需的温度后，代替两个thermogradient表盖，所述透明内的丙烯酸类片材盖子和一个较大幅度的聚氯乙烯（PVC），盖用聚苯乙烯绝缘，以包围该表。在地方两盖子提供最佳的绝缘性能，以减少测试过程中的热量和水分流失。 注意:如果环境光或辅助照明安装在桌子上面，只有内盖可被用于传输光。 </li><li>取下外盖通过内 - 丙烯酸类盖，检查表。取下内盖暂时补充水分或其他投入，检查温度，或记录数据。 注:在较高的温度下，水迅速从潮湿土壤和C蒸发ondenses上的内盖，因为表面是冷却器的底部。 </li><li>在实验过程中的停电，洗澡故障，泄漏或表温度波动过大密切监控系统。监控浴水库水位，并定期加液更换蒸发损失。 </li></ol>

<ol>
	<li>Chatterton, N. J., Kadish, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+temperature+gradient+germinator.">A temperature gradient germinator.</a> Agron. J. 61 (4), 643-644 (1969).</li><li>Clegg, M. D., Eastin, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Thermogradient+generating+sand+table.">A Thermogradient generating sand table.</a> Agron. J. 70 (5), 881-883 (1978).</li><li>Evans, R. A., Young, J. A., Henkel, R., Klomp, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+low+temperature-gradient+bar+for+seed+germination+studies.">A low temperature-gradient bar for seed germination studies.</a> Weed Science. 18, 575-576 (1970).</li><li>Grime, J. P., Thompson, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+apparatus+for+measurement+of+the+effect+of+amplitude+of+temperature+fluctuation+upon+the+germination+of+seeds.">An apparatus for measurement of the effect of amplitude of temperature fluctuation upon the germination of seeds.</a> Annals of Botany. 40 (4), 795-799 (1976).</li><li>Halldal, P., French, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Algal+growth+in+crossed+gradients+of+light+intensity+and+temperature.">Algal growth in crossed gradients of light intensity and temperature.</a> Plant Physiol. 33 (4), 249-252 (1958).</li><li>Thompson, K., Whatley, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+thermogradient+apparatus+for+the+study+of+the+germination+requirements+of+buried+seeds+in+situ.">A thermogradient apparatus for the study of the germination requirements of buried seeds in situ.</a> New Phytologist. 96, 459-471 (1984).</li><li>Bergman, T. L., Incropera, F. P., Lavine, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Fundamentals of Heat and Mass Transfer. , (2011).</li><li>McLaughlin, N. B., Bowes, G. R., Thomas, A. G., Dyck, F. B., Lindsay, T. M., Wise, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+design+for+a+seed+germinator+with+100+independently+temperature+controlled+cells.">A new design for a seed germinator with 100 independently temperature controlled cells.</a> Weed Research. 25, 161-173 (1985).</li><li>Webb, D. M., Smith, C. W., Schulz-Schaeffer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amaranth+seedling+emergence+as+affected+by+seeding+depth+and+temperature+on+a+thermogradient+plate1.">Amaranth seedling emergence as affected by seeding depth and temperature on a thermogradient plate1.</a> Agron. J. 79 (1), 23-26 (1987).</li><li>Welbaum, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Vegetable Production and Practices. , (2015).</li><li>Swoboda, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Environmental influences on subterranean termite foraging behavior and bait acceptance. , (2004).</li></ol>

The authors have nothing to disclose.

Thermogradient表已被使用了许多年，用于同时在一定温度范围内进行，主要在浅容器种子发芽实验。然而，实验的温度被限制在台面所以温度控制的深度是有限的。传统的梯度表进行种子检验协议，结束在培养皿或其他平面容器纸基上胚根出现，不实事求是地测试出苗和生长的自然会发生的土壤。今天，种子公司往往希望评估种子活力采用模拟现场条件种植者种植后可能会遇到（下少发芽比最佳条件的能力）。土壤测试也暴露出种子真菌和细菌性疾病的压力在无土介质标准化实验室发芽试验并不常见。当土壤被放置在平坦的非插角表5ºC或多个我们的大的变化再没有在土壤剖面位置和表面（未发表的结果）之间罕见。 与角撑板的一维梯度表被开发，以提高垂直温度控制，使得土壤可以在发芽试验和其他实验，其中土壤温度的精确控制是关键的使用。褶子限制在土层或合成的生长介质和控制温度。角板是铝，相同的材料的桌面，并且当垂直于表面焊接它们提供通过传导热传递之间的空间的温度控制。褶子能向下纵向表或横向桌子对面的被导向。这两种设计类似地进行，但在宽度方向联接片取向是方便的，因为联接板之间的空间可以用作单一实验温度时梯度被适当地调节。水平取向允许实验单位（在这个例子中的种子）被间隔开一交叉表中彼此相邻的线。角撑板间距可由于角板到位，因此替代定位焊接一次表施工完成后不能进行测试，只在制造过程中变化。 10.9厘米的间距扣板选择，以适应浅容器通常用于除土壤种子测试。更靠近联接板间距可提供更好的温度控制，但会限制可在桌上使用的容器的类型。 在thermogradient表生长介质的温度和湿度必须不断监视，以达到预期的实验条件。播种前，循环浴应略低于所需的最小和稍高于比调整，直到样品达到所需的实验的温度的最高温度来设定。大约24小时应允许对于样品热与梯度表平衡。次的水分含量Ë不断发展的媒体应该是足够了（田间持水量的70-80％）的种子发芽或其他生物过程进行。在地方，当该表绝缘和双眼睑减少温度波动和水的蒸发。 表1中的结果比较在不同温度下的4种幼苗生长。甜瓜和番茄种子的增长开始在15℃和40℃发芽很好解释为什么他们的特点是温暖季作物10。与此相反，莴苣发芽最好在低温下。燕麦种子发芽以上的温度比其它物种（ 表1）的范围更广。而可以使用一系列的生长室中的一系列协调实验得到类似的结果，在角撑板设计允许两萌发和幼苗生长到在一定范围的同时土壤温度进行比较。不同领域的土壤或成长媒体可以被取代，以模拟各种领域的条件。微生物或化学处理，化肥制度，干旱胁迫，和变化的光环境可以在温度上梯度表的罚款。 在桌子上的不同位置记录的小数据记录器温度。温度数据表明，相对均匀的温度下在表中的具有更大的变化的中间，特别是在暖端。定位记录仪与表面接触，并暴露于土壤表面上的空气可能加剧了极端。记录在中心位置的温度很可能更能说明大宗土壤条件。例如，栽在上的角撑板来模拟定植之间的梯度表中的土壤的种子将只暴露于散装土壤温度，而不是空气或表面温度。土壤中的水分含量和质地起着决定表的温度的作用。如果日戊土干燥，空气空间抵御温度变化而不能有效地从褶子传导热量。湿润的土壤几乎没有空气的空间和更多的液体水通过土壤剖面，有效地传导热量。在该实验中，土壤保持在其最大持水量的70％至80％，但更高的水含量可能降低土壤的温度变化。砂具有如比具有高有机质土壤较少的大孔隙，因此预计将提供更均匀的温度。 有在相对于冷端表中的热端在土壤温度更大的变化。一种可能的解释是在湿气横跨表的分布情况。水分趋于冷端得以保留，而热端趋于枯竭，因为更大的蒸发损失了。因为水有助于导热，该表中的水分含量是尽可能均匀是重要的。 Webb 等 。9中使用blott呃纸张通过毛细管作用穿过thermogradient表进行水，同时报纸工作以及在裆部thermogradient表更便宜的替代方案。尽管角撑板用亲水纸内衬补充水分的分布，既保持凉爽和温暖的两端均匀润湿是具有挑战性的。 在高温下迅速蒸发发生在所有的梯度表的设计。缩合通常是当容器实验在温度上的梯度表进行多高于环境，因为容器的底部比顶部使水收集冷却器盖的内侧暖的问题。在对角撑板的表土壤实验中，水从上部土壤层蒸发到空气中在上面的角撑板的表。如果土壤是非常潮湿，在表中的热端蒸发损失可能会凝结在冷却器内的丙烯酸盖。休息丙烯酸或聚苯乙烯保温直接的紧身件LY对角板顶部减少与表上空水汽交换保持土壤更均匀湿润，温度恒定（数据未显示）。当表嵌着聚苯乙烯绝缘，温度变化通过设置在极端温度土壤剖面仅为1〜2℃（数据未示出）。然而，聚苯乙烯保温防止幼苗出现和孵化成长初期小时后进行分析，必须拆除。为了防止暖土壤快速干燥另一个解决方案是优选添加更多的水热端，以补偿蒸发损失。手浇水是有问题的，因为盖子必须去除和应用卷不太精确。微灌发射器可被设计到一个梯度表，并可以调整，以优先地应用于更多的水热端。 Thermogradient表具有的功能和潜力作为替代生长室。 WHEÑ两个浴场设置相同，表平衡到单个实验温度为在不要求梯度的应用程序。昼夜光照和温度的波动也可以使用可编程循环水浴模拟和LED植物生长灯。填充带LED眼睑的内侧生长灯可提高照明亮度。该LED植物生长灯输入最少的热量到系统中，并没有随着干扰梯度因为类似的土壤温度，用灯光和关闭记录（数据未显示）。添加灯光使植物生长和更大的环境控制。 Thermogradient表已被主要由种子工业发芽研究在过去，但许多其它应用是可能的。昆虫行为已经研究了一个梯度表来确定某些行为11的最适温度。冰可以在梯度台面在零下T为冻结测试现象emperatures（数据未显示）。土壤和大气中，包括二氧化碳进化之间的气体交换，有可能在一个插角梯度表在不同的含水量，土壤的投入，和温度。研究在温度范围内的不同类型的媒体细菌和真菌的生长的效果，也可以与此实验系统。

Thermogradient表不是新的，它们的使用已在文献中几十年1-6的报道。早期表被用于经常实验室种子发芽测试纸基材上在宽范围的温度下在一个单一实验中（ 图1）表面上的发展。有thermogradient表的不同设计，但最常见的一种是由金属的相对厚的矩形片状，常常铝为其耐腐蚀性，与在相对的两端焊接在底部方管的一个循环。塑料管连接表入口和出口管道温度控制，循环上表下方相对端通过管道泵送冷却并加热的流体浴池。管道进行流体，通常是水防冻剂（乙二醇）混合物中，以防止冷冻系统是否接近或低于冰点的温度下进行操作。另一种设计是焊缝金属条一起CRE在与入口和出口为在任一端冷暖溶液循环表中的每个端部吃的流体贮存器。循环浴可定位在桌子下方的地板上或单独的并列表。与加热线圈和/或珀尔帖冷却模块电动thermogradient表已经建成，但成本高，挑战产生一致的低温和可靠性等问题阻碍了广泛的商业用途8。 循环液的设计被动创建经由热传导的一维梯度。如果该铝板是均匀的形状和厚度，并适当地绝缘，热均匀地从温暖的流向表建立一个连续的一维温度梯度的冷端，以下热力学7的第二定律。在表面上的梯度是表长度的函数和端温度之间的差异。该表和plumbing的通常装在绝缘外壳，带有盖子的访问。外壳分离与其周围的表，创建在表面均匀梯度很小的温度变化。绝缘外壳可通过腿来支撑或放置在一个平面上，如一个桌子或工作台。对于需要均匀的温度控制，而不梯度应用中，一个表格可以被设置以产生等温条件，如果两端在相同温度下循环的流体。 当梯度表被正常，培养皿中，密封的塑料袋，平底容器等，被放置在表面上，并热平衡到的各种温度（ 图1）。在每个容器中的试验温度取决于可能在容器和表面和厚度与每个容器的绝缘性能之间存在空域。梯度表有效地保持样品TEmperatures靠近表面，而是控制表面上方丢失。缺乏垂直温度控制限制了类型的实验可能对传统的梯度表。 铝条或角撑板被添加到传统的梯度表设计，提高表面以上的温度控制。角撑板被间隔垂直于表面的焊接。褶子方便垂直上方的平坦台面对流热流。样品放置角撑板之间，有三面温度调节表面提供更有效的温度控制。克莱格和伊斯汀2放置在梯度台面石英砂创建深入的温度控制。克莱格和伊斯汀2也尝试把绝缘的桌子上。 Webb 等9放置在努力均匀地控制温度装满土表上的管道。 新的TA这里报告BLE设计具有九个7.6厘米（3英寸），它们在表的长度（ 图2）焊接到所述表面高褶子（铝条）。 LED灯具发光光合有效频率被安装在桌子上的两侧，以支持幼苗生长时表被关闭。所述隔热的外壳的内裆部thermogradient表被构造为白色PVC板是水，经纱，以及抗裂。本文的目的是描述新插角梯度表的设计和可能的应用。

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	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:463px;">Thermogradient table</td>
			<td style="width:257px;">Appalachian Machinge Inc</td>
			<td style="width:176px;"></td>
			<td style="width:283px;">Custom made, gussetted thermogradient table (schematics are included in the manuscript). The aluminum fabrication and welding were peformed by Appalachian Machinge Inc. 5304 State Rd 790, Dublin, VA 24084.&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Insulated polymer board cabinet</td>
			<td>TASCO LLC</td>
			<td></td>
			<td>The insulated polymer board cabinet containing the aluminum plate was constructed by TASCO LLC,&#160; 1440 Roanoke Street, Christiansburg, VA 24073&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Blue Hawk Folding Steel Adjustable Sawhorse</td>
			<td>Lowes Home Improvement</td>
			<td>162111</td>
			<td>Model #: 60142 Folding Steel Adjustable Sawhorses</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Circulating Refrigerated water baths or comparable units</td>
			<td>Brookfield Engineering</td>
			<td>TC-550SD</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Seeds (200 seeds)</td>
			<td>Johnny&#39;s Selected Seeds</td>
			<td></td>
			<td>Oat, lettuce, tomato, melon seeds from Johnny&#39;s Selected Seeds 955 Benton Ave, Winslow, ME 04901 or any other seed for germination testing,&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Professional 550 Grow Light&#160;</td>
			<td>SolarOasis&#160;</td>
			<td>Pro550</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">ID braided PVC tubing</td>
			<td>United States Plastics Inc.</td>
			<td>60703</td>
			<td>&#160;0.6 m pieces of 200 cm OD, 130 mm (1/2&#34;)&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Super Tech 50/50 Antifreeze/Coolant Pre-Mix</td>
			<td>Walmart</td>
			<td>1012574</td>
			<td>4 liters distilled water-antifreeze (ethylene glycol) mixture</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">WatchDog Data Loggers</td>
			<td>Spectrum Technologies Inc</td>
			<td>Model 100</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Parafilm M 4 cm wide</td>
			<td>Fisher Scientific</td>
			<td>S37440</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Container Acrylic 5 1/4&#34;x5&#34;x1 3/8&#34; plastic boxes</td>
			<td>Hoffman Manufacturing Inc</td>
			<td></td>
			<td>&#160;Hoffman Manufacturing Inc. 16541 Green Bridge Road, Jefferson, OR&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">1&#34; Collared-screw&#160;</td>
			<td>Global Industrial</td>
			<td>CS16H</td>
			<td>Global Industrial,&#160; 11 Harbor Park Drive, Port Washington, NY&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Collared Screw Worm Gear Hose Clamp</td>
			<td>Global Industrial</td>
			<td>WGB513588</td>
			<td>3/4&#34; - 1-1/2&#34; Clamping Dia. 10-Pack .&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Everbilt Model Foam Pipe Insulation</td>
			<td>Home Depot</td>
			<td>ORP11812</td>
			<td>Internet # 204760805 Store SKU # 1000031792 1 in. x 6 ft.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Capillary Mat</td>
			<td>Farmtek</td>
			<td>106223</td>
			<td>greenhouse capillary matting - 4&#39; x 100&#39; or alternatively sheets of newspaper</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sunshine Mix #3</td>
			<td>TerraLink</td>
			<td>3236320</td>
			<td>&#160;3.8 cubic feet compressed bale,SKU: 3236320, Germinating media</td>
		</tr>
	</tbody>
</table>

a gusseted thermogradient table to control soil temperatures for evaluating plant growth and monitoring soil processes

Thermogradient tables were first developed in the 1950s primarily to test seed germination over a range of temperatures simultaneously without using a series of incubators. A temperature gradient is passively established across the surface of the table between the heated and cooled ends and is lost quickly at distances above the surface. Since temperature is only controlled on the table surface, experiments are restricted to shallow containers, such as Petri dishes, placed on the table. Welding continuous aluminum vertical strips or gussets perpendicular to the surface of a table enables temperature control in depth via convective heat flow. Soil in the channels between gussets was maintained across a gradient of temperatures allowing a greater diversity of experimentation. The gusseted design was evaluated by germinating oat, lettuce, tomato, and melon seeds. Soil temperatures were monitored using individual, battery-powered dataloggers positioned across the table. LED lights installed in the lids or along the sides of the gradient table create a controlled temperature chamber where seedlings can be grown over a range of temperatures. The gusseted design enabled accurate determination of optimum temperatures for fastest germination rate and the highest percentage germination for each species. Germination information from gradient table experiments can help predict seed germination and seedling growth under the adverse soil conditions often encountered during field crop production. Temperature effects on seed germination, seedling growth, and soil ecology can be tested under controlled conditions in a laboratory using a gusseted thermogradient table.

浅的容器，如培养皿中，可定位在一个传统的一维梯度表，以便多个实验的温度的效果，同时进行评估（ 图1）。以增加的研究应用可能的多样性上thermogradient表，7.6厘米（3英寸）高的铝褶子被缝交替焊接两侧所以每个角板垂直站立于表面10.9厘米（4.2英寸）的开与表面紧密接触（ 图2）。而广泛角形片间隔是可能的，10.9 cm的选择，以适应通常用于测试的小种子物种或其它生物样品（ 图3）的发芽方形塑料"三明治"车间或类似大小的容器中。不同于传统的平板梯度表中，衬垫设计为容纳受控彩画土壤和其他易碎非晶材料TURE实验。去除多余的水，筛选过滤排水孔被内置到一个角落。在每个角垫片或"脚"可调节倾斜表，以方便重力排水。角撑板端部和表的外侧之间的小间隙允许水沿一侧流向角漏极。 土壤温度下在70〜80％的土壤水分含量测定的浴已在恒温流传用于与盖24小时到位（ 图4）之后。在桌子对面四个不同位置的12小时的平衡期后测得的温度变化为0.4℃或更小（ 图4）。变异在三个土层测量土壤剖面的温度是在较大的极端。在13℃的目标温度，置于角板之间的铝表面上的数据采集器记录的11.0±0.0℃的平均值。记录仪PL一杆进洞在土壤表面平均13.5±0.1°C。整体平均土壤温度在所有三个级别的13℃的目标温度为12.3±0.1°C。在18℃的目标温度，在整个土壤剖面的平均温度为19.1±0.1℃。变化在23℃的目标温度低于18℃更大，平均23.8±0.2℃。在另一个极端的温度，29℃，表铝表面温度为30.8±0.2℃，而在土壤表面温度为25.7±0.4℃。整体平均土壤温度在29°C为28.2±0.3℃（ 图4）。 种子种可与角撑板一个thermogradient表其最佳萌发和幼苗生长的温度进行测试。番茄，甜瓜，既考虑暖季型作物，萌发了一个范围从14.1到40。2℃（ 表1， 图3）。 LED阵列安装在表盖子和/或侧面发射光合光谱使植物时表被封闭（ 图3）在试验土壤温度在土壤中生长。番茄最佳幼苗生长在29.6℃下出现100％的出苗百分比和平均时间为5.3天（ 表1， 图5）出现。出现是在其他温度下慢。对于瓜，最佳出苗百分率为96％，平均一次出现为5.1天后，两种在24.7℃（ 表1）。无论生菜和燕麦被认为是冷季作物。燕麦的种子发芽的范围内，从5.1至40.2℃，最宽的测试任何种子（ 表1， 图5）。为燕麦，最高出苗百分率是100％在24.7℃，并最快涌现在29.6℃（ 表1为3.4天， <st荣&gt;图5）。对于莴苣，观察出现的范围内的5.1至29.6℃。莴苣的最高比例出现在24.7℃，100％，出现了速度最快的在29.6℃（ 表1）为3.4天。 <img alt="图1" src="/files/ftp_upload/54647/54647fig1.jpg" /> 图 1: 拆除绝缘盖但有一个内在的丙烯酸盖覆盖½表格中的传统的平面thermogradient表温度对浅容器样品的传统的平表设计的测试效果。梯度的温度控制是在表面上方的距离迅速消失，因为没有障碍的空气混合。所需深度一致的温度都没有采用这种设计可行的实验。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54647/54647fig1large.jpg" target="_blank">请点击此处查看拉</a>rger版本这个数字。 <img alt="图2" src="/files/ftp_upload/54647/54647fig2.jpg" /> 图2: 用角撑板一个thermogradient板的示意图角板一针一线纵向隔着桌子垂直于表面焊接。在一个角落里漏极消除多余的水分。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54647/54647fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/54647/54647fig3.jpg" /> 图 3: 照明用角撑板填充泥土，草皮，和容器的种子发芽实验thermogradient表这个表中的坡度由左（暖端）设置为右（冷端）。虽然土，容器中使用的开发角撑板设计可以角撑板之间放置小样本的实验。该LED植物生长灯可以安装在盖子或外围，放出光合有效频率，让机箱内进行种植的植物。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54647/54647fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/54647/54647fig4.jpg" /> 从上一个裆部thermogradient表不同土壤的位置 。图4. 温度读数。温度记录器被放置在土壤桌子对面的左侧壁，左侧中心（从左侧壁20厘米），右中心（从左侧壁40厘米） ，在角撑板之间的右侧壁中间。温度记录仪的底部定位为铝台面下方的土壤表层8厘米附近，而放置中心是approximat伊利4cm处土壤下方。放置于土壤表层温度记录器被揭露。上述条值表示的整体平均温度±平均值（N = 72）的标准差。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54647/54647fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图5" src="/files/ftp_upload/54647/54647fig5.jpg" /> 图 5: 燕麦和番茄幼苗生长14天的温度范围内的5 thermogradient表至40℃的图片说明了如何萌发和多个物种的幼苗生长在土壤同时在一定温度范围在一个的评估单次实验以模拟油田条件。顶（左，右）的照片显示thermogradient表从垂直方向看时。底部（左和右）的图片显示在水平方向上的表。乙醇中升温度计置于土壤中快速监测温度在整个实验。 <table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td rowspan="2">目标温度</td><td rowspan="2">测得的温度</td><td colspan="2">番茄</td><td colspan="2">瓜</td><td colspan="2">生菜</td><td colspan="2">燕麦</td></tr><tr><td> EM† </td><td> MTE†† </td><td> EM </td><td> MTE </td><td> EM </td><td> MTE </td><td> EM </td><td> MTE </td></tr><tr><td> C </td><td> C </td><td> ％ </td><td>天</td><td> ％ </td><td>天</td><td> ％ </td><td>天</td><td> ％ </td><td>天</td></tr><tr><td>五</td><td> 5.1 </td><td> 0 </td><td> 0.0 </td><td> 0 </td><td> 0.0 </td><td> 78 </td><td> 11.4 </td><td> 46 </td><td> 12.7 </td></tr><tr><td> 10 </TD&gt; <td> 8.7 </td><td> 0 </td><td> 0.0 </td><td> 0 </td><td> 0.0 </td><td> 92 </td><td> 7.5 </td><td> 58 </td><td> 12.5 </td></tr><tr><td> 15 </td><td> 14.1 </td><td> 100 </td><td> 10.8 </td><td> 16 </td><td> 13.8 </td><td> 68 </td><td> 5.9 </td><td> 96 </td><td> 7.2 </td></tr><tr><td> 20 </td><td> 19.8 </td><td> 100 </td><td> 7.2 </td><td> 84 </td><td> 7.5 </td><td> 66 </td><td> 6.5 </td><td> 100 </td><td> 5.4 </td></tr><tr><td> 25 </td><td> 24.7 </td><td> 100 </td><td> 6 </td><td> 96 </td><td> 5.1 </td><td> 22 </td><td> 8.1 </td><td> 100 </td><td> 3.7 </td></tr><tr><td>三十</td><td> 29.6 </td><td> 100 </td><td> 5.3 </td><td> 92 </td><td>5.5 </td><td> 4 </td><td> 12.5 </td><td> 98 </td><td> 3.4 </td></tr><tr><td> 35 </td><td> 36.1 </td><td> 94 </td><td> 7 </td><td> 92 </td><td> 4.4 </td><td> 0 </td><td> 0.0 </td><td> 94 </td><td> 4.5 </td></tr><tr><td> 40 </td><td> 40.2 </td><td> 72 </td><td> 7.8 </td><td> 88 </td><td> 5.1 </td><td> 0 </td><td> 0.0 </td><td> 10 </td><td> 8.2 </td></tr><tr><td colspan="10"> †成功出苗（EM），当幼苗有至少一个开放子叶进行评分。 </td></tr><tr><td colspan="10"> ††平均时间出现（MTE）通过相加每一天出现按天数除以所出现每个治疗种子的总数的数量种子的乘积来计算。 </td></tr></tbody></table> 表1:格列敏在土壤和番茄，冬瓜，生菜的通货膨胀燕麦种子在上表Thermogradient八温度。粗体数字显示每个物种的最佳值，并说明不同作物品种的温度依赖性。实验在盆栽搭配14天进行，媒体每天浇水了，或根据需要，以保持土壤湿润明显。数据基于25种每个品种。

Watch this Scientific Journal Video about A Gusseted Thermogradient Table to Control Soil Temperatures for Evaluating Plant Growth and Monitoring Soil Processes at JoVE.com

A Gusseted Thermogradient Table to Control Soil Temperatures for Evaluating Plant Growth and Monitoring Soil Processes

Traditional thermogradient tables create a range of temperatures across the surface. Welding gussets perpendicular to the surface of a thermogradient table will control temperature in depth increasing possible research applications.

一个插角Thermogradient表来控制土壤温度为评估植物生长和监测土壤过程

Thermogradient tables were first developed in the 1950s primarily to test seed germination over a range of temperatures simultaneously without using a ...

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Universidad San Sebastian

Research

JoVE Journal

Environment

11.7K 次观看.  Virginia Polytechnic Institute and State University. Traditional thermogradient tables create a range of temperatures across the surface. Welding gussets perpendicular to the surface of a thermogradient table will control temperature in depth increasing possible research applications. 

视频: A Gusseted Thermogradient Table to Control Soil Temperatures for Evaluating Plant Growth and Monitoring Soil Processes

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes and soil organic matter formation to small-scale stable-isotope biomarker probing. Coupling multiple stable isotopes such as 13C with 15N, 18O or&#160;2H has the potential to reveal even more information about complex stoichiometric relationships during biogeochemical transformations. Isotope labeled plant material has been used in various studies of litter decomposition and soil organic matter formation1-4. From these and other studies, however, it has become apparent that structural components of plant material behave differently than metabolic components (i.e. leachable low molecular weight compounds) in terms of microbial utilization and long-term carbon storage5-7. The ability to study structural and metabolic components separately provides a powerful new tool for advancing the forefront of ecosystem biogeochemical studies. Here we describe a method for producing 13C and 15N labeled plant material that is either uniformly labeled throughout the plant or differentially labeled in structural and metabolic plant components.
Here, we present the construction and operation of a continuous 13C and 15N labeling chamber that can be modified to meet various research needs. Uniformly labeled plant material is produced by continuous labeling from seedling to harvest, while differential labeling is achieved by removing the growing plants from the chamber weeks prior to harvest. Representative results from growing Andropogon gerardii Kaw demonstrate the system&#39;s ability to efficiently label plant material at the targeted levels. Through this method we have produced plant material with a 4.4 atom%13C and 6.7 atom%15N uniform plant label, or material that is differentially labeled by up to 1.29 atom%13C and 0.56 atom%15N in its metabolic and structural components (hot water extractable and hot water residual components, respectively). Challenges lie in maintaining proper temperature, humidity, CO2 concentration,&#160;and light levels in an airtight 13C-CO2 atmosphere for successful plant production. This chamber description represents a useful research tool to effectively produce uniformly or differentially multi-isotope labeled plant material for use in experiments on ecosystem biogeochemical cycling.

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

This method explains how to build and operate a continuous 13C and 15N isotope labeling chamber for uniform or differential plant tissue labeling. Representative results from metabolic and structural labeling of Andropogon gerardii are discussed.

设计一个连续和操作<sup&gt; 13</sup&gt; C和<sup&gt; 15</sup&gt;Ñ贴标商会统一或差分，代谢和结构，植物同位素标记

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes ...

科研

环境科学

Experimental Protocol for Manipulating Plant-induced Soil Heterogeneity

Coexistence theory has often treated environmental heterogeneity as being independent of the community composition; however biotic feedbacks such as plant-soil feedbacks (PSF) have large effects on plant performance, and create environmental heterogeneity that depends on the community composition. Understanding the importance of PSF for plant community assembly necessitates understanding of the role of heterogeneity in PSF, in addition to mean PSF effects. Here, we describe a protocol for manipulating plant-induced soil heterogeneity. Two example experiments are presented: (1) a field experiment with a 6-patch grid of soils to measure plant population responses and (2) a greenhouse experiment with 2-patch soils to measure individual plant responses. Soils can be collected from the zone of root influence (soils from the rhizosphere and directly adjacent to the rhizosphere) of plants in the field from conspecific and heterospecific plant species. Replicate collections are used to avoid pseudoreplicating soil samples. These soils are then placed into separate patches for heterogeneous treatments or mixed for a homogenized treatment. Care should be taken to ensure that heterogeneous and homogenized treatments experience the same degree of soil disturbance. Plants can then be placed in these soil treatments to determine the effect of plant-induced soil heterogeneity on plant performance. We demonstrate that plant-induced heterogeneity results in different outcomes than predicted by traditional coexistence models, perhaps because of the dynamic nature of these feedbacks. Theory that incorporates environmental heterogeneity influenced by the assembling community and additional empirical work is needed to determine when heterogeneity intrinsic to the assembling community will result in different assembly outcomes compared with heterogeneity extrinsic to the community composition.

Understanding the role of environmental heterogeneity in species coexistence has typically focused on types of heterogeneity that are extrinsic to the community&#8217;s species composition. We provide novel detailed methods for creating soil heterogeneity treatments using soils subject to plant-soil feedback conditioning, or heterogeneity intrinsic to the community composition.

用于操纵植物诱导土壤异质性的实验协议

Coexistence theory has often treated environmental heterogeneity as being independent of the community composition; however biotic feedbacks such as ...

A Protocol for Collecting and Constructing Soil Core Lysimeters

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the landscape has complex and varied soil morphology, an accompanying disparity in flow paths for leachate through the soil macropore and matrix structure is present. The rate of flow through these paths is further affected by antecedent soil moisture. Lysimeters are used to quantify flow rate, volume of water and concentration of nutrients leaching downward through soils. While many lysimeter designs exist, accurately determining the volume of water and mass balance of nutrients is best accomplished with bounded lysimeters that leave the natural soil structure intact. 
Here we present a detailed method for the extraction and construction of soil core lysimeters equipped with soil moisture sensors at 5 cm and 25 cm depths. Lysimeters from four different Coastal Plain soils (Bojac, Evesboro, Quindocqua and Sassafras) were collected on the Delmarva Peninsula and moved to an indoor climate controlled facility. Soils were irrigated once weekly with the equivalent of 2 cm of rainfall to draw down soil nitrate-N concentrations. At the end of the draw down period, poultry litter was applied (162 kg TN ha-1) and leaching was resumed for an additional five weeks. Total recovery of applied irrigation water varied from 71% to 85%. Nitrate-N concentration varied over the course of the study from an average of 27.1 mg L-1 before litter application to 40.3 mg L-1 following litter application. While greatest flux of nutrients was measured in soils dominated by coarse sand (Sassafras) the greatest immediate flux occurred from the finest textured soil with pronounced macropore development (Quindocqua).

A detailed method for extraction and assembly of intact soil core lysimeters and their use for study of leachate and associated loss of nutrients from surface applied poultry litter is demonstrated.

一种用于收集和构建土芯协议测渗计

Leaching of nutrients from land applied fertilizers and manure used in agriculture can lead to accelerated eutrophication of surface water. Because the ...

Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

This study presents an excavation method for investigating subsurface hydrological, geochemical, and microbiological heterogeneity of a soil lysimeter. The lysimeter simulates an artificial hillslope which was initially under homogeneous condition and had been subjected to approximately 5,000 mm of water over eight cycles of irrigation in an 18-month period.

土壤蒸渗仪开挖加之水文，地球化学和微生物调查

Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled ...

Measuring and Mapping Patterns of Soil Erosion and Deposition Related to Soil Carbonate Concentrations Under Agricultural Management

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes in elevation are related to changes in near-surface soil carbonate (CaCO3) profiles. The objective is to describe a simple conceptual model and detailed protocol for repeatable field and laboratory measurements of these quantities. Here, accurate elevation is measured using a ground-based differential global positioning system (GPS); other data acquisition methods could be applied to the same basic method. Soil samples are collected from prescribed depth intervals and analyzed in the lab using an efficient and precise modified pressure-calcimeter method for quantitative analysis of inorganic carbon concentration. Standard statistical methods are applied to point data, and representative results show significant correlations between changes in soil surface layer CaCO3 and changes in elevation consistent with the conceptual model; CaCO3 generally decreased in depositional areas and increased in erosional areas. Maps are derived from point measurements of elevation and soil CaCO3 to aid analyses. A map of erosional and depositional patterns at the study site, a rain-fed winter wheat field cropped in alternating wheat-fallow strips, shows the interacting effects of water and wind erosion affected by management and topography. Alternative sampling methods and depth intervals are discussed and recommended for future work relating soil erosion and deposition to soil CaCO3.

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes in elevation are related to changes in near-surface soil carbonates. Repeatable methods for field and laboratory measurements of these quantities and data analysis methods are described here.

农业经营条件下土壤侵蚀和沉积与土壤碳酸盐浓度关系的测量与制图

Spatial patterns of soil erosion and deposition can be inferred from differences in ground elevation mapped at appropriate time increments. Such changes ...

Evaluating Dryocosmus Kuriphilus-induced Damage on Castanea Sativa

Dryocosmus kuriphilus Yasumatsu has become a major pest for Castaneasativa since its arrival in Europe. Its galling activity results in the formation of different gall types and prevents the development of normal shoots. Repeated and uncontrolled attacks cause, besides the production of galls and the attendant gall-related reduction in leaf area, progressive corruption of the branch architecture, including the death of branch parts, and an increase in dormant bud activation. Thus far, there have been few attempts to quantify branch architecture damage. Further, the different methods for assessing infestation degree (MAID) that have been developed focus only on the galls' presence and abundance.
Using the leaf area to sapwood area relationship as a green biomass indicator, we developed in a previous study a damage composite index (DCI) that takes into account the most important branch architectural features, allowing for realistic damage assessment during the entire epidemic process. 
The aim of this study is to present this novel method and highlight differences in the damage description with respect to other broadly used indices. Results show how the DCI depicts branch damage better, especially during the epidemic peak, compared to MAID, which tend to underestimate it. We conclude by suggesting how to properly evaluate the overall impact of the pest by means of our composite damage index, the infestation degree using classic methods, and crown transparency evaluations.

Evaluating Dryocosmus Kuriphilus-induced Damage on Castanea Sativa

It is common practice to assess the damage caused by Dryocosmus kuriphilus by considering the abundance of galls alone rather than by also taking related branch corruption into consideration. We propose a composite damage index that takes into account the most important branch features, thus enabling more realistic damage assessment.

栗瘿栗瘿致锥害的评价

Dryocosmus kuriphilus Yasumatsu has become a major pest for Castaneasativa since its arrival in Europe. Its galling activity results in the formation of ...

Use of Principal Components for Scaling Up Topographic Models to Map Soil Redistribution and Soil Organic Carbon

Landscape topography is a critical factor affecting soil formation and plays an important role in determining soil properties on the earth surface, as it regulates the gravity-driven soil movement induced by runoff and tillage activities. The recent application of Light Detection and Ranging (LiDAR) data holds promise for generating high spatial resolution topographic metrics that can be used to investigate soil property variability. In this study, fifteen topographic metrics derived from LiDAR data were used to investigate topographic impacts on redistribution of soil and spatial distribution of soil organic carbon (SOC). Specifically, we explored the use of topographic principal components (TPCs) for characterizing topography metrics and stepwise principal component regression (SPCR) to develop topography-based soil erosion and SOC models at site and watershed scales. Performance of SPCR models was evaluated against stepwise ordinary least square regression (SOLSR) models. Results showed that SPCR models outperformed SOLSR models in predicting soil redistribution rates and SOC density at different spatial scales. Use of TPCs removes potential collinearity between individual input variables, and dimensionality reduction by principal component analysis (PCA) diminishes the risk of overfitting the prediction models. This study proposes a new approach for modeling soil redistribution across various spatial scales. For one application, access to private lands is often limited, and the need to extrapolate findings from representative study sites to larger settings that include private lands can be important.

Landscape processes are critical components of soil formation and play important roles in determining soil properties and spatial structure in landscapes. We propose a new approach using stepwise principal component regression to predict soil redistribution and soil organic carbon across various spatial scales.

利用主成分扩展地形模型绘制土壤再分配和土壤有机碳

Landscape topography is a critical factor affecting soil formation and plays an important role in determining soil properties on the earth surface, as it ...

High-throughput Siderophore Screening from Environmental Samples: Plant Tissues, Bulk Soils, and Rhizosphere Soils

Siderophores (low-molecular weight metal chelating compounds) are important in various ecological phenomenon ranging from iron (Fe) biogeochemical cycling in soils, to pathogen competition, plant growth promotion, and cross-kingdom signaling. Furthermore, siderophores are also of commercial interest in bioleaching and bioweathering of metal-bearing minerals and ores. A rapid, cost effective, and robust means of quantitatively assessing siderophore production in complex samples is key to identifying important aspects of the ecological ramifications of siderophore activity, including, novel siderophore producing microbes. The method presented here was developed to assess siderophore activity of in-tact microbiome communities, in environmental samples, such as soil or plant tissues. The samples were homogenized and diluted in a modified M9 medium (without Fe), and enrichment cultures were incubated for 3 days. Siderophore production was assessed in samples at 24, 48, and 72 hours (h) using a novel 96-well microplate CAS (Chrome azurol sulphonate)-Fe agar assay, an adaptation of the traditionally tedious and time-consuming colorimetric method of assessing siderophore activity, performed on individual cultivated microbial isolates. We applied our method to 4 different genotypes/Lines of wheat (Triticum aestivum L.), including Lewjain, Madsen, and PI561725, and PI561727 commonly grown in the inland Pacific Northwest. Siderophore production was clearly impacted by the genotype of wheat, and in the specific types of plant tissues observed. We successfully used our method to rapidly screen for the influence of plant genotype on siderophore production, a key function in terrestrial and aquatic ecosystems. We produced many technical replicates, yielding very reliable statistical differences in soils and within plant tissues. Importantly, the results show the proposed method can be used to rapidly examine siderophore production in complex samples with a high degree of reliability, in a manner that allows communities to be preserved for later work to identify taxa and functional genes.

We present a protocol for rapid screening of environmental samples for siderophore potential contributing to micronutrient bioavailability and turnover in terrestrial systems.

从环境样品中筛选高通量的安德森菌: 植物组织、散装土壤和根际土壤

Siderophores (low-molecular weight metal chelating compounds) are important in various ecological phenomenon ranging from iron (Fe) biogeochemical cycling ...

Microplot Design and Plant and Soil Sample Preparation for 15Nitrogen Analysis

Many&#160;nitrogen fertilizer studies evaluate the overall effect of a treatment on end-of-season measurements such as grain yield or cumulative N losses. A stable isotope approach is necessary to follow and quantify the fate of fertilizer derived N (FDN) through the soil-crop system. The purpose of this paper is to describe a small-plot research&#160;design utilizing non-confined 15N enriched microplots for multiple soil and plant sampling events over two growing seasons and provide sample collection, handling, and processing protocols for total 15N analysis. The methods were demonstrated using a replicated study from south-central Minnesota planted to corn (Zea mays L.). Each treatment consisted of six corn rows (76 cm row-spacing) 15.2 m long with a microplot (2.4 m by 3.8 m) embedded at one end. Fertilizer-grade urea was applied at 135 kg N&#8729;ha-1 at planting, while the microplot received urea enriched to 5 atom % 15N. Soil and plant samples were taken several times throughout the growing season, taking care to minimize cross-contamination by using separate tools and physically separating unenriched and enriched samples during all procedures. Soil and plant samples were dried, ground to pass through a 2 mm screen, and then ground to a flour-like consistency using a roller jar mill. Tracer studies require additional planning, sample processing time and manual labor, and incur higher costs for 15N enriched materials and sample analysis than traditional N studies. However, using the mass balance approach, tracer studies with multiple in-season sampling events allow the researcher to estimate FDN distribution through the soil-crop system and estimate unaccounted-for FDN from the system.

Microplot Design and Plant and Soil Sample Preparation for 15Nitrogen Analysis

A microplot design for 15N tracer research is described to accommodate multiple in-season plant and soil sampling events. Soil and plant sample collection and processing procedures, including grinding and weighing protocols, for 15N analysis are put forth.

微图设计及植物和土壤样品制备，进行15次氮气分析

Many&#160;nitrogen fertilizer studies evaluate the overall effect of a treatment on end-of-season measurements such as grain yield or cumulative N losses. ...

Estimation of Crystalline Cellulose Content of Plant Biomass using the Updegraff Method

Cellulose is the most abundant polymer on Earth generated by photosynthesis and the main load-bearing component of cell walls. The cell wall plays a significant role in plant growth and development by providing strength, rigidity, rate and direction of cell growth, cell shape maintenance, and protection from biotic and abiotic stressors. The cell wall is primarily composed of cellulose, lignin, hemicellulose and pectin. Recently plant cell walls have been targeted for the second-generation biofuel and bioenergy production. Specifically, the cellulose component of the plant cell wall is used for the production of cellulosic ethanol. Estimation of cellulose content of biomass is critical for fundamental and applied cell wall research. The Updegraff method is simple, robust, and the most widely used method for the estimation of crystalline cellulose content of plant biomass. The alcohol insoluble crude cell wall fraction upon treatment with Updegraff reagent eliminates the hemicellulose and lignin fractions. Later, the Updegraff reagent resistant cellulose fraction is subjected to sulfuric acid treatment to hydrolyze the cellulose homopolymer into monomeric glucose units. A regression line is developed using various concentrations of glucose and used to estimate the amount of the glucose released upon cellulose hydrolysis in the experimental samples. Finally, the cellulose content is estimated based on the amount of glucose monomers by colorimetric anthrone assay.

The Updegraff method is the most widely used method for the cellulose estimation. The main purpose of this demonstration is to provide a detailed Updegraff protocol for estimation of cellulose content in plant biomass samples.

使用上格拉夫方法估计植物生物质的晶体纤维素含量

Cellulose is the most abundant polymer on Earth generated by photosynthesis and the main load-bearing component of cell walls. The cell wall plays a ...