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Nitrogen (N) management is critical in optimizing potato yield and quality and reducing environmental pollution. Six N rates from 34 to 270 kg ha−1, and different timing of N application were used in a 3-year field experiment to contrast SPAD-502 chlorophyll meter and QuickBird satellite imagery data against the conventional petiole sampling technique for assessing canopy N status. Overall treatment variations in SPAD readings were consistent with those in petiole nitrate-nitrogen (NO3-N) concentrations. However, the ability of the SPAD meter to detect treatment differences varied with growth stage and growing season. Severe N deficiency was detected about 1 month after emergence with SPAD readings, but as early as 2 weeks after emergence with petiole NO3-N concentrations. Petiole NO3-N concentrations tended to differentiate more treatment variations than SPAD readings at all growth stages except at hilling. N deficiency was detected with QuickBird image-derived vegetation indices (VIs) at the hilling stage in 2002, but not in 2003. At the post-hilling stage, treatment differences in VI values were minimal and insignificant except very late in the growing season. SPAD meters could be used as an indirect method for detecting N deficiency at the hilling stage when making supplemental N applications, but they are not as sensitive as the petiole sampling method. The sensitivity of QuickBird imagery to canopy N variations needs to be further tested with more pixel data. However, cloud interference and high cost of images could limit the use of QuickBird data in making timely management decisions. 相似文献
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不同种类老山芹总酚和总黄酮含量及抗氧化能力的初步研究 总被引:1,自引:0,他引:1
以红色老山芹、绿色老山芹、混合色老山芹的叶片和叶柄为试材,测定不同种类、不同部位老山芹的总酚、总黄酮含量及抗氧化能力,并分析功能活性与物质成分含量之间的相关性。结果表明:不同种类、不同部位老山芹的总黄酮含量、总酚含量大体上表现差异显著,3种老山芹叶片的总黄酮含量和总酚含量均显著高于叶柄;红色老山芹叶片醇提物的抗氧化能力最强,其次为混合色老山芹叶片,绿色老山芹叶柄最弱;各处理醇提物浓度在一定范围内与DPPH·自由基、OH·自由基、ABTS+自由基的清除能力均呈线性关系,醇提物浓度与抗氧化能力呈正相关;老山芹醇提物的抗氧化能力与叶片、叶柄总酚含量呈显著或极显著正相关,与总黄酮含量的相关性不显著。 相似文献
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氮肥对大白菜生理障害——小黑点病发生影响的初步研究 总被引:6,自引:0,他引:6
本研究通过对两个大白菜品种进行氮肥施用量及不同施用方法试验,研究氮肥对大白菜生理障害—小黑点病发生的影响。试验结果表明,每公顷施用400 kg氮素肥料的处理(处理3),2个品种小黑点的发生程度均明显高于每公顷施用300 kg氮素肥料的处理(处理1,2);在氮肥施用总量相同的情况下,基施用量大的处理(处理2),两个品种小黑点的发生程度也明显高于基施用量少的处理(处理1)。品种间的小黑点发生差异还表明大白菜小黑点病的发生存在着明显的基因型间的差异。 相似文献
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[目的]以蕨菜叶柄为外植体研究蕨菜的组织培养技术。[方法]在1/2 MS培养基中设置不同的6-BA和IBA浓度,研究6-BA和IBA对蕨菜叶柄组织培养的影响。[结果]1/2 MS+0.2 mg/L 6-BA+0.4 mg/L IBA为愈伤组织的最佳诱导培养基,诱导率为82%;1/2MS+0.2 mg/L IBA+0.2 mg/L 6-BA为愈伤组织的最佳增殖培养基,增殖倍数为8.07;1/2 MS+0.4 mg/L IBA为最佳生根培养基,生根率达100%,根数多、根长且健壮。[结论]结果为蕨菜植物的组培繁殖提供参考。 相似文献
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[目的]研究红掌优良品种相配套的组培快繁技术体系。[方法]以盆栽红掌新品种‘YNG5’为研究对象,采用附加6-BA 2.0mg/L和2,4-D 0.2 mg/L的1/2MS培养基,探讨了外植体的灭菌方法、材料种类、生理状态及取材部位对红掌初代培养效果的影响。[结果]在红掌叶片、叶柄、腋芽、花序及佛焰苞片5种外植体中,叶片与叶柄的培养效果较好,出愈率可达70%以上;在选取叶片与叶柄作为外植体时,用0.1%HgCl2处理5 min,可获得良好的灭菌效果;采用叶片为外植体时,以展叶5~8 d、不带主脉的幼嫩叶片为宜,采用叶柄为外植体时,以未展开叶、形态学上端的部位为宜。[结论]研究获得了红掌新品种‘YNG5’组织培养的最适外植体种类及灭菌方法,初步建立了红掌初代培养的技术体系。 相似文献
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Kati W. Migliaccio Bruce Schaffer Frederick S. Davies 《Agricultural Water Management》2010,97(10):1452-1460
An irrigation study was conducted to determine the effects of implementing different irrigation practices on growth and yields of papaya plants in south Florida. Treatments included using automated switching tensiometers based on soil water status, irrigation based on ET calculated from historic weather data and a set schedule irrigation regime. The study consisted of two trials (2006-2007 and 2008-2009). Water volumes applied, plant height and diameter, leaf gas exchange, leaf petiole nutrient levels, fruit yields and fruit total soluble solids were measured throughout the study. For both trials, significantly more water was applied in the set schedule irrigation treatment than in all other treatments; historic ET and soil water based treatments received only about 31-36% of the water applied in the set schedule irrigation. Trunk diameter and plant height per unit water volume applied values for the set schedule treatment were significantly lower than those from all other treatments during both trials. The set schedule treatment in both trials also had the lowest crop production water use efficiency (CP-WUE); CP-WUE values among all other treatments were generally not significantly different from each other. Soil water and historic ET-based irrigation methods were identified as more sustainable practices compared to set schedule irrigation due to the lower water volumes applied while maintaining plant nutrient content, growth, photosynthetic rates, and fruit yields for this production system. 相似文献
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不同基因型甜菜叶柄的组织培养及植株的再生 总被引:1,自引:0,他引:1
本文报导了6种不同基因型甜菜叶柄的离体培养结果。实验通过预培养、诱导分化培养,获得了再生植株,建立了甜菜快速繁殖程序。结果表明:甜菜幼苗先经MSB附加一定量的6-苄氨基嘌呤(6-BA)和萘乙酸(NAA)组合的培养基中预培养,再取叶柄(带叶片)转入MS附加6-BA和NAA的培养基中诱导分化,不定芽发生频率为18.3%~47.5%,不同基因型材料,诱导率不同。采用MSB或MS大量元素减半,附加一定量的萘乙酸生根培养基,诱导生根率在80%以上,移栽成活率高达10%。 相似文献