Systemic resistance against Sphaerotheca fuliginea in cucumber plants exposed to phosphate in hydroponics system, and its control by foliar spray of mono-potassium phosphate
Systemic resistance against Sphaerotheca fuliginea in cucumber plants exposed to phosphate in hydroponics system, and its control by foliar spray of mono-potassium phosphate
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DOI：
10.1016/s0261-2194(00)00029-6
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发表时间：
2000-06-01
期刊：
影响因子：
2.8
通讯作者：
Tuzun, S
中科院分区：
文献类型：
--
作者：
Reuveni, R;Dor, G;Tuzun, S
通过水培系统施用浓度为5、20和40 ppm的含磷营养液，可诱导黄瓜幼苗对白粉病菌的系统抗性（ISR）。保护表示为显着减少（高达92%，与对照相比），在霉变的叶面积。ISR还表示为S的数量减少53-91%。在接种后9天，在叶片1（第一片真叶）和2上，以及在接种后12天，在叶片1-3上测定的每感染叶面积的烟曲霉菌分生孢子。浓度为20 ppm的P在水培溶液中被认为是最佳的ISR。最适磷浓度促进了钙的吸收，使叶片中钙含量比对照提高了50%。一旦真菌已经建立，根施磷不影响发育良好的殖民地，但，叶面施用1%的磷酸二氢钾（MKP）溶液有效地保护了叶片免受白粉病，无论营养液中的P浓度。该处理可持续至接种后21天，与对照相比，它显著抑制了白粉病的发展，并导致真菌产孢减少72.3%。结果表明，这两种现象的不同机制，并强调P在ISR中的作用。(C)2000爱思唯尔科技有限公司版权所有。
P-containing nutrient solutions at concentrations of 5, 20 and 40 ppm, applied through a hydroponics system, provided induced systemic resistance (ISR) against Sphaerotheca fuliginea in young cucumber plants. Protection was expressed as a significant reduction (up to 92% compared with control) in the mildewed leaf area. ISR was also expressed as a 53-91% reduction in the number of S. fuliginea conidia per infected leaf area as determined on leaves 1(first true leaf) and 2, at 9 days after inoculation, and on leaves 1-3 at 12 days after inoculation. A concentration of 20 ppm P in the hydroponics solution was found to be optimal for ISR. The optimal P concentration enhanced the uptake and increased the content of Ca in the leaves by 50% compared with the controls. Once the fungus had been established, root-applied P did not affect well-developed colonies, but, foliar application of 1% solution of mono-potassium phosphate (MKP) effectively protected the foliage against powdery mildew, regardless of the P concentration in the nutrient solutions. This treatment was persistent up to 21 days after inoculation, it significantly inhibited powdery mildew development and caused a reduction of 72.3 % in sporulation of the fungus as compared with the control. The results suggest different mechanisms for the two phenomena and highlight the role of P in ISR. (C) 2000 Elsevier Science Ltd. All rights reserved.