Selection of arbuscular mycorrhizal fungi for citrus growth promotion and Phytophthora suppression
Selection of arbuscular mycorrhizal fungi for citrus growth promotion and Phytophthora suppression
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DOI：
10.1016/j.scienta.2011.02.007
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发表时间：
2011-05
影响因子：
4.3
通讯作者：
N. Watanarojanaporn;N. Boonkerd;S. Wongkaew;Phrarop Prommanop;N. Teaumroong
中科院分区：
文献类型：
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作者：
N. Watanarojanaporn;N. Boonkerd;S. Wongkaew;Phrarop Prommanop;N. Teaumroong
为了减少柑橘园不必要的磷肥施用量，减轻疫霉根腐病的严重程度，特开展本试验。从泰国柑橘园的根际土壤中分离出 13 种本土丛枝菌根 (AM) 真菌，然后通过诱集培养将其繁殖到三种寄主植物 [高粱 (Sorghum bicolor)、玉米 (Zea mays) 和韭菜 (Allium cepa)] 中。我们还测试了本土 AMF 物种（13 个不同物种）是否可以定植到三个柑橘接穗和砧木品种中（幕府将军：Citrus reticulata Blanco cv. Shogun；橘子：C. reticulata；以及 C-35 柑橘：Citrus sinensis×Poncirus trifoliata）。就根部定殖率而言，结果表明，在所有柑橘品种中，结核无梗孢菌和球囊霉提供了最好的定殖率。因此，我们选择这些 AMF 物种来验证它们对柑橘生长和疫霉根腐病抗性的影响。将两种有效的本土 AMF 物种 G. etunicatum 或 A. tuberculata 接种到三个柑橘接穗和砧木品种 Shogun、Tangerine 和 C-35 citrange 上，以确定其对柑橘生长的影响。对植物进行研究以确定菌根效率指数 (MEI)、AM 定殖、磷含量和其他参数。还在 Shogun 接穗/C-35 柑橘砧木中进行了 AMF 物种（G. etunicatum 或 A. tuberculata）与烟草疫霉的联合接种。柑橘生长结果表明，接种 G. etunicatum 的 Shogun 和 Tangerine 产生最高的 MEI。施肥处理的柑橘和C-35枳橙以及紫花苜蓿的叶片中磷含量最高。这表明 G. etunicatum 对柑橘生长和磷吸收有影响，表明它是高效菌株。接种烟草假单胞菌和不同 AM 真菌（G. etunicatum 或 A. tuberculata）的幕府接穗/C-35 枳橙砧木组合表现出根部损伤，但根部腐烂症状水平较低。然而，在单独接种烟草疫霉的处理中，嫁接在砧木上的幕府接穗部分表现出严重的茎枯死症状，而接种不同AM物种(G.etunicatum或A.tuberculata)和烟草疫霉的处理比接种疫霉处理的茎枯死症状较轻。首先表现出低水平的芽枯症状，然后恢复健康的幼芽。我们的结果表明，不同的寄主植物和不同的 AMF 物种产生不同的生长结果和病原体抗性。因此，这两种 AM 分离株的应用在生产柑橘园接种物方面具有巨大的潜力。
In order to reduce unnecessary amount of P-fertilizer and severity of Phytophthora root rot in citrus orchards, the experiment was set up. Thirteen indigenous arbuscular mycorrhiza (AM) fungi species were isolated from rhizosphere soil of citrus orchards in Thailand and were then propagated into three host plants [sorghum (Sorghum bicolor), maize (Zea mays), and leek (Allium cepa)] by trap culture. We also tested whether indigenous AMF species (13 different species) could colonize into three cultivars of citrus scions and rootstocks (Shogun: Citrus reticulata Blanco cv. Shogun; Tangerine: C. reticulata; and C-35 citrange: Citrus sinensis×Poncirus trifoliata). With root colonization rates, the results indicated that Acaulospora tuberculata and Glomus etunicatum provided the best colonization in all citrus cultivars. We selected, therefore, those AMF species to verify their influences on citrus growth and Phytophthora root rot resistance. Three cultivars of citrus scions and rootstocks, Shogun, Tangerine and C-35 citrange, were inoculated with two effective indigenous AMF species, G. etunicatum or A. tuberculata in order to determine the influences on citrus growth. The plants were investigated to determine the mycorrhizal efficiency index (MEI), AM colonization, P content, and other parameters. Co-inoculation of AMF species (G. etunicatum or A. tuberculata) with Phytophthora nicotianae was also carried out in Shogun scion/C-35 citrange rootstocks. The results of citrus growth revealed that Shogun and Tangerine inoculated with G. etunicatum produced the highest MEI. Tangerine and C-35 citrange amended with fertilizers and G. etunicatum showed the highest P content in leaves. This indicated that G. etunicatum has an influence on citrus growth and P uptake, suggesting it to be the highly effective strain. Shogun scion/C-35 citrange rootstock combinations that were inoculated by both P. nicotianae and different AM fungi (G. etunicatum or A. tuberculata) showed root injury at low level of root rot symptom. However, the part of Shogun scions grafted on rootstocks showed severe symptom of shoot die back in treatment inoculated with P. nicotianae alone, while treatment inoculated with different AM species (G. etunicatum or A. tuberculata) and P. nicotianae rendered lower shoot die back symptoms than that of Phytophthora treatment. The low level of shoot die back symptom was shown at first, then healthy young shoot was restored. Our results indicated the facts that different host plants and different AMF species produced different outcomes of growth and pathogen resistance. The application of both AM isolates, therefore, has an enormous potential to be produced the inoculum for citrus orchards.