Séry D Jean-Marc, Kouadjo Z G Claude, Voko B R Rodrigue, Zézé Adolphe
Laboratoire de Biotechnologies Végétale et Microbienne, Unité Mixte de Recherche et d'Innovation en Sciences Agronomiques et Génie Rural, Institut National Polytechnique Felix Houphouët-Boigny Yamoussoukro, Côte d'Ivoire.
Laboratoire Central de Biotechnologies, Centre National de la Recherche Agronomique Abidjan, Côte d'Ivoire.
Front Microbiol. 2016 Dec 22;7:2063. doi: 10.3389/fmicb.2016.02063. eCollection 2016.
The use of arbuscular mycorrhizal fungal (AMF) inoculation in sustainable agriculture is now widespread worldwide. Although the use of inoculants consisting of native AMF is highly recommended as an alternative to commercial ones, there is no strategy to allow the selection of efficient fungal species from natural communities. The objective of this study was (i) to select efficient native AMF species (ii) evaluate their impact on nematode and water stresses, and (iii) evaluate their impact on cassava yield, an important food security crop in tropical and subtropical regions. Firstly, native AMF communities associated with cassava rhizospheres in fields were collected from different areas and 7 AMF species were selected, based upon their ubiquity and abundance. Using these criteria, two morphotypes (LBVM01 and LBVM02) out of the seven AMF species selected were persistently dominant when cassava was used as a trap plant. LBVM01 and LBVM02 were identified as (most abundant) and , respectively, after phylogenetic analyses of LSU-ITS-SSU PCR amplified products. Secondly, the potential of these two native AMF species to promote growth and enhance tolerance to root-knot nematode and water stresses of cassava (Yavo variety) was evaluated using single and dual inoculation in greenhouse conditions. Of the two AMF species, it was shown that significantly improved the growth of the cassava and enhanced tolerance to water stress. However, both and conferred bioprotective effects to cassava plants against the nematode spp., ranging from resistance (suppression or reduction of the nematode reproduction) or tolerance (low or no suppression in cassava growth). Thirdly, the potential of these selected native AMF to improve cassava growth and yield was evaluated under field conditions, compared to a commercial inoculant. In these conditions, the single inoculation and the dual inoculation significantly improved cassava yield compared to the commercial inoculant. This is the first report on native AMF species exhibiting multiple benefits for cassava crop productivity, namely improved plant growth and yield, water stress tolerance and nematode resistance.
丛枝菌根真菌（AMF）接种在可持续农业中的应用目前在全球范围内广泛普及。尽管强烈推荐使用由本地AMF组成的接种剂作为商业接种剂的替代品，但尚无从自然群落中选择高效真菌物种的策略。本研究的目的是：（i）选择高效的本地AMF物种；（ii）评估它们对线虫和水分胁迫的影响；（iii）评估它们对木薯产量的影响，木薯是热带和亚热带地区一种重要的粮食安全作物。首先，从不同地区收集田间与木薯根际相关的本地AMF群落，并根据其普遍性和丰度选择了7种AMF物种。基于这些标准，当木薯用作诱捕植物时，所选的7种AMF物种中的两种形态型（LBVM01和LBVM02）持续占主导地位。对LSU-ITS-SSU PCR扩增产物进行系统发育分析后，LBVM01和LBVM02分别被鉴定为（最丰富的）和。其次，在温室条件下使用单接种和双接种评估了这两种本地AMF物种促进木薯（Yavo品种）生长并增强其对根结线虫和水分胁迫耐受性的潜力。在这两种AMF物种中，结果表明显著改善了木薯的生长并增强了对水分胁迫的耐受性。然而，和都赋予木薯植株对线虫 spp.的生物保护作用，范围从抗性（抑制或减少线虫繁殖）到耐受性（木薯生长中抑制作用低或无抑制作用）。第三，与商业接种剂相比，在田间条件下评估了这些选定的本地AMF改善木薯生长和产量的潜力。在这些条件下，与商业接种剂相比，单接种和双接种显著提高了木薯产量。这是关于本地AMF物种对木薯作物生产力具有多种益处的首次报道，即改善植物生长和产量、水分胁迫耐受性和线虫抗性。
