Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
Braz J Microbiol. 2020 Dec;51(4):1929-1939. doi: 10.1007/s42770-020-00344-8. Epub 2020 Aug 7.
The antagonistic efficacy of a biocontrol agent in combination with oilseed cake against fungal phytopathogens has been sparsely explored. The present study aimed to evaluate the antifungal activity of a biocontrol agent (Trichoderma harzianum MTCC 3928) formulated with oilseed cake (OSC) against Fusarium oxysporum f. sp. lycopersici responsible for causing vascular wilt in Solanum lycopersicum. In in vitro studies, OSC of mustard (Brassica juncea) exhibited significant mycelial inhibition against the pathogen. The volatile plate assay showed mycelial inhibition of 70 and 40% with unautoclaved and autoclaved mustard cakes, respectively. The aqueous extract (10% v/v) of the mustard cake was the most effective with 47.3% mycelial inhibition of pathogen over control. In addition, volatiles and aqueous extract of mustard cake subjected to GC-MS analysis revealed a range of antifungal bioactive compounds with hexanedioic acid, dioctyl ester (16.57%), and oleic acid trimethylsilyl ester (12.41%) being predominant compounds. In in vitro studies, it was noticed that the T. harzianum strain was compatible with mustard cake, and hence used as a growth substrate for its mass multiplication. SEM analysis revealed no distortion in spores and mycelium of T. harzianum grown on the mustard cake. Further, seed germination assay suggested the optimum concentration of mustard cake (10%) supporting the germination rate and economics of formulation development. In in planta assay, the combination of biocontrol agent and mustard cake showed 48% disease reduction, and ~ 40% with T. harzianum alone in comparison to untreated control. Also, the combination of mustard cake and T. harzianum significantly enhanced the growth parameters of S. lycopersicum. The findings of the current study identified an environmentally friendly alternative for mitigation of Fusarium wilt, thereby providing a sustainable option for mitigation of wilt disease and enhancement of plant health.
生物防治剂与菜籽饼联合防治真菌病原菌的拮抗功效研究甚少。本研究旨在评估生物防治剂（哈茨木霉 MTCC 3928）与菜籽饼（OSC）联合防治番茄枯萎病菌（引起番茄维管束萎蔫的病原菌）的抑菌活性。在体外研究中，芥菜籽油饼对病原菌表现出显著的抑菌作用。挥发性平板测定显示，未灭菌和灭菌的芥菜籽油饼分别对病原菌的抑菌率为 70%和 40%。菜籽饼的水提物（10%v/v）对病原菌的抑菌效果最显著，抑菌率为 47.3%，明显高于对照。此外，经 GC-MS 分析，芥菜籽油饼的挥发物和水提取物中含有一系列具有抗真菌活性的化合物，其中己二酸二辛酯（16.57%）和油酸三甲基硅酯（12.41%）是主要化合物。在体外研究中，注意到哈茨木霉菌株与芥菜籽油饼相容，因此可用作其大量繁殖的生长基质。SEM 分析显示，芥菜籽油饼上生长的哈茨木霉孢子和菌丝没有变形。进一步的种子发芽试验表明，芥菜籽油饼的最佳浓度（10%）支持发芽率和制剂开发的经济性。在植株试验中，与未处理对照相比，生物防治剂和芥菜籽油饼的组合使番茄枯萎病的发病率降低了 48%，而单独使用哈茨木霉的发病率降低了约 40%。此外，芥菜籽油饼和哈茨木霉的组合还显著提高了番茄的生长参数。本研究的结果确定了一种环境友好的替代方案，可用于减轻枯萎病，为缓解枯萎病和提高植物健康提供了可持续的选择。
