Trichoderma exhibits great ecological and agricultural relevance because it improves plant growth, development and productivity. In this study, Trichoderma isolates (T01, T02, T04, T74, T76 and T96 of T. asperelloides; T77 of T. asperellum; or T44, T78 and T92 of T. harzianum) were evaluated in vitro for their ability to solubilize phosphate and produce indole-3-acetic acid (IAA). Afterwards, a completely randomized experimental design with 12 treatments was used to investigate physiological changes in cowpea plants inoculated with Bradyrhizobium sp. BR 3267 (bradyrhizobia) or coinoculated with bradyrhizobia and those Trichoderma isolates in the greenhouse conditions. All Trichoderma isolates showed the ability to solubilize phosphate and to produce IAA. Cowpeas were positively influenced by coinoculation with bradyrhizobia and Trichoderma, with the highlight being cowpea plants coinoculated with bradyrhizobia and T. asperelloides T02. These plants display significant increases in height; relative growth rate; stem diameter; dry weight of shoots, roots and nodules; total dry weight; and specific root length in relation to other symbiotic pairs and absolute control. In contrast, negative responses were registered in cowpea plants coinoculated with bradyrhizobia and T. asperelloides T04, bradyrhizobia and T. harzianum T44 or bradyrhizobia and T. harzianum T92. These plants, together with the absolute control, display lower values of stem diameter, total dry weight, specific root length, and total chlorophyll and carotenoids; the absence of root nodules; and a higher root length and anthocyanin content in relation to other treatments. Our hypothesis is that the increase in root length may be related to IAA produced by Trichoderma, while anthocyanin accumulation is associated with nitrogen deficiency, suggesting that these plants are under stress. To our knowledge, this is the first evidence of antagonistic relationships between bradyrhizobia and Trichoderma in the cowpea rhizosphere. Our findings demonstrated that Trichoderma promotes positive effects on cowpeas nodulated by bradyrhizobia and acts as stimulators of plant growth, but an adequate microbial consortium of bradyrhizobia-Trichoderma could represent a promising practical method for increasing the productivity of cowpea and other legumes.

中文翻译：

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木霉和缓生根瘤菌协同作用，提高了在受控条件下生长的cow豆（Vigna unguiculata）的生长速度，生物量和光合色素

木霉菌具有极大的生态和农业意义，因为它可以改善植物的生长，发育和生产力。在这项研究中，木霉属菌株（T01，T02，T04，T74，T76和T96的T. asperelloides ;的T77 T.棘孢;或T44，T78和T92的哈茨木霉）在体外评价它们的能力，以溶解磷酸盐并生产吲哚-3-乙酸（IAA）。此后，采用完全随机的实验设计和12种处理方法来研究接种了根瘤菌属的sp豆植物的生理变化。BR 3267（根瘤菌）或与根瘤菌和那些木霉菌共接种在温室条件下分离。所有木霉菌分离物均具有溶解磷酸盐和产生IAA的能力。coin豆与缓生根瘤菌和木霉共接种对positive豆有积极影响，其中最突出的是coin稻和根瘤菌T02共接种的oc豆植物。这些植物的高度显着增加。相对增长率 茎直径 芽，根和根瘤的干重；总干重；以及相对于其他共生对和绝对控制的特定根长。相比之下，在同时接种了缓生根瘤菌和T. asperelloides T04，缓生根瘤菌和哈茨木霉的cow豆植物中发现了阴性反应T44或缓生根瘤菌和哈茨木霉T92。这些植物与绝对对照相比，茎直径，总干重，比根长，叶绿素和类胡萝卜素总含量较低；没有根瘤；与其他处理方法相比，根长和花青素含量更高。我们的假设是，根长的增加可能与木霉产生的IAA有关，而花色苷的积累与氮缺乏有关，表明这些植物处于胁迫状态。据我们所知，这是the豆根际中缓生根瘤菌和木霉之间拮抗关系的第一个证据。我们的发现表明木霉属促进对根瘤菌根瘤菌形成的cow豆具有积极作用，并刺激植物生长，但是足够的微生物根瘤菌-木霉菌财团可以代表一种有前途的实用方法，可提高cow豆和其他豆类的生产力。