The assessment of a new bioinoculant formula composed of a cytokinin producing beneficial Methylobacterium on growth and yield of soybean

在作物生产中使用植物生长促进细菌（PGPB）作为天然生长增强剂近来已成为现代农业的非常重要的关注领域（Tsavkelova等人，2006年）。特别地，甲基杆菌属的物种由于其独特的生长促进特性和植物激素细胞分裂素（CK）的广泛产生而获得了很多关注（Holland，1994）。细胞分裂素是植物生长发育的关键因子。CK调节植物所有部位的细胞分裂，但从农业角度来看，最重要的属性是它们促进开花和新种子生长，从而提高产量（Sakakibara，2006年）。先前已报道使用甲基杆菌属物种作为生物接种剂以增强发芽、刺激幼苗生长和增加植物的抗病性（Duorado et al.，2015）。然而，植物细菌产生激素的机制 （甲基营养型内生菌），以及任何细菌产生的CK在宿主植物中的作用方式仍处于早期研发阶段。此外，其农业应用还有待研究。该项目建议在大豆田间试验中评估选定的甲基杆菌菌株作为新的生物肥料，这将揭示其在加拿大大豆种植的典型生长条件下促进植物性能的全部潜力。生物接种剂的任何成功都将使NutriAg有限公司能够开发一种新的促进生长的生物肥料产品。未来，可以测试基于甲基杆菌的生物肥料对其他作物的有益影响，目的是开发通用和/或特定作物的产品线。最终，新的甲基杆菌接种物刺激的生长促进和植物质量改善将为加拿大农民增加收入创造可能性。

Using plant growth promoting bacteria (PGPB) as natural growth enhancers in crop production has recently become a very important area of interest for modern agriculture (Tsavkelova et al., 2006). In particular, species of Methylobacterium are gaining a lot of attention, due to their unique, growth promoting characters, and extensive production of plant hormones, the cytokinins (CK) (Holland, 1994). Cytokinins are critical factors responsible for plant growth and development. CKs regulate cell divisions in all parts of a plant, but from an agricultural perspective, the most important attribute is their promotion of flowering and new seed growthwhich leads to improved yields (Sakakibara, 2006). The use of Methylobacterium species as bioinoculants has been previously reported to enhance germination, stimulate seedling growth, and increase disease resistance in plants (Duorado et al., 2015). However, the mechanisms of hormone production by plant-dwelling bacteria (methylotrophic endophytes), as well as the mode of action of any bacterially-produced CK in the host-plant are still at an early stage of R&D. Moreover, its agricultural application has yet to be investigated. This project proposes to evaluate selected Methylobacterium strains as new bio-fertilizers in field trials of soybean, and this will reveal its full potential to promote plant performance in growing conditions that are typical for soybean cultivation in Canada. Any success of the bio-inoculant will allow NutriAg Ltd. to develop a new growth promoting biological fertilizer product. In the future, Methylobacterium-based bio-fertilizer can be tested for beneficial effects on other crop plants, with the aim to develop universal and/or crop-specific product lines. Ultimately, growth promotion and plant quality improvement, as stimulated by new Methylobacterium inoculants, will create possibilities for increased revenue for Canadian farmers.