SummaryInoculation of symbiotic N2-fixing rhizobacteria (rhizobia) in legumes is an alternative to reduce synthetic N fertiliser input to crops. Even though common bean benefits from the biological N2 fixation carried out by native rhizobia isolates, the low efficiency of this process highlights the importance of screening new strains for plant inoculation. Two rhizobial strains (SEMIA 4108 and SEMIA 4107) previously showed great potential to improve the growth of common beans under greenhouse conditions. Thus, this study evaluated the growth and grain yield of common bean plants inoculated with those strains in field experiments. The rhizobial identification was performed by 16S rRNA sequencing and the phylogeny showed that SEMIA 4108 and SEMIA 4107 are closely related to Rhizobium phaseoli, within a clade containing other 18 Rhizobium spp. type strains. Common bean plants inoculated with SEMIA 4107 showed similar productivity to N-fertilised (N+) plants in the first experiment (2016/17) and higher productivity in the second experiment (2018/19). The development of inoculated plants was different from that observed for N+. Nonetheless, comparing inoculated treatments with N-fertilised control, no yield or productivity losses at the end of the growing process were detected. Our results showed that inoculation of the rhizobial isolates SEMIA 4108 and SEMIA 4107 improved the growth and grain yield of common bean plants. The observed agronomical performance confirms that both strains were effective and can sustain common bean growth without nitrogen fertilisation under the edaphoclimatic conditions of this study.

中文翻译：

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用于普通豆类接种的本土根瘤菌菌株 SEMIA 4108 和 SEMIA 4107：用于更清洁和更可持续农业的生物技术工具

摘要共生N的接种2- 固定豆科植物中的根瘤菌（rhizobia）是减少作物合成氮肥投入的替代方法。即使普通豆类受益于生物氮2通过本地根瘤菌分离株进行固定，该过程的低效率凸显了筛选用于植物接种的新菌株的重要性。两种根瘤菌菌株（SEMIA 4108 和 SEMIA 4107）先前显示出在温室条件下改善普通豆类生长的巨大潜力。因此，本研究在田间试验中评估了接种这些菌株的普通豆类植物的生长和籽粒产量。根瘤菌鉴定采用16S rRNA测序，系统发育表明SEMIA 4108和SEMIA 4107与根瘤菌密切相关。菜豆根瘤菌, 在包含其他 18 个根瘤菌spp. 型菌株。接种 SEMIA 4107 的普通豆类植物在第一个实验 (2016/17) 中显示出与施氮 (N+) 植物相似的生产力，在第二个实验 (2018/19) 中显示出更高的生产力。接种植物的发育与观察到的 N+ 不同。尽管如此，将接种处理与施氮对照进行比较，在生长过程结束时未检测到产量或生产力损失。我们的研究结果表明，接种根瘤菌分离株SEMIA 4108和SEMIA 4107提高了普通豆类植物的生长和籽粒产量。观察到的农艺性能证实，在本研究的土壤气候条件下，这两种菌株都是有效的，并且可以在不施氮肥的情况下维持普通豆类的生长。