Bio-fertilisation with plant growth promoting rhizobacteria (PGPR) can be extremely beneficial for plant development and growth under harsh environments. PGPR have been recently successfully applied in restoration programmes, but locally adapted strains are needed for successful outcomes. In this study, we evaluated the effect of bio-fertilisation with selected native PGPR strains on the growth and physiological response to drought of (Mol.) Kuntze (tara), the main tree species of the Atiquipa forest, a highly valuable and unique ecosystem in the middle of the Atacama Desert in Peru. We compared the growth and physiological status of tara seedlings that were bio-fertilised with three PGPR strains, chemically fertilised and a non-fertilised control, under well-watered and under drought conditions. Seedlings inoculated with sp. strain RC5.5 showed enhanced tolerance to drought, although under favourable, stress-free conditions it did not promote growth and only significantly increased quantum yield of photosystem II (F/F). On the other hand, chemical fertilisation highly enhanced plant growth, but led to substantial hydric demand under water limitation. Under drought, RC5.5 bio-fertilised plants showed lower reduction of leaf relative water content, net carbon assimilation rate, stomatal conductance, and a balanced shoot-to-root ratio compared with control plants. Therefore, strain RC5.5 is highlighted as a valuable candidate to be used as inoculant of tara in reforestation and restoration programmes in arid zones, in particular the Atiquipa forest, or in local tara plantations.

中文翻译：

---

本地植物生长促进根际细菌的生物施肥提高了新热带豆科植物刺云实对水分亏缺的耐受性

使用促进植物根际生长的细菌（PGPR）进行生物施肥对于恶劣环境下的植物发育和生长极为有益。PGPR 最近已成功应用于恢复计划，但需要适应当地的菌株才能取得成功。在这项研究中，我们评估了选定的本地 PGPR 菌株的生物施肥对 (Mol.) Kuntze (tara) 生长和对干旱的生理反应的影响，Kuntze (tara) 是 Atiquipa 森林的主要树种，这是一个非常有价值且独特的生态系统位于秘鲁阿塔卡马沙漠中部。我们比较了用三种 PGPR 菌株生物施肥、化学施肥和未施肥对照的塔拉幼苗在浇水良好和干旱条件下的生长和生理状态。幼苗接种 sp。菌株 RC5.5 显示出增强的干旱耐受性，尽管在有利的无胁迫条件下它不会促进生长，仅显着增加光系统 II (F/F) 的量子产率。另一方面，化肥极大地促进了植物生长，但在水分限制下导致大量的需水量。在干旱条件下，与对照植物相比，RC5.5生物施肥植物的叶片相对含水量、净碳同化率、气孔导度和平衡的茎根比的降低幅度较小。因此，菌株 RC5.5 被认为是在干旱地区（特别是阿蒂基帕森林）或当地塔拉种植园的重新造林和恢复计划中用作塔拉接种剂的有价值的候选者。