Artificial selection of microbiota opens new avenues for improving plants. However, reported results lack consistency. We hypothesised that the success in artificial selection of microbiota depends on the stabilisation of community structure. In a ten-generation experiment involving 1,800 plants, we selected rhizosphere microbiota of Brachypodium distachyon associated with high or low leaf greenness, a proxy of plant performance. The microbiota structure showed strong fluctuations during an initial transitory phase, with no detectable leaf greenness heritability. After five generations, the microbiota structure stabilised, concomitantly with heritability in leaf greenness. Selection, initially ineffective, did successfully alter the selected property as intended, especially for high selection. We show a remarkable correlation between the variability in plant traits and selected microbiota structures, revealing two distinct sub-communities associated with high or low leaf greenness, whose abundance was significantly steered by directional selection. Understanding microbiota structure stabilisation will improve the reliability of artificial microbiota selection.

中文翻译：

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人工选择稳定的根际微生物群导致可遗传的植物表型变化

微生物群的人工选择为改良植物开辟了新途径。然而，报告的结果缺乏一致性。我们假设人工选择微生物群的成功取决于群落结构的稳定。在涉及 1,800 株植物的十代实验中，我们选择了Brachypodium distachyon 的根际微生物群与高或低叶绿度相关，这是植物性能的代表。微生物群结构在最初的过渡阶段表现出强烈的波动，没有可检测的叶绿度遗传力。五代之后，微生物群结构稳定下来，伴随着叶绿度的遗传性。最初无效的选择确实按预期成功地改变了选定的属性，特别是对于高选择。我们展示了植物性状的变异性与选定的微生物群结构之间的显着相关性，揭示了与高或低叶绿度相关的两个不同的亚群落，其丰度受到定向选择的显着控制。了解微生物群结构的稳定性将提高人工微生物群选择的可靠性。