Background and aims

The Kiwifruit Vine Decline Syndrome (KVDS) is a disease that is currently a challenge for kiwifruit production in Italy, and it is spreading in new production areas. However, the causal agent of this syndrome has not been clearly identified, and we still know little about the overall effects of KVDS on the interactions between the host plant and its microbiome.

Methods

In this study, we combined metabarcoding and targeted isolation (leaf baiting) to characterize the changes in the rhizosphere and root microbiomes associated with symptoms of KVDS.

Results

Our results suggest that KVDS has little impact on the bacterial, fungal, and oomycete communities associated with soil and roots, and we detected weak signatures of potential dysbiosis. On the other hand, we found a consistent association of the oomycete Phytopythium vexans with samples from plants symptomatic to KVDS, which matches the nucleotide sequences of the isolates obtained through baiting and, partially, the isolates from previous studies.

Conclusion

While our results support the idea that P. vexans might be the major candidate agent of KVDS, there are still several unanswered questions that need to be addressed before being able to provide effective solutions to this emerging challenge in kiwifruit production.

中文翻译：

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对植物和土壤微生物组的综合分析确定了 Phytopythium v​​exans 是猕猴桃藤蔓衰退综合症的病原体

 背景和目标

猕猴桃藤蔓衰退综合症（KVDS）是一种目前对意大利猕猴桃生产构成挑战的疾病，并且正在新的产区蔓延。然而，这种综合征的致病因素尚未明确，而且我们对 KVDS 对宿主植物与其微生物组之间相互作用的总体影响仍然知之甚少。

 方法

在这项研究中，我们结合了元条形码和靶向分离（叶诱饵）来表征与 KVDS 症状相关的根际和根微生物组的变化。

 结果

我们的结果表明，KVDS 对与土壤和根相关的细菌、真菌和卵菌群落几乎没有影响，并且我们检测到了潜在生态失调的微弱特征。另一方面，我们发现卵菌Phytopythium v​​exans与具有 KVDS 症状的植物样本存在一致的关联，这与通过诱饵获得的分离株的核苷酸序列相匹配，部分与之前研究中的分离株的核苷酸序列相匹配。

 结论

虽然我们的结果支持P. vexans可能是 KVDS 的主要候选媒介的观点，但在能够为猕猴桃生产中这一新兴挑战提供有效的解决方案之前，仍然有几个悬而未决的问题需要解决。