Arbutus unedo L. (strawberry tree) is a multipurpose Ericaceae tree with a circum-Mediterranean distribution and tolerant to abiotic and biotic stresses. The bioactive compounds and edible berries make this species attractive from an economical perspective, which causes a high demand for true to type plants. As micropropagation techniques are quite popular for the production of strawberry tree clonal plants, the characterization of its microbiome is essential, due to the possible impact in micropropagation success, including acclimatization. Thus, this study aims to identify the endophytic communities on strawberry tree plant tissues in vitro, as well as their prevalence and/or alteration upon plant acclimatization. For this purpose, the microbiome of two genotypes under micropropagation and ex vitro was identified using a culture-independent method. Bacterial OTUs were assigned to 7 phyla and 79 genera whereas only one Archaea genus was identified. The most abundant and diverse bacterial phylum was Actinobacteriota (48%) followed by Proteobacteria (43%), Firmicutes (6%) and Bacteroidota (3%). Noticeable differences in terms of composition and diversity were found when the microbiome of genotypes in vitro was compared, whereas the composition of ex vitro samples was similar. A significant higher diversity was found on both genotypes ex vitro when compared to the respective in vitro plants. This study presents the very approach into the identification and characterization of strawberry tree microbiome, including in vitro plants, using a culture-independent method. The genotype proved to be a determinant factor shaping microbiota structure. The relevance of this results for micropropagation and breeding are discussed.

Arbutus unedo L.（草莓树）是一种多用途杜鹃花科树木，分布在地中海沿岸，对非生物和生物胁迫具有耐受性。从经济角度来看，生物活性化合物和可食用浆果使该物种具有吸引力，这导致对真正类型植物的高需求。由于微繁殖技术在草莓树克隆植物的生产中非常流行，因此对其微生物组的表征至关重要，因为可能会影响微繁殖成功，包括驯化。因此，本研究旨在在体外鉴定草莓树植物组织上的内生群落，以及它们在植物驯化后的流行和/或改变。为此，在微繁殖下的两种基因型的微生物组和使用不依赖培养的方法鉴定体外。细菌 OTU 被分配到 7 个门和 79 个属，而只鉴定了一个古生菌属。最丰富和多样化的细菌门是放线菌门 (48%)，其次是变形菌门 (43%)、厚壁菌门 (6%) 和拟杆菌门 (3%)。当比较体外基因型的微生物组时，发现在组成和多样性方面存在显着差异，而体外样本的组成相似。一个显著较高的多样性上，两种基因型发现前体外相比分别时，在体外植物。本研究提出了使用独立于培养的方法鉴定和表征草莓树微生物组（包括体外植物）的方法。基因型被证明是塑造微生物群结构的决定因素。讨论了该结果与微繁殖和育种的相关性。