MED - Mediterranean Institute for Agriculture, Environment and Development, Instituto de Investigação e Formação Avançada, Universidade de Évora, Pólo da Mitra, Évora, Portugal.
PLoS One. 2021 Sep 8;16(9):e0256284. doi: 10.1371/journal.pone.0256284. eCollection 2021.
The olive fruit fly, specialized to become monophagous during several life stages, remains the most important olive tree pest with high direct production losses, but also affecting the quality, composition, and inherent properties of the olives. Thought to have originated in Africa is nowadays present wherever olive groves are grown. The olive fruit fly evolved to harbor a vertically transmitted and obligate bacterial symbiont -Candidatus Erwinia dacicola- leading thus to a tight evolutionary history between olive tree, fruit fly and obligate, vertical transmitted symbiotic bacterium. Considering this linkage, the genetic diversity (at a 16S fragment) of this obligate symbiont was added in the understanding of the distribution pattern of the holobiont at nine locations throughout four countries in the Mediterranean Basin. This was complemented with mitochondrial (four mtDNA fragments) and nuclear (ten microsatellites) data of the host. We focused on the previously established Iberian cluster for the B. oleae structure and hypothesised that the Tunisian samples would fall into a differentiated cluster. From the host point of view, we were unable to confirm this hypothesis. Looking at the symbiont, however, two new 16S haplotypes were found exclusively in the populations from Tunisia. This finding is discussed in the frame of host-symbiont specificity and transmission mode. To understand olive fruit fly population diversity and dispersion, the dynamics of the symbiont also needs to be taken into consideration, as it enables the fly to, so efficiently and uniquely, exploit the olive fruit resource.
油橄榄果蝇，在几个生命阶段专门变成单食性，仍然是最重要的橄榄树害虫，造成高直接生产损失，但也影响橄榄的质量、成分和固有特性。它被认为起源于非洲，如今在所有种植橄榄树的地方都有存在。油橄榄果蝇进化为携带一种垂直传播的专性细菌共生体-Candidatus Erwinia dacicola-，从而导致橄榄树、果蝇和专性垂直传播共生细菌之间有着紧密的进化历史。考虑到这种联系，在对地中海盆地四个国家的九个地点的整个holobiont 分布模式的理解中，增加了这种专性共生体的遗传多样性（在 16S 片段上）。这与宿主的线粒体（四个 mtDNA 片段）和核（十个微卫星）数据相补充。我们专注于先前为 B. oleae 结构建立的伊比利亚群集，并假设突尼斯样本将落入分化的群集。从宿主的角度来看，我们无法证实这一假设。然而，在共生体方面，仅在来自突尼斯的种群中发现了两个新的 16S 单倍型。这一发现是在宿主-共生体特异性和传播模式的框架内讨论的。为了了解油橄榄果蝇种群的多样性和分散性，还需要考虑共生体的动态，因为它使果蝇能够如此高效和独特地利用橄榄果实资源。
