Ben Abdelkrim Ahmed, Hattab Tarek, Fakhfakh Hatem, Belkadhi Mohamed Sadok, Gorsane Faten
Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie. Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis, Tunisie.
Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
PLoS One. 2017 Oct 3;12(10):e0185724. doi: 10.1371/journal.pone.0185724. eCollection 2017.
Combining landscape ecology and genetics provides an excellent framework to appreciate pest population dynamics and dispersal. The genetic architectures of many species are always shaped by environmental constraints. Because little is known about the ecological and genetic traits of Tunisian whitefly populations, the main objective of this work is to highlight patterns of biodiversity, genetic structure and migration routes of this pest. We used nuclear microsatellite loci to analyze B. tabaci populations collected from various agricultural areas across the country and we determine their biotype status. Molecular data were subsequently interpreted in an ecological context supplied from a species distribution model to infer habitat suitability and hereafter the potential connection paths between sampling localities. An analysis of landscape resistance to B. tabaci genetic flow was thus applied to take into account habitat suitability, genetic relatedness and functional connectivity of habitats within a varied landscape matrix. We shed light on the occurrence of three geographically delineated genetic groups with high levels of genetic differentiation within each of them. Potential migration corridors of this pest were then established providing significant advances toward the understanding of genetic features and the dynamic dispersal of this pest. This study supports the hypothesis of a long-distance dispersal of B. tabaci followed by infrequent long-term isolations. The Inference of population sources and colonization routes is critical for the design and implementation of accurate management strategies against this pest.
将景观生态学与遗传学相结合，为理解害虫种群动态和扩散提供了一个绝佳的框架。许多物种的遗传结构总是受到环境限制的影响。由于对突尼斯粉虱种群的生态和遗传特征了解甚少，这项工作的主要目标是突出这种害虫的生物多样性模式、遗传结构和迁移路线。我们使用核微卫星位点分析从该国不同农业地区收集的烟粉虱种群，并确定它们的生物型状态。随后，在物种分布模型提供的生态背景下解释分子数据，以推断栖息地适宜性以及此后采样地点之间的潜在连接路径。因此，应用了对烟粉虱基因流动的景观抗性分析，以考虑不同景观矩阵中栖息地的适宜性、遗传相关性和功能连通性。我们揭示了三个地理上划分的遗传群体的存在，每个群体内部都有高度的遗传分化。然后建立了这种害虫的潜在迁移走廊，这为理解这种害虫的遗传特征和动态扩散取得了重大进展。这项研究支持了烟粉虱远距离扩散后长期隔离不频繁的假设。推断种群来源和定殖路线对于设计和实施针对这种害虫的准确管理策略至关重要。
