Data from: Landscape genetics of a pollinator longhorn beetle [Typocerus v. velutinus (Olivier)] on a continuous habitat surface

Landscape connectivity, the degree to which the landscape structure facilitates or impedes organismal movement and gene flow, is increasingly important to conservationists and land managers. Metrics for describing the undulating shape of continuous habitat surfaces can expand the usefulness of continuous gradient surfaces that describe habitat and predict the flow of organisms and genes. We adopted a landscape gradient model of habitat and used surface metrics of connectivity to model the genetic continuity between populations of the banded longhorn beetle [Typocerus v. velutinus (Olivier)] collected at 17 sites across a fragmentation gradient in Indiana, USA. We tested the hypothesis that greater habitat connectivity facilitates gene flow between beetle populations against a null model of isolation by distance (IBD). We used next-generation sequencing to develop 10 polymorphic microsatellite loci and genotype the individual beetles to assess the population genetic structure. Isolation by distance did not explain the population genetic structure. The surface metrics model of habitat connectivity explained the variance in genetic dissimilarities 30 times better than the IBD model. We conclude that surface metrology of habitat maps is a powerful extension of landscape genetics in heterogeneous landscapes.

景观连通性（landscape connectivity）指景观结构促进或阻碍生物移动与基因流的程度，其对保护生物学家与土地管理者的重要性与日俱增。用于描述连续生境表面起伏形态的连通性指标，可拓展描述生境的连续梯度表面的应用范围，助力预测生物与基因的流动。本研究采用生境景观梯度模型，结合连通性表面指标，对美国印第安纳州沿生境破碎化梯度的17个采样点所获带纹长角甲虫（Typocerus v. velutinus (Olivier)）种群间的遗传连续性进行建模。本研究以距离隔离（isolation by distance, IBD）零模型为对照，验证了"更高的生境连通性可促进甲虫种群间基因流"这一假说。本研究借助下一代测序（next-generation sequencing）技术，开发了10个多态性微卫星位点（microsatellite loci），并对单个甲虫进行基因分型以解析种群遗传结构。研究结果显示，距离隔离无法解释该种群的遗传结构。生境连通性表面指标模型对遗传差异方差的解释能力，是距离隔离模型的30倍。本研究结论表明，生境地图的表面计量学方法，是非均质景观中景观遗传学研究的有力拓展方向。