The population structure of invasive <i>Lantana camara</i> is shaped by its mating system.

Abstract

Over the last century, invasive species have emerged as an important driver of global biodiversity loss. <i>Lantana camara</i> is one of the hundred most problematic invasive species globally, yet its genetic diversity patterns remain poorly understood. Previous studies hypothesize that invasive <i>L. camara</i> is a species complex of hybrid origin, though this remains untested. We investigated the population genetic patterns of <i>L. camara</i> by sampling 359 plants representing diverse flower colour variants across 36 locations in India. Analyses of the population structure using 19,008 SNPs revealed a strong genetic structure in India. However, this structure showed little correlation with geography; instead, individuals with similar flower colours clustered together irrespective of location in the structure analysis. Low genetic distance between most of the individuals indicated the absence of multiple species. A high inbreeding coefficient and low proportion of heterozygous sites suggested predominant self-fertilization, confirmed by bagging experiments. Thus, we infer that <i>L. camara</i> exists as homozygous inbred lines formed by self-fertilization, associated with distinct flower colours. These results refute the hypothesis that <i>L. camara</i> is a species complex. Our findings highlight a hitherto unknown role for mating systems in invasive species, furthering our understanding of evolution in invasive species.