Biology subjects

Reatini, B.

Publications and source records attributed to Reatini, B..

4 recordsLinked to original sources

bioRxiv2023

The role of self-fertilization in plant colony establishment

Increased rates of self-fertilization are often found in plant colonies, but the factors driving the observed higher selfing rates remain unclear. Specifically, the higher selfing rates in colonist populations may be due to 1) source populations with a higher selfing rate being more likely to successfully establish colonies (a filter effect), 2) the in situ evolution of selfing rate or a plastic selfing rate increase rescuing the colony from extinction, 3) selfing rate evolution post establishment. Using individual-based simulations and eco-evo models, we show that under both single and multiple dispersal, colony establishment may often be driven by a filter effect, due to a higher initial selfing rate and lower genetic load, which are correlated since selfing can purge deleterious mutations. Moreover, the role of the filter effect is weaker under multiple dispersal than single dispersal. The evolution of a higher selfing rate is unlikely to contribute directly to colony establishment. Although selfing rate evolution occurs during the colonization process, most of the selfing rate evolution may occur post establishment. Plasticity in selfing rates is more effective in facilitating colony establishment than the evolution of selfing.

evolutionary biology↗

bioRxiv2022

Local exclusion and regional decline of an endemic Galapagos tree species (Psidium galapageium) by an invasive relative (P. guajava)

Invasive species can interact with native relatives in a variety of ways which may jeopardize their long-term coexistence. Here we show that interactions with an invasive species of guava (Psidium guajava) appear to be driving the local exclusion and regional decline of guayabillo (Psidium galapageium), a tree species endemic to the Galapagos archipelago. We find evidence consistent with recent historic exclusion of guayabillo from the highlands of San Cristobal Island, signatures of ongoing demographic decline in sympatric populations at lower elevations, and evidence suggesting that the four coinhabited islands represent points along a time series of regional decline, with the extent of guayabillo decline depending on the date that guava was introduced to each island. Based on these results, we then use the percentage of guava cover surrounding guayabillo populations to target populations that are at imminent risk of exclusion to aid in prioritizing management targets.

ecology↗

bioRxiv2022

Chromosome-scale reference genome and RAD-based genetic map of yellow starthistle (Centaurea solstitialis) reveal putative structural variation and QTLs associated with invader traits

Invasive species offer outstanding opportunities to identify the genomic sources of variation that contribute to rapid adaptation, as well as the genetic mechanisms facilitating invasions. The Eurasian plant yellow starthistle (Centaurea solstitialis) is highly invasive in North and South American grasslands and known to have evolved increased growth and reproduction during invasion. Here we develop new genomic resources for C. solstitialis and map the genetic basis of invasiveness traits. We present a chromosome-scale (1N = 8) reference genome using PacBio CLR and Dovetail Omni-C technologies, and functional gene annotation using RNAseq. We find repeat structure typical of the family Asteraceae, with over 25% of gene content derived from ancestral whole genome duplications (paleologs). Using an F2 mapping population derived from a cross between native and invading parents, with a restriction site-associated DNA (RAD)-based genetic map, we validate the assembly and identify 13 QTL underpinning size traits that have evolved during invasion. We find evidence that large effect QTL may be associated with structural variants between native and invading genotypes, including a variant with an overdominant and pleiotropic effect on key invader traits. We also find evidence of significant paleolog enrichment under two QTL. Our results add to growing evidence of the importance of structural variants in evolution, and to understanding of the rapid evolution of invaders. Significance StatementInvasive species often evolve rapidly in new environments, potentially informing our understanding of the genomic basis of adaptation, but genomic studies of these non-model systems are limited. We provide a chromosome-scale reference genome, annotation, and genetic map for the invasive plant yellow starthistle, and we investigate the genetic basis of invader trait evolution in this system. We find regions of the genome with large effects on traits that differ between native and invading genotypes, and evidence suggesting genome structural variants and past genome duplications could play a role in rapid adaptation of invading populations. These genomic resources and evolutionary insights aid in our understanding of the sources of genomic variation for adaptation, and how their evolution facilitates invasion.

genomics↗

bioRxiv2019

Genetic architecture influences when and how hybridization contributes to colonization

The role of genetic architecture in adaptation to novel environments has received considerable attention when the source of adaptation variation is de novo mutation. Relatively less is known when the source of adaptive variation is inter- or intraspecific hybridization. We model hybridization between divergent source populations and subsequent colonization of an unoccupied novel environment using individual-based simulations in order to understand the influence of genetic architecture on the timing of colonization and the mode of adaptation. We find that two distinct categories of genetic architecture facilitate rapid colonization but that they do so in qualitatively different ways. For few and/or tightly linked loci, the mode of adaptation is via the recovery of adaptive parental genotypes. With many unlinked loci, the mode of adaptation is via the generation of novel hybrid genotypes. The first category results in the shortest colonization lag phases across the widest range of parameter space, but further adaptation is mutation limited. The second category takes longer and is more sensitive to genetic variance and dispersal rate, but can facilitate adaptation to environmental conditions which exceed the tolerance of parental populations. These findings have implications for understanding the origins of biological invasions and the success of hybrid populations.

evolutionary biology↗