Tagged: phylogeography





Xeric flora

Effect of climatic fluctuations of the Quaternary on xeric flora

Quaternary glaciations strongly affected the distribution of species from arid and semi-arid environments, as temperature drops were accompanied by strong fluctuations in rainfall. In this study, Ossa and colleagues examined the response of xerophytic species to glacial cycles, determining the genetic patterns and climatic niche of Echinopsis chiloensis var. chiloensis, an endemic columnar cactus of arid and semi-arid regions of Chile. The authors found a decline in genetic diversity towards high latitudes and a significant IBD pattern that together with ENM predictions suggest that E. chiloensis var. chiloensis experienced range contraction northwards during wet–cold conditions of the LGM, followed by...

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Patterns of mtDNA variation reveal complex evolutionary history of a relict and endangered peat bog pine

Assessments of eco-evolutionary mechanisms that shape the genetic structure of populations are important to understand the influence of environmental changes on plant ecosystems.In recent years, molecular markers greatly improved our ability to assess genetic differentiation within and among species. However, due to genome complexity and limited access to suitable genomic resources, phylogenetic investigations remain challenging, especially in many non-model plant species. Assessments of species boundaries and their underlying population structure are needed not only to improve taxonomic knowledge, but also to properly guide decision-making in conservation of endangered tree species In a recent study published in AoBP, Łabiszak et al. used...

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Distribution model of Astragalus edulis

Phylogeography of an Endangered Disjunct Herb: Long-distance Dispersal, Refugia, and Colonization Routes

Current diversity patterns are influenced by both historic and recent environmental conditions. Quaternary glacial cycles appear to have had a consistent role in shaping the genetic diversity and structure of plant species. Yet despite the unusual combination of the characteristics of the western Mediterranean–Macaronesian area, there are no studies that have specifically examined the effects of palaeoclimatic and palaeogeographic factors on the genetic composition and structure of annual herbs. A recent study by Bobo-Pinilla et al., published as an Editor’s Choice article in AoBP, sought to reconstruct the phylogeographic patterns of intraspecific lineages within Astragalus edulis, with the general aim...

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Expansive reed populations – alien invasion or disturbed wetlands?

In southern Africa a pattern of Phragmites spp. reed expansion has occurred in recent decades that has shown a similar trend to cryptic invasions reported in North and South America. A recent Editor’s Choice article published in AoB PLANTS by Canavan et al. used molecular techniques to explore the phylogeography of P. australis and P. mauritianus and found no evidence of cryptic invasion. The expansion of P. australis and P. mauritianus is therefore occurring within native haplotypes and is most likely a result of anthropogenic activity that has disturbed wetlands.

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Dioon

Diversification of Dioon in the Mexican transition zone

The Mexican transition zone originated from the overlap of the Nearctic and the Neotropical biotas. By analysing the genetic variation within the cycad genus Dioon, a relict Neotropical group, Gutiérrez-Ortega et al. test the association betweenthe diversification of Dioon with the biogeographic provinciality of the Mexican transition zone. The variation of two chloroplast DNA fragments and genome-wide single nucleotide polymorphisms reveals four Dioon lineages that are geographically structured. The reconstruction of the expansion of Dioon suggests that Dioon migrated along the mountain chains of Mexico. While dispersing towards their current distribution, each geographic region provided disparate ecological conditions that facilitated...

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Methodological framework to address major questions on the impact of domestication on the evolution of olive and its associated biotic communities.

Origins and domestication of the olive

The olive, Olea europaea (Oleaceae), is an iconic species in Mediterranean agriculture yet its origin is complex. Besnard et al. review the literature on the timeline of Mediterranean olive evolution and discuss the questions that remain unanswered. They also propose new avenues of multidisciplinary approaches to investigate the ecological genomics of olive domestication. These findings offer a roadmap which may help to unravel the puzzle of olive domestication and more generally the evolutionary processes involved in phenotypic and molecular evolution, and adaptation of perennial crops, thereby contributing to the sustainable management of olive germplasm and agrosystems, particularly in the current...

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Floristic sub-division of the Aegean region

Island fragmentation and colonisation drove diversification of Aegean Nigella

Island organisms are generally understood to diverge through geographical (allopatric) speciation. This paradigm, however, might be too simplistic for continental islands that were connected with each other and/or the mainland during Pleistocene low-sea-level periods. Floristic sub-division of the Aegean region (after Rechinger, 1950) into five major zones, namely the Western (WAe), Northern (NAe) and Eastern Aegean (EAe), the Cyclades (Cyc) and the ‘Southern Aegean Island Arc’ (SAe; Crete, Karpathos/Kasos and Rhodos), with ‘Rechinger’s line’ (Strid, 1996) highlighted in bold. Based on amplified fragment length polymorphisms (AFLPs), Jaros et al. find population genetic evidence that an annual plant group from the mostly...

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Anthoxanthum

The Mediterranean cradle of Anthoxanthum diploid diversity

The Mediterranean region has cradled the evolution of many European plant taxa, including grass genera. Chumová et al. use a multidisciplinary approach combining sequence data, rDNA FISH, climatic niche characterization and spatio-temporal modelling to investigate the evolutionary relationships of diploid Anthoxanthum (Poaceae) members. The Balkans and Apennines are identified as the source area of diploid diversity, with climatic changes starting in the Miocene acting as the main factors promote taxa differentiation. A. gracile and A. alpinum were the only well-differentiated lineages. The taxonomically uncertain ‘Mediterranean diploid’ is a possible relic of the most recent common ancestor of the other diploid...

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Arachnitis uniflora

Genetic diversity and evolution of arbuscular mycorrhizal fungi in Arachnitis uniflora

Arachnitis uniflora is a mycoheterotrophic plant that obtains nutrients via arbuscular mycorrhizal fungi of neighbouring autrotrophic plants. Some mycoheterotrophic plants have the ability to associate with more than one fungal family. Renny et al. identified fungal taxa associated with A. uniflora over 25 sites across its geographic range. High genetic diversity was associated with temperature, rainfall and soil features. Molecular tools reveal phylogenetic and phylogeographic fungal structures, uncovering associations with three Glomeromycotan families, with Glomeraceae emerging as the dominant symbiont. The fungal lineage originated around the Upper Cretaceous epoch, diversifying at the Miocene. The two families not previously found in...

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