Multiple introductions can play a prominent role in explaining the success of biological invasions. One often cited mechanism is that multiple introductions of invasive species prevent genetic bottlenecks by parallel introductions of several distinct genotypes that, in turn, provide heritable variation necessary for local adaptation. Here, we show that the invasion of Aegilops triuncialis into California, USA, involved multiple introductions that may have facilitated invasion into serpentine habitats. Using microsatellite markers, we compared the polymorphism and genetic structure of populations of Ae. triuncialis invading serpentine soils in California to that of accessions from its native range. In a glasshouse study, we also compared phenotypic variation in phenological and fitness traits between invasive and native populations grown on loam soil and under serpentine edaphic conditions. Molecular analysis of invasive populations revealed that Californian populations cluster into three independent introductions (i.e. invasive lineages). Our glasshouse common garden experiment found that all Californian populations exhibited higher fitness under serpentine conditions. However, the three invasive lineages appear to represent independent pathways of adaptation to serpentine soil. Our results suggest that the rapid invasion of serpentine habitats in California may have been facilitated by the existence of colonizing Eurasian genotypes pre-adapted to serpentine soils.

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Development of high yielding and stable cultivars of various legume crops across different environments is very important for their adoption by farmers. In addition, climate change sets new challenges to major crop species and especially to grain legumes such as faba bean (Vicia faba L.) for adaptation to stressful environments. The present study focused on evaluating faba bean genotypes developed for yield and stability across different environments. The study was conducted in three areas of Greece (South, Central, and North) for two consecutive growing seasons (2018–2019 and 2019–2020). Biomass yield, seed yield, and yield components were studied together with plant height, earliness, and water use efficiency. Genotype, environment, and their interaction affected most of the studied characteristics. The environment was the major source of variation for most of the characteristics, as it explained 81–93% of total variation, and only in the thousand seed weight the variation was 49% for the environment and 40% for the genotype. Genotype had a much smaller effect on the remaining characteristics (1.2–3.9%), and the interaction between environment x genotype accounted for up to 0.5–17% of the variation. GGE-biplot analysis for high yield and stability across different environments revealed three genotypic types: genotypes well adapted either for biomass or seed yield and genotypes with high adaptation capacity for both traits under typical Mediterranean conditions. These results indicated that screening faba bean genotypes under different environmental field conditions is essential to identify adaptable cultivars to be cultivated for biomass and/or seed yield or to be used in breeding programs.

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Transhumance, the seasonal movement of herds between highlands and lowlands following precise, repeated routes, is a common practice in many Mediterranean regions. This livestock movement exploits natural vegetation in both winter and summer pastures. In Greece transhumant herders, drawn by relatively abundant vegetation, usually relocate to mountainous areas between April and October. Mount Vermio was an ideal summer pasture for the nomadic, ethnic group Sarakatsanoi of Thessaly, who used to own big herds. Socio-economic conditions of the 20th century led to the gradual decline of transhumance, resulting in reduction in grazing pressure and changes in vegetation dynamics. The purpose of this study was to monitor changes in landscape patterns in response to transhumance abandonment. Landscape metrics were employed to estimate land use/cover in two altitudinal zones. Results reveal that due to the abandonment of transhumance in the highlands landscape fragmentation increased. Meanwhile, in the lowlands, due to the uninterrupted presence of animals, landscape structure is more stable and diversified. Grasslands and agroforestry systems became smaller and more isolated. In OPEN ACCESSSustainability 2015, 7 15653 conclusion, the abandonment of transhumance led to the overall deterioration of the rural landscape in the highlands.