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Interspecific hybridization events have played a major role in plant speciation, yet the evolutionary origin of hybrid species often remains enigmatic. Here, we inferred the evolutionary origin of the allotetraploid species Coffea arabica, which is widely cultivated for Arabica coffee production. We estimated genetic distances between C. arabica and all species that are known to be closely related to C. arabica using genotyping‐by‐sequencing (GBS) data. In addition, we reconstructed a time‐calibrated multilabeled phylogenetic tree of 24 species to estimate the age of the C. arabica hybridization event. Ancestral states of self‐compatibility were also inferred to shed new light on the evolution of self‐compatibility in Coffea. Coffea canephora and C. eugenioides were confirmed as the putative progenitor species of C. arabica. These species most likely hybridized between 1.08 million and 543 000 years ago, coinciding with periods of environmental upheaval, which may have induced range shifts of the progenitor species that facilitated the emergence of C. arabica. [ABSTRACT FROM AUTHOR]

To effectively monitor, manage and protect aquatic species and understand their interactions, knowledge of their spatiotemporal distribution is needed. In this study, we used a fine‐scale spatiotemporal water sampling design, followed by environmental DNA (eDNA) 12S metabarcoding, to investigate occupancy patterns of a natural community of fish and amphibian species in a lentic system. In the same system, we experimentally estimated the spatial and temporal dispersion of eDNA by placing a community of different fish and amphibian species in cages at one side of the pond, creating a controlled point of eDNA emission. Analyses of this cage community revealed a sharp spatial decline in detection rates and relative eDNA quantities at a distance of 5–10 m from the source, depending on the species and its abundance. In addition, none of the caged species could be detected 1 week after removal from the system. This indicates high eDNA decay rates and limited spatial eDNA dispersal, facilitating high local resolution for monitoring spatial occupancy patterns of aquatic species. Remarkably, for seven of the nine cage species, the presence of a single individual could be detected by pooling water of subsamples taken across the whole water body, illustrating the high sensitivity of the eDNA sampling and detection method applied. Finally, our work demonstrated that a fine‐scale sampling design in combination with eDNA metabarcoding can cover total biodiversity very precisely and allows the construction of consistent spatiotemporal patterns of relative abundance and local distribution of free‐living fish and amphibian species in a lentic ecosystem. [ABSTRACT FROM AUTHOR]

* Background and Aims The high productivity of Miscanthus x giganteus has been at least partly ascribed to its high chilling tolerance compared with related C4 crops, allowing for a longer productive growing season in temperate climates. However, the chilling tolerance of M. x giganteus has been predominantly studied under controlled environmental conditions. The understanding of the underlying mechanisms contributing to chilling tolerance in the field and their variation in different miscanthus genotypes is largely unexplored. * Methods Five miscanthus genotypes with different sensitivities to chilling were grown in the field and scored for a comprehensive set of physiological traits throughout the spring season. Chlorophyll fluorescence was measured as an indication of photosynthesis, and leaf samples were analysed for biochemical traits related to photosynthetic activity (chlorophyll content and pyruvate, Pi dikinase activity), redox homeostasis (malondialdehyde, glutathione and ascorbate contents, and catalase activity) and water-soluble carbohydrate content. * Key Results Chilling-tolerant genotypes were characterized by higher levels of malondialdehyde, raffinose and sucrose, and higher catalase activity, while the chilling-sensitive genotypes were characterized by higher concentrations of glucose and fructose, and higher pyruvate, Pi dikinase activity later in the growing season. On the early sampling dates, the biochemical responses of M. x giganteus were similar to those of the chilling-tolerant genotypes, but later in the season they became more similar to those of the chilling-sensitive genotypes. * Conclusions The overall physiological response of chilling-tolerant genotypes was distinguishable from that of chilling-sensitive genotypes, while M. x giganteus was intermediate between the two. There appears to be a trade-off between high and efficient photosynthesis and chilling stress tolerance. Miscanthus x giganteus is able to overcome this trade-off and, while it is more similar to the chilling-sensitive genotypes in early spring, its photosynthetic capacity is similar to that of the chilling-tolerant genotypes later on. [ABSTRACT FROM AUTHOR]

Phylogenetic relationships among gall-forming plant parasitic nematodes of the subfamily Anguininae are reconstructed by maximum parsimony and maximum likelihood analyses. Sequences of the ITS of rDNA from 53 populations and species of gall-forming nematodes and five populations of the Ditylenchus dipsaci species complex were analysed. The phylogenetic trees strongly support monophyly of the genus Anguina and show nonmonophyly for the genera Mesoanguina and Heteroanguina. Morphological and biological characters are generally congruent with the anguinid groups identified in the rDNA phylogeny. Analyses of evolution of different gall types among anguinids reveal that there are apparent evolutionary trends in gall evolution: from abnormal swelling and growth of infested plant organs toward small localised galls, and from infestation of vegetative toward generative organs. Our study demonstrates that the main anguinid groups are generally associated with host plants belonging to the same or related systematic groups. The comparison of the ITS phylogenies of anguinids parasitising Poaceae and their host grasses shows a high level of cospeciation events. [Copyright &y& Elsevier]