Population Structure in the Model Grass Brachypodium distachyon Is Highly Correlated with Flowering Differences across Broad Geographic Areas

The small, annual grass Brachypodium distachyon (L.) Beauv., a close relative of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), is a powerful model system for cereals and bioenergy grasses. Genome-wide association studies (GWAS) of natural variation can elucidate the genetic basis of complex traits but have been so far limited in B. distachyon by the lack of large numbers of well-characterized and sufficiently diverse accessions. Here, we report on genotyping-by-sequencing (GBS) of 84 B. distachyon, seven B. hybridum, and three B. stacei accessions with diverse geographic origins including Albania, Armenia, Georgia, Italy, Spain, and Turkey. Over 90,000 high-quality single-nucleotide polymorphisms (SNPs) distributed across the Bd21 reference genome were identified. Our results confirm the hybrid nature of the B. hybridum genome, which appears as a mosaic of B. distachyon-like and B. stacei-like sequences. Analysis of more than 50,000 SNPs for the B. distachyon accessions revealed three distinct, genetically defined populations. Surprisingly, these genomic profiles are associated with differences in flowering time rather than with broad geographic origin. High levels of differentiation in loci associated with floral development support the differences in flowering phenology between B. distachyon populations. Genome-wide association studies combining genotypic and phenotypic data also suggest the presence of one or more photoperiodism, circadian clock, and vernalization genes in loci associated with flowering time variation within B. distachyon populations. Our characterization elucidates genes underlying population differences, expands the germplasm resources available for Brachypodium, and illustrates the feasibility and limitations of GWAS in this model grass

From common and used to rare and forgotten: Past and present distribution of the archaeophyte Euphorbia lathyris L. (Euphorbiaceae) in southern Italy and Sicily

Our study aimed at clarifying the current and previous occurrence, distribution and status (native vs. introduced) of Euphorbia lathyris L., the caper spurge, in S Italy and Sicily: most of the recent Italian floras and checklists, in fact, do not report this species for this area. To do this, a multi-disciplinary research was carried out taking into account not only botanical but also ethnobotanical and dialectological sources and a survey of the main herbaria of central and southern Italy. Our results point out that E. lathyris was much more frequent, well-known and commonly used in the whole southern Italy and in Sicily until 2-3 centuries ago, and that it probably experienced isolated cases of short naturalization at that time. Nowadays the caper spurge still occurs with few, small and scattered populations only in Molise and Calabria

Isoëtes sabatina (Isoëtaceae, Lycopodiopsida):taxonomic distinctness and preliminary ecological insights

Abstract Isoëtes sabatina is the rarest aquatic quillwort in Europe. Although recently found (2013) in Lake Bracciano (central Italy), the species is just one step away from extinction with an estimated population not exceeding 400 individuals and a spatial range of a few hundred square metres. Lake Bracciano is a deep, oligo-mesotrophic Mediterranean volcanic lake that has been subjected to human activities. From January to October 2017, the lake experienced a dramatic water level decrease (up to −1.50 m), which significantly affected the littoral zone and the habitat of I. sabatina. To improve the chances of survival of I. sabatina, the first eco-taxonomic investigation on this species was carried out to describe its genetic distinctness, physical and chemical requirements and companion species. The phylogenetic position of I. sabatina was investigated by applying standard DNA barcoding methods. Simultaneously, during summer 2019, the physical and chemical features of water and sediments of the I. sabatina population and five small Alpine lakes colonized by Isoëtes echinospora — a supposed close relative — were characterized. These data were then compared with the available data on the trophic requirements of the target obligate aquatic Isoëtes, together with Isoëtes lacustris and Isoëtes malinverniana. The present survey confirmed the taxonomic and ecological distinctness of I. sabatina — providing the first evidence of genetic differentiation from I. echinospora. Isoëtes sabatina grows in waters with temperature, conductivity and total alkalinity up to 30°C, 561 μS cm⁻¹ and 3.45 meq L⁻¹, respectively. The edaphic requirements of I. sabatina confirm its outstanding conservation value, and this study offers a basic understanding of how to prevent its extinction. Now, all possible actions must be taken immediately to save this species

Best practices, errors and perspectives of half a century of plant translocation in Italy

: Conservation translocations are becoming common conservation practice, so there is an increasing need of understanding the drivers of plant translocation performance through reviews of cases at global and regional levels. The establishment of the Italian Database of Plant Translocation (IDPlanT) provides the opportunity to review the techniques used in 186 plant translocation cases performed in the last fifty years in the heart of the Mediterranean Biodiversity Hotspot. In this study, we describe techniques and information available in IDPlantT and use these data to identify drivers of translocation outcomes. To this end, we tested the effect of 15 variables on survival translocated propagules at the last monitoring date, using binomial logistic Mixed Effect Models. The analysis revealed that 11 variables significantly affected survival of transplants, namely: life form, site protection, material source, number of source populations, propagation methods, propagule life stage, planting methods, habitat suitability assessment, site preparation, aftercare and costs. Plant translocations in Italy and in the Mediterranean area should consider the complexity of speciation, gene flow and plant migrations that has led to local adaptations with important implications on the choice and constitution of source material. The integration of vegetation studies for the selection of suitable planting sites can significantly increase the success of translocation efforts. Whilst post-translocation watering has a general positive effects on traslocation outcome, other aftercare techniques do not always increase transplant survival. Finally, we found that how funds are spent appears to be more important than their actual amount. This article is protected by copyright. All rights reserved