Phylogeography and modes of reproduction in diploid and tetraploid halophytes of Limonium species (Plumbaginaceae): evidence for a pattern of geographical parthenogenesis

Background and Aims The genus Limonium (Plumbaginaceae) has long been recognized to have sexual and apomictic (asexual seed formation) modes of reproduction. This study aimed to elucidate phylogeographical patterns and modes of reproduction in diploid and tetraploid Limonium species, namely three putative sexual diploid species with morphological affinities (L. nydeggeri, L. ovalifolium, L. lanceolatum) and three related, probably apomict tetraploid species (L. binervosum, L. dodartii, L. multiflorum). Methods cpDNA diversity and differentiation between natural populations of the species were investigated using two chloroplast sequence regions (trnL intron and trnL–trnF intergenic spacer). Floral heteromorphies, ovule cytoembryological analyses and pollination and crossing tests were performed in representative species of each ploidy group, namely diploid L. ovalifolium and tetraploid L. multiflorum, using plants from greenhouse collections. Key Results and Conclusions Genetic analyses showed that diploid species have a higher haplotype diversity and a higher number of unique (endemic) haplotypes than tetraploid species. Network analysis revealed correlations between cpDNA haplotype distribution and ploidy groups, species groups and geographical origin, and haplotype sharing within and among species with distinct ploidy levels. Reproductive biology analyses showed that diploid L. ovalifolium mainly forms meiotically reduced tetrasporic embryo sacs of Gagea ova, Adoxa and Drusa types. Limonium multiflorum, however, has only unreduced, diplosporic (apomictic) embryo sacs of Rudbeckia type, and autonomous apomictic development seems to occur. Taken together, the findings provide evidence of a pattern of ‘geographical parthenogenesis’ in which quaternary climatic oscillations appear to be involved in the geographical patterns of coastal diploid and tetraploid Limonium speciesinfo:eu-repo/semantics/publishedVersio

Is technology optimism justified? A discussion towards a comprehensive narrative

This paper is based on a discussion developed by one of the thematic working groups at the Biennial International Workshop Advances in Energy Studies (BIWAES) 2017 hold in Naples, Italy. The topic was the role of technology in energy transition and global problems. Owing to the heterogeneity of the participants in the working group, different viewpoints were put together, leading to some shared conclusions. In particular, the role played by the different narratives used in discussing the role of technology in facing global problems was pointed out as the origin of cognitive dissonance. The presented reflections address some conceptual weaknesses in the current debate on technology and global issues, framed in global policies that appear incapable to obtain tangible results. The technology optimism seems, in fact, to be based on the elusive use of both the concepts of technology and sustainability, that are put together for narrative purposes without an explicit conceptual assessment. On one hand, the factual role of technology and its beneficiary are almost never clearly addressed in the debate. On the other hand, the fact that any new technology will serve the cause of sustainability is not questioned whatsoever, without taking into account the social, political and ethical framework in which technology is supposed to be operated