Conservation of genetic diversity in British populations of the diploid endemic Coincya monensis ssp monensis (Isle of Man Cabbage): the risk of hybridisation with the tetraploid alien, Coincya monensis ssp cheiranthos

Coincya monensis is represented in the British flora by two, cytologically distinct subspecies. Coincya monensis ssp monensis is an endemic diploid with a coastal sand dune distribution that includes a number of isolated populations. Coincya monensis ssp cheiranthos is a tetraploid alien, well established in South Wales in early successional habitats. Both subspecies share similar life form traits, flowering times and pollinators. Cluster analysis and phylogenetic reconstruction based on sequences of the mitochondrial nad4 gene confirmed the distinction between alien and endemic taxa. Tetraploid populations carry more polymorphic RAPDs loci and their genetic diversity is partitioned more within than among populations. In contrast, C. monensis ssp monensis has a distinct population genetic structure. Analysis of the multilocus genetic data confirmed a structure of genetically isolated, endemic population clusters in Scotland, Arran, the Isle of Man and South Wales. Experimental hybridisation showed the two subspecies are interfertile. Multivariate analysis of RAPDs data resolved hybrids between alien and endemic clusters and hybrids contained a proportion of alien-specific polymorphic loci. Hybrids of alien maternal parentage contained the mitochondrial nad4 sequence characteristic of the alien subspecies. Since the alien subspecies can invade mobile sand dune communities from urban sites and compete for pollinators, there is a risk that alien and endemic populations will mix and introgress. Conservation of endemic genetic diversity in Britain will require protection for all C. monensis ssp monensis populations. Currently, the most disjunct endemic population in South Wales is most at risk from introgression.

The man who mistook Marat for Sade: 'living' memory and the video archive

Digital video archives, which are growing at an exponential rate, will become increasingly important to Theatre History and Performance Studies, and questions of how scholars negotiate the relationships between memory, technology and performance events in theoretical and practical terms will become crucial. Indeed, there is already a considerable body of scholarly material on this topic. This article considers these questions with specific reference to the relationship between video records deposited in digital archives and human memory. First and foremost, this article raises questions about the authority of the archive and the ways in which archival technologies, in the words of Maaike Bleeker, 'transform how we remember, how our and others' memories are entangled in the here-and-now, and, in the end, even how we think and imagine'.