Assessment of Trifolium spp. across the UK - the importance ofouter islands

摘要

Wild populations of plant species can be subject to hybridisation and consequently gene flow from introduced, taxonomically related plant material, such as widely grown crop varieties. Gene flow from domesticated plants to their wild relatives can lead to a 'homogenisation' of the gene pool, stifling local adaptation, a serious concern when the aim is to conserve the genetic diversity of the species. Isolation of wild populations from introduced plants through increasing distance or other geographicbarriers can provide some protection against this genetic contamination. The UK comprises many remote groups of islands, which may act as refuges for genetic diversity. In conjunction with BSBI county recorders, wild populations of Trifolium pratense (Red Clover) and wild populations of T. dubium (Lesser Trefoil) were collected across mainland UK from Devon, Dorset, East Sussex, Cumbria and Inverness-shire, as well as island populations from the Inner and Outer Hebrides, the Isles of Stilly and ShetlandIslands. We compared the genetic diversity patterns observed in T. pratense, a native, cultivated species, with T. dubium, a species with no known cultivation history in the UK, using molecular marker assessments. Using these measures this project aimsto provide: clarification of the role of islands as a key component of UK biodiversity strategies, information on current Trifolium distribution across the UK and information on genetic diversity for developing conservation strategies and in situ conservation plans for Trifolium. The BSBI aided this project by funding the molecular marker assessments of over half the populations assessed in this study.