Genetics, taxonomy and the conservation of British Euphrasia

Abstract

In Britain the genus Euphrasia comprises ca 20 diploid and tetraploid plant species, including several endemics. However, their conservation is impeded by taxonomic uncertainty. Analysis of cpDNA and AFLP variation was used to assess their taxonomic status and establish the extent of barriers to gene exchange among them. Differences in ploidy level constitute a very strong barrier to genetic exchange, although this is not absolute. The diploid endemics E. vigursii and E. rivularis form morphologically and genetically definable units which show some level of reproductive isolation. Within tetraploid Euphrasia, the species showed varying degrees of distinctness. Analysis of geographically paired samples from two widespread outcrossing taxa E. arctica and E. nemorosa provides evidence for extensive genetic exchange between them. However AFLP data indicate that this outbreeding species complex possesses a gene pool distinct from that of the widespread inbreeding tetraploids. The widespread and endemic inbreeding tetraploids contain examples of morphologically and genetically definable taxa, but also species whose distinctness is more equivocal. The conservation implications of this study are that species-based action plans are potentially suitable for conservation of the diploid endemics E. vigursii and E. rivularis. In contrast we contend that a species-based conservation framework, developed with reproductively isolated and genetically distinct groups in mind, requires modification for conservation of the complex and dynamic diversity found within the tetraploids. The adoption of 'taxonomic' action plans, designed to protect the evolutionary processes generating Euphrasia diversity, may provide a supplementary solution for conserving this type of variation.

Early evolution in a hybrid swarm between outcrossing and selfing lineages in Geum

“…However, there are situations in which self-fertilizing lineages, after a period of independent evolution, hybridize with their outcrossing relatives. Such hybridization has the potential to generate novel biodiversity based on recombination of genetic information derived from the contrasting selfing and outcrossing taxa (Ennos et al, 2005;Hollingsworth et al, 2007;French et al, 2008;Chapman and Abbott, 2010).…”

Strengthening the scientific contribution of botanic gardens to the second phase of the Global Strategy for Plant Conservation

“…Although species‐based action plans were appropriate for the diploid endemics, this approach needed modification to conserve the complex and dynamic diversity found within the tetraploids. As a solution, French et al . (2008) proposed the adoption of ‘taxonomic’ action plans, designed to protect the evolutionary processes generating Euphrasia diversity.…”

“…Although species-based action plans were appropriate for the diploid endemics, this approach needed modification to conserve the complex and dynamic diversity found within the tetraploids. As a solution, French et al (2008) proposed the adoption of 'taxonomic' action plans, designed to protect the evolutionary processes generating Euphrasia diversity. This highlights the need for careful definition of the goals of conservation which must not be narrowly restricted to the protection of threatened species but need to encompass ecological interactions and processes that generate diversity.…”

Interspecific hybridization among indigenous New ZealandConvolvulus(Convolvulaceae) and the affinities of the Awahokomo limestone population

“…In this article, we present the results of an amplified fragment length polymorphism (AFLP) DNA fingerprinting study to resolve the status of the Awahokomo Convolvulus. AFLP is a technique capable of generating many polymorphic genetic markers and is widely used in studies of genetic variation within species (Jorgensen & Mauricio 2004), hybridization between species (Ma et al 2010) and species delimitation (French et al 2008;Zeng et al 2010). …”