Process‐Based Species Action Plans: an approach to conserve contemporary evolutionary processes that sustain diversity in taxonomically complex groups

Many endemic plant species belong to taxonomically complex groups. These endemics have often arisen as a consequence of recent and rapid evolutionary divergence facilitated by processes such as hybridization, polyploidy and/or breeding system transitions. The rapid and dynamic nature of divergence in taxonomically complex groups leads to problems in the implementation of traditional species‐based approaches for the conservation of the biodiversity that they contain. Firstly, the taxa of interest can be difficult to define and identify, leading to practical difficulties in implementing conservation measures. Secondly, a species‐based approach often fails to capture the complexity of diversity present in the taxonomically complex group. To accommodate these challenges, we have developed a Process‐Based Species Action Plan approach. This is designed to conserve the processes leading to the generation of biodiversity, rather than focusing on the preservation of individual named taxa. We illustrate the approach using a group of endemic tree species (Sorbus) on the Scottish island of Arran that have originated via a combination of multiple recent hybridization events and apomixis. The plan focuses on the optimization of habitat management to ensure the reproduction and regeneration of Sorbus in the zone in which these evolutionary processes operate, and to facilitate hybridization that will ensure the continued generation of diversity in this group. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 194–203.     

The Use of an Escherichia coli Lys- Auxotroph to Assay Nutritionally Available Lysine in Biological Materials

A new bacterial method for determining amino acids in protein foods is described. Instead of the 'natural'microbial auxotrophs e.g. Tetrahymena, Streptococcus , and Leuconostoc , currently used for such assays, an 'artificial'mutant is used, viz. an auxotroph of Escherichia coli . Test proteins (Bovine serum albumin, legume and maize meals) were predigested with a mixture of pronase and intestinal peptidases, the efficiency and extent of proteolysis being monitored by pH stat titration. Final digests were examined by Sephadex gel filtration to ensure that all protein cleavage products were small enough to pass through the E. coli cell wall and to reach its cyto-plasmic amino acid and peptide permeases. The lysine content of the meals, as determined from the growth of an E. coli lysine auxotroph upon the digests, was found to be greater than 90° of the lysine determined chemically in acid hydrolysates. Practical and theoretical advantages of using this latter type of bacterium rather than the fastidious species are discussed. In addition, the particular value of using an intestinal bacterium like E. coli to assay nutritional availability of amino acids is considered in relation to its normal utilization of digested protein foods in vivo , and the similarities between its amino acid and peptide permeases and those of the intestine.     

Detection by Gel Electrophoresis of Oligomers Formed by the Association of High-Molecular-Weight Glutenin Protein Subunits of Wheat Endosperm

Evidence is presented that the high-molecular-weight gluteninprotein subunits of hexaploid wheat can form oligomers whichare detectable by sodium dodecyl sulphate-polyacrylamide gelelectrophoresis. The oligomers appear when trace amounts of2-mercaptoethanol (2-ME) are used in the extracting solvent,although the presence of a small disulphide compound (cystaminedi HC1) was found to enhance their resolution. These oligomersare not present when high levels of 2-ME are used, which indicatesthat disulphide bonds (probably inter-molecular) are essentialto maintain the association of the constituent polypeptides.It was found that (i) the subunits show specificity when theyassociate to form oligomers, for some subunit associations werenot detected amongst the oligomers (ii) the subunits controlledby chromosome ID are extensively involved in oligomer formationand (iii) different combinations of subunits controlled by chromosomeIB apparently differ in their ability to associate with subunitscontrolled by other chromosomes. The role of the oligomers inthe structure of native glutenin is discussed and their possibleinfluence on bread-making quality considered. Key words: Gel electrophoresis, Oligomers of glutenin, Wheat glutenin     

Host range and virulence of five baculoviruses from lepidopterous hosts

The host range and virulence of five insect baculoviruses (two multiply-enveloped nuclear polyhedrosis viruses (MNPVs) from Agrotis segetum and Mamestra brassicae; one singly-enveloped NPV from Plusia gamma and two granulosis viruses (GVs) from A. segetum and Pieris brassicae) were studied for seven lepidopterous pests of temperate agriculture (A. segetum, Agrotis exclamationis, Lacanobia oleracea, M. brassicae, Noctua pronuba, P. gamma and Pieris rapae). None of the viruses killed all species but M. brassicae MNPV failed to infect only P. rapae. The other viruses were restricted to the homologous host, or members of its genus or subfamily. In all examples except A. segetum GV, the median lethal dose for the most susceptible host, was less than 22 virus inclusion bodies and median lethal times for all infections ranged from 5·5 to 16·6 days. The low susceptibility of A. segetum and other noctuids to GV infections is discussed in relation to the structure of inclusion bodies and the nature of the infectious unit in baculoviruses.