Some structural and functional properties of nerves and muscles in the oviduct of the pink bollworm moth,Pectinophora gossypiella (Saund.)

The oviduct of the pink bollworm is innervated by an intrinsic neural network arising from 4 nerves from the terminal ganglion. The nerve tracts in this network often contained elliptical swellings, each with a central nucleus.

A distinct surface topography was evident in the muscular sheath of the common and lateral oviduct. A very thin muscular envelope consisting of an inner band of circular fibers and an outer layer of longitudinal fibers was also found in the ovarioles. Although conventional A and I bands were recognized, the z-disk was composed of an irregular and loose meshwork, suggesting that the visceral muscles of the reproductive tract possess super-contracting properties. Even when the oviduct and the ovarioles were isolated from the central nervous system, an endogenous rhythmic activity was evident.

Two types of spontaneous excitatory postsynaptic potentials were detected in the oviduct. The type most frequently observed had a complex of multiple spikes with a duration of 18–32 msec. The other type had a saw-tooth shape and a duration of 80–160 msec. Spontaneous action potentials with a plateau-type configuration and a duration of 280–320 msec were also observed. After the removal of the terminal ganglion, endogenous electrical activity distinct from the events just described was found in the midand upper common oviduct. Such discharges seem to originate from the intrinsic neural network and had durations similar to those found for neurosecretory cells.     

Spatial distribution of genetic relatedness in a moorland population of red grouse (Lagopus lagopus scoticus)

Several aspects of the ecology and biology of red grouse (Lagopus lagopus scoticus) could prevent the complete admixture of genes within and between populations. Male red grouse display a high degree of natal philopatry, are territorial, and show less aggression to kin man to non-kin. Such factors acting in combination predict limited male-mediated gene flow, which will promote social structure within a population by the formation of stable kin clusters, and facilitate a rapid rise in allelic coancestry and/or inbreeding. In this study we utilize hypervariable microsatellite polymorphisms to examine the extent of social affiliation between relatives in a moorland population of grouse from NE Scodand. Levels of genetic relatedness between individual male red grouse occupying territories at Glas Choille in die spring and autumn of 1995 were examined, and kin clusters delimited. Nine kin groups (mean size = 2.4 individuals) were identified prior to breeding in the spring, which increased to 11 kin groups (mean size =4.0 individuals) when territories were reformed in the autumn. The majority of tiiose individuals that were recruited into the adult population during the autumn already had a first-order male relative established, supporting the hypothesis that recruitment is facilitated by behavioural interactions among relatives. The demographic and population genetic consequences of philopatric recruitment and kin clustering are examined and discussed.     

Androdioecy in the entomophilous tree Fraxinus ornus (Oleaceae)

Androdioecy (the coexistence of two genders, cosexuals and males, in a single population) is a rare breeding system. In terms of functional gamete production, androdioecy has been reported in a small number of wind-pollinated and insect-pollinated species. In this study we examine the floral biology, stability of gender, and fruit and seed production after self-pollination and outcrossing pollination in a potentially androdioecious tree, Fraxinus ornus , in southern France. Individual trees have either hermaphrodite flowers or male flowers, the latter lacking a well-developed gynoecium. The two genders produce morphologically similar pollen and were present in 1:1 or slightly male-biased ratios. Only hermaphrodites set fruit during 2–4 yr of observation at four different sites in southern France. Experimental pollinations of eight trees in two different sites showed that hermaphrodites produce viable pollen in dehiscent anthers and viable seeds. Thus, in terms of functional gamete production, F. ornus is a new case of functional androdioecy. Seven hermaphrodites were self-compatible, and such self-compatibility of hermaphrodites might improve the colonizing ability of F. ornus in a region where this species is actively expanding its range.     

Phylogenetic relationships in brown argus butterflies (Lepidoptera: Lycaenidae: Aricia) from northwestern Europe

Lycaenid butterflies of the Aricia agestisartaxerxes complex pose an unresolved taxonomic and conservation problem in northwestern Europe. Two key issues require resolution: (i) how many species of Aricia occur in northwestern Europe and what are their distributions?; (ii) how is the morphological variation observed in northwestern Europe best explained? We investigated phylogenetic relationships and phylogeographic patterns in this species group using mitochondrial and nuclear markers in comparison with morphological variation. A 325 bp fragment of the mitochondrial cytochromeb gene was sequenced from 179 individuals representing 18 populations from the UK and Scandinavia. Seventeen enzymecoding loci were analysed from 538 individuals from the same populations. Highly congruent phylogenies between mitochondrial and allozyme markers demonstrate that the sample is composed of two closely related species, A. agestis and A. artaxerxes. Both marker types also suggest that Scottish and northern Scandinavian A. artaxerxes populations are conspecific, and consequently do not support the endemic status of A. artaxerxes in the UK. The subspecies division of British populations of A. artaxerxes is also not supported by phylogenetic analyses. Allozyme and mitochondrial analyses cluster two populations from the Peak District, UK, differently. The former suggests that they are A. artaxerxes whilst the latter suggests they are A. agestis. Further research is required to find the reason for this disagreement, which could be associated with the different dynamics of nuclear and mitochondrial genes across a hybrid zone between the two species. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society, 2002, 75 , 27–37.     

Bioremediation – prospects for the future application of innovative applied biological research

It has been estimated that there may be as much as 300 000 ha in the UK where contamination from previous industrial land use has occurred. The ‘Source‐Pathway‐Receptor’ model is used to evaluate these risks. Traditional engineering approaches have dominated remediation technology, but biological methods have become increasingly important in recent years. ‘Bioremediation’ has been defined as ‘the elimination, attenuation or transformation of polluting or contaminating substances by the use of biological processes’. Techniques to treat soil materials include biopiling, windrowing, landfarming and bioventing, all of which depend on microbiological degradation. However, increasingly it also includes the use of vegetation to take up and/or degrade contaminants (phytoremediation) or restrict contaminant movement (phytostabilisation). Phytoremediation can be encouraged by manipulation of the rhizosphere, using selected fungal isolates in a process now defined as phytobial remediation.