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Research has been conducted on genetic variation in the common warthog. The authors have investigated the effect of past environmental fluctuations on the patterns of this variation via the use of mitochondrial nucleotide sequence variation and allele length variation at microsatellite loci.

Research has been conducted on introgression between oilseed rape and Brassica rapa. The authors have investigated various offspring from maternal plants from the introgressed population via the use of AFLP markers in the effort to describe the progress of this introgression, and they report the high outcrossing rate of the introgressed maternal plants.

The magnitude and variation of inbreeding depression (ID) within populations is important for the evolution and maintenance of mixed mating systems. We studied ID and its genetic variation in a range of floral and fitness traits in a small and large population of the perennial herb Silene nutans, using controlled pollinations in a fully factorial North Carolina II design. Floral traits and early fitness traits, that is seed mass and germination rate, were not much affected by inbreeding (δ<0.2). In contrast, ‘late’ fitness traits and multiplicative fitness suffered severely from inbreeding (δ>0.4). Lack of genetic correlations indicated that ID in floral, early and late traits is genetically decoupled. There was a trend that the smaller population was less affected by ID than the large one, although the differences were not significant for most traits. Hence, evidence for purging of deleterious alleles remains inconclusive in this study. Genetic variation in ID among paternal families was statistically significant in most floral and all seed traits, but not in late fitness traits. However, some paternal families had δ<0.5, even in the multiplicative fitness measure that suffered most from ID (δ=0.74), suggesting that the mixed mating system of S. nutans might be evolutionary stable. [ABSTRACT FROM AUTHOR]

This comment is presented concerning an article published in a previous issue of "Molecular Ecology," wherein the author questioned the merit of a statistical methodology employed in assessing genetic differentiation that is known as GST. Such a claim has wide ranging implications for research within the disciplines of population genetics, phylogeography, and conservation genetics. The author of this comment allows that limitations exist in GST, and that they particularly arise when population diversity is high. It is posited that this is the case for many microsatellite data sets. Three statistical methods are evaluated and the faults inherent in each are illuminated.

Gene flow from sugar beets to sea beets occurs in the seed propagation areas in southern Europe. Some seed propagation also takes place in Denmark, but here the crop–wild gene flow has not been investigated. Hence, we studied gene flow to sea beet populations from sugar beet lines used in Danish seed propagation areas. A set of 12 Danish, two Swedish, one French, one Italian, one Dutch, and one Irish populations of sea beets, and four lines of sugar beet were analysed. To evaluate the genetic variation and gene flow, eight microsatellite loci were screened. This analysis revealed hybridization with cultivated beet in one of the sea beet populations from the centre of the Danish seed propagation area. Triploid hybrids found in this population were verified with flow cytometry. Possible hybrids or introgressed plants were also found in the French and Italian populations. However, individual assignment test using a Bayesian method provided 100% assignment success of diploid individuals into their correct subspecies of origin, and a Bayesian Markov chain Monte Carlo (MC MC) approach revealed clear distinction of individuals into groups according to their subspecies of origin, with a zero level of genetic admixture among subspecies. This underlines that introgression beyond the first hybridization is not extensive. The overall pattern of genetic distance and structure showed that Danish and Swedish sea beet populations were closely related to each other, and they are both more closely related to the population from Ireland than to the populations from France, the Netherlands, and Italy. [ABSTRACT FROM AUTHOR]

Abstract An earlier study of the morphological variation in the circumpolar genus Dryas in Greenland revealed that populations in east Greenland are highly variable and this variation was interpreted as a hybrid zone between D. octopetala and D. integrifolia. It was proposed that populations of Dryas in east Greenland immigrated postglacially from Svalbard. The purpose of our study was to investigate the population structure of the Dryas integrifolia–octopetala complex using a combination of morphological and genetic characters. Populations of Dryas were sampled in Greenland, Svalbard, Iceland and north Scandinavia (Sweden). The morphological traits clearly separated west Greenland from Svalbard, Iceland and north Scandinavia. A large number of individuals from east Greenland and some from north Greenland could be interpreted as hybrids between the morphs. The genetic pattern was, however, partly different as the greatest amount of differentiation among regions was found between west and north Greenland (F RT = 0.65). The highest degree of genetic variation appeared within east Greenland. This was in accordance with the putative hybrid origin of the populations, as concluded based on the morphological results. The total amount of genetic differentiation found among the six regions (F RT = 0.61) was larger than between the two species (F RT = 0.44). The genetic pattern matched the proposed postglacial migration routes. [ABSTRACT FROM AUTHOR]

Focuses on the genetic structure and variability of vector snail Bulinus globosus in Zimbabwe. Determination of population genetic structure; Enzyme systems analyzed in individual snails; Analysis on population structure and geographical variation; Factors influencing the genetic structure of B. globosus.