O. Mastenbroek

Geographic trends in flavone-glycosylation genes and seed morphology in EuropeanSilene pratensis (Caryophyllaceae)

Three of the loci controlling isovitexin glycosylation inSilene pratensis are polymorphic and show geographic trends which are compared with geographic trends in seed morphology (and other phenotypic characters) as demonstrated by multivariate analysis. Various lines of evidence support the hypothesis thatS. pratensis spread into Europe from at least two genetically differentiated sources.S. dioica, by contrast, shows little interpretable geographic variation in morphology or flavonoid content.

The possible evolution of Silene pratensis as deduced from present day variation patterns

Abstract Variation within and between European populations of Silene pratensis has been determined at different levels: morphological, biochemical and genetic. The various data sets were analysed separately and comparison of the patterns led to a number of conclusions concerning the evolution of the species. Coinciding patterns were found for flavone glycosylating genes, seed, pollen and capsule morphology. Together with observations on habitat and with some historical evidence, these patterns elucidated the evolutionary history of S. pratensis in Europe since the last Ice Age. The isozyme data and the flower morphology, on the other hand, presents us with knowledge about the ontogenesis and the influence of the environment on S. pratensis. Finally we can begin to determine the evolutionary relationships within section Elisanthe by comparing the variation of S. pratensis with the variation known for other species.

The geographic distribution of flavone-glycosylating genes in Silene pratensis (Rafn.) Godron and Gren. (Caryophyllaceae)

In Silene pratensis three loci (g, gl and fg) control the glycosylation of isovitexin. Three alleles are known for both the g-locus (g, gGand gX) and the gl-locus (gl, glAand glR); for the fg-locus there are only two alleles (fg and Fg). The distribution of these alleles over 285 European populations of S. pratensis has been investigated. It was concluded that there are three different chemical races within S. pratensis in Europe. The first race contains the populations in western and southern Europe and displays high frequencies of gG, gl and fg. The frequencies of gGand glRare very high in the second chemical race, which can be found in the USSR, Scandinavia and eastern Poland. The third chemical race occurs in central Europe and in this race the frequencies of both g and glRare high, Fg has low to moderate frequencies in the second and third groups. The alleles glAand gXare seldom found in S. pratensis, but are present in the closely related S. dioica. They do occur with low frequencies in some populations of S. pratensis, possibly as a result of hybridization with S. dioica.

Corresponding patterns of geographic variation among populations ofSilene latifolia (=S. alba =S. pratensis) (Caryophyllaceae)

Morphological and biochemical data were analysed from 30 greenhouse-grown populations of EuropeanSilene latifolia. Six separate character sets (flavones, seed, pollen, capsules, male and female flower morphology) were used in the analyses. There was broad-scale congruence between trends of geographic variation in most character sets, with the populations being assigned to western (or southern and western) and eastern clusters. The eastern and western clusters abut along a transition zone that runs roughly from Belgium to the northern Balkans; this zone represents a region of relatively rapid change and contains populations intermediate between the eastern and western clusters. Variation in flower morphology was weak and discordant with variation in the other character sets. The origin and maintenance of the variation pattern is discussed in terms of migrational history and “hybrid zones”.

A pattern analysis of the geographical distribution of flavone-glycosylating genes in Silene pratensis

Abstract The three flavone glycosylating genes in European Silene pratensis shows a distinct geographical variation. Three genetically different races can be distinguished on the basis of gene frequencies. Pattern recognition techniques and cluster analysis have been used on the data set of frequencies of the flavone-glycosylating genes in 285 European populations of S. pratensis . The combined results of these analyses confirm the previously recognized races and reveal a steep cline between races 7 and 2(+3) and a wide wide transition zone between races 2 and 3.

Isozyme Variation in Silene pratensis: a Response to Different Environments

The isozymes of nine enzyme systems were screened and the frequencies of the flavone glycosylating genes were determined in an outdoor experiment with 70 populations of European S. pratensis and an indoor experiment with 30 populations of the same species. Cluster analysis (using Wards cluster criterion) were performed on all data sets. In the outdoor experiment, cluster analysis of the flavonoid data gave the same pattern that we obtained in an ealier survey of a larger set of populations and showed clearly that there are eight chemical races in European S. pratensis. No comparable geographic distributiion could be found in the isozyme data set, although the dendrogram showed two very clearly separated groups. The two groups represented the two years in which the populations were grown. This result indicates that isozyme variation in European S. pratensis is largely determined by environmental factors. Observations on changes in isozyme patterns during ontogeny and on differences between indoor and outdoor grown plants of the same F2 crosses confirm this. Differences in isozyme patterns can be caused by very small differencs in environment as is shown by the results of the indoor experiment, in which a slight gradient in environmental conditions was present in the greenhouses. The cluster analysis of the isozyme data from the indoor experiment revealed three distinct groups of populations that could be related to location within the greenhouses. As in the outdoor experiment, the dendrogram for the flavonoids gave the same geographic pattern as found with the earlier survey.

Changes in Isoenzyme Patterns during the Ontogeny of Silene alba

Summary Protein variation within and between populations can be caused by genetic differences or by variation during ontogeny. We have observed enzyme variation during the development of 42 individuals of Silene alba. For the 7 enzymes (AcP, EST, GOT, LAP, MDH, NADH DH and PO) variation was found in all sta,dia of development. Only in the stem leaves of the young plant the pattern was constant within a plant. However, the isoenzyme patterns of the stem leaves of senescent plants deteriorated. Therefore only young plants can be used to estimate the genetic variation in S. alba.

07g and D6a: Two Flavone Glycosylating Genes in Silene, which are Only Expressed in Cotyledons and Rosette Leaves

Two further loci can be added to the three already known (g, gl and fg) in Silene controlling the 7-O and 2″-O-glycosylation of the C-glycosylflavone isovitexin (6-C-glucosylapigenin). These loci, O7g for the 7-O-galactosylation and D6a for the 2″-O-arabinosylation, appear only to be expressed in cotyledons and rosette leaves and control the biosynthesis of isovitexin 7-O- galactoside and isovitexin 7-O-galactose 2″-O-arabinoside in these parts of plants in which the recessive alleles of the loci g, gl and fg are homozygous (Steyns et al. [9]). The possibility that locus g, whose dominant alleles gG and gX control the 7-O-glucosylation and the 7-O-xylosylation of isovitexin respectively, controls the synthesis of isovitexin-7-O- galactoside was excluded by demonstrating the presence of isovitexin-7-O-galactoside and the 7-O-galactosyltransferase catalyzing its biosynthesis in addition to isovitexin-7-O-glucoside and the 7-O-glucosyltransferase in cotyledons of gGgG seedlings. The synthesis of the 2″-O-arabinoside is neither controlled by locus gl, whose dominant alleles glR and glA control the 2″-O-rhamnosylation and 2″-O-arabinosylation of isovitexin respectively, nor by locus fg, whose dominant allele Fg controls the biosynthesis of isovitexin 2″-O-glucoside. This was shown by the presence of isovitexin-7-O-galactose 2″-O-arabinoside and the 2″-O-arabinosyltransferase catalyzing the synthesis of the 2″-O-arabinoside in addition to isovitexin-7-O-galactose 2″-O-rhamnoside in cotyledons of glRglR seedlings and by the presence of isovitexin-7-O-galactose 2″-O-arabinoside and the 2″-O-arabinosyltransferase in addition to isovitexin-7-O-galactose 2″-O-glucoside and the 2″-O-glucosyltransferase in cotyledons of Fg Fg seedlings.

Utrecht electronic library: Planning an ambitious innovation

Abstract In a 1994 visit to the University of Utrecht Library, I was introduced to treasures which are the grist of classical studies— such as the Utrecht Psalter and the Nuremberg Chronicle, rich collections of manuscripts and incunabula. It is the same sort of experience one may have at the Bodleian in Oxford or the Bibliotheque Nationale in Paris. These irreplaceable antiquities serve to highlight the transition through which we are passing. At Utrecht they receive the care one would expect, and while they are treasured, they are part of a long tradition of providing information needed by scholars which goes back to the beginning of the 16th century in the Utrecht Library. To that extent they are taken for granted as part of a continuous accretion of information which collectively supports current scholarly activity. In a library which is at the same time digitizing 17th century masters and current scientific technical reports, there is a longer perspective on the management of information than those of us working in libraries with principally modern collections may have. What is striking, however, is that at Utrecht staff are grappling with precisely those problems we all are—how to maintain the information “legacy” of the past, build the infrastructure to support electronic information in the future, and serve current needs at the same time. The answers are not immediately obvious, but Natalia Grygierczyk presents the case for international dialog and benchmarking that may help find those answers, and the current thinking at Utrecht on the plan for a digital library—CBL, Carnegie Mellon University.

The Flavones of the European Species of Silene Section Elisanthe

The flavones present in three European species of Silene section Elisanthe (Silene diclinis, S. heuffelii and S. marizii) have been identified. The flavones of these species were compared with the flavones present in the three remaining species of section Elisanthe in Europe (5. dioica, 5. noctiflora and 5. pratensis). It was found that isovitexine-7-O-glucoside is present in all these species. The other flavones. notably the 2′-O-glycosylated ones, show a distribution over the species. The presence of flavone glycosylating genes in 5. diclinis, S. heuffelii and S. marizii was tested by biochemical means. The results of this experiment show that the gene g-G. controlling the formation of isovitexin-7-O-glucoside, is the basic flavone glycosylating gene in European species of section Elisanthe. The other flavone glycosylation genes, g-X, gl, gl-A, gl-R, fg and Fg are not present in all specie