Chemotaxonomy of theSymphytum officinale agg. (Boraginaceae)

In a chemotaxonomic study of the genusSymphytum pyrrolizidine alkaloids and triterpenes were used as chemotaxonomical markers. A micro-extraction methods was developed for screening compounds of very small pieces of herbarium material. The occurrence of the pyrrolizidine alkaloids symphytine and (acetyl-)lycopsamine is very general forSymphytum taxa. Echimidine is present in someS. officinale L. plants and inS. tanaicense Steven. The triterpene isobauerenol is present inS. officinale, S. bohemicum Schmidt,S. tanaicense and inS. officinale var.lanceolatum Weinm. The chemotaxonomic hypothesis, proposed byGadella and collaborators, based on the presence of the triterpene isobauerenol inS. officinale and its absence inS. asperum Lepech. and the presence of the pyrrolizidine alkaloid echimidine inS. asperum and its absence inS. officinale, can no longer be applied absolutely to theS. officinale species complex. The pyrrolizidine alkaloid and triterpene pattern ofS. officinale (2n = 24) andS. bohemicum (2n = 24) is identical.S. bohemicum is morphologically, cytologically and phytochemically very similar toS. officinale. Furthermore, it readily crosses with the white flowered W. European diploids ofS. officinale. Therefore it seems likely that these two taxa are conspecific.S. tanaicense shows a pyrrolizidine alkaloid and triterpene pattern similar toS. officinale (2n = 40). Also on morphological and cytological grounds they are very similar. It seems highly probable thatS. tanaicense is conspecific withS. officinale (2n = 40) and represents an intraspecific variant only.S. officinale var.lanceolatum contained no pyrrolizidine alkaloids but did contain isobauerenol. This feature points to an origin fromS. officinale.     

Glandular trichomes ofSolanum berthaultii alter host preference of the Colorado potato Beetle,Leptinotarsa decemlineata

Choice and no-choice studies were conducted to determine how the glandular trichomes of the wild potato,Solanum berthaultii Hawkes, affect host preference of the Colorado potato beetle,Leptinotarsa decemlineata (Say). Given a feeding choice betweenS. tuberosum andS. berthaultii, larvae and adults preferred the foliage ofS. tuberosum, but adults were more discriminating. When foliage ofS. berthaultii was appressed toS. tuberosum leaflets, fewer adults fed on the appressed leaflets. When given a choice between ‘trichome-intact’ and ‘trichome-removed’S. berthaultii foliage, adults preferred to feed on the latter. The preference for ‘trichome-removed’ foliage and the percent of adults initiating feeding, increased with the degree of trichome removal. These studies provide evidence that the resistance ofS. berthaultii is associated with feeding deterrents localized in the glandular trichomes, thatS. berthaultii possesses more than one mechanism of resistance to the Colorado potato beetle, and that the expression of resistance is dependent on the developmental stage of the insect.     

Parasitism ofLygus lineolaris eggs onCoronilla varia,solanum tuberosum,and three host weeds in southeastern Québec

Parasitism ofLygus lineolaris (Palisot de Beauvois) eggs by three species ofMymaridae, Anaphes iole Girault,Erythmelus miridiphagus Dozier andPolynema pratensiphagum Walley and one species ofScelionidae, Telenomus sp., was investigated at Ste-Anne-de-Bellevue, Québec. The maximum level of field parasitism ofL. lineolaris eggs by individual species was 15.4, 53.8, 70.0 and 16,7%, respectively. Parasitoids were retrieved from eggs ofL. lineolaris inserted in stems and branches ofAmaranthus retroflexus L.,Chenopodium album L.,Coronilla varia L.,Rumex obtusifolius L. andSolanum tuberosum L. Amaranthus retroflexus andS. tuberosum sustained a large population ofL. lineolaris and egg parasitism was high enough to consider it as a potential control factor.      

Floral development and systematics ofCistaceae

The floral development of representatives of six genera ofCistaceae has been studied. Calyx development involves the formation of a ring primordium in several taxa. Androecium development in species with intermediate or higher stamen numbers starts with the formation of a ring meristem on which the stamens are initiated in a centrifugal direction. In many taxa five alternipetalous leading stamen primordia can be observed. In the apetalous (cleistogamous) flowers ofTuberaria inconspicua androecium development appears to be unordered; this is probably due to the lack of petals. InLechea intermedia (also cleistogamous) the corolla is trimerous and three complex stamen primordia are produced, which give rise either to one or three stamens. Relationships withinCistaceae are discussed. Floral development inCistaceae is compared with that in otherMalvanae. Among the eight families ofMalvanae from which information on floral development is availableCochlospermaceae andBixaceae exhibit the greatest similarities toCistaceae. InCistaceae the leading stamen primordia are alternipetalous. InBixa the same condition seems to be present. InMalvales s. str. mostTiliaceae also show earliest stamen initiation in alternipetalous sectors, whereas the stamens of the innermost alternipetalous position are retarded early or even suppressed inSterculiaceae, Bombacaceae, andMalvaceae. WithinMalvales s. str. the diversity of androecial developmental patterns seems to decrease inBombacaceae andMalvaceae due to increasing synorganization in the mature androecium. The derivation of polyandry inMalvanae from diplo- or obdiplostemony is discussed by comparison with the sister clades ofMalvanae as shown in recentrbcL studies (i.e.Sapindales, Rutales, the glucosinolate producing clade, andMyrtales).     

Studies in the morphology and systematics of berberidaceae

The floral vasculature in three allied genera,Plagiorhegma, Jeffersoria andAchyls is investigated, and the results are compared with those ofEpimedium andVancouveria which are related closely toPlagiorhegma andJeffersonia. The vasculature in the receptacle ofPlagiorhegma andJeffersonia is similar, but that ofAchlys is much simpler. Slightly different trace patterns are observed in the sepals ofPlagiorhegma andJeffersonia. InJeffersonia, the 3-trace condition leaving 2 or 3 gaps is most frequently observed, but inPlagiorhegma traces of a double nature leaving a single gap are more frequent. The traces to the innermost sepals, petals and stamens are usually of a double nature leaving a single gap in both genera. Regular division and fusion are not observed in the receptacular stele. The vascular differentiation between sepals and petals is more advanced inPlagiorhegma andJeffersonia than inEpimedium andVancouveria. InAchlys, the traces are all staminal and single throughout their course. Two parts recognized in the pistils ofPlagiorhegma, Jeffersonia andAchlys are traversed by independent vasculature. The comparisons of pistil morphology including vasculature ofPlagiorhegma, Jeffersonia, Achlys, Epimedium andVancouveria lead to the interpretation that the pistils are based on the same morphological plan. The probable evolutionary trend in pistil is then suggested in these five genera.     

Alkaloids of theSedum acre-group (Crassulaceae)

The 16 species of theSedum acre-group were investigated for the presence of alkaloids. They areS. acre ofS. ser.Acria, S. alpestre, S. annuum, S. apoleipon, S. borissovae, S. euxinum, S. grisebachii, S. laconicum, S. multiceps, S. sexangulare, S. tuberiferum, S. tuberosum, S. ursi, andS. urvillei ofS. ser.Alpestria, S. samium ofS. ser.Samia, andS. litoreum ofS. ser.Litorea. S. acre differs significantly from the other species. It contains sedamine, hydroxy sedamine, and a number of 2,6-disubstituted piperidine alkaloids. The leafy parts of the species ofS. ser.Alpestria, S. ser.Samia, andS. ser.Litorea contain 4 piperidine alkaloids which also occur inS. acre, and in addition 4 pyrrolidine alkaloids not present inS. acre. The composition of the alkaloid fraction agrees with the infrageneric classification (series) based on the hybridization patterns of the species (comparia).     

Studies on the early floral development inCleomoideae (Capparaceae) with emphasis on the androecial development

Floral ontogeny ofCleome spinosa, Cleome violacea andPolanisia dodecandra subsp.trachysperma was studied in the context of the question whether the fascicled androecium ofReseda andCapparis (with fused fascicles) or the 2 + 4-pattern of theBrassicaceae is primitive in theCapparales. InPolanisia dodecandra, the 9–18 stamens show unidirectional initiation from the adaxial side toward the abaxial side of the flower. InCleome violacea, the six stamens also are formed in an unidirectional order, but development starts abaxially and a zigzag-like pattern is superimposed. InCleome spinosa, two stamen primordia in transversal (lateral) position are followed by four stamens which arise on a somewhat higher level in two pairs in front of the median sepals. It is assumed that the evolutionary steps in the androecial development proceed fromReseda viaCapparis andPolanisia/Cleome toBrassicaceae. This interpretation is supported byrbcL-studies (Chase & al. 1993,Rodman & al. 1993).Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

rbcL sequences support exclusion ofRetzia,Desfontainia, andNicodemia from theGentianales

The taxonomic positions ofRetzia, Desfontainia, andNicodemia have been much discussed, and all three genera have been included inLoganiaceae (Gentianales). We have made a cladistic analysis ofrbcL gene sequences to determine the relationships of these taxa toGentianales. Four newrbcL sequences are presented; i.e., ofRetzia, Desfontainia, Diervilla (Caprifoliaceae), andEuthystachys (Stilbaceae). Our results show thatRetzia, Desfontainia, andNicodemia are not closely related toLoganiaceae or theGentianales. Retzia is most closely related toEuthystachys and is better included inStilbaceae. The positions ofDesfontainia andNicodemia are not settled, butDesfontainia shows affinity for theDipsacales s.l. andNicodemia for theLamiales s.l.     

A chemotaxonomical study of someBoraginaceae: pyrrolizidine alkaloids and phenolic compounds

By means of thin layer chromatography pyrrolizidine alkaloids and phenolic compounds in some members of the familyBoraginaceae, subfamiliesHeliotropioideae andBoraginoideae, were studied. FromOmphalodes verna a main alkaloid was isolated with an isoretronecanol (or stereoisomeric) nucleus. The chemotaxonomical model ofTétényi forBoraginaceae based on fatty acids is generally supported, but relationships betweenHeliotropioideae andCynoglosseae appear to be closer, suggesting parallel developments from common ancesters.     

Interactions ofCandida albicans with bacteria and salivary molecules in oral biofilms

The yeastCandida albicans coaggregates with a variety of streptococcal species, an interaction that may promote oral colonization by yeast cells.C. albicans andCandida tropicalis are the yeasts most frequently isolated from the human oral cavity and our data demonstrate that both these species bind toStreptococcus gordonii NCTC 7869 while two otherCandida species (Candida krusei andCandida kefyr) do not. Adherence ofC. albicans was greatest when the yeast had been grown at 30° C to mid-exponential growth phase. For 21 strains ofC. albicans there was a positive correlation between the ability to adhere toS. gordonii and adherence to experimental salivary pellicle. Whole saliva either stimulated or slightly inhibited adherence ofC. albicans toS. gordonii depending on the streptococcal growth conditions. The results suggest that the major salivary adhesins and coaggregation adhesins ofC. albicans are co-expressed.     

A cladistic analysis ofDipsacaceae (Dipsacales)

A cladistic study ofDipsacaceae (Asteridae, Dipsacales) was undertaken, based mainly on morphological and palynological characters, obtained by investigations of herbarium material and from the literature. Outgroups includedMorinaceae, Triplostegiaceae, and a subset ofValerianaceae. The consensus tree resulting from three equally parsimonious cladograms shows thatDipsacaceae are divided into two major clades, one withDipsacus andCephalaria, the other including the remaining genera. Within the latter clade,Knautia is the sister group of the rest of the taxa. This study is a reappraisal ofDipsacaceae phylogeny, and the results broadly match previous evidence.     

Preliminary analysis of numerical taxonomy of the genusSaguinus based on dental measurements

Although several investigations have been made from different viewpoints, the classification or interspecific relationships ofSaguinus still remain uncertain. In the present study, we applied multivariate analysis methods to dental measurements of part ofSaguinus populations of sufficient sample size and obtained the following conclusions.Saguinus can be classified into two main groups: one consists ofS. oedipus andS. leucopus, and the other ofS. fuscicollis, S. nigricollis, S. labiatus, andS. mystax. Concerning the former group, the two subspecies ofS. oedipus, S. o. oedipus, andS. o. geoffroyi, show a close affinity with each other and also a close relationship toS. leucopus, while the latter group consists of two subgroups of species, one includingS. fuscicollis andS. nigricollis, and the other includingS. labiatus andS. mystax. The biological distance betweenS. oedipus oedipus andS. o. geoffroyi is slightly larger than that between the pairs ofS. fuscicollis andS. nigricollis and ofS. labiatus andS. mystax. Factor analysis revealed significant factors which could explain the differences among the seven maleSaguinus populations. Taking all the results into account, it seems necessary to reconsider the phylogenetic relationships within the genusSaguinus.     

The allopolyploid origin ofSedum rupestre subsp.rupestre (Crassulaceae)

InSedum rupestre L. a polyploid series (x = 16) occurs in which aneuploid chromosome numbers and odd levels of ploidy prevail. The most common and widely distributed cytotype,S. rupestre subsp.rupestre, is 2n = 112. Plants resemblingS. rupestre subsp.rupestre can be obtained by hybridizing the tetraploid cytotypes ofS. forsterianum Sm. (2n = 48) andS. rupestre subsp.erectum 't Hart (2n = 64). Comparison of these artificial hybrids with their parents and a large number of plants ofS. rupestre subsp.rupestre (2n = 112) from nature showed thatS. rupestre subsp.rupestre and the artificial hybrids are morphologically indistinguishable, and intermediate betweenS. forsterianum andS. rupestre subsp.erectum. MorphologicallyS. rupestre subsp.rupestre is closer to subsp.erectum than toS. forsterianum. Chloroplast DNA restriction patterns ofS. rupestre subsp.rupestre, however, resembleS. forsterianum more closely. The combined results of the hybridization experiments, the analysis of the cpDNA restriction patterns, and the morphological variation indicate the allopolyploid origin ofS. rupestre subsp.rupestre. Natural hybrids inSedum (Crassulaceae) 4.     

A cladistic analysis of interspecific relationships ofSaguinus

The dental and cranial morphologies of all species ofSaguinus, S. oedipus, S. geoffroyi, S. leucopus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas are examined. The following hypotheses are developed by cladistic methodology, using only synapomorphic characters to assess the interspecific relationships ofSaguinus.Saguinus are divided into two main groups; one consists ofS. oedipus, S. geoffroyi, andS. leucopus, and the other includesS. inustus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas. In the former group,S. oedipus is more closely related toS. geoffroyi than either is toS. leucopus. In the latter group,S. labiatus, S. mystax, andS. imperator are classified into one group, andS. bicolor andS. midas form one monophyletic group.     

Comparative karyotype analysis ofCeratozamia mexicana andMicrocycas calocoma (Zamiaceae) using fluorochrome banding (CMA/DAPI) and fluorescence in situ hybridization of ribosomal DNA

Orcein staining, differential staining with CMA and DAPI, and FISH with an rDNA probe were used to compare somatic chromosomes ofCeratozamia mexicana andMicrocycas calocoma. CMA-positive dots and hybridization signals appeared on chromosomes at early interphase and mitotic prophase, but in significantly different number in the two species. InCeratozamia mexicana, the CMA-positive and DAPI-negative bands and the hybridization signal were located at the terminal region of the long arm of three median-centromeric chromosomes, the terminal region of the short arm of two median-centromeric chromosomes and the terminal region of the long arm of two subterminal-centromeric chromosomes. InMicrocycas calocoma, they were located at the pericentric region of two median-centromeric chromosomes. These chromosome data suggested thatMicrocycas has no simple Robertsonian relationship toCeratozamia.     

Lokalisierung von rRNA-Genorten und Sekundäreinschnürungen beiVicia narbonensis undVicia sativa

Sites of 18/25S RNA genes and those of secondary constrictions have been located in metaphase chromosomes ofV. narbonensis andV. sativa by RNA/DNA in situ hybridization and Feulgen staining. InV. narbonensis the rRNA genes are located in median position on one pair of chromosomes, which is the shortest of all in the genome. InV. sativa rRNA genes are located in two pairs of chromosomes. The two heterologous sites differ markedly in the level of labeling. Strong labeling is found in a submedian position of a short pair of chromosomes. Weaker labeling is found in a median position on the longest pair of chromosomes. InV. narbonensis andV. sativa the position of the grain clusters correlate with the position of the secondary constrictions in chromosomes stained by Feulgen. The implications with respect to karyograms ofV. narbonensis andV. sativa known from the literature are discussed.

     

Biosystematic study ofRoegneria tenuispica, R. ciliaris andR. pendulina (Poaceae:Triticeae)

Morphological and cytological studies of three tetraploidRoegneria species,R. tenuispica, R. pendulina andR. ciliaris, and their artificial hybrids were carried out.Roegneria tenuispica was morphologically similar toR. pendulina. The general appearance of the interspecific hybrids was intermediate between the parents. The hybrids showed comparatively high chromosome pairing at meiosis, but were completely or almost completely sterile. The results indicate that the three independent species share two basic genomes (S_tY) and thatR. tenuispica is more closely related toR. pendulina than toR. ciliaris. The genomes ofR. tenuispica could be designated as S _t ^t Y^t.     

Systematic relationships of theLactoridaceae,an endemic family of the Juan Fernandez Islands,Chile

The systematic relationships ofLactoridaceae are problematical, with alternative assignments toMagnoliales, Laurales, andPiperales. Phenetic analyses suggest thatLactoridaceae are best accomodated withinMagnoliales and are most closely related toAnnonaceae. Cladistic analyses indicate that the family is a relatively derived member of theMagnoliales, with affinities toAnnonaceae, Eupomatiaceae, Himantandraceae, andMyristicaceae. These analyses together with fossil pollen data are used to interpret the phylogeny ofLactoridaceae and its relatives.     

Tritrophic interactions between aphids (Aphis jacobaeae Schrank), ant species,Tyria jacobaeae L., and Senecio jacobaea L. lead to maintenance of genetic variation in pyrrolizidine alkaloid concentration

Summary We hypothesize that the tritrophic interaction between ants, the aphid Aphis jacobaeae, the moth Tyria jacobaeae, and the plant Senecio jacobaea can explain the genetic variation observed in pyrrolizidine alkaloid concentration in natural populations of S. jacobaea. The ant Lasius niger effectively defends S. jacobaea plants infested with A. jacobaeae against larvae of T. jacobaeae. S. jacobaea plants with A. jacobaeae which are defended by ants escape regular defoliation by T. jacobaeae. Plants with aphids and ants have a lower pyrrolizidine alkaloid concentration than plants without aphids and ants. When these data are fitted to an existing theoretical model for temporal variation in fitness it is shown that varying herbivore pressure by T. jacobaeae in interaction with ants defending aphid-infested plants with a low pyrrolizidine alkaloid concentration can lead to a stable polymorphism in pyrrolizidine alkaloid concentration. Costs of the production and maintenance of pyrrolizidine alkaloids are not accounted for in the model.Publication of the Meijendel-comité, new series no. 114     

Serologische Untersuchungen zur Gliederung derBrassicaceae

The serological investigations support the opinion ofJanchen (1942) to combine the generaBunias, Isatis, andSisymbrium in the tribeSisymbrieae; Cheiranthus, Erysimum, andMatthiola in the tribeHesperideae; andBrassica, Crambe, Sinapis, andSuccowia in the tribeBrassiceae. They further underline the central position of theSisymbrieae and the isolated position of theHeliophileae. In accordance withEigner (1973) theBrassiceae are placed closer to theSisymbrieae than inJanchen; the same holds for thePringleeae. No serological justification could be found to uniteArabis andBarbarea in the tribeArabideae, andAlyssum andLunaria in theAlysseae. From the antigen-systems used among the representatives ofJanchen's Lepidieae the generaLepidium andNeslia show remarkable correspondence both toCamelina andThlaspi, but not toCochlearia which appears distant fromCamelina andThlaspi also.

Teil 1/Part 1.