Studies on systematic embryology inScilla (Hyacinthaceae)

Scilla persica and 5 species of the so-calledS. hohenackeri group, namely,S. furseorum, S. puschkinioides, S. vvedenskyi, S. hohenackeri, andS. greilhuberi, have been investigated embryologically with special reference to embryo sac and endosperm development.Polygonum-type embryo sac development was stated inS. puschkinioides andS. greilhuberi. 8-nucleate, normally structured embryo sacs, which could not be specified further due to sparse availability of the material, were stated inS. furseorum, S. vvedenskyi, andS. hohenackeri. InS. persica the embryo sac develops according to the bisporicAllium-type. In most species endosperm development was stated to be nuclear, exceptS. hohenackeri, where the type could not be specified. Other traits of possible taxonomic significance are the number of layers in the outer integument, which is mostly 4, or 5–6 inS. furseorum, and the occurrence of polyploid versus haploid and early degenerating antipodal nuclei, the latter occurring only inS. persica andS. furseorum. These embryological characters may be useful for assessing taxonomic relationship of the present species with other allied groups withinScilla, in particular, theS. siberica alliance,S. messeniaca, and theS. bifolia alliance. TheAllium-type embryo sac, which occurs inS. persica, is also characteristic for theS. siberica alliance, and may be a common derived character. Lack of antipodal polyploidization, as characteristic forS. persica andS. furseorum, occurs also in theS. siberica alliance, and is perhaps another common derived trait indicating phylogenetic relationship. Nuclear endosperm development is more frequent in spring-flowering squills than helobial development, which has previously been stated inS. messeniaca, some species of theS. siberica alliance, and inS. litardierei. While helobial endosperm may be primitive forHyacinthaceae in general, it may, by reversal, also occur as a derived character, at least in some species of theS. siberica alliance.     

Haustorienbefall und inäquale Teilungen desNostoc-Phycobionten vonLempholemma botryosum (Lichinaceae)

In fully developed parts of thalli ofLempholemma botryosum a relatively high number of algal cells is attacked by haustoria. They differ specifically in form and effect from haustoria of otherLempholemma species. Cells of theNostoc phycobiont attacked by hyphae developing into haustoria may divide to give inequal besides equal daughter cells.

     

DNA evidence for multiple origins of intergeneric allopolyploids in annualMicroseris (Asteraceae)

Seventy populations of North American annualMicroseris, Stebbinsoseris, andUropappus species were examined for chloroplast and nuclear ribosomal DNA restriction site variability to determine the origin of the allotetraploid speciesS. heterocarpa andS. decipiens. Previously identified chloroplast DNA restriction site variants were used in concert with restriction site variation forNco I in the nuclear-encoded ribosomal DNA repeat. The presence of two, mutually exclusive restriction site gains were observed in diploid populations ofM. douglasii; these same variants were also found in populations of allotetraploidS. heterocarpa, indicating mutiple origins of this species from different maternal diploid populations ofM. douglasii. Variation in the rDNA repeat between the diploid annual species and the putative paternal genome ofU. lindleyi was found to be additive inS. heterocarpa. A similar relationship was observed for the origin ofS. decipiens; cpDNA restriction site variants found inM. bigelovii andM. douglasii were present inS. decipiens. The rDNANco I variants also were additive in this purported allotetraploid. These results confirm the reticulate evolutionary pattern inStebbinsoseris and provide another example of multiple origins of intergeneric allopolyploids.     

Beobachtungen anLempholemma-Arten aus dem Ostalpenraum (Lichenes,Lichinaceae)

The phycobiont of all species ofLempholemma analyzed is attacked by haustoria. The haustoria of these five species ofLempholemma and of two species with unknown apothecium but with a thallus quite similar toLempholemma are described. They show distinct morphological and functional characters which allow species delimitation.

Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.     

Evolution alpiner Populationen vonEuphrasia (Scrophulariaceae): Chromosomenzählungen an diploiden und polyploiden Sippen aus den Ostalpen

Chromosome counts are reported for several E. Alpine taxa ofEuphrasia sect.Euphrasia. First records of diploidy for small-flowered taxa are 2n = 22 forE. inopinata andE. sinuata, related toE. minima (4 x). Aberrant E. AlpineE. hirtella is 2 x, just as the typical W. Alpine populations of this species. Tetraploidy, 2n = 44, has been found inE. pumila, close toE. stricta (also 4 x). The limitation of ploidy levels within sect.Euphrasia to 2 x and 4 x on the chromosome base number x = 11 is confirmed.

     

Étude cytotaxinomique de quelquesDipsacaceae d'Iran

Chromosome numbers for 28 Iranian populations ofDipsacaceae, corresponding to 14 taxa, are presented. New are those forScabiosa aff.olivieri var.pinnatisecta, S. persica, Pterocephalus canus, P. kurdicus, Dipsacus strigosus, Cephalaria dichaetophora, C. hirsuta, C. microcephala, C. subindivisa andC. aff.sublanata. Except forC. syriaca (x = 5) andC. dichaetophora (x = 7 : new basic chromosome number forCephalaria), all species examined are characterized by the basic chromosome number (x = 9). Instances of aneusomaty, B-chromosomes, aneuploidy, dysploidy, and polyploidy have also been found.

     

Cynoglossopsis somaliensis,sp. nov., und die GattungCynoglossopsis (Boraginaceae)

Cynoglossopsis somaliensis H. Riedl, sp. nov., is described as a new species of the hitherto monotypic genusCynoglossopsis Brand which is closest related toCynoglossum L. but has to be included inBoraginoideae-Eritrichieae from the way the nutlets are attached to the gynobasis.

     

Beiträge zur Systematischen Anatomie derAnthemideae: Die Spaltöffnungsapparate

The subdivision of theAnthemideae into two subtribes purely on the grounds of the presence or absence of receptacular paleae can no longer be maintained. Anatomical data may serve as a basis for a more adequate division of the tribe. This survey of the stomatal apparatus types within theAnthemideae is based on the investigation of 29 species from 15 genera and the evaluation of literature data: Anomocytic stomatal apparatus occur in all species examined, anisocytic at least in all genera investigated by us. We even found representatives of some rare types, such as polo-, helico- or hemiparacytic apparatus, in nearly all species. Diacytic types were not found inOtanthus, Artemisia, Tripleurospermum, Tanacetum corymbosum, and they also appear to be lacking inSantolina andEriocephalus. Paracytic stomatal apparatus and a new type which links paracytic with actinocytic and cyclocytic was discovered inOtanthus maritimus andArtemisia stellerana.

     

Elliptochloris bilobata,gen. et spec. nov., der Phycobiont vonCatolechia wahlenbergii

The phycobiont ofCatolechia wahlenbergii belongs to a new genus of theChlorococcales. It has mostly ellipsoidal, more rarely spherical cells with one bilobate through-shaped chloroplast and in general alveolar cytoplasm. Reproduction occurs by 2 or 4 autospores as well as by 16 or 32 motionless, small rodlike spores, which are formed and released in the same way as zoospores. They are aplanospores, and their formation apparently is fixed genetically, and not modificatorily, as in other species.

     

Population structure and interspecific differentiation of the peat moss sister speciesSphagnum rubellum andS. capillifolium (Sphagnaceae) in northern Europe

Isozyme electrophoresis was used to study the morphologically similar sister speciesSphagnum rubellum andS. capillifolium from a sample of 1313 plants representing 37 populations from Scandinavia, Great Britain and S Germany. The mean pairwise genetic identities (I) among conspecific populations were 0.976 forS. rubellum and 0.969 forS. capillifolium, versus 0.627 between populations of the two species. Interspecific gene flow was indicated by the observation of occasional plants in sympatric populations with alleles otherwise unique to the other species. Populations of bisexualS. capillifolium were significantly more variable than populations of unisexualS. rubellum. Alpine populations ofS. rubellum andS. capillifolium were dominated by few genotypes, and differentiation among populations was pronounced, indicating a low level of sexual recombination. InS. rubellum, maximum variability was found in western areas with high annual precipitation. Distribution of alleles inS. rubellum indicated restricted gene flow between Great Britain and Scandinavia. Postglacial migration from separate refugia may explain large-scale variation inS. rubellum.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

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.     

Tillandsia carminea — eine interessante neue Bromeliacee aus dem Orgelgebirge bei Rio de Janeiro (Brasilien)

Tillandsia carminea is a new, morphologically and ecologically distinct species, related toT. stricta Solander, which occurs in the Serra dos Orgaos near Teresopolis, Brazil. It has been taken forT. rosea Lindley, but new investigations have shown thatT. rosea is a synonym toT. stricta and thatT. carminea is a good and distinct species.

     

Genetic variation and putative hybridization inSalix alba andS. fragilis (Salicaceae): Evidence from allozyme data

Genetic variability was estimated by enzyme electrophoresis in 239 Belgian clones from theSalix alba-S. fragilis complex. This morphological complex suggested a high frequency of hybrids. To test this hypothesis, the clones were pooled as a single co-adapted species complex and secondly as belonging to either species, i.e. beingS. alba-like orS. fragilis-like. The standard genetic variability measures showed higher values for the complex than for the separate species. However, the observed mean heterozygosity was lower in the putative hybrid complex than for each of the species separately. The fixation indices were more variable at the species level and indicated that mostS. fragilis locations appeared fixed forlap-1, whereas no fixation occured inS. alba locations. Averaged at the regional (i.e. catchment) level, this difference between the two species remained and values ranged from 0.457 to 0.617 inS. alba and were much higher, fixed homozygous or monomorph inS. fragilis. Hierarchical F-statistics revealed that most of the differentiation occured at the lower levels of localities and tributaries and that there was no further differentiation between catchments. Tributaries which are 10–25km in length were proposed as the most likely entities for further examination of putative hybridization and events of allelic fixations. By considering the two abovementioned approaches of data input, it could be suggested that most of the allozyme differentiation was between the species and less between the regions.     

Intracellular pH inSchizosaccharomyces pombe — Comparison withSaccharomyces cerevisiae

We examined cytoplasmic pH regulation inSchizosaccharomyces pombe andSaccharomyces cerevisiae using pH-sensitive fluorescent dyes. Of several different fluorescent compounds tested, carboxy-seminaphthorhodafluor-1 (C.SNARF-1) was the most effective. Leakage of C.SNARF-1 fromS. pombe was much slower than leakage fromC. cerevisiae. Using the pH-dependent fluorescence of C.SNARF-1 we showed that at an external pH of 7, mean resting internal pH was 7.0 forS. pombe and 6.6 forS. cerevisiae. We found that internal pH inS. pombe was maintained over a much narrower range in response to changes in external pH, especially at acidic pH. The addition of external glucose caused an intracellular alkalinization in both species, although the effect was much greater inS. cerevisiae than inS. pombe. The plasma membrane H⁺-ATPase inhibitor diethylstilbestrol reduced both the rate and extent of alkalinisation, with an IC₅₀ of approximately 35 M in both species. Amiloride also inhibited internal alkalinisation with IC₅₀'s of 745 M forS. cerevisiae and 490 M forS. pombe.Abbreviations C.SNARF-1 carboxy-seminaphthorhodafluor-1 (-AM-acetoxy-methylester) - DES diethylstilbestrol - IC₅₀ apparent inhibitory constant - BCECF 2,7-bis-(carboxyethyl)-5(6)-carboxyfluorescein (-AM--pentaacetoxymethyl ester) - FDA fluorescein diacetate     

Zur Morphologie und Systematik desTrebouxia-Phycobionten im Thallus vonUsnea longissima (Lecanorales)

In the lichen genusUsnea different species ofTrebouxia-phycobionts as well as different haustorial types are known. The isolated and cultivated phycobiont ofUsnea longissima Ach. was studied by light- and electron microscopy and resembles in cytomorphological details the type ofTrebouxia impressa Ahmad. In addition to simple wall-to-wall contacts between the symbiotic components also intraparietal (=intrawall-)haustoria could be observed as the normal interaction type.

Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.     

Hybridisation,genomic constitution and generic delimitation inElymus s. l. (Poaceae: Triticeae)

Intergeneric crosses were made between representatives of the genomically-defined generaElymus, Agropyron, Elytrigia, Pseudoroegneria, andThinopyrum. The genomic constitution ofElytrigia repens, the type species ofElytrigia, is shown to be SSH, a genomic combination otherwise found only inElymus. The S genome ofPseudoroegneria has almost always a dominant influence on the morphology of the taxa of which it is a component.Wang (1989) showed that the J genome inThinopyrum and the S genome have considerable homoeology, with a mean c-value of 0.35 in diploid SJ hybrids. A genetic coherence from S to SJ^e, J^e, J^eJ^b, and J^b can be expected, agreeing with the continuous morphologic variation pattern observed. Because of the absence of morphological discontinuities between the taxa,Pseudoroegneria (S),Elymus (SH, SY, sometimes with additional genomes),Elytrigia (SSH, SSHX), andThinopyrum (SJ, SJJ, J) are best treated as a single genus,Elymus, following the generic concept ofMelderis in Flora Europaea and Flora of Turkey. The basic genomic constituents ofElymus will then be the S and/or J genomes.Agropyron, with diploids, tetraploids, and hexaploids based on the P genome is morphologically distinct from other genera inTriticeae. In a few species ofElymus andPseudoroegneria, a P genome is an additional constituent. In these cases the P genome has a negligible morphological influence. Therefore, it seems reasonable to maintainAgropyron as a separate genus.     

The annual species ofAdonis (Ranunculaceae)—a polyploid complex

The five annual species ofAdonis L., sect.Adonis, growing in Israel, form a series of diploid, tetraploid and hexaploid species. Their somatic chromosome numbers are 2n = 16 inA. annua L.,A. dentata Del. andA. palaestina Boiss., 2n = 32 inA. microcarpa DC., 2n = 48 inA. aestivalis L.; counts forA. dentata, A. palaestina andA. microcarpa are new records. There are indications that alloploidization may have been involved in the process of speciation in sect.Adonis. A taxonomic survey of the 8 species of the section reveals that a higher ploidy level is usually combined with a larger distribution area.     

Über die weite Verbreitung lichenisierter Sippen vonDictyochloropsis und die systematische Stellung vonMyrmecia reticulata (Chlorophyta)

Catinaria grossa is lichenized withDictyochloropsis splendida var.gelatinosa, var. nova. When cultured isolated from the fungus the cells of this variety are covered individually by thick gelatinous envelopes. The phycobionts ofMegalospora gompholoma subsp.gompholoma andM. atrorubicans subsp.australis belong to a new variety ofD. symbiontica, i.e. var.pauciautosporica, which preferentially reproduces by zoo- and aplanospores. The phycobiont ofPseudocyphellaria aurata does not belong toMyrmecia reticulata as formerly thought, but toDictyochloropsis symbiontica. Specimens from one locality in Tenerife and from New Zealand are lichenized with a strain ofD. symbiontica var.symbiontica, those from another locality in Tenerife with a strain ofD. symbiontica var.pauciautosporica. These strains differ in certain characters from other lichenized strains of these varieties.