Chromosome numbers in AustralianEuphrasia (Scrophulariaceae)

Chromosome numbers for six Australian taxa ofEuphrasia have been determined. Improved staining techniques have shown that numbers for four of the taxa published previously by the first author were incorrect. The investigated taxa show high ploidy levels with an apparent base number of x = 11, the same as for the genus outside Australia.Dedicated to Prof. DrElisabeth Tschermak-Woess on the occasion of her 70th birthday.     

Robertsonian differentiation and preferential pairing revealed in species and F1 hybrids of theGibasis linearis group (Commelinaceae)

Three closely related species of theG. linearis group are differentiated by their basic numbers and ploidy levels. The change in basic number involves Robertsonian fusion, but the species also differ by interchange and cryptic structural changes revealed by meiotic pairing in F₁ hybrids.Chromosome Evolution in theGibasis linearis Group (Commelinaceae), II.—Part I:Kenton (1981a).     

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.

     

Chromosome number of theOxalis tuberosa alliance (Oxalidaceae)

Twelve taxa of theOxalis tuberosa alliance were analysed and found to share the same basic chromosome number x = 8. The karyotypes are composed by small metacentric and submetacentric chromosomes. Different ploidy levels were found among the taxa: there were 9 diploids, 1 tetraploid, 1 hexaploid and 1 octoploid. The last ploidy level corresponds toO. tuberosa, the only tuber bearing taxon found so far in the alliance. Cytotaxonomic evidence and evolutionary considerations suggest to classify theO. tuberosa alliance in sect.Herrerea.     

Taxonomical study ofAster leiophyllus complex (Compositae) in Kanto district,Japan, with special reference to ploidy level

TheAster leiophyllus complex is complicated taxonomically and includes many related taxa representing polyploid series. It has been reported that this group is diversified throughout the Kanto district, central Japan, and there are three taxa endemic to the Kanto district. However, as neither morphological variation range nor distribution pattern is sufficiently investigated, taxonomic confusion sometimes occurs. In this study, morphological variation was examined in relation to the ploidy level, and taxonomic consideration was given. As a result, four morphologically recognized taxa occur in the Kanto district;A. leiophyllus (2x, 6x),A. leiophyllus var.sawadanus (2x, 3x, 4x),A. semiamplexicaulis (2x), andA. sugimotoi (4x, 5x). The distribution ranges ofA. leiophyllus var.sawadanus, A. semiamplexicaulis andA. sugimotoi are small, whileA. leiophyllus is distributed over most of the Kanto district. Morphological and cytological observations indicate that one of the reasons of the taxonomic confusion is the presence of presumed hybridization betweenA. leiophyllus and other taxa.     

A reexamination of infraspecific taxa of a wild potato,Solanum microdontum (Solanum sect.Petota:Solanaceae)

Current taxonomic interpretations ofSolanum microdontum Bitter partition the species into two or three infraspecific taxa, variously recognized as subspecies or varieties. The present study reexamines these taxa using morphological data from four individuals each of 69 accessions from most of the range of the species, planted in a common field plot. Our results show that the character states used to recognize infraspecific taxa inS. microdontum often vary within accessions and have no correlation with geography. We conclude that past hypotheses have used typological concepts and that infraspecific taxa are not warranted. This study questions other hypotheses of infraspecific taxa in sect.Petota.     

Electrophoretic confirmation of the intergeneric hybrid ×Ruttyruspolia (Acanthaceae)

A plant collected in South Africa in the early 1960's has been considered an intergeneric hybrid with the parental taxa beingRuspolia hypocrateriformis (Vahl)Milne-Redhead var.australis Milne-Redhead andRuttya ovata Harv. The intermediate morphology of the plant provided the strongest evidence of its hybrid origin. The natural hybrid, named formally as ×Ruttyruspolia A. Meeuse & de Wet, is highly sterile. Crosses between the two presumed parental taxa produced two plants that are very similar to the putative natural hybrid. We had examined the presumed parental species and the natural and artificial hybrids using enzyme electrophoresis. The two parental species are highly differentiated at genes specifying soluble enzymes; they have a genetic identity of 0.51. They have no common alleles at two genes, and contain alternative alleles in very different frequencies at two loci.Ruttya andRuspolia exhibit both unique and common alleles at two additional genes. The natural and artificially produced plants of ×Ruttyruspolia are identical electrophoretically and contain alleles unique to each of the parental species at two genes. In addition, individuals of ×Ruttyruspolia combine alternative high frequency alleles from each parent at two loci. Allozymes provide strong confirming evidence for the hybrid origin of naturally occurring ×Ruttyruspolia because the products of specific alleles either unique to or highly characteristic of the two putative parental taxa are found combined in ×Ruttyruspolia.     

A taxonomical revision ofThymus sect.Teucrioides (Lamiaceae)

TheThymus teucrioides Boiss. & Spruner aggregate is revised and the following new taxa, all from the alpine zone in the Greek mountains, are described:Th. leucospermus Hartvig from the calcareous mountains of Pindhos and Mt Parnassos in Sterea Ellas,Th. rechingeri Hartvig with the subsp.macrocalyx Hartvig from calcareous mountains in Sterea Ellas and N Peloponnissos, andTh. teucrioides subsp.alpinus Hartvig from the serpentine areas of N Pindhos. In the variableTh. teucrioides s. str. many characters have turned out to be markedly geographically correlated and many local populations can be distinguished by a particular combination of characters.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.     

Pollen morphology ofSonchus and related genera,and a general discussion

The pollen morphology of the taxa belonging to the generaAetheorhiza Cass.,Launaea Cass.,Reichardia Roth andSonchus L. in the Iberian Peninsula has been studied with light and electron microscopy. The pollen is 3(-4)-zonocolporate and echinolophate (without polar lacunae, but in general with prelacunae), with equatorial ridges and 15–20 lacunae: 3–4 poral, 6–8 abporal and 6–8 paraporal. Small to medium size, P × E = 19–36 × 23–42 µm; sometimes two different sizes have been found. Exine 3–9 µm thick and ornamentation microreticulate and echinate. The results clearly show the relationships between genera. Moreno-Socías, E., Mejías, J. A., Díez, M. J., 1994: Morfología polínica deLactuceae (Asteraceae) en la Península Ibérica, I.Lactuca y géneros relacionados. — Acta Bot. Malacitana.19: 103–113.     

Morphological and molecular comparisons ofCampsis grandiflora andC. radicans (Bignoniaceae), an eastern Asian and eastern North American vicariad species pair

Morphological and molecular comparisons were made forCampsis grandiflora (Thunb.)K. Schumann (Bignoniaceae) from eastern Asia andC. radicans (L.)Seemann from eastern North America. Chloroplast DNA (cpDNA) variation was surveyed with 20 restriction endonucleases. The cpDNA divergence between the two vicariad species was 2.44%, which is the highest reported among North Temperate disjunct taxa and one of the highest reported for infrageneric taxa. Detailed morphological comparisons also suggest a high level of divergence. Cluster analyses based on 22 morphological characters and 39 OTUs revealed two distinct groups corresponding with the two species. The average taxonomic distance between the two species was 1.806. Analyses of variance (ANOVA) revealed that 12 of the 18 quantitative characters differed significantly ( 0.01) betweenC. grandiflora andC. radicans. Divergence time based on cpDNA data was estimated as 24.4 million years. The Bering land bridge hypothesis was favored over the North Atlantic land bridge hypothesis based on the estimated divergence time and the geological history of the North Temperate region. The high levels of morphological and cpDNA divergence are not consistent with morphological stasis, which has been proposed as a common mode of evolution for North Temperate disjunct taxa.     

Microgametophytic plastid nucleoid content and reproductive and life history traits of tribeTrifolieae (Fabaceae)

Microgametophytic plastid nucleoids were quantified for 18 species representing the four core genera of the tribeTrifolieae (Fabaceae),Medicago, Melilotus, Trigonella, andTrifolium. Generative cells of all taxa contained nucleoids, establishing that biparental plastid inheritance is common in theTrifolieae. Nucleoid number and volumes of pollen grains and generative cell nuclei differed among taxa. Nucleoid number was positively correlated with pollen grain and generative cell nuclear volumes, flower size and style length. These relationships disappeared after adjusting nucleoid number for pollen grain and generative cell nuclear volumes. Adjusted nucleoid numbers provided no evidence to support hypotheses that plastid content is associated with ploidy level, mating system, perenniality or size of the reproductive apparatus.     

Morphometrics and character state recognition for cladistic analyses in theBletia reflexa complex (Orchidaceae)

Different criteria have been suggested for decisions on character state recognition for morphological characters showing continuous variation from taxon to taxon. A method proposed byMishler andDe Luna seeks to recognize as many character states as the groups of taxon means that are revealed by an analysis of variance (ANOVA) followed by multiple range tests. We apply this method as a guide in decisions of selecting taxonomic characters in species of theBletia reflexa complex. Seven species of the complex, represented by 156 individuals belonging to 54 populations, were the terminal taxa of the study. Character state codes were assigned to 20 characters. These characters together with 12 non-quantitative characters were incorporated into cladistic analyses. Results indicate that the complex is monophyletic only under one outgroup combination.     

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.     

Die Stipeln derIrvingioideae undRecchioideae und ihre systematische Wertung nebst Bemerkungen zur Holzanatomie und Palynologie

TheSimaroubaceae generally have no true stipules. The stipule-like appendages of some genera proved to be pseudo- or metastipules (Weberling & Leenhouts 1965). There seem to be some exceptions, however: the generaCadellia (incl.Guilfoylia) andRecchia on the one hand, and theIrvingioideae on the other. As these taxa, with exception ofRecchia, have simple leaves, there are no indications that their stipule-like appendages might be pseudo- or metastipules. In regard to their position and ontogeny these appendages behave completely like true stipules. Assuming the view ofForman, one could conceive a morphological line from the long, broadly inserted axillary stipules of mostIrvingioideae to the small scaly triangular stipules ofIxonanthoideae. The similarities between the stipules ofIrvingioideae andErythroxylaceae (already emphasized byHallier and others), become even more evident when their ontogeny is investigated. TheIrvingioideae, therefore, might be regarded as a separate family (perhaps with some relation to theErythroxylaceae,Hallier) or as a subfamily ofIxonanthaceae (Forman).—In addition to data on stipules some results on the palynology and shoot anatomy of the generaCadellia (incl.Guilfoylia) andRecchia are reported. Their relationship with theSimaroubaceae also appears doubtful. If they are to be included, they represent a somewhat isolated group near the base of the family which otherwise has lost its stipules.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

Serial reconstruction of the mitochondrial reticulum in the antarctic flagellate,Pyramimonas gelidicola (Prasinophyceae,Chlorophyta)

Summary A serial reconstruction ofPyramimonas gelidicola McFadden, Moestrup andWetherbee has revealed a large reticulated mitochondrion branching throughout the cell. The possibility of single mitochondria in other members of thePrasinophyceae and the uniformity of the morphology of this organelle within the class is discussed.     

Morphology and anatomy ofCaloplaca coralligera (Teloschistaceae) as adaptation to extreme environmental conditions in the maritime Antarctic

The anatomical and morphological structure of the lichenCaloplaca coralligera (Hue.)Zahlbr. was investigated in connection with mechanisms of colonization and adaptation to the special conditions of maritime Antarctic.Caloplaca coralligera seems to be endemic to the antarctic region. The lichen is unique in its morphology, growing like a crustose lichen with a prothallus, but the very thallus being composed of many vertical, frutescent branches not higher than large isidia. Due to fusions of the distal parts of the branches the morphology is characterized by air-filled cavities between the erect thallus parts where the phycobionts are located only close to the outermost surface. But also anatomically a system of air-filled cavities is developed by a net-like structure of hyphae. This may result in an insulation from temperature exchanges with the rocky substrate. It is speculated that this peculiar thallus structure might be advantageous to a lichen growing on compact substrates by buffering the diurnal temperature extremes which are characteristic for rocks under a strong radiation exchange with the atmospheric surrounding.Dedicated to Prof. DrO. L. Lange on the occasion of his retirement and of his 65th birthday.     

Mitotic cycle time and DNA content in annual and perennialMicroseridinae (Compositae,Cichoriaceae)

Within eight annual and perennialMicroseridinae species studied, the duration of the mitotic cycle is positively correlated with the nuclear DNA content, cycle time (hrs) = 7.3 + 0.32 × pg DNA/nucleus. Within the generaAgoseris andMicroseris, the annuals have lower DNA contents and more rapid mitotic cycle times than do the perennials. This relationship is predicted by the nucleotypic theory ofBennett. Annual species ofPyrrhopappus have relatively high DNA contents and a proportionately longer mitotic cycle time, but contrary to that expected by the nucleotypic theory as originally proposed have the fastest growth rate and shortest generation time observed in theMicroseridinae. This rapid developmental rate is discussed, nucleotypically, however, by analyzing relationships between DNA content, mitotic cycle time, and cell size.     

A phylogenetic analysis of Pisum based on morphological characters, and allozyme and RAPD markers

Cladistic analyses of 17 wild and cultivated pea taxa were performed using morphological characters, and allozyme and RAPD (random amplified polymorphic DNA) markers. Both branch-and-bound and bootstrap searches produced cladograms that confirmed the close relationships among the wild species and cultivars of Pisum proposed by a variety of systematic studies. Intraspecific rankings were supported for northern P. humile, southern P. humile, P. elatius and P. sativum, which together comprise a single-species complex. P. fulvum, while clearly the most divergent of the pea taxa, could also be assigned to the same species complex without violating the hierarchial logic of the cladogram. Its inclusion or exclusion depends on whether the level of interfertility it displays with other pea taxa or its overall morphological and chromosomal distinction are emphasized. As suggested by previous studies, northern P. humile was the most likely sister taxon to cultivated P. sativum; although, rigorous phylogenetic evaluation revealed a close genealogical affinity among P. elatius, northern P. humile and P. sativum. Despite their limited number, the 16 morphological characters and allozyme markers used precisely organized the pea taxa into established taxonomic groupings, perhaps in part reflecting the role morphology has played historically in pea classification. The RAPD data also generally supported these same groupings and provided additional information regarding the relationships among the taxa. Given that RAPDs are relatively quick and easy to use, are refractory to many environmental influences, can be generated in large numbers, and can complement traditional characters that may be limited in availability, they provide a valuable new resource for phylogenetic studies.     

Cytotaxonomische Untersuchungen in der Artengruppe desRanunculus alpestris (Ranunculaceae)

Morphological and cytological investigations as well as crossing experiments were carried out with the 5 species of theRanunculus alpestris group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. etKit.,R. magellensis Ten.). A key to the species is presented; localities and distribution are given in addition to extensive diagnoses. Crossing experiments between the 5 taxa were successful (F₁-F₃ individuals, backcross types, tripeland quadrupelbastards); the morphology of the experimentally obtained F₁-hybrids was mostly intermediate. All 5 species as well as all hybrids have a chromosome number of 2n = 16; there is no statistically significant difference between the karyotypes of the 5 taxa. According to the results of the morphological investigations and the crossing experiments we can distinguish 2 subunits of very closely related species: a)R. alpestris, R. traunfellneri, R. bilobus; b)R. crenatus, R. magellensis. The speciation within the group ofRanunculus alpestris is discussed.

     

Variety of mitochondrial shapes,sizes, and volumes inChlamydomonas reinhardii

Summary Mitochondria in cells ofChlamydomonas reinhardii, which at an intermediate stage of the vegetative cell cycle have been submitted to gametogenesis under dark and cold conditions, remain more or less unchanged with and without the addition of chloramphenicol. They exist in various number, shapes, and sizes and can be branched or unbranched as well as small or large. Giant mitochondria can be fused to a mitochondrial network, which, in contrast to the previously reported network (Grobe andArnold 1975), lies predominantly in the center of the cell. Mitochondrial volumes were revealed by means of morphometrical analyses from serial sections of four entire cells.