Nachruf. (A. Goffin.)

Ohne Zusammenfassung     

Nitrogen Fixation Associated with the New Zealand Mangrove (Avicennia marina (Forsk.) Vierh. var. resinifera (Forst. f.) Bakh.)

Nitrogenase activity in mangrove forests at two locations in the North Island, New Zealand, was measured by acetylene reduction and ¹⁵N₂ uptake. Nitrogenase activity (C₂H₂ reduction) in surface sediments 0 to 10 mm deep was highly correlated (r = 0.91, n = 17) with the dry weight of decomposing particulate organic matter in the sediment and was independent of light. The activity was not correlated with the dry weight of roots in the top 10 mm of sediment (r = −0.01, n = 13). Seasonal and sample variation in acetylene reduction rates ranged from 0.4 to 50.0 μmol of C₂H₄ m⁻² h⁻¹ under air, and acetylene reduction was depressed in anaerobic atmospheres. Nitrogen fixation rates of decomposing leaves from the surface measured by ¹⁵N₂ uptake ranged from 5.1 to 7.8 nmol of N₂ g (dry weight)⁻¹ h⁻¹, and the mean molar ratio of acetylene reduced to nitrogen fixed was 4.5:1. Anaerobic conditions depressed the nitrogenase activity in decomposing leaves, which was independent of light. Nitrogenase activity was also found to be associated with pneumatophores. This activity was light dependent and was probably attributable to one or more species of Calothrix present as an epiphyte. Rates of activity were generally between 100 and 500 nmol of C₂H₄ pneumatophore⁻¹ h⁻¹ in summer, but values up to 1,500 nmol of C₂H₄ pneumatophore⁻¹ h⁻¹ were obtained.     

Taxonomic notes on Cheilothela (Lindb.) Broth. and Dicranella (C. Muell.) Schimp.

Abstract

The widespread occurrence of a number of bryophytes on British saltmarshes is reported. The communities in which bryophytes are most frequently found are discussed. These communities are more common on marshes on the west coast of Britain. Differences between moss assemblages on salt marshes in England and Wales and in Scotland are emphasised and the greater range of habitat preference demonstrated by Grimmia maritima in Scotland is commented upon.     

Zur Fasanen-Zucht. (II.)

Ohne Zusammenfassung     

A contribution to the embryology of Desmodium motorium (Houtt.) Merr. (= D. gyrans (L.f.) DC.) (Fabaceae)

Abstract

The anthers are tetrasporangiate. The anther wall comprises epidermis, fibrous endothecium, middle layer and tapetal layer. The tapetum is of the Glandular type and its cells remain uninucleate. Meiosis in pollen mother cells is normal and simultaneous cytokinesis leads to the formation of tetrahedral and decussate microspore tetrads. The pollen grains are shed at 2-celled stage. The ovule is campylotropous, bitegmic and crassinucellate. Meiosis in megaspore mother cell results in the formation of linear or occasionally T-shaped megaspore tetrad. The chalazal megaspore develops into Monosporic Polygonum type of embryo sac. Endosperm development is of the Nuclear type.     

Cytological Investigations on Porphyra umbilicalis(L.) Kutz. var. laciniata(Lightf.) J.Ag.

1. Vegetative mitosis of Porphyra umbilicalis var. laciniatais normal, the chromosome number as seen in late prophase beingfive. Special features of this mitosis are the appearance ofseveral stained chromatin segments in early pro-phase and theformation of a crescent-shaped group of chromosomes during metaphaseand anaphase. 2. Genuine monospores have not been seen in the material investigated. 3. Both spores and spermatia arise by repeated division of amother-cell and in identical ways. Evidence is presented toshow that the first division in the mother-cell forming sporesis longitudinal. There is no evidence of reduction divisionin this division, and the chromosome number in the mother-cellis five. 4. The first division in the germinating spore is mitotic andshows five chromosomes. 5. The Conchocelis-phase is haploid throughout and produces‘fertile cell rows’ and ‘plantlets’,but spore liberation has not been observed. It is suggestedthat the ‘plantlets’ may grow out directly intothe leafy phase or may give rise to spores according to prevailingenvironmental conditions. 6. No evidence of sexual reproduction has been obtained in thepresent work and the role of the spermatium in the life-cycleis not clear. It is suggested that further work may profitablybe concerned with investigating the nature of the spermatium.     

Anther culture of kale (Brassica oleracea L. convar.acephala (DC.) Alef.)

The pollen development and androgenic ability of 18 kale (Brassica oleracea convar.acephala) genotypes was observed during an anther culture study. Anther culture was successful in 6 of the genotypes and the highest yield obtained was 17 embryos per 100 anthers plated. Two stages of anther development were identified as being responsive to anther culture. The first and most responsive was that corresponding to the late uninucleated stage and the second to the late binucleated stage. These stages correspond with the onset of mitotic events in the microspores. Pollen viability was studied and low viability was noted which declined to zero after 9 days of anther culture. The initial viability level however was not clearly related to androgenic ability. The significance of the production of haploid and dihaploid kale genotypes in the study and breeding of resistance to clubroot is discussed.     

Mielichhoferia elongata (Hornsch.) Hornsch. and Saelania glaucescens (Hedw.) Broth. in Scotland

Abstract

Lamella margins of Polytriehadelphus from throughout the range of the genus have been examined by SEM. All specimens clearly referable on other characters to the genus have characteristically crenate lamella margins covered with angular flakes of epicuticular wax. In this respect they resemble species of Dawsonia but differ from all other Polytrichaceae examined. The lamella margin characters are useful for critical identification of non-fruiting plants of Polytriehadelphus from other vegetatively similar Polytrichaceae. They confirm that P. erieoides and the North American P. lyallii Mitt. do not belong to this genus. Polytriehadelphus has a trans-Pacific and essentially Southern Hemisphere distribution extending from Sulawesi and New Guinea through New Zealand and the Fuegian region to the northern Andes, with a north-western outpost in Costa Rica. It is likely that this distribution is derived from a continuous Antarctic range in the late Cretaceous, and that much of the radiation of the genus at the two northern ends of its present range took place in the mid to late Tertiary. Outlying stations on Tristan da Cunha and the Marquesas probably result from long-distance dispersal.     

Beobachtungen an Pogonatum nanum (Schreb.) P. B. und Pog. aloides (Hedw.) P. B.

Ohne ZusammenfassungMit 22 Textabbildungen.     

Vorversuche zur Massenkultur vonBeauveria bassiana (bals.) vuill. undSpicaria farinosa (fr.) Vuill.

Ohne Zusammenfassung     

Production ecology ofBolboschoenus maritimus (L.)Palla (Scirpus maritimus L. s.l.)

Measurements were made, for several seasons, both of the growth rate and biomass production of stands ofBolboschoenus maritimus, the seasonal development of the vertical stand structure together with parallel measurements of microclimatological data including incoming global radiation. Water and bottom soil chemical analyses in relation to the nutrient content in the biomass were compared. The ecological adaptation of the acidophilic subspeciesB. m. ssp.maritimus, growing in south-Bohemian oligotrophic fishpond waters with that of the halophilic ssp.compactus was studied in experimental hydroponic cultures and the results discussed with the findings of other authors from different European habitats. The efficiency of solar energy conversion of incoming radiation was calculated by means of energy content biomass analysis.     

1065. Codonopsis pilosula (Franch.) Nannf. subsp. tangshen (Oliv.) D.Y. Hong: Campanulaceae

Codonopsis pilosula subsp. tangshen is illustrated: its relationships, history and pollination are discussed. Instructions for its successful cultivation are given, and references are given to its use in Traditional Chinese medicine.     

Fusarium moniliforme Sheld. In Israel (Gibberella Fujikuroi (Saw.) Wollenw.)

In studies with 58–76 Israeli isolates and 5–9 foreign isolates ofF. moniliforme, growth in vitro on wheat and PDA was best at 24–30° C, with little growth at 6° C and none at 40° C. In the optimal temperature range, equal growth was made in light and darkness. F. moniliforme is widespread in agricultural soils in Israel, but in some 170 samples rarely exceeded about 5 % of the totalFusarium population.Of seventy-six Israeli and nine foreign isolates, seventy-four induced toxic reactions on rabbit skin. This is an unusually high proportion. The histological changes induced by such skin application are described.Inoculation tests were performed with eighty-three Israeli isolates from six field and five fruit crops, and with thirteen foreign isolates (including six from varieties ofF. moniliforme) on ten crop plants. Onions and all dicotyledonous plants tested were affected by a high proportion of the isolates, while wheat was not, and maize was little affected. There was therefore little pathogenic specialization among these isolates.The studies carried out in Israel onF. moniliforme as cause of the black heart disease of banana fruits and of fruit rots of avocado and citrus are reviewed.Morphological studies of all Israeli isolates and of those received from abroad, and a survey of the literature on the taxonomy of the Liseola section ofFusarium, have led to the following conclusion: The section should containF. moniliforme as its only species, andF. moniliforme var.anthophilum andF. moniliforme var.subglutinans as its only two varieties.From the present distribution ofF. moniliforme and its environmental relationships it is concluded that this fungus constitutes a potential danger to crops in warm countries to which irrigation is being introduced, and especially to dense plantation crops.

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Zusammenfassung In vitro Wachstum von 58–76 Isolierungen derF. moniliforme aus Israel und aus anderen Ländern, auf Weizenkörnern und PDA, war optimal bei 24–30° C; bei 6° C entwickelte sich der Pilz kaum, und bei 40° C überhaupt nicht. Bei den optimalen Temperaturen war das Wachstum in Licht und Dunkelheit gleich gut. F. moniliforme ist in den Agrarböden Isracls weit verbreitet, jedoch überschritt der Pilz in 170 Bodenproben nur selten 5 % der gesamtenFusarium Bevölkerung.Von 76 Isolierungen aus Israel und 9 aus dem Ausland erregten nicht weniger als 74 Isolierungen toxische Reaktionen als sie auf die Haut von Kaninchen aufgetragen wurden. Die histologischen Aenderungen, die durch solches Auftragen bewirkt werden, werden hier beschrieben.Infektionsversuche an 10 Agrarpflanzen wurden mit 83 Isolierungen aus Israel und 13 aus dem Ausland durchgeführt. Alle Dicotyledone sowie Zwiebeln wurden von vielen dieser Isolierungen befallen, dagegen wurde Mais selten und Weizen fast gar nicht befallen. Es konnte daher nur eine geringe pathologische Spezialisierung unter den Isolierungen vonF. moniliforme festgestellt werden.In Israel ausgeführte Forschungen überF. moniliforme als Erreger der Black Heart Fäule von Bananen Früchten und von Avokado- und Zitrusfruchtfäulen werden hier besprochen.Morphologische Studien an Isolierungen aus Israel und dem Ausland, und eine Literaturübersicht der Liseola Sektion führten zur folgenden Schlussfolgerung: Diese Sektion sollF. moniliforme als ihr einziges Spezies enthalten, undF. moniliforme var.anthophilum sowieF. moniliforme var.subglutinans sind als Varietäten anzuerkennen.Die gegenwärtige Verbreitung vonF. moniliforme und seine Umweltsbeziehungen lassen darauf schliessen, dass dieser Pilz in warmen Ländern in denen Bewasserung eingeführt wird, eine Gefahr für verschiedene Agrarplfanzen, insbesondere dichte Pflanzungen, darstellt.

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The support given this study by the Central Research Fund of the Hebrew University is gratefully acknowledged.     

A comparison of Dichodontium flavescens (Dicks.) Lindb. and D. pellucidum (Hedw.) Lindb. (Bryopsida)

Abstract

Fifty-three herbarium samples of the genus Dichodontium, originating from 15 countries in Europe and North America, were examined to critically assess new distinguishing characters between D. flavescens and D. pellucidum. The examination, including SEM, revealed some new characteristics in the gametophyte, notably leaf shape, leaf length: width ratio, and width of the nerve, permitting accurate determinations even on sterile material. D. flavescens is recognized here as a distinct species.     

Constituents of the leaves of Pseuderanthemum carruthersii (Seem.) Guill. var. atropurpureum (Bull.) Fosb.

A new iridoid, 5β,6β-dihydroxyantirrhide (1) was isolated from the dried leaves of Pseuderanthemum carruthersii (Seem.) Guill. var. atropurpureum (Bull.) Fosb. (Acanthaceae), together with 13 known compounds, including two iridoids, linarioside and antirrhinoside; five phenylethanoids, echipuroside A, verbascoside, isoverbascoside, isomartynoside and osmanthuside B; and six flavonoids, luteolin 7-O-β-d-glucopyranoside, luteolin 7-O-rutinoside, apigenin 7-O-rutinoside, apigenin 6-C-α-l-arabinopyranosyl–8-C-β-l-arabinopyranoside, apigenin 6,8-di-C-α-l-arabinopyranoside and apigenin 6-C-β-d-xylopyranosyl–8-C-α-l-arabinopyranoside. Their chemical structures were elucidated by 1D and 2D NMR as well as HR-ESI-MS spectroscopic analysis. Some purified compounds were evaluated the acetylcholinesterase inhibition and cytotoxic activities against the HeLa cervical cancer cell line and the MCF-7 breast cancer cell line at the concentration of 100 μg/mL. Luteolin 7-O-β-d-glucopyranoside exhibited cytotoxic activities against both the HeLa cervical cancer cell line and the MCF-7 breast cancer cell line. Verbascoside and isoverbascoside showed strong cytotoxic activity against the MCF-7 breast cancer cell line. The tested compounds showed the AChE inhibitory activity fairly weak.