The forgotten remains of a leptocleidid plesiosaur (Sauropterygia: Plesiosauroidea) from the Early Cretaceous of Gronau (Münsterland, Westphalia, Germany)

Gronausaurus wegneri n. gen. n. sp. represents a newly discovered leptocleidid sauropterygian based on one individual from the Early Cretaceous (Berriasian) of Gronau in Westphalia, Germany. The holotype and only known specimen consists of a skeleton, which lacks most of the dermal skull bones, a large number of cervical vertebrae and distal limb elements. Gronausaurus wegneri is unique in having distinct cavities, the subdiapophyseal fossae, below the transverse processes of the pectoral and anterior dorsal vertebrae, that probably stabilised the bones against tensile forces of the rotator and levator muscles in the living animal.     

The ‘A’ genome donor of Eleusine coracana (L.) Gaertn. (Gramineae)

Summary In an attempt to discover A and B genome donor(s) to finger millet, Eleusine coracana, or its progenitor species, E. africana (both allotetraploid 2n=4x=36), five diploid species, E. Indica, E. Floccifolia, E. multiflora, E. tristachya and E. intermedia, were crossed to finger millet and its progenitor taxon. Crosses were successful only with E. coracana. Three combinations of triploid hybrids E. coracana x E. indica, E. coracana x E. floccifolia, and E. coracana x E. multiflora were obtained and analysed. Meiotic behaviour was perfectly normal in parental species. The regular number of 18 bivalents in E. coracana, 9 bivalents in E. indica, E. intermedia, E. tristachya and E. floccifolia and 8 bivalents in E. multiflora were invariably noticed. In E. coracana x E. indica hybrids a mean chromosome pairing of 8.84_I+8.80_II+0.03_III+0.10_IV per cell was found. About 86.5% of the cells showed the typical 9_I+9_II configuration, suggesting that E. indica (AA) is one of the diploid genome donors to cultivated species E. coracana. A mean chromosome pairing of 11.08_I+7.63_II+0.16_III+0.04_IV per cell was found in E. coracana x E. floccifolia hybrids. Two to ten bivalents and varying numbers of univalents were seen in 55% of the cells. About 45% of the cells showed the 9_I+9_II configuration. Various evidence suggests that perennial E. floccifolia is a primitive member of the A genome group of Eleusine species, and it may not be a genome donor to E. coracana. In E. coracana x E. multiflora hybrids (2n=26) mean chromosome pairing of 21.45_I+1.97_II+0.13_III+0.04_IV per cell was found. About 91% of the cells were observed to have 20–26 univalents. Only a small percentage of the cells contained bivalents or multivalents. This pairing behaviour indicates that E. multiflora lacks genomic homology with the A or B genome of E. coracana. Genomically E. multiflora is a distinct species and a genomic symbol of C is assigned to it. Identification of the B genome donor species to cultivated millet. E. coracana remains elusive.     

Chilling and heat requirements for the prediction of the beginning of the pollen season of Alnus glutinosa (L.) Gaertner in Ponferrada (León, Spain)

Winter-flowering trees such as the alder (Alnus glutinosa (L.) Gaertner) can survive periods of adverse climatic conditions, entering a period of dormancy in the early fall. The end of dormancy and the start of the pollen season require a period of low temperatures followed by another of warm temperatures. These requirements were studied from 1995 to 2002, in order to develop a model to predict the onset of the alder pollen season in Ponferrada (Spain). Chilling accumulation took place from late October to late December or early January. The best result was obtained with a threshold temperature of 6.5 °C and an average of 848 chilling hours (CH). Heat requirements were calculated at maximum temperature, an average 143 growth degree days (GDD) were needed, with a threshold temperature of 0 °C. In order to validate models, predicted values were compared with real values for 2002–2003, 2003–2004 and 2004–2005, years not used in developing the models. Predictions for the pollen-season start-date differed only slightly from observed dates: in 2002–2003 predicted and observed dates were the same, in 2003–2004 there was a difference of 7 days and in 2004–2005 a difference of 3 days.     

Selachian teeth from Campanian sediments (Upper Cretaceous) of the Münsterland Cretaceous Basin (NW-Germany)

Selachian teeth obtained from trial samples of the Bosenberg quarry near Vorhelm (Beckumer Beds; lower Upper Campanian) and from outcrops along the Hamelbach brook near Stromberg/Oelde (Stromberger Beds; upper Lower Campanian) are presented. Both sites are located in the central southeast of the Münsterland Cretaceous Basin. Fifteen different taxa were identified but only seven could be assigned to a known species. Compared with other taxa the fauna is clearly dominated by squaliform selachians in terms of the number of species and number of specimens. The mixture of selachians presumed to inhabit both deep and shallow waters corresponds with typical taphonomic assemblages of turbiditic deposits and fits very well with the geological setting of the sampled locations.     

Chiasma frequency variation inCepaea hortensis (Müll.) and a comparison withC. nemoralis (L.)

Chiasma frequency variation has been studied in 12 populations ofCepaea hortensis and the results compared with those previously obtained forC. nemoralis from the same populations. Variation in chiasma frequency is effectively restricted to a single large bivalent. In both species there are significant differences between populations in chiasma frequency. Although mean population mean chiasma frequencies are similar inC. hortensis andC. nemoralis, C. hortensis is less variable thanC. nemoralis. This can be seen, to a greater or lesser extent, at several levels-(i) within cells, (ii) between cells, (iii) between snails, and (iv) between populations-and is most noticeable when interstitial chiasmata are considered separately from terminal chiasmata. Data from 6 populations suggest that chiasma frequency remains stable between successive years. It is suggested that, since sympatric populations were studied, the most likely explanation for differences in chiasma frequency statistics between the two species is thatC. hortensis andC. nemoralis are responding differently to similar selective pressures.     

Olpidiopsis antithamnionis n. sp. (Oomycetes,Olpidiopsidaceae), a parasite of Antithamnion floccosum (O. F. Müll.) Kleen from Newfoundland

Summary Olpidiopsis antithamnionis n. sp. (Oomycetes, Olpidiopsidaceae) parasitic on Antithamnion floccosum (O. F. Müll.) Kleen (Rhodophyta, Ceramiaceae) is described from three sites in Newfoundland, Canada, and from culture.Axial cells of the main and determinate branches of the host are the primary sites of fungal attack, although tetrasporangia and rhizoidal cells are also susceptible. Successful re-infection of A. floccosum was achieved in the laboratory although A. boreale and the trailliella-phase of Bonnemaisonia hamifera, both occurring with A. floccosum in the field, were immune. Regeneration of the host cells was observed, a phenomenon not previously reported in the fungal parasitism of other filamentous benthic marine algae.Studies in Biology from Memorial University of Newfoundland No. 256.     

Chemical constituents from the roots of Fallopia convolvulus (L.) A. Löve

Twenty compounds, including three sterols (1–3), three phenols (4, 14 and 15), four anthraquinones (5, 7, 8 and 16), one chromone (6), two stilbenes (9 and 10), three amides (11–13), three flavonoids (17–19) and one organic acid (20), were obtained by modern phytochemical isolation methods. Their structures were identified by spectroscopic methods and in comparison with the published data in the references. Among them, compound 2, 3, 11 and 13 were firstly discovered from genus Fallopia, and compounds 1, 5–8, 10, 14, 15, 17, 19 and 20 were obtained from F. convolvulus for the first time. The chemotaxonomic significance of these compounds was also discussed, which revealed the relationships between F. convolvulus and some other species of Polygonaceae family.     

Eine Zwillingsblüte beiGymnadenia conopea (L.) R. Br.

Ohne Zusammenfassung     

An improved protocol for micropropagation of Mallotus repandus (Willd.) Müll.Arg.

Node and internode explants of Mallotus repandus were precultured on basal medium (BM: Murashige and Skoog (MS) medium with 3% sucrose and 0.55% Agargel) for 0–18 d before culture on shoot induction Medium (SIM: BM added with 4.44 μM of benzylaminopurine) for 4 wk. The cultures were subsequently transferred to BM for 4 wk for shoot elongation. Node explants precultured on BM for 14 d before incubation on SIM were at an optimum for shoot regeneration with the response rate of 95%, compared to a 21% response for the control without preculture. Internode explants precultured on BM for 16 d responded with an optimal shoot formation response rate of 69%, whereas the control response rate was 6%. The maximum shoot regeneration rates were 3.1 ± 0.3 and 2.7 ± 0.4 shoots/responding explant in node and internode explants, respectively. This study demonstrates for the first time that shoot organogenesis can be induced from internode explants of M. repandus. Furthermore, the results suggest that the explants need to acquire competence before shoot organogenesis. Rooting was obtained by incubation of regenerated shoots on half-strength MS with 10.74 μM of 1-naphthylacetic acid for a week before culture on half-strength MS for 4 wk. Regenerated plants were successfully transferred to soil.     

Photoacclimation in a tropical population of Cladophora glomerata (L.) Kützing 1843 (Chlorophyta) from southeastern Brazil.

Photoacclimation of photosynthesis was investigated in a tropical population of C. glomerata (S?o Paulo State, southeastern Brazil, 20 degrees 48' 24" S and 49 degrees 22' 24" W) by chlorophyll fluorescence parameters and chlorophyll a content. Plants were acclimated to two levels of irradiance: low (65 +/- 5 micromol.m(-2).s(-1)) and high (300 +/- 10 micromol.m(-2).s(-1)) and exposed short-term (4 days) and long-term (28 days) under a light-dark cycle of 12:12 hours. Photosynthesis-irradiance (PI) curves revealed distinct strategies of photoacclimation. In long-term exposure, plants acclimated by altering the photosynthetic units (PSU) number and keeping fixed the PSU size, revealed by increased rates of maximum photosynthesis (Pmax), lower photosynthetic efficiency (alpha) and higher values of the saturation parameter (Ik) under high irradiance. The short-term acclimation strategy consisted of changing the PSU size, with a fixed number of PSUs, as revealed by similar Pmax but higher alpha and lower Ik under low irradiance. Chlorophyll a contents followed the general pattern reported in green algae of higher concentrations under lower irradiance. Dark/light induction curves revealed consistently higher values of potential quantum yield under low irradiance. Initial and final values showed a higher recovery capacity in the short (84.4-90.6%) term exposure than in the long-term case (81.4-81.5%). ETR (electron transport rate) and NPQ (non-photochemical quenching) values were consistently higher under low irradiance. ETR showed a continuous and steady increase along the light exposure period in the short and long-term experiments, whereas NPQ values revealed a rapid increase after 15 seconds of light exposure, kept a slightly increasing trend and stabilized in most treatments. Lower photosynthetic performance (ETR) and recovery capacity of potential quantum yield were observed, particularly in long-term exposure, suggesting that this population is constrained by the typical high light environment of tropical regions.     

The Discovery of Diploid Lycoris radiata (L′Her.) Herb. from Anhui

Lycoris radiata (L′Her. ) Herb. containing wild and cultural types, is distributed in China and Japan. The karyotype variation in three populations of the species from Anhui is studied in this paper. (1) Wuhu wild population has a karyotype 2n=21+1B= 1m+12st +8t+1B. The chromosomes range in length from 7.50 to 14.10 µm with the ratio of the longest to the shortest 1.88. The karyotype belongs to Stebbins’(1971) 3A. (2) Huangshan wild population has two cytotypes: 2n=22 and 2n=22+1B. Type Ⅰ: The karyotype formula is 2n=22=12st+10t. The chromosomes range in length from 6.85 to 9.95 µm. with the ratio of the longest to the shortest 1.45. The karyotype belongs to 4A. Type Ⅱ: The karyotype formula is 2n=22+1B=6st+14t+2T+1B (plate 1: 7,8). The chromosomes range in length from 6.50 to 11.02 µm. with the ratio of the longest to the shortest 1.70. The karyotype belongs to 4A. (3) Wuhu cultural type has a karyotype 2n=33=30st +3t. The chromosomes range in length from 7.10 to 9.35 µm with the ratio of the longest to the shortest 1.32. The karyotype belongs to 4A. This result agrees well with the previous reports. The diploid types of Lycoris radiata (L´Her.) Herb. are found in Anhui for the firsttime.     

Ueber eine Vergrünung vonSinapis arvensis L. (form,dasycarpa Neilr.)

Ohne Zusammenfassung     

Versuche zur Heterosiszüchtung bei Kohlrabi (Brassica oleracea L. var.gongylodes L.)

Zusammenfassung Eine Verbesserung der Frühzeitigkeit der Sorte Prager weißer Treib durch Selektion war nicht möglich.Durch langjährige Selbstung konnten morphologisch einheitliche, z. T. inzuchtgeschädigte Stämme entwickelt werden.Durch Kreuzung dieser Stämme untereinander konnten Heterosiseffekte erzielt werden, die signifikant über der Leistung der Vergleichssorte lagen.Die Kreuzungen mit Sorten ergaben Heterosiseffekte, die die Leistungen der Stammeskreuzungen signifikant übertrafen.Eine Steigerung der Frühzeitigkeit unter Ausnutzung des Heterosiseffektes konnte nachgewiesen werden.Für die sorgfältige Betreuung und Auswertung der Versuche möchte ich an dieser Stelle der technischen Assistentin Frl. M. Nowak besonders danken.Mit 4 AbbildungenQuedlinburger Beiträge zur Züchtungsforschung Nr. 51.     

A review of the reproductive behavior of Polyphemus pediculus (L.) Müller (Crustacea: Branchiopoda)

The reproductive behavior of Polyphemus pediculus (L.) includes mating, laying of resting eggs and giving birth to juveniles. All these forms of behavior are performed in a population daily and simultaneously by means of individual and social actions. Individual behavior is manifested by certain sets of stereotyped movements which can be observed at any time of the day and at any location in a water body. Individual behavior has an episodic, stable character and low intensity. Social behavior is accomplished by specimens of similar physiological state who form transitory swarms. They form within the main continually existing main swarms of the population. Social behavior is rhythmic and of high intensity. Reproductive parthenogenetic swarms first form around dawn and later during the day: about noon in May–July and before sunset in Autumn. As swarms of parthenogenetic females disintegrate, swarms of old gamogenetic females form and mass laying of resting eggs begins. Young gamogenetic females and males swarm only when resting-egg-laying swarms disintegrate. Parthenogenetic reproduction peaks in northern Russia in May and August and persists until late September. Swarms of resting-egg-laying females form once a day around dawn, from May to September. Mating swarms form in summer in midmorning, at twilight and on moonlit nights. In Autumn, there is only one peak of mating, in midmorning. Intensity, duration and time of manifestation of different forms of social behavior change from spring to autumn. Location and character of their manifestation are predictable.