Neue Taxa vonTillandsia subgenusDiaphoranthema (Bromeliaceae) aus Bolivien und Argentinien

5 new taxa are described and illustrated; their position within the subgenus is discussed:T. hirta W. Till & L. Hromadnik,T. cotagaitensis L. Hromadnik,T. caliginosa W. Till, andT. gilliesii Baker subsp.polysticha W. Till & L. Hromadnik are members of a group includingT. myosura Grisebach exBaker,T. mandonii E. Morren exMez in DC.,T. retorta Grisebach exBaker em.Grisebach andT. andicola Gillies exBaker. T. brealitoensis L. Hromadnik is related toT. angulosa Mez in DC. but distinct and possibly of hybrid origin.

     

Harpacticoiden (Crustacea, Copepoda) aus dem Küstengrundwasser der französischen Mittelmeerküste

Investigations of the ground water of the French Mediterranean coast gave 28 different species of harpacticoid copepods. Among them, six species are new to the French coast and three species and one form are described as new, viz. Ectinosoma mediterraneum sp.n., Sigmatidium rouchi sp.n., Ameira atlántica mediterránea forma n., and Taurocletodes gallicus sp.n. Comparison of the harpacticoid fauna of the French coast with other marine districts shows close relations to the fauna of the Black Sea, while the relations to the Atlantic coast (Portugal) and the Baltic Sea (Bay of Kiel) are only remote. A genus is established, Taurocletodes gen.n. Sigmatidium noodti sp.n. is described from the Sea of Marmara.     

Acquisition and transmission of potato mop-to furovirus by a culture of Spongospora subterranea f.sp. subterranea derived from a single cystosorus

Potato mop-top virus (PMTV) was detected by ELISA in primary zoospores from four out of six isolates of Spongospora subterranea f.sp. subterranea. One virus-free isolate (N) of S. subterranea was used to acquire PMTV from potato roots and to transmit the virus to healthy plants. A mono-fungal culture of S. subterranea (isolate N) was derived by infecting tomato plant roots with a single cystosorus. The culture was used successfully to acquire PMTV from the roots of infected Nicotiana debneyi plants that had been manually inoculated with virus isolates, and subsequently to transmit the virus to healthy bait plants. These experiments confirm that S. subterranea is a vector of PMTV. Two PMTV isolates that had been maintained by manual inoculation for 19 and 21 passages were also acquired and transmitted by the fungus culture.     

Nitrogen fixation in bambara groundnut,Voandzeia subterranea (L.) Thouars

Summary To improve biological nitrogen fixation in bambara groundut (Voandzeia subterranea (L.) Thouars), the relative effectiveness of 24 cultivars was studied in the field at two experimental stations selected for their different ecological conditions. Thirty oneRhizobium strains were isolated and 12 cultivars were screened during this study. Both indigenous and introduced NiftalRhizobium strains were used during a second study on host cultivars xRhizobium strains interactions. Nodulation index and shoot dry weight were used to assess the efficiency. The widest effectiveness spectrum was observed with the indigenous strain MAO 113 and the introduced strain TAL 22.

---

Resumen Afín de mejorar la fijación biológica de nitrógeno en el cacahuete de Bambara (Voandzeia subterranea (L.) Thouars), se realizó un estudio de su efectividad relativa en campo en dos estaciones experimentales seleccionadas por sus distintas condiciones ecológicas. Durante este estudio se aislaron treintaiuna cepas deRhizobium y se probaron doce cultivares del huésped. En un segundo ensayo se estudiaron las interacciones huésped xcepa deRhizobium para lo cual se utilizaron cepas deRhizobium Niftal tanto indígenas como introducidas. La eficiencia se valoró determinado el índice de nodulación y el peso seco de la parte aerea. El espectro más amplio de eficacia se observó con la cepa indígena MAO 113 y la introducida TAL 22.

---

Résumé Dans le but d'améliorer la fixation biologique d'azote dans la noix de Bambara (Voandzeia subterranea (L.) Thouars), l'efficacité relative de 24 cultivars a été étudiée sur le terrain dans deux stations expérimentales choisies pour leurs conditions écologiques différentes. Trente-etune souches deRhizobium ont été isolées et 12 cultivars ont été testés au cours de cette étude. Tant les souches indigènes deRhizobium que celles Niftal introduites ont été utilisées au cours d'une deuxième étude sur les interractions entre les souches deRhizobium et les cultivarshôtes. L'indice de nodulation et le poids sec de la pousse ont été utilisés pour l'établissement de l'efficience. Le spectre d'efficience le plus large a été observé avec la souche indigène MAO 113 et la souche introduite TAL 22.

     

Selenium deficiency in Crustacea

Summary The effect of selenium deprivation onDaphnia magna was examined under controlled rearing conditions in a synthetic culture medium. After three generations, fertility was significantly reduced in deprived (Se^–) animals. Growth and mortality of parent daphnids and development of parthenogenetic eggs were not affected during this period. In the fourth generation Se^– daphnids rejected parts of their second antennae. At the ultrastructural level antennal muscle tissue was severely affected. Animals deprived of selenium had mitochondria and sarcoplasmic reticulum with myelin-like alterations. Giant lysosomes were present and complete lysis of muscle fibrils was observed in antennal muscle cells. These alterations are characteristic features of peroxidic damage in tissues. This interpretation is consistent with the function of selenium as a constituent of the enzyme glutathione peroxidase which protects cells from peroxidation. Selenium should be included in synthetic culture media for daphnids.Abbreviations GSH-Px selenium dependent glutathione peroxidase - Se⁺/Se^– selenium supplemented (control)/selenium deprived animals - SOD Superoxide dismutase - SR sarcoplasmic reticulum     

Neurosecretory systems in decapod Crustacea

Summary The sinus glands of the Brachyura are composed of swollen nerve fiber endings, which store and release secretory material synthesized within cells of the eyestalks, the brain and probably the thoracic ganglionic mass. Removal of the sinus glands from the land crab, Gecarcinus lateralis, does not induce molt, because sinus glands are reservoirs, not sources, of molt-inhibiting hormone. Increase in respiratory rate and fall in respiratory quotient, which follow eyestalk removal and signify the approach of molt, do not occur after sinus gland removal.From recent studies on the eyestalks and brain of the crayfish, Cambarus virilis, it is clear that morphologically the neurosecretory system of this crayfish is similar to that of the land crab. There is a marked resemblance in arrangement of neurosecretory cells and in pathways followed by the fibers, the endings of which form the sinus glands. Maps of eyestalks and brain of Cambarus and Gecarcinus emphasize this fundamental likeness between an astacuran and a brachyuran. Regions in which neurosecretory cells are found have been numbered so that these maps may guide cytological and physiological study on these species and on other decapod Crustacea.This paper was delivered at the Symposium on Neurosecretion held May 11–16, 1953, at the Stazione Zoologica, Naples, Italy. An abstract of this paper. together with summaries of other papers presented at the Symposium, is appearing in the Pubblicazioni della Stazione Zoologica di Napoli.The preparation of this paper was aided by a National Science Foundation (USA.) grant to the first author and by the use of the American Table at the Naples Zoological Station.     

Some Crustacea Copepoda from Venezuela

The study of 38 samples of aquatic fauna from Venezuela increased the number of known species here from 28 to 66. Fifteen new species for science are described. A list of Copepoda known from the other regions of South America is presented. From this list, it can be said that only 50% of the inland water Copepoda living actually in Venezuela are known.     

Some properties of starch phosphorylase from cotyledons of germinating seeds of Voandzeia subterranea.

Two isoenzymes (Forms I and II) of starch phosphorylase (1,4-alpha-D-glucan: orthophosphate alpha-glucosyltransferase, EC 2.4.1.1) were found in cotyledons of germinating seeds of Voandzeia subterranea L. Thouars. Phosphorylase I, which was the major component, had a pH optimum of 5.5--5.6, whereas phosphorylase II had a pH optimum of 6.1--6.3. Phosphorylase I had a molecular weight of 204 000 +/- 4000 and a subunit molecular weight of about 95 000. Phosphorylase I was stimulated by Mg2+, Mn2+, AMP, cyclic AMP, pyruvate and EDTA, but inhibited by Fe2+, Cu2+, Zn2+ and ATP. Stimulation of phosphorulase I by AMP was accompanied by changes in the affinity of the enzyme for glucose-1-phosphate in the presence of increasing AMP concentrations, and of AMP in the presence of increasing glucose-1-phosphate concentrations. Double-reciprocal plots of initial velocity data were non-linear (convex up) at low glucose-1-phosphate concentrations but became linear in the presence of AMP or ATP. Double-reciprocal plots were linear at high glucose-1-phosphate concentrations in the absence or presence of modifiers.     

Ultrastructure of the nuchal organ in the interstitial polychaete Stygocapitella subterranea (Parergodrilidae)

The nuchal organs of Stygocapitella subterranea are paired narrow pits. They are lined by unciliated cells at the opening and by ciliated cells at the basal parts. The primary sensory cells (6–8) are arranged in a single patch at the bottom of the nuchal pit. The nuclei of the sensory cells are located in the posterior portion of the brain. Their dendrites form the nuchal nerve which is sheathed by the ciliated cells. Each sensory cell bears up to 4 modified sensory cilia and several microvilli extending into the olfactory chamber. The sensory cilia show various patterns of axonemal organization and have no rootlets. The olfactory chamber is covered by a cuticular matrix. Another primary sensory cell lies at the opening of the nuchal pit. It bears cilia which penetrate the cuticle but are enveloped by the epicuticle. Retractor muscles insert caudally on the organ. The nuchal organ of S. subterranea shows similarities to those of opheliids but exhibits several features not to be found in other nuchal organs.     

The calcium nutrition of bambara groundnut (Vigna subterranea (L.) Verdc.)

Iron chlorosis induced by Fe-deficiency is a widespread nutritional disorder in many woody plants and in particular in grapevine. This phenomenon results from different environmental, nutritional and varietal factors. Strategy I plants respond to Fe-deficiency by inducing physiological and biochemical modifications in order to increase Fe uptake. Among these, acidification of the rhizosphere, membrane redox activities and synthesis of organic acids are greatly enhanced during Fe-deficiency. Grapevine is a strategy I plant but the knowledge on the physiological and biochemical responses to this iron stress deficiency in this plant is still very poor. In this work four different genotypes of grapevine were assayed for these parameters. It was found that there is a good correlation between genotypes which are known to be chlorosis-resistant and increase in both rhizosphere acidification and Fe^III reductase activity. In particular, when grown in the absence of iron, Vitis berlandieri and Vitis vinifera cv Cabernet sauvignon and cv Pinot blanc show a higher capacity to acidify the culture medium (pH was decreased by 2 units), a higher concentration of organic acids, a higher resting transmembrane electrical potential and a greater capacity to reduce Fe^III-chelates. On the contrary, Vitis riparia, well known for its susceptibility to iron chlorosis, fails to decrease the pH of the medium and shows a lower concentration in organic acids, lower capacity to reduce Fe^III and no difference in the resting transmembrane electrical potential. H Marschner Section editor     

Modulation of Neural Circuits in Crustacea

Recent research has shown that neuromodulators play importantroles in shaping simple behaviors. They act at many differentsites within the animal in a coordinated fashion, modulatingthe motor circuits in the central nervous system, altering motoneuronexcitability, and modulating muscle response to motoneuron input.Within the central circuits that co-ordinate simple movements,neuromodulators play a dramatic sculpting role, changing thecells that participate in the circuit, altering their intrinsicproperties, and affecting the strength of synaptic interactionsthat form the "wiring diagram" of the circuit. As a result,they are able to shape a family of related circuits out of asingle anatomically identified network, each driving a uniquevariant on the basic motor theme. Examples of these actionsfrom the Crustacea are described in this paper, focussing onthe modulation of posture in the lobster, and on modulationof rhythmic motor programs for stomach movements in the stomatogastricganglion of lobsters and crabs.     

Cladocera (Crustacea) from Nicaragua

Thirty-one Cladocera taxa are recorded from lakes, rivers and ponds of Western Nicaragua. They include Alona bromelicola sp. nov. found in water accumulations in epiphytic Bromeliads. The Cladocera recorded are neotropical and circumtropical. Other invertebrates found are also listed.     

Neuroendocrinology of Osmoregulation in Decapod Crustacea

Experimental evidences for neuroendocrine control of osmoreregulationin decapod crustaceans are mounting. The eyestalk system, brainand thoracic ganglionic centers, and the pericardial organ appearto be involved in this control. Evidences based on experimentationwith eyestalk removal and the injection of extracts of neuroendocrinecenters are presented. Neuroendocrine extracts affect the movementsof salts and water in the gills, stomach, intestine and antennalglands. The pericardial organ material may affect osmoregulationby increasing rate of circulation and influencing salt movement. Three factors have been partially separated from CNS tissues.A factor of the freshwater crayfish, and other freshwater decapods,increases the influx of salt. Two factors from an estuarinecrab influence the movement of water, an acetone-soluble factorincreasing its influx and a water-soluble factor decreasinginflux and increasing efflux. The factors may be involved inthe adaptation of the animals to their osmotic environments. None of the factors have yet been identified in circulationnor in effector tissues. Future research must place specialemphasis on the identification of the CNS factors in circulationas well as in secretory cells and effector tissues to establishtheir true hormonal nature.