Effects of a nursery CO2 enriched atmosphere on the germination and seedling morphology of two Mediterranean oaks with contrasting leaf habit

Abstract: The use of an enriched CO2 atmosphere in tree nurseries has been envisaged as a promising technique to increase productivity and to obtain seedlings with a higher root/shoot ratio, an essential trait to respond to water stress in Mediterranean-type ecosystems. In that framework, we have analyzed the effects of three levels of atmospheric CO2 concentration (350, 500 and 700 ppm) on the germination rate, growth and morphology of seedlings of two Mediterranean oaks used in reforestation programs: the evergreen Quercus ilex L. and the deciduous Quercus cerrioides Wilk. et Costa. CO2 enrichment increased the germination rate of Q. cerrioides (from 70±7 to 81±3 %) while it decreased that of Q. ilex (from 71±10 to 41±12 %). Seedlings of both species increased approximately 60% their total biomass in response to CO2 enrichment but at two different CO2 concentrations: 500 ppm for Q. cerrioides and 700 ppm for Q. ilex. This increase in seedlings biomass was entirely due to an augmentation of root biomass. Considering germination and biomass partitioning, an enriched CO2 atmosphere might not be appropriate for growing Mediterranean evergreen oaks, such as Q. ilex, since it reduces acorn germination and the only gains in root biomass occur at a high concentration (700 ppm). On the other hand, a moderate CO2 enrichment (500 ppm) appears as a promising nursery technique to stimulate the germination, growth and root/shoot ratio of deciduous oaks, such as Q. cerrioides. Resumen: El uso de una atmósfera enriquecida en CO2 durante la fase de vivero puede contribuir a aumentar la producción viverística, a la vez que ayudar a conseguir plántulas con una mayor relación biomasa subterránea/biomasa aérea, más adecuadas para hacer frente al severo estrés hídrico que generalmente limita el éxito de las repoblaciones en el clima Mediterráneo. En este estudio hemos analizado el efecto de tres niveles de abonado carbónico atmosférico (350, 500 y 750 ppm) en la germinación y morfología de plántulas de encina (Quercus ilex) y roble cerrioide (Quercus cerrioides). Una atmósfera enriquecida en CO2 incrementó la germinación de Q. cerrioides (de 70±7 a 81±3 %) mientras que disminuyó la de Q. ilex (de 71±10 a 41±12 %). Las plántulas de ambas especies incrementaron aproximadamente un 60% su biomasa en respuesta a una mayor concentración de CO2, aunque esta respuesta se produjo a diferentes dosis: 500 ppm en Q. cerrioides y 700 ppm en Q. ilex. El aumento en la biomasa total de las plántulas se debió enteramente a un mayor desarrollo de su sistema radical, Considerando tanto la germinación como los efectos sobre la relación biomasa subterránea/biomasa aérea, una atmósfera enriquecida en CO2 no parece ser un tratamiento adecuado para la producción en vivero de plántulas de Q.ilex, puesto que diminuye su germinación y solo aumenta su sistema radicular a dosis muy elevadas (700 ppm). Por el contrario, un aumento moderado en la concentración de CO2 (500 ppm) aparece como una técnica interesante para estimular el crecimiento y obtener plántulas de Q. cerrioides con un sistema radical más desarrollado.

Effects of domain morphology in phase-separation dynamics at low temperature

We present numerical results of the deterministic Ginzburg-Landau equation with a concentration-dependent diffusion coefficient, for different values of the volume fraction phi of the minority component. The morphology of the domains affects the dynamics of phase separation. The effective growth exponents, but not the scaled functions, are found to be temperature dependent.

Influence of an inert electrolyte on the morphology of quasi-two-dimensional electrodeposits

The influence of an inert electrolyte (sodium sulfate) on quasi-two-dimensional copper electrodeposition from a nondeaerated aqueous copper sulfate solution has been analyzed. The different morphologies for a fixed concentration of CuSO4 have been classified in a diagram in terms of the applied potential and the inert electrolyte concentration. The main conclusion is the extension of the well-known Ohmic model for the homogeneous growth regime for copper sulfate solutions with small amounts of sodium sulfate. Moreover, we have observed the formation of fingerlike deposits at large applied potential and inert electrolyte concentration values, before hydrogen evolution becomes the main electrode reaction.

Morphology and segregation in two-component diffusion-limited aggregation

A diffusion-limited-aggregation (DLA) model with two components (A and B species) is presented to investigate the structure of the composite deposits. The sticking probability PAB (=PBA) between the different species is introduced into the original DLA model. By using computer simulation it is shown that various patterns are produced with varying the sticking probabilities PAB (=PBA) and PAA (= PBB), where PAA (=PBB) is the sticking probability between the same species. Segregated patterns can be analyzed under the condition PAB < PAA, assumed throughout the paper. With decreasing sticking probability PAB, a clustering of the same species occurs. With sufficiently small values of both sticking probabilities PAB and PAA, the deposit becomes dense and the segregated patterns of the composite deposit show a striped structure. The effect of the concentration on the pattern morphology is also shown.

Fruit and seed morphology of Euphorbia aggr. flavicoma. Taxonomic implications

Capsula and seed morphology of W. European species of Euphorbia aggr. flavicoma has been studied. A total of 1500 seeds coming from 13 taxa have been investigated under light microscope, scanning electron microscope and binocular stereoscope. Data were processed by multivariate analysis and the corresponding dendrogram is presented. At de end of the paper, a key is presented allowing to the separation of taxa down to the species level.

Seed morphology of the genus Delphinium L. (Ranunculaceae) in Turkey

La morfologia de les granes de 28 espècies de Delphinium recollides a Turquia ha estat estudiada per mitjà de la Microscòpia Electrònica de Rastreig (MER). Quatre tipus principals de granes són reportats: subgloboses amb anells continus de lamelles, subpiramidals amb esquames amples o primes, subpiramidals allargades amb esquames i sector-esferoïdals reticulades, que es corresponen amb les seccions reconegudes en els sistemes taxonòmics habituals del gènere, cosa que indica llur bona resolució taxonòmica. Es discuteixen les implicacions biogeogràfiques i sistemàtiques.

Seed morphology of Iberian Species of the genus Aconitum L.

Es presenta un estudi morfològic-biomètric de les granes deis taxons del genere Aconitum L. presents a la Península Ibérica. Es tracten aspectes que fan referencia a: 1) disposició de les granes al fol-licle, 2) definido de paramètres (forma general i ornamentado de l'episperma), 3) biometria i 4) descripció de les granes deis représentants ibérics. Els microcaràcters relacionats fonamentalment amb el relleu epispérmic, forma i ornamentado de la base d'inserció (hílum i cél-lules umbil-licals), son els que es mostren mes utils per discriminar els taxons i els que proporcionen mes informado filogenética. Els résultats que s'exposen coincideixen, en línies generals, amb els d'altres autors (SEITZ, 1969; CAPPELETTI & POLDINI, 1984). Es presenten, tanmateix, discrepancies importants pel que fa a la morfología seminal, en especial de l'ornamentació de l'episperma, en les especies A. anthora, A. napellus s.l., A. burnatii i A. vulparia subsp. ranunculifoiium. Es presenta, sovint, polimorfisme seminal en les diferentes poblacions, aïllades geogràficament, d'una mateixa especie o subspècie, tant en el context ibèric com d'Europa central i meridional. Es conclou que aquest polimorfisme és una manifestado mes de la plasticitat fenotípica del genere, particularment intensa en les especies colonitzadores d'àmplia valencia ecológica (A. napellus, s.l.; A. vulparia, s.l.), possiblement conseqiiència de la deriva genética de les poblacions.

Morphology in phonology : introduction

This fourth volume of Catalan Journal of Linguistics is devoted to a topic discussed at length in the literature but which nevertheless remains a challenge for any view of phonology: the morphology-phonology interaction. The papers collected address two related issues, the role of morphological information in phonology and the role of phonological information in morphology. The first six articles (i.e. McCarthy, Wheeler, Downing, van Oostendorp, José and Auger, and Rice) deal with the former topic; the last three (i.e. Bertinetto and Jetchev, Pérez Saldanya and Vallès, and Viaplana), with the latter. Several papers (Wheeler, van Oostendorp, Rice, Bertinetto and Jetchev, Pérez Saldanya and Vallès, and Viaplana) further discuss the role and concept of paradigms, an old Neogrammarian notion to which renewed attention has been payed both from the phonological perspective (cf. work by Benua 1995, 1997; Burzio 1994 and subsequent work; Kenstowicz 1996, 2002; Steriade 2000, and the articles in the recent volume edited by Downing et al. 2005, among others) and from the morphological perspective (cf. work by Aronoff 1994; Bauer 1997, 2001; Carstairs-McCarthy 1994, 1998; Stump 1991, 1997; van Marle 1985, 1994; Wurzel 1989, and several articles in the recent volume edited by Boucher 2002, among others).

Vegetative and reproductive morphology of Kallymenia patens (Kallymeniaceae, Rhodophyta) in the Mediterranean Sea

Reproductive morphology of the Mediterranean red alga Kallymenia patens is described for the first time, confirming its position in the genus. K. patens is characterized by a non-procarpic female reproductive apparatus, carpogonial branch systems consisting of supporting cells bearing both three-celled carpogonial branches and subsidiary cells that lack a hypogynous cell and carpogonium; fusion cells develop numerous connecting filaments, and tetrasporangia are scattered over the thallus and are probably cruciately divided. Old fertile spathulate specimens of K. patens are morphologically similar to K. spathulata, but they can be distinguished by the length of spathulated proliferations (up to 0.6 cm and 6 cm, respectively), the length of inner cortical cells (up to 70 and 30 μm, respectively), and the gonimoblast location (in proliferations from the perennial part of the blade and over all the thallus surface, respectively)

Effect of growth selection on morphology in Pirenaica cattle

Twelve variables were identified to define morphology in 109 calves sired by eight Pirenaica bulls widely used in artificial insemination. The effect of selection for weight at 210 days of age (W210) was detected from the regression coefficient between the 12 variables and the selection index for W210 used in the breeding plan. Unbiased estimates of the genetic correlated responses on the morphology were obtained without previously estimating the genetic correlation among traits. In Pirenaica cattle, selection for W210 increased slaughter live weight, chest depth and corporal length. The expected changes on height (withers, back and rump), rump width and thoracic perimeter were lower but positive and statistically significant.

Seedling development and biomass as affected by seed size and morphology in durum wheat

This work evaluated the effect of seed size and morphology on the development and biomass of durum wheat seedlings. Three different seed-grading sizes selected by sieving were used in glasshouse experiments, and a set of three developmental and 23 biomass-related indices were measured on eight genotypes, at two moisture levels. The influence of seed size on seedling development was studied at high and low temperatures (22\12 mC, and 15\5 mC day\night temperatures, respectively), in growth chambers. The area of the seed and the area of the embryo were the seed morphological traits most affected by seed size. Seed size was strongly associated with seedling development and seedling biomass until the complete extension of the first two leaves, at the fourth leaf stage. The rate of first-leaf growth and the area of the first leaf were the developmental and biomass traits, respectively, most sensitive to seed-grading size.

The changing milliarcsecond radio morphology of the gamma-ray binary LS 5039

LS 5039 is one of the few TeV emitting X-ray binaries detected so far. The powering source of its multiwavelength emission can be accretion in a microquasar scenario or wind interaction in a young nonaccreting pulsar scenario. Aims.To present new high-resolution radio images and compare them with the expected behavior in the different scenarios. Methods.We analyze Very Long Baseline Array (VLBA) radio observations that provide morphological and astrometric information at milliarcsecond scales. Results.We detect a changing morphology between two images obtained five days apart. In both runs there is a core component with a constant flux density, and an elongated emission with a position angle (PA) that changes by 12 $\pm$ $3\degr$ between both runs. The source is nearly symmetric in the first run and asymmetric in the second one. The astrometric results are not conclusive. Conclusions.A simple and shockless microquasar scenario cannot easily explain the observed changes in morphology. An interpretation within the young nonaccreting pulsar scenario requires the inclination of the binary system to be very close to the upper limit imposed by the absence of X-ray eclipses.

Reproductive morphology in Mediterranean Seirospora giraudyi (Ceramiales, Rhodophyta)

This paper presents a detailed description of the reproductive characters of Mediterranean Seirospora giraudyi based on fresh material collected in the northwestern coast of Spain. Vegetative cells are uninucleate. The plant is monoecious. Spermantangial parent’s cells are clustered on modified dwarf determinate filaments, usually situated on adaxial surfaces of branches. One to four spermatia are formed by elongation and proximal divisions of the spermatangial parent cells. Spermatium with a nucleus situated ina mec. The thallus is procarpic. The four-celled carpogonial branch is initially L-shaped, and it is situated on a periaxial supporting fertile axial cell. The mature carpogonial branch is U-shaped and the supporting cell and second periaxial cell enlarge and divide transversely to reproduce a pair uninicleate auxiliary cell. The nucleus in the ferlilized carpogonium divides twice and the carpogonium cleaves vertically into two cells that, turn, cut off a pair of uninucleate connecting cells that fuse with the auxiliary cells on opposite sides; the diploid nuclei in the connecting cells divide at the site of fusion and one of the nuclei enters the auxiliary cell white the other is extruded. Each auxiliary cell gives to a terminal primary gonimolobe initials. Gonimolobes form lax chains of carposporangia. As the gonimoblasts mature, both lobes of the foot cell which is situated on the supporting cell elongate the upper one secondary connecting with the supporting cell, and the lower one with the fertile axial cell. The gonimoblasts are subtended at maturity by one to several clusters of involucral flaments. Seirospora is currently placed in the tribe Euptiloteae; however the reproductive character of S.giraudyi is dentical to those described for the Cañllithamnieae. Molecular studies are needed to confirm the taxonomic position of S.giraudyi as well as that of the other species placed Seirospora

Effects of adult dysthyroidism on the morphology of hippocampal neurons.

This study investigates the effect of thyroid hormones on the morphology of hippocampal neurons in adult rats. Hypo- and hyperthyroidism were induced by adding 0.02% methimazole and 1% l-thyroxine, in drinking water from 40 days of age, respectively. When the rats were 89 days old their brains were removed and stained by a modified Golgi method and blood samples were collected in order to measure T4 serum levels. Neurons were selected and drawn using a camera lucida. Our results show that methimazole administration reduces the dendritic branching of the apical shafts of CA3 and CA1 pyramidal neurons mainly by increasing the distance to the first branch point in both types of neurons, and reducing branch points in the radius of 50 μm from the soma in CA1 neurons. Nevertheless, it was observed an increase of apical spine density in CA3 neurons from this group. Thyroxine reduces apical and basal tree of CA3 pyramidal neurons increasing the distance to the first branch point, reducing branch points in the radius of 50 μm from the soma and increases their apical and basal spine density. In CA1 field, thyroxine reduces the number of basal branch points. Both treatments seems to provoke alterations in the same direction reducing the dendritic branching and increasing spine density, although no significances appeared in some of the parameters analyzed. The effects are more evident in thyroxine than methimazole group; and in CA3 neurons than in CA1 neurons. In discussion it is pointed that the increase of spine density could be a mechanism to compensate the functionality reduction that can be provoke by the treatment effect on dendritic branching.

Improving Pitch Tracking Performance in Hard Noise Conditions by a Preprocessing Based on Mathematical Morphology

In this paper we show how a nonlinear preprocessing of speech signal -with high noise- based on morphological filters improves the performance of robust algorithms for pitch tracking (RAPT). This result happens for a very simple morphological filter. More sophisticated ones could even improve such results. Mathematical morphology is widely used in image processing and has a great amount of applications. Almost all its formulations derived in the two-dimensional framework are easily reformulated to be adapted to one-dimensional context