<Emphasis Type="Italic">Pinus halepensis</Emphasis> somatic embryogenesis is affected by the physical and chemical conditions at the initial stages of the process

Pinus halepensis has been described as a drought-tolerant species with high plasticity to growth in different environments. Its eco-physiological characteristics could facilitate the use of this species in large afforestations in the future scenery of climate change. Somatic embryogenesis is a biotechnological tool with potential for large-scale clonal propagation. In order to establish an improved regeneration protocol for Pinus halepensis, the effects of different temperatures (18, 23, and 28 °C) and water availability conditions (2, 3, and 4 g L^?1 Gelrite^®), during initiation of embryonal masses on the rate of initiation, proliferation, maturation, and the number of embryos developed, were evaluated. It was found that environmental conditions during the initiation stage of Pinus halepensis somatic embryogenesis influence the success of initiation and proliferation. In contrast, there was no effect of these conditions on the maturation rates and the number of somatic embryos. Somatic embryos were obtained in all treatments tested, indicating that plants can be produced from extreme conditions of induction, such as high temperatures (28 °C) and low water availability conditions (4 g L^?1).     

Beziehungen zwischen der Ausbreitung künstlicher Fomes annosus-Infektionen in den Stämmchen zweier Fichtenklone und einigen holzchemischen Eigenschaften

The spread of Fomes annosus from artificial infections of stems, in relation to the chemical characteristics of timber of two spruce clones . Differences in the spread of Fomes annosus in two spruce clones (Picea abies Karst.), which were found by DIMITRI, may be attributed to differences in the properties of the wood from the two clones, detected in laboratory tests. Wood meal from the more resistant clone R inhibited Fomes annosus in bioassays more than wood meal from the more susceptible clone A. Wood from clne A-trees showed a higher nitrogen content than wood from clone R-trees.     

Chloroplast DNA variation in cultivated and wild Prunus avium L: a comparative study

Chloroplast DNA variation in 96 Prunus avium L. cultivars was assessed and compared with the results of a previous study of cpDNA diversity in 23 wild populations of the species. The polymerase chain reaction‐restriction fragment length polymorphism method was used in these studies. Approximately 9% of the chloroplast genome was analyzed, using five universal primer pairs and three restriction enzymes. Ten polymorphic fragments were common to both the wild and sweet cherry; eight polymorphic fragments were found only in the wild cherry. In the cultivars, all mutations were small (5‐30 bp) indels. In the wild populations, a point mutation was also detected in addition to indels. The mutational combinations revealed three haplotypes in the cultivars, which are the main haplotypes in the wild cherry populations. Chloroplast DNA diversity in wild cherry is higher (16 haplotypes) than in sweet cherry cultivars (three haplotypes). The probable wild origin of the sweet cherry cultivars in the maternal line, on the basis of haplotypic similarity, was discussed.     

The nutritional background of the host alters the disease course in a fish-myxosporean system

The aim of the present work was to determine if a practical plant protein-based diet containing vegetable oils (VO) as the major lipid source could alter the disease course when challenged with the myxosporean Enteromyxum leei, a wide-spread parasite in the Mediterranean basin causing heavy economic losses. Gilthead sea bream (Sparus aurata) fed for 9 months either a fish oil (FO) diet or a blend of VOs at 66% of replacement (66VO diet) were challenged by exposure to parasite-contaminated water effluent. All fish were periodically and non-lethally sampled to obtain biometrical data and to know their infection status. After 102 days of exposure, fish were euthanized and haematological, biometrical, histological, immunological, glutathione and anti-oxidant data were obtained from tissue, blood and serum samples. Anorexia appeared in both exposed groups, but feed intake reduction was higher in 66VO fish. The signs of disease (lower growth, condition factor, specific growth rate, haematocrit) as well as the disease course were worse in fish from 66VO group, with a higher prevalence and intensity of infection, a higher percentage of fish harbouring the parasite in the entire intestinal tract, and a faster establishment of the parasite. Parasite intensity of infection was negatively correlated with growth parameters and haematocrit in both groups, and with complement, lysozyme and hepatic total glutathione in 66VO fish.     

Microbial Monitoring of the Recovery of Soil Quality During Heavy Metal Phytoremediation

Soil pollution with heavy metals is a worldwide environmental problem. Phytoremediation through phytoextraction and phytostabilization appears to be a promising technology for the remediation of polluted soils. It is important to strongly emphasize that the ultimate goal of a heavy metal remediation process must be not only to remove the heavy metals from the soil (or instead to reduce their bioavailability and mobility) but also to restore soil quality. Soil quality is defined as the capacity of a given soil to perform its functions. Soil microbial properties are increasingly being used as biological indicators of soil quality due to their quick response, high sensitivity, and, above all, capacity to provide information that integrates many environmental factors. Indeed, microbial properties are among the most ecologically relevant indicators of soil quality. Consequently, microbial monitoring of the recovery of soil quality is often carried out during heavy metal phytoremediation processes. However, soil microbial properties are highly context dependent and difficult to interpret. For a better interpretation of microbial properties as indicators of soil quality, they may be grouped within categories of higher ecological relevance, such as soil functions, ecosystem health attributes, and ecosystem services.

     

Rank reversals in tree growth along tree size, competition and climatic gradients for four forest canopy dominant species in Central Spain

? Interspecific differences in tree growth patterns with respect to biotic and abiotic factors are key for understanding forest structure and dynamics, and predicting potential changes under climate change.

? Repeated observations from the Spanish Forest Inventory (SFI) were used to parameterize maximum likelihood estimators of tree growth as a function of tree size, competition indices and climate for Pinus pinaster, P. sylvestris, Quercus ilex and Q. pyrenaica.

? Significant responses to both biotic and abiotic factors were found, with interspecific differences in species performance along competition, temperature and precipitation gradients. Q. ilex was the species most tolerant to competition while P. pinaster was the species most sensitive to climatic variation. Species relative positions shifted along gradients of these factors with rank reversals in species performance along size, competition and climatic gradients.

? The results based on average growth matched previous forestry classifications and experimental studies on relative growth rate (RGR).

? When examining growth along studied abiotic and biotic gradients, a mismatch was found between species performance ranks as predicted by our models and information derived from previous knowledge. Those discrepancies highlight the relevance of ontogeny and environmental heterogeneity in defining species performance along competition gradients.

     

Chloroplast DNA study in sweet cherry cultivars (Prunus avium L.) using PCR-RFLP method

The chloroplast DNA of 96 sweet cherry cultivars (Prunus avium L.) and five cultivars of sour cherry (P. cerasus L.) were analysed to reveal their haplotypes using PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) method. The main advantages of the PCR-RFLP technique are: resolutive, time and cost effective and reproducible. Approximately 9.6% of the chloroplast genome was analysed, using six universal primer pairs and two restriction enzymes. All the mutations detected were insertion-deletions, ranging between 5–30 bp. The combination of all the mutations resulted in three haplotypes (H1, H2 and H3) in the 96 sweet cherry cultivars and a single haplotype (H4) in the five cultivars of sour cherry. The cpDNA polymorphism determined by PCR-RFLP markers helped to understand the maternal inheritance of chloroplast genome in sweet cherry, clearly distinguished the sour from the sweet cherry, and supported that P. avium is not the maternal species of P. cerasus.     

Glacial refugia: hotspots but not melting pots of genetic diversity

Glacial refuge areas are expected to harbor a large fraction of the intraspecific biodiversity of the temperate biota. To test this hypothesis, we studied chloroplast DNA variation in 22 widespread European trees and shrubs sampled in the same forests. Most species had genetically divergent populations in Mediterranean regions, especially those with low seed dispersal abilities. However, the genetically most diverse populations were not located in the south but at intermediate latitudes, a likely consequence of the admixture of divergent lineages colonizing the continent from separate refugia.     

Chemosystematic survey of cultivated Cucurbita species

Results of flavonoid, total protein and peroxidase analyses in different organs from cultivare belonging to four Cucurbita species: C. ficifolia, C. moschata, C. maxima, and C. pepo are presented. Special attention is given to ‘zapallo criollo’ and ‘zapallo macre’, names of the strongly variable local races from the coastal valleys in northern Peru. A multivariate analysis produced a dendrogram relating the biotypes studied. A marked similarity was obtained for total proteins in most cases, while different patterns occurred for flavonoids and peroxidases. Relationships between the studied cultivars are discussed.     

Influence of Neospora caninum intra-specific variability in the outcome of infection in a pregnant BALB/c mouse model

Previous assays in pregnant animals have demonstrated the effect of different host factors and timing of infection on the outcome of neosporosis during pregnancy. However, the influence of Neospora caninum isolate itself has been poorly investigated. Here, we compared the effects on clinical outcome and vertical transmission observed in a pregnant mouse model following infection with 10 different N. caninum isolates. The isolates in our study included the Nc-Liv isolate and nine N. caninum isolates obtained from calves. Female BALB/c mice were inoculated with 2 × 10⁶ tachyzoites at day 7 of pregnancy. Morbidity and mortality, in both dams and offspring during the course of infection, and transmission to progeny at day 30 postpartum were evaluated. The serum IgG1 and IgG2a production in dams were also examined. All dams showed elevated IgG1 and IgG2a responses, confirming N. caninum infection, although signs of disease were only exhibited in dams infected with 4 of the 10 isolates (Nc-Spain 4H, Nc-Spain 5H, Nc-Spain 7 and Nc-Liv). In neonates, clinical signs were observed in all N. caninum-infected groups, and neonatal mortality rates varied from greater than 95% with the isolates mentioned above to less than 32.5% with the other isolates. Vertical transmission rates, as assessed by parasite PCR-detection in neonate brains, also varied from 50% to 100% according to the isolate implicated. These results confirm the wide pathogenic and transmission variability of N. caninum. The intra-specific variability observed herein could help us explain the differences in the outcome of the infection in the natural host.