Genetic parameter estimation and gene association analyses for meat quality traits in open-air free-range Iberian pigs

Meat quality of Iberian pigs is defined by the combination of their genetic characteristics and the particular production system. To carry out a genetic analysis of the main meat quality traits, we estimated their heritabilities, genetic correlations and the association effects of 32 selected SNPs of 12 candidate genes. A total of ten traits were measured in longissimus dorsi samples from 1,199 Iberian pigs fattened in the traditional free-range system: water holding capacity (thawing, cooking and centrifuge force water losses), instrumental colour (lightness L*, redness a* and yellowness b*), myoglobin content, shear force on cooked meat, and shear force and maximum compression force on dry-cured loin. Estimated heritability values were low to moderate (0.01 to 0.43) being the lowest for L* and the highest for cooking loss. Strong genetic correlations between water holding capacity traits (0.93 to 0.96) and between myoglobin content and a* (0.94) were observed. The association analyses revealed 19 SNPs significantly associated with different traits. Consistent and strong effects were observed between PRKAG3 SNPs (rs319678464G > C and rs330427832C > T), MYH3_rs81437544T > C, CASP3_rs319658214G > T and CTSL_rs332171512A > G and water losses. Also for CAPN1_rs81358667G > A and CASP3_rs319658214G > T and shear force. The SNPs mapping on PRKAG3 showed the highest effects on Minolta colour traits. Genotyping of these SNPs could be useful for the selection of Iberian young boars with similar estimated breeding values for productive traits.     

Mapping genomic regions for reproductive traits in beef cattle: Inclusion of the X chromosome

Although the second largest chromosome of the genome, the X chromosome is usually excluded from genome-wide association studies (GWAS). Considering the presence and importance of genes on this chromosome that are involved in reproduction, the aim of this study was to evaluate the effect of its inclusion in GWAS on reproductive traits (scrotal circumference [SC], early pregnancy [P16] and age at first calving [AFC]) in a Nelore herd. Genotype data from 3,263 animals with the above-mentioned phenotypes were used. The results showed an increase in the variances explained by the autosomal markers for all traits when the X chromosome was not included. For SC, there was an increase of more than 10% for the windows on chromosomes 2 and 6. For P16, the effect was increased by almost 20% for windows on chromosome 5. The same pattern was found for AFC, with an increase of more than 10% for the most important windows. The results indicate that the noninclusion of the X chromosome can overestimate the effects of autosomes on SC, P16 and AFC not only because of the additive effect of the X chromosome itself but also because of its epistatic effect on autosomal genes.     

AhaP,A Quorum Quenching Acylase from Psychrobacter sp. M9-54-1 That Attenuates Pseudomonas aeruginosa and Vibrio coralliilyticus Virulence

Although Psychrobacter strain M9-54-1 had been previously isolated from the microbiota of holothurians and shown to degrade quorum sensing (QS) signal molecules C6 and C10-homoserine lactone (HSL), little was known about the gene responsible for this activity. In this study, we determined the whole genome sequence of this strain and found that the full 16S rRNA sequence shares 99.78–99.66% identity with Psychrobacter pulmonis CECT 5989^T and P. faecalis ISO-46^T. M9-54-1, evaluated using the agar well diffusion assay method, showed high quorum quenching (QQ) activity against a wide range of synthetic N-acylhomoserine lactone (AHLs) at 4, 15, and 28 °C. High-performance liquid chromatography-mass-spectrometry (HPLC-MS) confirmed that QQ activity was due to an AHL-acylase. The gene encoding for QQ activity in strain M9-54-1 was identified from its genome sequence whose gene product was named AhaP. Purified AhaP degraded substituted and unsubstituted AHLs from C4- to C14-HSL. Furthermore, heterologous expression of ahaP in the opportunistic pathogen Pseudomonas aeruginosa PAO1 reduced the expression of the QS-controlled gene lecA, encoding for a cytotoxic galactophilic lectin and swarming motility protein. Strain M9-54-1 also reduced brine shrimp mortality caused by Vibrio coralliilyticus VibC-Oc-193, showing potential as a biocontrol agent in aquaculture.     

Chemically and biologically activated biochars slow down urea hydrolysis and improve nitrogen use efficiency

Biochar is considered a potential technology to enhance chemical fertilizer use efficiency through intensification of the interactions between nutrients and the functional groups on biochar surfaces. However, little is known about how the application of activated biochars mixed with urea influences nitrogen(N) mineralization and crop performance in paddy fields. Here, a sawdust-derived fresh biochar (FBC)(ca. 400?C) was activated chemically with 15%hydrogen peroxide and biologically with a nutri...     

Effect of Substrate Reutilization on Yield and Properties of Melon and Tomato Crops

Certain ecologically-friendly substrates have recently been shown to be perfectly viable alternatives to other more traditional ones such as rockwool, perlite, or some hydroponic systems. However, in order to be competitive for vegetable production in the Mediterranean region, substrates must be used for at least one year. The present study assessed random samples of two commercial substrates, almond shell and compost from greenhouse vegetable residue. The substrates were evaluated as growing media for long-term soilless production. Three experiments were conducted to evaluate the effects of reusing these substrates, comparing them with rockwool in terms of yield and fruit quality characteristics of melon and tomato. The physical, physico-chemical, and chemical properties studied differed significantly on reutilizing these materials. However, these differences did not prove to be limiting factors when fertigation parameters applied were adjusted according to substrate properties. The results suggest that compost and commercial almond shells seem to be acceptable growing media after at least 265 and 530 days of reutilization, respectively.     

Effect of Copper on Antioxidant Enzyme Activities and Mineral Nutrition of White Lupin Plants Grown in Nutrient Solution

We analyzed the effect of different copper (Cu) concentrations (0.10, 0.15, 0.20 and 0.35 mM) and time (1 day to 9 days) on several growth and biochemical parameters of roots and shoots of white lupin plants (Lupinus albus cv Estoril) grown in nutrient solution. A significant decrease in leaf fresh weight and leaf area was detected. Copper accumulated in the roots, and an impairment of nutrient translocation was only observed after six days at the highest Cu concentrations applied. A transient increase in the activity of polyphenoloxidase (EC 1.10.3.1) enforces a role for lignification as a defense strategy under enhanced Cu levels. The activities of several antioxidative enzymes were enhanced after Cu application. Our results indicate that Lupinus albus cv ‘Estoril’ is a rather resistant plant that can cope with moderate concentrations of copper, mostly by controlling up to a certain point, the uptake of excessive amounts of this metal.     

Growth and Fruit Chemical Characteristics of Blackberry (Rubus Fruticosus) Cultivated with Vermicompost,Glomus Mosseae and Phosphate Rock

Abstract

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe (AMF). Plant growth parameters, total phenol compounds and total flavonoids were evaluated on leaves. Anthocyanin contents, soluble solids (SS), pH, titratable acidity (TA) and SS/TA ratio was evaluated in blackberries fruits. Blackberry plants were obtained from cuttings from field plants, which were distributed in soil according to a randomized complete block design with three repetitions. Treatments were vermicompost (10?g plant^?1), phosphate rock (1?g plant^?1), Glomus mosseae (AMF), (1?g plant^?1), PR + AMF, V + PR, V +AMF, V + PR+ AMF and control without any amended. Plant height and stem diameter were measured five months after treatments, while total phenols and total flavonoids in leaves were evaluated eight months later. Anthocyanins, SS, pH, and TA were determined in blackberry fruits ten months after. Plant height was not statistically affected (p≤0.05), although total phenol compounds were higher (21.1?mg g^?1 dry plant) in the V+PR+AMF treatment, whereas the V + AMF treatment produced more dry plant total flavonoids (1.4?mg g^?1), compared with control plants. Blackberries produced with the vermicompost treatment had more anthocyanins (9.54?mg g^?1) than control plants. Soluble solids, pH and titratable acidity were not statistically (p≤0.05) affected by any treatment.     

Dispersal potentials determine responses of woody plant species richness to environmental factors in fragmented Mediterranean landscapes

While maximizing plant species richness continues to be central in the design, conservation and reforestation action plans, plant life histories are receiving increasing attention in assessments for the conservation of biodiversity in fragmented landscapes. We investigated the determinants of woody plant species (trees, shrubs and climbers) richness in the forest patches of the Guadalquivir river valley, a Mediterranean agricultural landscape with ∼1% forest cover. We analyzed three species richness variables, total, and those corresponding to species with short-distance (ballistic, barochorous, myrmecochorous and short-distance anemochorous) and long-distance (anemochorous, endozochorous, exozoochorous, hydrochorous and dyszoochorous) dispersal systems, which significantly characterize earlier and late successional stages, respectively. We selected eleven predictor variables related to habitat structure (patch area, shape, distances to the nearest patch and reserve, and general isolation), physical environment (temperature, precipitation, elevation, and lithological heterogeneity), and anthropogenic influences (disturbance and proportion of old-growth forest). We used ordinary-least-squares multiple regression (OLS) and the Akaike's information criterion (corrected for spatial autocorrelation) and derived indices to generate parsimonious models including multiple predictors. These analyses indicated that plant species richness increase primarily along with increasing patch area and decreasing disturbance, but also detected secondary effects of other factors when dispersal was considered. While the number of species with potential long-distance dispersal tended to increase in more isolated patches of areas with greater precipitation and lithological heterogeneity (e.g. highlands at the valley edges), the number of species with short-distance dispersal increased towards drier and less lithologically complex zones with shorter between-patch distances (e.g. central lowlands). Beyond emphasizing the need to consider dispersal in fragmentation studies, our results show that woody plant species richness would be favoured by actions that increase patch area and reduce anthropogenic disturbances particularly in lowland forests.     

Large-scale structural variation and long-term growth dynamics of Juniperus thurifera trees in a managed woodland in Soria, central Spain

? Juniper woodlands have a great conservational and productive importance in Spain. However, basic traits of their structural variation and growth dynamics are unknown.

? To characterize the structural variation and assess both height and radial growth patterns, we sampled and measured stem cross-sections every 0.5 m in height from 107 Spanish juniper (Juniperus thurifera L.) trees, which were selected based on a 350 m regular grid over a whole woodland of 3 300 ha in area. We used dendroecological techniques and spatial analysis to study tree structure and growth.

? Structural traits such as bole diameter and height were mainly determined by tree life-related parameters such as tree age and growth rate variation, while abiotic factors such as altitude played a minor role in determining structural variation. Over the last 300 years, juniper establishment has been continuous in time but discontinuous in space. Large-scale spatial heterogeneity of tree establishment, and the presence of an early growth suppression and abrupt growth changes in junipers > 100 years old are consequences of an intense management that almost ceased in the late 19th century.

? Abrupt growth releases and suppressions were synchronic among different age classes, and coincided with documentary records on livestock decrease and key historical changes in land use. Growth patterns suggest that juniper is a brow sing-tolerant species that is able to survive large periods of intense browsing pressure.