Segregation and associations of enological and agronomic traits in Graciano × Tempranillo wine grape progeny (Vitis vinifera L.)

The main objective of this research was the evaluation of the variability present in a segregating wine grape population derived from a cross between Graciano × Tempranillo, two Spanish varieties, in order to select improved genotypes with potential for producing high-quality wines in a climate change scenario. For that purpose, the phenotypic segregation of 16 agronomic traits related to production and phenology and 11 enological traits related to technical and phenolic maturity was studied in the progeny for three consecutive years. All traits presented transgressive segregation and continuous variation. Year effect was significant for all traits except total, extractable and skin anthocyanins content. However, a high level of genotype consistency for enological traits was revealed by repeatabilities and correlations between years. Significant correlations among traits were observed but most associations were weak. Furthermore, the CAPS (Cleaved Amplified Polymorphic Sequence) marker for the VvmybA genotype was tested to determine whether it would be useful in indirect selection for berry anthocyanins content. The results showed that the number of homozygous and heterozygous genotypes for the functional colour allele adjusted to a 1:1 segregation ratio, and that homozygous genotypes had significantly higher anthocyanins content. Principal component analysis found eight variables that contributed up to 80 % of the phenotypic variability present in the population. Seven groups of hybrids were distinguished based on ripening time, cluster weight, berry weight and anthocyanins content by cluster analysis; and fourteen genotypes were pre-selected for further research.     

Faba bean gene-pools development for low-input agriculture: understanding early stages of natural selection

Six faba bean gene-pools were cultivated to develop locally adapted genetic material for low-input (LI) systems that take advantage of the observed benefit of LI agriculture in pollinator density and diversity. Bee pollinators intensify selection on floral traits important in attraction and mechanical-fit but may also select for traits that increase seed set through outcrossing and aided selfing. Our research is focused on examining the impact of natural selection in crop performance under different pollination management strategies, taking into account traits relevant for the inter-phase plant and pollinator. Architectural and floral patterns are the result of natural selection and they reflect local adaptation to factors of the environment and adaptations to differences in pollination management strategy. However, seed production patterns seem to be affected by natural selection in an inconsistent way. Principal Component models showed a large proportion of the temporal variation accounted by plant height and number of open flowers and by floral shape and sexual dimensions. Discriminant Analysis indicated that plant architecture and floral traits related to pollinators are also the result of selection for particular patterns in each pollination management strategy. Flowers with an increase in the zygomorphy were favored under the open-pollination. Our work confirms the need for careful management of plant-pollinator inter-phase in faba bean breeding for LI systems.     

Origin of the acetylated structures present in white birch (Betula pendula Roth) milled wood lignin

The occurrence and nature of acetate groups in the milled wood lignin (MWL) isolated from birch (Betula pendula Roth) has been addressed by spectroscopic (2D-NMR) and chemical degradative (derivatization followed by reductive cleavage, DFRC) methods. Considerable amounts of acetate groups were present in the MWL preparation. However, 2D-NMR analysis indicated that the lignin polymer is not extensively acetylated and that the major part of the acetate groups is attached to the xylan moieties present in the MWL preparation. Nevertheless, evidence of the presence of minor acetylation of the γ-carbon of the lignin side chain (<3% of both syringyl and guaiacyl lignin units) was provided by DFRC analysis.     

Determination of volatile organic compound patterns characteristic of five unifloral honey by solid-phase microextraction-gas chromatography-mass spectrometry coupled to chemometrics

We report the evaluation of the floral origin of honey by analysis of its volatile organic compounds (VOCs) profile, joined with the use of combined pattern recognition techniques. Honey samples, from five floral origins, were analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry, selecting 35 VOCs out of the entire profiles, which were analyzed by hierarchical cluster analysis (HCA), stepwise discriminant analysis (SDA), and K-nearest-neighbor (KNN). Both HCA and SDA were used as exploratory tools to select a group of VOCs representing similitude and differences among studied origins. Thus, six out of 35 VOCs were selected, verifying their discriminating power by KNN, which afforded 93% correct classification. Therefore, we drastically reduced the amount of compounds under consideration but kept a good differentiation between floral origins. Selected compounds were identified as octanal, benzeneacetaldehyde, 1-octanol, 2-methoxyphenol, nonanal, and 2-H-1-benzopyran-2-one. The analysis of VOC profiles, coupled to HCA, SDA, and KNN, provides a feasible alternative to evaluate the botanical source of honey.     

Phenylalanine ammonia‐lyase activity and ortho‐diphenolic content with regard to boron nutrition in sunflower leaves.

Homogenates were prepared from the leaves of hydroponically cultivated sunflower (Helianthus annuus, L.) under deficient, normal and toxic B conditions and the phenylalanine ammonia‐lyase activity together with the ortho‐diphenolic and micronutrient content were measured every week from one month to flowering

The restoration of enzymatic activity on the exogenous addition of borate “in vivo”; was also studied.

Both B toxicity and deficiency resulted in increased phenylalanine ammonia‐lyase activity in the homogenates

The toxicity effect was early and sustained and the deficiency effect late and transitory. “In vitro”; borate addition to the reaction mixture did not significantly change the phenylalanine‐ammonia‐lyase activity in the homogenates.

There was no statistical correlation between the phenylalanine‐ammonia‐lyase activity and any micronutrient content in leaves.

A high accumulation of ortho‐diphenolics appeared in B‐deficient leaves only after 28 days of differential culture and may be responsible for the drop in phenylalanine‐ammonia‐lyase activity noted at this time.     

Thinning decreased soil respiration differently in two dryland Mediterranean forests with contrasted soil temperature and humidity regimes

The effects of a thinning treatment on soil respiration (Rs) were analysed in two dryland forest types with a Mediterranean climate in east Spain: a dry subhumid holm oak forest (Quercus ilex subsp. ballota) in La Hunde; a semiarid postfire regenerated Aleppo pine (Pinus halepensis) forest in Sierra Calderona. Two twin plots were established at each site: one was thinned and the other was the control. Rs, soil humidity and temperature were measured regularly in the field at nine points per plot distributed into three blocks along the slope for 3 years at HU and for 2 years at CA after forest treatment. Soil heterotrophic activity was measured in laboratory on soil samples obtained bimonthly from December 2012 to June 2013 at the HU site. Seasonal Rs distribution gave low values in winter, began to increase in spring before lowering as soil dried in summer. This scenario indicates that with a semiarid climate, soil respiration is controlled by both soil humidity and soil temperature. Throughout the study period, the mean Rs value in the HU C plot was 13% higher than at HU T, and was 26% higher at CA C than the corresponding CA T plot value, being the differences significantly higher in control plots during active growing periods. Soil microclimatic variables explain the biggest proportion of variability for Rs: soil temperature explained 24.1% of total variability for Rs in the dry subhumid forest; soil humidity accounted for 24.6% of total variability for Rs in the semiarid forest. As Mediterranean climates are characterised by wide interannual variability, Rs showed considerable variability over the years, which can mask the effect caused by thinning treatment.