Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Mature seeds for in vitro sanitation of the Grapevine leafroll associated virus (GLRaV-1 and GLRaV-3) from grape (Vitis vinifera L.)
Get PDFThe conservation of old grapevine varieties is important since they are adapted to specific climate conditions and may carry genes interesting to breeders. As virus infection is common in grapevine varieties, the use of virus free materials is of great importance. In this work, we used somatic embryogenesis for the sanitation of GLRaV-1 and GLRaV-3 viruses that were found after analyzing the putative presence of the five most common, economically important grape viruses by real-time multiplex RT-PCR in the old cultivar “Grumet Negre”. Unopened and opened inflorescences, fecundated ovaries, and, also, mature seeds were used as starting explants. Explants were cultured on plates with two embryogenesis induction media (Nitsch & McCown Woody plant medium) that contained the growth regulator thidiazuron and differed in their salt and vitamin compositions. One half of each kind of explant was cut prior to being cultured. After five months of culture, embryos had only developed from seeds that were cut previous to sowing. To the best of our knowledge, this is the first time that mature seeds have been used for inducing embryogenesis in grape. A total of 42% of the embryos transferred to tubes for germination regenerated into normal plantlets. The absence of both the GLRaV-1 and GLRaV-3 viruses in all regenerated plants was confirmed by real-time uniplex RT-PCR. So, this protocol can be used for sanitation and also for micropropagation
Evaluation of feeds from tropical origin for in vitro methane production potential and rumen fermentation in vitro
Get PDFEnteric methane arising due to fermentation of feeds in the rumen contributes substantially to the greenhouse gas emissions. Thus, like evaluation of chemical composition and nutritive values of feeds, methane production potential of each feed should be determined. This experiment was conducted to evaluate several feeds for methane production potential and rumen fermentation using in vitro gas production technique so that low methane producing feeds could be utilized to feed ruminants. Protein- and energy-rich concentrates (n=11), cereal and grass forages (n=11), and different straws and shrubs (n=12), which are commonly fed to ruminants in India, were collected from a number of locations. Gas production kinetics, methane production, degradability and rumen fermentation greatly varied (p<0.01) among feeds depending upon the chemical composition. Methane production (mL/g of degraded organic matter) was lower (p<0.01) for concentrate than forages, and straws and shrubs. Among shrubs and straws, methane production was lower (p<0.01) for shrubs than straws. Methane production was correlated (p<0.05) with concentrations of crude protein (CP), ether extract and non-fibrous carbohydrate (NFC) negatively, and with neutral detergent (NDF) and acid detergent fiber (ADF) positively. Potential gas production was negatively correlated (p=0.04) with ADF, but positively (p<0.01) with NFC content. Rate of gas production and ammonia concentration were influenced by CP content positively (p<0.05), but by NDF and ADF negatively (p<0.05). Total volatile fatty acid concentration and organic matter degradability were correlated (p<0.05) positively with CP and NFC content, but negatively with NDF and ADF content. The results suggest that incorporation of concentrates and shrubs replacing straws and forages in the diets of ruminants may decrease methane production
Vertical integration and profitability of the agrifood industry in an economic crisis context
Get PDFIn a setting of economic and financial crisis, most companies experienced a reduction in their profitability. Thus, our study allows us to identify vertical integration strategies developed by companies to overcome the crisis. This paper is aimed at unveiling the determining factors of the profitability of Spanish agrifood firms, depending on whether they are backwards vertically integrated or not. In order to attain our objective, we implemented a first difference regression model. The main contributions of the article lie in the incorporation of a variable that distinguishes integrated firms from the rest and the separate analysis of the two groups of firms. The results suggest that firms that seek to differentiate themselves, either through offering a specific product or through providing higher quality with a view to maintaining their reputation, are more likely to adopt vertical integration due to the higher transaction costs of relations with suppliers. The grouping carried out in this study is shown to be highly relevant as asset structure implies different strategies for actions aimed at increasing profitability
Short communication: Short and long-term efficacy and phytotoxicity of phosphine against Rhynchophorus ferrugineus in live Phoenix canariensis palms
Get PDFThe red palm weevil, Rhynchophorus ferrugineus, is a palm borer native to South Asia which has spread mainly due to the unintended movement of infested planting material. As a result, this species has become the most destructive palm pest in the world. The difficulty of detecting the early stages of infestation due to its cryptic life cycle has led many countries to implement, strict pre- and post-entry quarantine regulations to prevent further spread. However, there are no quarantine protocols to ensure that palm material for planting is free of R. ferrugineus. The aim of this study has been to determine the efficacy of aluminium phosphide as a safe quarantine treatment against different stages of R. ferrugineus and the possible phytotoxic effects on live Phoenix canariensis palms. Our results confirm that a dose of 1.14 g/m3 for 2 days is enough to kill all stages of R. ferrugineus in live palms with no phytotoxic effects on treated palms for up to one year after the treatment. This procedure, which could be easily applied in sealed containers used for palm trade, could drastically reduce risks associated to palm movement worldwide
Climate-influenced ponderosa pine (Pinus ponderosa) seed masting trends in western Montana, USA
Get PDFAim of study: The aim of this study was to analyze 10-year records of ponderosa pine (Pinus ponderosa) seed production, in order to confirm synchronic seed production and to evaluate cyclical masting trends, masting depletion effect, and climate-masting relationships.Area of study: The study area was located in a P. ponderosa stand in the northern Rocky Mountains (western Montana, USA).Material and methods: The study was conducted in one stand that had been subjected to a silvicultural study of uneven-aged management techniques that was carried out in 1984, and which resulted in three separate units consisting of one control, one cut/no-burn treatment, and one cut/burn treatment. Seeds were collected during the 10 years following treatment in 15 traps systematically deployed within each of the stand’s three units. The total numbers of seeds collected in each unit were plotted over time to analyze crop synchrony, with Spearman rank correlation coefficient used to test for masting cycles and crop depletion after a mast year. Meteorological records over the period 1983-1994 were related to the occurrence of a mast event (defined as crops exceeding 50,000 viable seeds/ha).Main results: The seed production pattern was non-cyclical, synchronous, and independent of silvicultural treatment history. A mast-depletion effect was evident but was not statistically significant. Mast events seem to be promoted by the occurrence of optimum mean temperatures at the beginning of spring during both the first (11 °C) and second (9 °C) years of cone maturation. The probability of a mast year was also affected by summer temperature (number of late frost days; negative effect) and precipitation amount (positive effect). All these factors would seemingly explain the observed synchronous pattern in cone production.Research highlights: The non-cyclical trend of ponderosa pine seed mast years is influenced by specific climate determinants. Fluctuations in mean early spring temperatures, late frost and water availability are likely to affect P. ponderosa seed production, with implications for natural regeneration in this region.Key words: natural regeneration; seed periodicity; reproduction; uneven-aged management; Rocky Mountains
Point processes statistics of stable isotopes: analysing water uptake patterns in a mixed stand of Aleppo pine and Holm oak
Get PDFAim of study: Understanding inter- and intra-specific competition for water is crucial in drought-prone environments. However, little is known about the spatial interdependencies for water uptake among individuals in mixed stands. The aim of this work was to compare water uptake patterns during a drought episode in two common Mediterranean tree species, Quercus ilex L. and Pinus halepensis Mill., using the isotope composition of xylem water (δ18O, δ2H) as hydrological marker.Area of study: The study was performed in a mixed stand, sampling a total of 33 oaks and 78 pines (plot area= 888 m2). We tested the hypothesis that both species uptake water differentially along the soil profile, thus showing different levels of tree-to-tree interdependency, depending on whether neighbouring trees belong to one species or the other.Material and Methods: We used pair-correlation functions to study intra-specific point-tree configurations and the bivariate pair correlation function to analyse the inter-specific spatial configuration. Moreover, the isotopic composition of xylem water was analysed as a mark point pattern.Main results: Values for Q. ilex (δ18O= -5.3 ±0.2‰, δ2H=-54.3±0.7‰) were significantly lower than for P. halepensis (δ18O= -1.2±0.2‰, δ2H = -25.1±0.8‰), pointing to a greater contribution of deeper soil layers for water uptake by Q. ilex. Research highlights: Point-process analyses revealed spatial intra-specific dependencies among neighbouring pines, showing neither oak-oak nor oak-pine interactions. This supports niche segregation for water uptake between the two species.Key words: Cross-pair correlation function; Deuterium; Mark correlation function; Oxygen-18; Point patterns; Xylem.Abbreviations: d18O, oxygen isotope composition; d2H, hydrogen isotope composition; BA, basal area
Forest structure of Mediterranean yew (Taxus baccata L.) populations and neighbor effects on juvenile yew performance in the NE Iberian Peninsula
Get PDFAim of study: In the Mediterranean region, yew (Taxus baccata L.) usually grows with other tree species in mixed forests. Yew recruitment and juvenile growth may depend on the structure of the forest and the net balance between competition for soil water and nutrients with neighbors and facilitation that these neighbors exert by protecting the plants from direct sun exposure. This study aims, at a regional scale, to analyze the structure of forests containing yew, and, on an individual level, to analyze the effect of the surrounding vegetation structure on the performance of yew juveniles.Area of study: The structural typologies of yew populations were defined based on field inventories conducted in 55 plots distributed in 14 localities in the North-Eastern (NE) Iberian Peninsula, covering a wide range of yew distribution in the area. In a second step, an analysis of neighboring species' effects on juveniles was conducted based on the data from 103 plots centered in yew juveniles in five localities.Main Results: A cluster analysis classified the inventoried stands into four forest structural types: two multi-stratified forests with scattered yew and two yew groves. Multiple regression modeling showed that the δ13C measured in last year's leaves positively relates to the basal area of conifer neighbors, but negatively with the cover of the yew crown by other trees.Research highlights: At a stand-level, the density of recruits and juveniles (625 ± 104 recruits ha-1, 259 ± 55 juveniles ha-1) in mixed forests was found to be higher than that on yew dominant stands (181 ± 88 recruits ha-1 and 57 ± 88 juveniles ha-1). At an individual-level, the water stress (estimated from leaf δ13C) of yew juveniles seems alleviated by the crown cover by neighbors while it increases with the basal area of conifers. Yew conservation should focus on selective felling for the reduction of basal area of neighbors surrounding the target tree, but avoid affecting the canopy cover to contribute to enhanced yew juvenile growth.Keywords: Biodiversity conservation; δ13C; forest management; plant-plant interaction; recruitment; Taxus baccata; water use efficiency
Taxus globosa Schltdl. (Mexican yew) and Taxus baccata L. (European yew): intra and interspecies analysis of taxol content and biological activity according to different sources
Get PDFAim of study: Taxus globosa is the only species of Taxus genus that grows in Mexico, and is a tree which is protected by the Mexican Government. This plant shares, with the European species T. baccata, the ability to produce taxanes, such as taxol. The objective of this work was to compare representative samples from two Taxus species: T. globosa Schltdl. (“Mexican yew”), and T. baccata L. (“European yew”), by employing different methodological chemical and pharmacological tests.Area of study: Representative samples of Mexican yew were collected from states of Nuevo León, Querétaro, Hidalgo, and Oaxaca. The samples of European yew were taken from a clonal live collection located in the CIEF-Vaersa-Valencia (Spain).Materials and Methods: The aerial parts of all samples were extracted with methanol and subjected to TLC and HPLC analysis. Five extracts were selected for their anti-inflammatory evaluation. The extracts were tested on male ICR mice with ear inflammation induced with TPA, at a dose of 3.2 mg/ear. For T. globosa, an acute toxicity assay in female mice, according to OECD, was also conducted. Main results: Taxol was only detected in the yew trees samples collected in States of Hidalgo and Nuevo León (Mexico). In the inflammatory assay, in all treatments (except for that of MX35) induced slight, but significant, inhibition of inflammation, and only European sample M-9 showed inhibition of edema of >50%. T. globosa in the acute toxicity test causes only mild symptoms associated with a general depression of CNS, without being lethal.Research highlights: The aim of the present study was to perform a chemical analysis through quantification of taxol in the Mexican yew compared to European yew. In this research work was evaluated too for the first time the anti-inflammatory effect from both the Mexican and European yew.Keywords: Acute toxicity; anti-inflammatory activity; European yew; HPLC; Mexican yew.
A state-and-transition model of Iberian dehesas based on spatial patterns
Get PDFAim of study: In this study a process based on a Geographic Information System (GIS) is proposed as a tool for analyzing the spatial structure of the Mediterranean dehesa ecosystem.Area of study: Western Peninsular Spain.Material and methods: The method allows a semi-quantitative “state and transitions” (S&T) net that provides original information derived from spatial patterns that cannot be obtained by other means.Main results: This GIS analysis also supplies a spatial basis which complements the conceptual framework of vegetation series successional proposals. Moreover, the proposed method can be a useful tool for understanding landscape changes.Research highlights: Our work proposes not only a descriptive model but also a methodology based on spatial metrics and topological relationships.Keywords: geographic information systems; successional net; landscape management.Abbreviations used: S&T: State and Transition; RFP: Regional Forest Plan
Throughfall nutrients in a degraded indigenous Fagus orientalis forest and a Picea abies plantation in the of North of Iran
Get PDFAim of study: The objective of this study was to compare the quantity and quality of TF (throughfall) in an indigenous, but degraded, stand of Fagus orientalis and Picea abies plantation.Area of study: Forests of Kelar-Dasht region located in Mazandaran province, northern Iran.Material and Methods: TF measured by twenty collectors that were distributed randomly underneath each stand. For 21 storms sampled in 2012 (August-December) and 2013 (April-June), we analyzed pH, EC, Ca2+, Mg2+, K+, NO3-, and P of gross rainfall (GR) and TF.Main results: Cumulative interception (I) for F. orientalis and P. abies were 114.2 mm and 194.8 mm of the total GR, respectively. The amount of K+ (13.4 mg L-1) and Ca2+ (0.9 mg L-1) were higher (for both elements, p = 0.001) in the TF of P. abies compared to those of F. orientalis (6.8 and 0.5, mg L-1, respectively) and GR (3.2 and 0.37 mg L-1, respectively). Conversely, mean P concentration was doubled (p = 0.022) in the TF of F. orientalis (11.1 mg L-1) compared to GR (5.8 mg L-1).Research highlights: P. abies plantations may provide a solution for reforestation of degraded F. orientalis forests of northern Iran, yet how P. abies plantations differentially affect the quality and quantity of rainfall reaching subcanopy soils (TF) compared to F. orientalis is unknown. Understanding the connection between hydrological processes and nutrient cycling in forest ecosystems is crucial for choosing the appropriate species to rehabilitate the degraded indigenous forests with nonindigenous species. Keywords: concentration; hydrological process; interception; reforestation