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A combination of physiological and chemometrics analyses reveals the main associations between quality and ripening traits and volatiles in two loquat cultivars
No full textA combined analysis of physiological traits, volatile composition and sensory evaluation of aromatic quality was conducted on the ‘Algerie’ and ‘Golden Nuggett’ cultivars at six maturity stages, covering colour breaking to complete ripening. The main difference between cultivars during ripening was aromatic character; organoleptic differences between cultivars were assessed by a taste panel and could be explained by the volatile profile at harvest, and more specifically by those volatiles showing a rapid increase as fruits fully ripened. Among the 121 volatile compounds identified in loquat fruits, 2-methyl butanoic acid was the only cultivar-specific VOC, detected only in ‘Algerie’, while the levels of other common VOCs also contributed to differentiation between cultivars. A correlation analysis ran between volatile compounds levels and loquat aroma and flavour intensity revealed that 1,2-dimethoxy-4-(2-methoxyethenyl)benzene, elemicin, (Z)-2-hexen-1-ol, methyl 2-methylbutanoate, methyl 3,4,5-trimethoxybenzoate, cis-geranylacetone, (E)-methyl cinnamate, (E)-2-decenal, cis-edulan and 1-hydroxycyclohexyl phenyl ketone were volatiles which could importantly contribute to loquat’s aromatic character, some of which are reported here for the first time as key volatiles in aromatic quality. The correlations among the physiological parameters, the volatile compounds and physiological traits, and the parallelisms between precursors and volatile product, are discussed as they offer clues about loquat quality-associated metabolic changes during ripening
Comparison of extensive and intensive pig production systems in Uruguay in terms of ethologic, physiologic and meat quality parameters
Get PDFThe objective of this work is to characterize two contrasting systems of fattening pigs in Uruguay. A total of 96 pigs (average 41.7 kg) were divided into eight groups of 12 animals, representing two production systems: (IN) pigs confined in pens of 12 m(2) or (OUT) kept in plots with field shelters and access to pasture. Behavioral observations were performed by scan sampling at 5-minute intervals, three times a day during weeks 6, 8, 10 and 12 of the experiment. Aggressions were also observed at the end of the experimental period. Blood samples were taken for cortisol analysis and other physiological parameters, during growth period and slaughter and meat quality characteristics were assessed after slaughter. Differences were found in carcass characteristics, wherein IN presented a higher dorsal fat. These animals presented an overall lower activity and spent less time resting, with a stable pattern throughout the day. In OUT, pigs usually rested at midday hours, more active in the morning and afternoon. The number of total reciprocal aggressions in the observation period was 4.2 +/- 3.7 for IN and 2.3 +/- 2.2 for OUT. Cortisol levels and biochemical profile did not show evidence of important problems in the animals. Welfare is not compromised in any of the systems, although higher levels of cortisol and aggressions could be indicating some stress problems in the confinement system. Meat characteristics in OUT were considered better than in IN from a nutritional point of view
Regulated deficit irrigation in persimmon trees (Diospyros kaki) cv. 'Rojo Brillante'
No full textThe response of persimmon trees to deficit irrigation applied in three different phenological stages was evaluated during three consecutive seasons in a commercial orchard planted with the cv. ‘Rojo Brillante’, the most important cultivar in the Mediterranean basin. The experiment was performed in a drip-irrigated orchard located in Valencia, Spain, planted with eight-year-old trees at a spacing of 5.5 m × 4 m and grafted on the rootstock Diospyrus lotus. Three regulated deficit irrigation (RDI) regimes were tested and compared to a Control treatment irrigated at full water requirements. In the RDI treatments, moderate water restrictions (50% of Control irrigation), were applied during one of three periods (I) RDIspring, where water restrictions were applied from late May to mid July; (II) RDIsummer, deficit irrigated from mid July to late August and; (IV) RDIfall, in which water restrictions were applied from late August early September to mid November. Results showed that persimmon fruit growth was sensitive to water stress. RDI reduced final fruit weight being this reduction more marked in the most stressed treatment (RDIsummer). This decrease in fruit weight was also because spring and specially summer RDI treatments increased the number of fruit harvested. Thus, RDI techniques allowed water savings of up to 20% without any reduction in yield increasing significantly the water use efficiency. In spite of the similar yields obtained in RDI and control trees, the economic return was negatively affected by deficit irrigation, because the lower fruit weight resulted in a decrease in the fruit commercial value. In conclusion, fruit growth of persimmon cv. ‘Rojo Brillante’ was shown as highly sensitive to deficit irrigation. Based on the results obtained, RDI would need further research in order to define an RDI strategy that could increase water use efficiency without affecting the economic return
Allometric Models for Estimating Carbon Fixation in Citrus Trees
No full textCitrus fruits play an important part in the Spanish agricultural sector. These orchards could play an important role as a terrestrial C sink and contribute to C fixation. We proposed quantifying the net primary production in different-aged citrus trees through the measurement of annual increases in the C content of the biomass of trees of different ages completely excavated. The measured net primary production in mature citrus was 27 kg C tree(-1) (1143 g C m(-2) yr(-1); 11.4 Mg C ha(-1) yr(-1)) with a similar behavior to that of different forests. Moreover, in this experiment, allometric equations for the estimation of annual net primary production in citrus orchards based on the relationship between net primary production and biometric variables were established. These equations could be a useful tool to calculate the potential C fixation in citrus areas. Canopy volume was the best variable for predicting above- and belowground biomass. Leaf area index and trunk diameter could also be selected as reliable and easily measurable variables to estimate net primary production in the whole tree
The complete genome sequence of Lamium mild mosaic virus, a member of the genus Fabavirus
No full textLamium mild mosaic virus (LMMV) is the only one of the five members of the genus Fabavirus for which there are no nucleotide sequence data. In this study, the complete genome sequence of LMMV was determined and compared with the available complete genome sequences of other members of the genus Fabavirus. The genome was the largest of the genus but maintained the typical organization, with RNA 1 of 6080 nucleotides (nt), RNA 2 of 4065 nt, and an unusually long 3' untranslated region in RNA 2 of 603 nt. Phylogenetic analysis of the amino acid sequences of the protease-polymerase (Pro-Pol) region and the two coat proteins confirmed that LMMV belongs to a distinct species within the genus Fabavirus
Horticultural mineral oil treatments in nurseries during aphid flights reduce Plum pox virus incidence under different ecological conditions
No full textThe application of horticultural mineral oil (HMO) treatments has been reported as a possible control strategy to reduce Plum pox virus (PPV) incidence in Prunus nurseries. The effect of Sunspray Ultrafine HMO at 1% on the natural viral spread was evaluated in experimental nursery plots of Nemaguard and Mariana GF8-1 Prunus rootstock blocks established under high natural inoculum pressure of the most prevalent PPV-types. Tests were conducted in experimental nursery plots in Plovdiv, Bulgaria (PPV-M and PPV-Rec), in Bistrita, Romania (PPV-D and PPV-Rec) and in Lliria, Spain (PPV-D). Horticultural mineral oil treatments were applied weekly during the vegetative period from spring to fall (treatments were interrupted in the summer). Nursery plants were analysed yearly by double-antibody sandwich enzyme-linked immunosorbent assay with 5B-IVIA/AMR monoclonal antibodies. The population dynamics of the aphids visiting plants in each experimental nursery plot was monitored by the sticky-shoot method and also by Moericke yellow water traps. At all three locations, the aphid population first peaked in the springtime. Furthermore, a variable second peak of aphid population was observed in Plovdiv and Bistrita in autumn. The treatments reduced PPV incidence in the three experimental locations and plots and in both assayed Prunus rootstocks grown under high PPV-inoculum pressure. A reduction from 10% to 20% of PPV-incidence between treated and control plants (P<0.05) in Plovdiv and Bistrita, respectively, was observed at the end of the tests. However, HMO treatments did not prevent PPV infection altogether, probably because of the high PPV prevalence in the area near the experimental nursery blocks. The control of PPV in nursery blocks based on HMO is presented as an environmentally friendly strategy based on the physical action of the treatments
Genomic analysis reveals MATH gene(s) as candidate(s) for Plum pox virus (PPV) resistance in apricot (Prunus armeniaca L.)
Get PDFSharka disease, caused by Plum pox virus (PPV), is the most important viral disease affecting Prunus species. A major PPV resistance locus (PPVres) has been mapped to the upper part of apricot (Prunus armeniaca) linkage group 1. In this study, a physical map of the PPVres locus in the PPV-resistant cultivar 'Goldrich' was constructed. Bacterial artificial chromosome (BAC) clones belonging to the resistant haplotype contig were sequenced using 454/ GS-FLX Titanium technology. Concurrently, the whole genome of seven apricot varieties (three PPV-resistant and four PPV-susceptible) and two PPV-susceptible apricot relatives (P. sibirica var. davidiana and P. mume) were obtained using the Illumina-HiSeq2000 platform. Single nucleotide polymorphisms (SNPs) within the mapped interval, recorded from alignments against the peach genome, allowed us to narrow down the PPVres locus to a region of similar to 196 kb. Searches for polymorphisms linked in coupling with the resistance led to the identification of 68 variants within 23 predicted transcripts according to peach genome annotation. Candidate resistance genes were ranked combining data from variant calling and predicted functions inferred from sequence homology. Together, the results suggest that members of a cluster of meprin and TRAF-C homology domain (MATHd)-containing proteins are the most likely candidate genes for PPV resistance in apricot. Interestingly, MATHd proteins are hypothesized to control long-distance movement (LDM) of potyviruses in Arabidopsis, and restriction for LDM is also a major component of PPV resistance in apricot. Although the PPV resistance gene(s) remains to be unambiguously identified, these results pave the way to the determination of the underlying mechanism and to the development of more accurate breeding strategies
Acta Horticulturae
No full textFlesh browning is one of the most important disorders in the commercialisation of 'Rojo Brillante' persimmons. Mechanical damage on the packaging line has been found to be the main cause of this disorder. However the form of the tannins, that is in their soluble or insoluble-form, affects the incidence of flesh browning. 'Rojo Brillante' contains a high content of soluble tannins at harvest which results in the human perception of astringency. Therefore, fruits are subjected to postharvest deastringency treatment which leads to tannin insolubilisation (condensation). The objective of this research was to study changes in 'Rojo Brillante' tannins during deastringency process and browning expression. We used thiolytic cleavage reactions and chromatographic techniques to determine the proportion of flavan-3-ol at harvest, after deastringency treatment with CO2, and also after expression of flesh browning as a consequence of mechanical impacts. Our result showed that epigallocatechin and epigallocatechin-gallate are the major units of 'Rojo Brillante' tannins while epicatechin and epicatechin-gallate are present in lower proportions. The application of CO2-treatment clearly increased the proportion of tannins in the insoluble form. The analysis of tannins from browned flesh areas showed a chromatographic profile that suggests the formation of oligomers probably associated with the process of oxidation
Volatile compounds associated to the loss of astringency in persimmon fruit revealed by untargeted GC-MS analysis
No full textHigh resolution volatile profiling (67 compounds identified) of fruits from 12 persimmon cultivars was established and used to characterize the different astringency types of persimmon fruit before and after deastringency treatment. Analysis of the volatile profile of fruit enables us to differentiate between cultivars that at the moment of harvest produced non-astringent fruit (Pollination Constant Non Astringent-PCNA-type) from astringent ones (non-PCNA-type). Fruit failing to accumulate astringent compounds naturally (PCNA fruit) showed high levels of 3(2H)-benzofuranone, while this compound was not detected in any astringent type fruit (non-PCNA). In addition to this, PCNA cultivars also showed at harvest higher accumulation of benzeneacetaldehyde and lipid-derived aldehydes (hexanal, heptanal, octanal and decanal) than non-PCNA fruit. The application of postharvest deastringency treatment to all non-PCNA cultivars resulted on an important insolubilization of tannins. In general the CO2-treatment enhanced the levels of acetaldehyde, however those cultivars showing high levels of dihydrobenzofuran at harvest did not present an increment of acetaldehyde. In contrast, all non-PCNA cultivars exhibited an important accumulation of lipid-derived aldehydes due to CO2-treatment. Therefore, we propose that lipid-derived aldehydes (mainly decanal, octanal and heptanal) may be playing a role in the astringency loss. Our results suggest that 3(2H)-benzofuranone, benzeneacetaldehyde and lipid-derived aldehydes could be used as markers for both natural and artificial loss of astringency
Evaluation of postharvest treatments with chemical resistance inducers to control green and blue molds on orange fruit
No full textPreventive and curative activities of postharvest treatments with selected chemical resistance inducers to control postharvest green (GM) and blue (BM) molds on oranges (cvs. 'Valencia' or 'Lanelate') artificially inoculated with Penicillium digitatum and Penicillium italicum, respectively, were evaluated. In vivo primary screenings to select the most effective chemicals and concentrations were performed with benzothiadiazole (BTH), beta-aminobutyric acid (BABA), 2,6-dichloroisonicotinic acid (INA), sodium silicate (SSi), salicylic acid (SA), acetylsalicylic acid (ASA) and harpin. INA at 0.03 mM, SA at 0.25 mM, BABA at 0.3 mM and BTH at 0.9 mM were selected and tested afterwards as dips at 20 degrees C for 60 or 150 s with oranges artificially inoculated before or after the treatment and incubated for 7 d at 20 degrees C. Although it was an effective treatment, SSi at 1000 mM was discarded because of potential phytotoxicity to the fruit rind. Preventive or curative postharvest dips at room temperature had no effect or only reduced the development of GM and BM very slightly. Therefore, these treatments cannot be recommended for inclusion in postharvest decay management programs for citrus packinghouses. (c) 2013 Elsevier B.V. All rights reserved