1,720,980 research outputs found
Development and application of protocols to certify the authenticity and traceability of Apulian typical products in olive sector
No full textMethods to trace food through the different stages of production, processing and distribution, play a key role in assuring food safety and in protecting product authenticity. Biotechnologies provide innovative tools useful for these purposes. Among the Italian regions, Apulia has the highest number of typicality brands in the olive sector, with five PDO (Protected Designation of Origin) extra virgin olive oils and one PDO table olive. In this article, authors review the studies on molecular and metabolic tracking of PDO products in the Apulian olive sector, with particular focus on the "Terra di Bari", "Collina di Brindisi" and "Terra d'Otranto" PDO olive oils and the "Bella di Cerignola" PDO table olive
A DNA methylation survey of NCED gene in Vitis vinifera, under stress conditions.
No full textThe phytohormone abscisic acid (ABA) regulates many key processes in
plants, such as seed germination, seedling growth, and abiotic stress tolerance. In
particular, drought stress signals are transmitted through at least two pathways: one
is abscissic acid (ABA)-dependent, and the other is ABA-independent. In the ABAdependent
pathway, drought stress increases the cellular ABA levels, which induce
the expression of drought stress-responsive genes, such as 9-cis-epoxycarotenoid
dioxygenase (NCED). The stress memory can be stored in the short-term, depending
on the half-life of stress-induced proteins, RNAs, and metabolites, or for the longterm,
by reprogramming phenology and morphology. DNA methylation and histone
modification are stable and heritable epigenetic processes involved in long-term
stress memory. Recent discoveries reveal that, in addition to genetic regulation,
epigenetic regulation plays a key role in ABA-mediated plant processes. Our interest
is on studying the methylation status of NCED genes as candidate genes under
normal and drought-stressed conditions in the framework of “epigenetic memory”
in Vitis vinifera. We have identified symmetric and asymmetric CpG islands in the
full sequences of genes which carry on DNA methylation by bisulfite analysis. These
results will be considered along with the expression patterns of stress-induced genes
Rapid identification of tomato Sw-5 resistance-breaking isolates of <i>Tomato spotted wilt virus</i> using high resolution melting and TaqMan SNP Genotyping assays as allelic discrimination techniques
Get PDFIn tomato, resistance to Tomato spotted wilt virus (TSWV) is conferred by the dominant gene, designated Sw-5. Virulent Sw-5 resistance breaking (SRB) mutants of TSWV have been reported on Sw-5 tomato cultivars. Two different PCR-based allelic discrimination techniques, namely Custom TaqMan™ SNP Genotyping and high-resolution melting (HRM) assays, were developed and compared for their ability to distinguish between avirulent (Sw-5 non-infecting, SNI) and SRB biotypes. TaqMan assays proved to be more sensitive (threshold of detection in a range of 50–70 TSWV RNA copies) and more reliable than HRM, assigning 25 TSWV isolates to their correct genotype with an accuracy of 100%. Moreover, the TaqMan SNP assays were further improved developing a rapid and simple protocol that included crude leaf extraction for RNA template preparations. On the other hand, HRM assays showed higher levels of sensitivity than TaqMan when used to co-detect both biotypes in different artificial mixtures. These diagnostic assays contributed to gain preliminary information on the epidemiology of TSWV isolates in open field conditions. In fact, the presented data suggest that SRB isolates are present as stable populations established year round, persisting on both winter (globe artichoke) and summer (tomato) crops, in the same cultivated areas of Southern Italy.</div
The coexistence of oleaster and traditional varieties affects genetic diversity and population structure in Algerian olive (Olea europaea) germplasm
No full textThe present work was aimed at assessing the genetic diversity of 42 local cultivars and oleaster genotypes from the area of Bejaia in Algeria. Fifteen highly polymorphic Simple Sequence Repeat markers were evaluated and proved to be very informative, producing a total number of 160 alleles with an average value of 10.7 per locus; the SSRs DCA09 and DCA16 were the most informative, distinguishing 17 and 19 genotypes, respectively. Phylogenetic and population structure analysis split the accessions in two main groups corresponding to most of oleasters and most of traditional varieties, respectively. Interestingly, ten traditional varieties resulted strictly related to the oleasters, indicating hybridization between the two botanical varieties. Genetic parameters and private alleles of groups confirmed this observation and indicated a wide genetic variability in Algerian olive germplasm. The results suggest the need to preserve and characterize this germplasm in order to limit the risk of losing potential important genetic traits present in the crop wild relatives
Screening auxin response, in vitro culture aptitude and susceptibility to agrobacterium-mediated transformation of Italian commercial durum wheat varieties
Get PDFThe development of a robust Agrobacterium-mediated transformation protocol for a recalcitrant species like durum wheat requires the identification and optimization of factors affecting T-DNA delivery and plant regeneration. The purpose of this research was to compare the behavior of diverse durum wheat genotypes during in vitro culture and Agrobacterium tumefaciens-mediated transformation, using immature embryos as explants. Apart from plant genotype, two of the main influencing factors for a successful genetic transformation have been examined here, i.e., auxin source (Dicamba and 2,4-D) and duration of the pre-culture period (one, seven and 21 days). The addition of Dicamba to the media in combination with seven days pre-cultivation resulted in a general enhancement of T-DNA delivery for most of the analyzed cultivars, as revealed by β-glucuronidase (GUS) histochemical assay. Although all genotypes were able to produce calli, significant differences were detected in regeneration and transformation efficiencies, since only two (Karalis and Neolatino) out of 14 cultivars produced fertile transgenic plants. The estimated transformation efficiencies were 6.25% and 1.66% for Karalis and Neolatino, respectively, and χ2; analysis revealed the stable integration and segregation of the gus transgene in T1 and T2 progenies. This research has demonstrated that, among the influencing factors, genotype and auxin type play the most important role in the success of durum wheat transformation
Traceability of PDO olive oil "terra di Bari" using high resolution melting
Get PDFThe aim of the research was to verify the applicability of microsatellite (SSR) markers in High Resolution Melting (HRM) analysis for the identification of the olive cultivars used in the "Terra di Bari" PDO extra virgin olive oil. A panel of nine cultivars, widespread in Apulia region, was tested with seventeen SSR primer pairs and the PCR products were at first analysed with a Genetic Analyzer automatic sequencer. An identification key was obtained for the nine cultivars, which showed an unambiguous discrimination among the varieties constituting the "Terra di Bari" PDO extra virgin olive oil: Cima di Bitonto, Coratina, and Ogliarola. Subsequently, an SSR based method was set up with the DCA18 marker, coupled with HRM analysis for the distinction of the Terra di Bari olive oil from non-Terra di Bari olive oil using different mixtures. Thus, this analysis enabled the distinction and identification of the PDO mixtures. Hence, this assay provided a flexible, cost-effective, and closed-tube microsatellite genotyping method, well suited to varietal identification and authentication analysis in olive oil
Characterization of virgin olive oil from Leucocarpa cultivar by chemical and DNA analysis
No full textLeucocarpa is an olive cultivar characterized by small fruits which assume a peculiar ivory-white color when ripe. The aim of this research was to characterize its oil by analyzing some chemical parameters as well as DNA microsatellites. Monovarietal Leucocarpa oils, produced under controlled conditions, were compared for two consecutive years to oils derived from Coratina, an olive cultivar very diffused in Italy. Both the cultivars were grown in the same field. The values of phenolic compounds observed in Leucocarpa oils were quite low and corresponded to those usually found in sweet tasting oils. Also levels of pigments appeared to be low compared to Coratina monovarietal oils. Microsatellite analysis were carried out by using 11 primer pairs and Leucocarpa oils were compared to six monovarietal oils from cultivars diffused in Southern Italy. The primer pairs lead to 213 amplified fragments, with a mean of 7 different alleles per primer, and a power of discrimination ranging from 0.49 to 0.91. A single microsatellite, GAPU103A, was sufficient to distinguish Leucocarpa oil from the other samples. An identification key based on the amplification profile of this microsatellite was set up to distinguish the oils from different cultivars. The assessed DNA microsatellite profile, independent from environmental conditions, could be helpful to verify the authenticity of Leucocarpa oil samples
High resolution melting analysis of DNA microsatellites in olive pastes and virgin olive oils obtained by talc addition
No full textTalc(hydratedmagnesiumsilicate)is a physicalcoadjuvantthat can be employedin the productionofextravirginoliveoil to increaseyield.Theadsorbentpropertiesof talc couldhamperDNArecovery,leadingto falsenegativesin DNAanalysis.Theaim of this workwas to verifythe effectof talc additionon oliveoil DNAby targetingfourselectedmicrosatellites.Oliveprocessingtrialswerecarriedout attwo differentlevelsof talc (1 and 2%)and withouttalc (control).DNAextractionyieldand puritylevelwereascertained,and HighResolutionMelting(HRM)analysisof microsatelliteswas subsequentlyappliedto the extractedDNA.Neitherthe DNAextractionyieldnor the A260/230and A260/280ratiosshowedsignificantdifferencesbetweencontroland talc-treatedsamples.Highervaluesof A260/230andloweryieldswereobservedin oliveoils thanin olivepastes.TheDNAmicrosatellitesanalyzedshowedidenticalHRMprofilesin all the samples,excludingany effectof talc andconfirmingthe genetichomogeneityof the olivelot processed(cv.Coratina).Practicalapplications:Highadded-valuemono-cultivarextravirginoliveoils are nicheproductsveryappreciatedby consumers.DNAanalysisis ableto revealmixingwithcultivarsdifferentfromthosedeclaredin the label.Theuse of talc in oliveoil industrieshas progressivelyincreasedto improveyield.Theresultsobtainedprovethat the DNA-basedmethodsset up untilnowto checkthe authenticityofextravirginoliveoil can be effectivelycarriedout also in oils producedby usingtalc.In addition,theresultsare amongthe first applicationsof HRMto the foodsectorand evidencethe feasibilityof thistechniquealongthe oliveoil chainfor checkingbotholivepastesand oil
Evolution and perspectives of cultivar identification and traceability from tree to oil and table olives by means of DNA markers
No full textIn recent years, an increasing number of typicality marks has been awarded to high-quality olive oils produced from local cultivars. In this case, quality control requires effective varietal checks of the starting materials. Moreover, accurate cultivar identification is essential in vegetative-propagated plants distributed by nurseries and is a pre-requisite to register new cultivars. Food genomics provides many tools for cultivar identification and traceability from tree to oil and table olives. The results of the application of different classes of DNA markers to olive with the purpose of checking cultivar identity and variability of plant material are extensively discussed in this review, with special regard to repeatability issues and polymorphism degree. The characterization of olive germplasm from all countries of the Mediterranean basin and from less studied geographical areas is described and innovative high-throughput molecular tools to manage reference collections are reviewed. Then the transferability of DNA markers to processed products – virgin olive oils and table olives – is overviewed to point out strengths and weaknesses, with special regard to (i) the influence of processing steps and storage time on the quantity and quality of residual DNA, (ii) recent advances to overcome the bottleneck of DNA extraction from processed products, (iii) factors affecting whole comparability of DNA profiles between fresh plant materials and end-products, (iv) drawbacks in the analysis of multi-cultivar versus single-cultivar end-products and (v) the potential of quantitative polymerase chain reaction (PCR)-based techniques. © 2016 Society of Chemical Industry
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