1,721,028 research outputs found
IDENTIFICATION AND CHARACTERIZATION OF INDUCED MUTATIONS IN A SUNFLOWER TILLING PLATFORM
No full textThe TILLING strategy has been successfully applied to the sunflower genome in our
laboratory (“sunTILL platform”). The interest was first focused on some key enzymes of the fatty
acid pathway, because of the interest in increasing the nutritional value of sunflower oil by the
reduction of the ratio of saturated to unsaturated fatty acids. Moreover, P. halstedii is one of the
most dangerous pathogens that affects sunflower cultivation in the Mediterranean area. Therefore
the availability of a stable and effective system, as genetic resistance, for the pest-control results of
prime importance. Thereby, a pilot assay on 1,152 sunflower M2 lines was carried out by the
reverse genetic screening of four genes: the kasII and kasIII genes, respectively codifying the
isoforms II and III of the β-keto-acyl-ACP-synthetase; the fad2-1 gene, encoding the enzyme
responsible of the converting reaction of oleic acid to linoleic acid; the AY490791 gene, involved in
P. halstedii resistance.
Since few genomic sequences are publicly available for sunflower, the reverse genetic
screening was preceded by an accurate reconstruction of candidate gene models, by the
amplification and the subsequent sequencing of short overlapping fragments. For each candidate
gene the most promising region for TILLING analysis was thereby identified. In this way, new
primer pairs flanking this region were set on the intronic sequences, with the aim to improve the
screening efficiency on the coding regions.
In the pilot assay, nine mutant lines have been totally identified. The four mutations scored in
the kasII gene were homozygous; three of them were localized in introns, while one caused a G/T
transversion, resulting in a premature stop-codon (E139*). No mutant lines were identified for the
kasIII gene. In the case of fad2-1 gene, three mutations were identified: one resulted in a missense
change (F26L), a second caused a silent change (R46=) and a third was situated in the non-coding
region. The AY490791 gene screening revealed two mutations, both localized in non-coding
sequence. Each mutant line was then confirmed by sequencing and genotyped by microsatellite
markers to exclude any individuals originating from cross-pollination events. The results of this first
reverse genetic screening translated into an average mutation frequency of 1/475 kb
FAD7 GENE IDENTIFICATION AND FATTY ACIDS PHENOTYPIC VARIATION IN AN OLIVE COLLECTION BY ECOTILLING AND SEQUENCING APPROACHES
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AFLP molecular markers to identify virgin olive oils from single Italian cultivars
No full textOlive oil traceability becomes instrumental to ensure the consumer's protection, particularly for extra virgin olive oil, the quality of which is highly related to the cultivars employed. The aim of this investigation was to evaluate the possibility of identifying the cultivar used to obtain the derived olive oil by the analysis of amplified fragment length polymorphism (AFLP) markers. To this purpose, ten virgin olive oils were prepared in the laboratory from ten different very common Italian cultivars and were then analysed using six AFLP primer combinations. The technique was optimised for fragmented DNA of oil in order to enhance the intensity of the bands in the AFLP patterns. The obtained results indicated a percentage of polymorphism ranging from 16% for Pst-AGC/Mse-AGT to 43% for Pst-AGC/Mse-ACA. The diversity index was comprised between 90.2% for Pst-AGC/Mse-AGT and 95.2% for Pst-AGG/Mse-AGG. One of the six primer combination analysed, namely Pst-AGG/Mse-AGG, was able to distinguish all the olive oil examined, and a similarity tree of the samples was elaborated
SSR-based identification key of cultivars of Olea europaea L. diffused in Southern-Italy
No full textOlive (Olea europaea L.) is an important fruit species in Italy and Mediterranean basin constituted by a wide germplasm with a large number of cultivars present in all the Mediterranean area. SSRs are becoming the markers of choice for variability studies in olives as they are simple to perform, transferable, hypervariable, highly polymorphic and show a high information content.
Olive genetic diversity was studied using 16 SSR markers on 30 cultivars diffused in Southern-Italy. Resolving Power (RP) and Power of Discrimination (PD) were calculated to evaluate the efficiency of the SSR markers investigated in Studies of cultivars fingerprinting. Based on their high efficiency, two SSR markers, UDO43 and DCA16 were chosen to set up an identification key to distinguish the entire set of cultivars, confirming the high biodiversity of the Southern-Italian olive germplasm and the suitability of SSR markers in studies of cultivar diagnosis
Development of an olive mapping population: in vitro culture and selection of cross-derived embryos by SSR markers
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