A Robust DNA Isolation Protocol from Filtered Commercial Olive Oil for PCR-Based Fingerprinting

Extra virgin olive oil (EVOO) has elevated commercial value due to its health appeal, desirable characteristics and quantitatively limited production, and thus it has become an object of intentional adulteration. As EVOOs on the market might consist of a blend of olive varieties or sometimes even of a mixture of oils from different botanical species, an array of DNA-fingerprinting methods have been developed to check the varietal composition of the blend. Starting from a comparison between publicly available DNA extraction protocols, we set up a timely, low-cost, reproducible and effective DNA isolation protocol, which allows an adequate amount of DNA to be recovered even from commercial filtered EVOOs. Then, in order to verify the effectiveness of the DNA extraction protocol herein proposed, we applied PCR-based fingerprinting methods starting from the DNA extracted from three EVOO samples of unknown composition. In particular, genomic regions harboring nine simple sequence repeats (SSRs) and eight genotyping-by-sequencing-derived single nucleotide polymorphism (SNP) markers were amplified for authentication and traceability of the three EVOO samples. The whole investigation strategy herein described might favor producers in terms of higher revenues and consumers in terms of price transparency and food safety

Quality characteristics of parental lines of wheat mapping populations

The aim of this work was to evaluate the main quality traits in the parental lines of wheat segregating populations to identify the best for subsequent genetic mapping of the traits. Significant differences (p < 0.001) among wheat genotypes were observed. Many of the examined crosses appeared to be suitable for the purpose, showing differences among parental lines as high as 4.6% for protein content, 6.4% for gluten content, 69 for gluten index, 50 mL for sodium dodecyl sulphate sedimentation volume, and 33.9 g for thousand-kernel weight, whereas differences accounting for 4.8, 2.4, and 7.3 were observed for yellow index, red index and brown index, respectively. The results pointed out that for studying at the same time the quantitative and qualitative features of gluten, the wheat populations derived from Latino x MG29896 and Saragolla x 02-5B-318 could be particularly appropriate. In addition, the latter cross was suitable to deepen the knowledge of yellow index regulation

Effect of composted sewage sludge on durum wheat: Productivity, phenolic compounds, antioxidant activity, and technological quality

The beneficial effects of whole meal wheat products are mainly attributed to dietary fibre and secondary metabolites related to it, such as phenolic compounds. To date, no studies have investigated the effect of fertilization with sewage sludge on the levels of wheat phenolic compounds. The aim of this study was to point out the effects of increasing doses of composted sewage sludge, also in combination with mineral fertilization, on phenolic compounds and antioxidant activity of durum wheat. Moreover, the effects on productivity and technological quality were verified. A randomized block experimental system with six replicates was adopted and seven treatments were compared: unfertilized control (absence of any fertilization or composted sewage sludge application); four doses of composted sewage sludge (3, 6, 9, and 12 Mg ha-1); mineral fertilization (MF) consisting of 120, 100 and 100 kg ha-1 of N, P2O5 and K2O, respectively; combined fertilization with 6 Mg ha-1 of composted sewage sludge and 60 kg ha-1 of N. There was a significantly positive effect of sewage sludge application on productivity as well as on phenolic compounds, antioxidant activity, and technological quality of durum wheat whole meal. Regarding the productivity, the use of 12 Mg ha-1 of composted sewage sludge can effectively substitute mineral fertilization. Regarding phenolics and antioxidant activity, a further increase can be achieved by employing a combination of composted sewage sludge (at the level of 6 Mg ha-1) and mineral fertilization. The phenolic compounds of whole meal raised from 1.31 mg ferulic acid equivalents (FAE) g-1 (unfertilized control) to 1.93 mg FAE g-1 (combined application of 6 Mg ha-1 of sewage sludge and 60 kg ha-1 N). The antioxidant activity range was 1.89-2.02 μmol 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) g-1 d.m., corresponding to a level of scavenging capacity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical ranging from 56.26% (unfertilized control) to 62.29% (6 Mg ha-1 of sewage sludge plus 60 kg ha-1 N)

Fine Mapping and Candidate Gene Analysis of <i>Pm36</i>, a Wild Emmer-Derived Powdery Mildew Resistance Locus in Durum Wheat

Powdery mildew (PM) is an economically important foliar disease of cultivated cereals worldwide. The cultivation of disease-resistant varieties is considered the most efficient, sustainable and economical strategy for disease management. The objectives of the current study were to fine map the chromosomal region harboring the wild emmer PM resistance locus Pm36 and to identify candidate genes by exploiting the improved tetraploid wheat genomic resources. A set of backcross inbred lines (BILs) of durum wheat were genotyped with the SNP 25K chip array and comparison of the PM-resistant and susceptible lines defined a 1.5 cM region (physical interval of 1.08 Mb) harboring Pm36. The genetic map constructed with F2:3 progenies derived by crossing the PM resistant line 5BIL-42 and the durum parent Latino, restricted to 0.3 cM the genetic distance between Pm36 and the SNP marker IWB22904 (physical distance 0.515 Mb). The distribution of the marker interval including Pm36 in a tetraploid wheat collection indicated that the positive allele was largely present in the domesticated and wild emmer Triticum turgidum spp. dicoccum and ssp. dicoccoides. Ten high-confidence protein coding genes were identified in the Pm36 region of the emmer, durum and bread wheat reference genomes, while three added genes showed no homologous in the emmer genome. The tightly linked markers can be used for marker-assisted selection in wheat breeding programs, and as starting point for the Pm36 map-based cloning

Genetic variation for phenolic acids concentration and composition in a tetraploid wheat (Triticum turgidum L.) collection

Phenolic acid intake through the consumption of whole-wheat foods provides important health benefits associated with reduced risks of cardiovascular diseases and colon cancer. The genetic variation for phenolic acids was extensively studied in common wheat, but a comprehensive survey in tetraploid wheat is lacking. In this study we evaluated the genetic variability for individual and total phenolic acids concentration existing in a large collection of tetraploid wheat (Triticum turgidum L.). A 2-year evaluation was undertaken on the whole-meal flour of 111 genotypes belonging to seven T. turgidum subspecies including cultivars, landraces and wild accessions. Durum cultivars [T. turgidum subsp. durum (Desf.) MacKey], had the highest average concentration of total phenolic acids (828.7 μg g−1 dm in 2012; 834.5 μg g−1 dm in 2013) with amounts varying from 550.9 μg g−1 dm to 1701.2 μg g−1 dm, indicating a variation of greater than threefold fold. The lowest concentration of phenolic acids was found in T. turgidum subsp. dicoccum (Schrank ex Schübler) Thell. Rivet wheat (T. turgidum L. subsp. turgidum) had phenolic acid concentrations similar to those in durum, but less variation was noted among the accessions. On the other hand, the accessions of the four remaining subspecies showed lower phenolic acid concentrations and variation among the accessions as compared to durum. A total of six phenolic acids were identified across the wheat genotypes. The effects of genotype, year and year × genotype were estimated by ANOVA and resulted significant for all phenolic acids. The ratio of genotypic variance to total variance suggested the possibility of improving phenolic acid content in elite wheat germplasm through appropriate breeding programs. Moreover, significant correlations between phenolic acids and other quality characteristics of the grain were detected

New resistance genes for leaf rust and powdery mildew derived from T. turgidum ssp. dicoccum

Trabajo presentado en el International Wheat Innovation Workshop, celebrado en Clermont-Ferrand (France) el 16 y 17 de noviembre de 2015.The tetraploid wheat relative Triticum turgidum ssp. dicoccum shows particular promises as a donor of useful genetic variation for several traits including disease resistances to be introgressed in cultivated wheat. The accession MG5323 of ssp. dicoccum, which showed useful level of resistance to leaf rust and powdery mildew diseases, was crossed with the susceptible durum wheat cultivar Latino. A total of 110 recombinant inbred lines (RILs) were produced and a high resolution linkage map was developed based on the 90K Infinium (Illumina). The parents and RIL population were phenotyped using two Puccinia triticina (VMC03 and 12766) and one Blumeria graminis (O2) isolates. Quantitative trait loci (QTL) analysis led to the identification of one major resistance gene conferring resistance to leaf rust on the short arm of chromosome 1B, explaining a total phenotypic variation ranging from 41.4 to 49.5%. Two additional minor resistance genes located on chromosome 7B explained a phenotypic variation ranging between 17.8 and 25.8%. For both QTLs the resistant allele was provided by MG5323. A significant positive epistatic effect was detected between QTLs , indicating that different QTLs contribute different degrees of resistance. Moreover, analys is of the leaf rust responses of the RILs demonstrated complementary actions between genes on chromosomes 1B and 7B. Analysis of powdery mildew resistance identified a single dominant gene on the short arm of chromosome 2B explaining 78.7% of total phenotypic variation. MG5323 provided the resistant allele at the QTL. A fine mapping approach of the major genes for both diseases was undertaken by developing a large F2-based high resolution mapping population and the flanking and peak markers were used to select a number of recombinant lines that are currently under phenotypic evaluation. The closest linked markers have been converted into PCR-based markers and are suitable for marker assisted selection (MAS) in resistance breeding.N