Allelic Variation at Glutenin Loci (Glu-1, Glu-2 and Glu-3) in a Worldwide Durum Wheat Collection and Its Effect on Quality Attributes

Durum wheat grains (Triticum turgidum L. ssp. durum) are the main source for the production of pasta, bread and a variety of products consumed worldwide. The quality of pasta is mainly defined by the rheological properties of gluten, an elastic network in wheat endosperms formed of gliadins and glutenins. In this study, the allelic variation at five glutenin loci was analysed in 196 durum wheat genotypes. Two loci (Glu-A1 and Glu-B1), encoding for high-molecular-weight glutenin subunits (HMW-GS), and three loci (Glu-B2, Glu-A3 and Glu-B3), encoding for low molecular weight glutenin subunits (LMW-GS), were assessed by SDS-PAGE. The SDS-sedimentation test was used and the grain protein content was evaluated. A total of 32 glutenin subunits and 41 glutenin haplotypes were identified. Four novel alleles were detected. Fifteen haplotypes represented 85.7% of glutenin loci variability. Some haplotypes carrying the 7 + 15 and 7 + 22 banding patterns at Glu-B1 showed a high gluten strength similar to those that carried the 7 + 8 or 6 + 8 alleles. A decreasing trend in grain protein content was observed over the last 85 years. Allelic frequencies at the three main loci (Glu-B1, Glu-A3 and Glu-B3) changed over the 1915–2020 period. Gluten strength increased from 1970 to 2020 coinciding with the allelic changes observed. These results offer valuable information for glutenin haplotype-based selection for use in breeding programs

Facetas del pensamiento de Nicolás Gómez Dávila

La obra de Nicolás Gómez Dávila (1913-1994), estudiada y traducida en múltiples lugares y lenguas, tiene un lugar privilegiado en la investigación académica no solo por su singular colaboración entre lo filosófico y lo literario, sino porque la distancia del pensador con su tiempo, con su país y con su tradición cultural constata su inscripción en una forma del presente. Una de las posiciones que se toman en este libro va en contra de una imagen construida desde su primera recepción: la de un escritor excepcional, pero radicalmente desconectado de su contexto intelectual y cultural, la de un hombre aislado de los hombres, parapetado en una biblioteca. Por el contrario, su talante reaccionario, como temple de ánimo filosófico, se puede reconocer como posición histórica o política ante el presente, sin que se pretenda carente de arraigo. Facetas del pensamiento de Nicolás Gómez Dávila, más que desarrollar un debate, muestra los múltiples aspectos de la obra de Gómez Dávila y la diversidad de enfoques de aproximación tanto para conocerla por primera vez como para profundizar en su investigación. Este libro, fruto de un seminario prolongado y minucioso en el que participaron estudiosos colombianos y extranjeros, realizado con el apoyo del Instituto Caro y Cuervo, se ofrece como una contribución al estudio del trabajo de Gómez Dávila y, en definitiva, al debate sobre el pensamiento colombiano.Bogot

The Global Durum Wheat Panel (GDP): An International Platform to Identify and Exchange Beneficial Alleles

Representative, broad and diverse collections are a primary resource to dissect genetic diversity and meet pre-breeding and breeding goals through the identification of beneficial alleles for target traits. From 2,500 tetraploid wheat accessions obtained through an international collaborative effort, a Global Durum wheat Panel (GDP) of 1,011 genotypes was assembled that captured 94-97% of the original diversity. The GDP consists of a wide representation of Triticum turgidum ssp. durum modern germplasm and landraces, along with a selection of emmer and primitive tetraploid wheats to maximize diversity. GDP accessions were genotyped using the wheat iSelect 90K SNP array. Among modern durum accessions, breeding programs from Italy, France and Central Asia provided the highest level of genetic diversity, with only a moderate decrease in genetic diversity observed across nearly 50 years of breeding (1970-2018). Further, the breeding programs from Europe had the largest sets of unique alleles. LD was lower in the landraces (0.4 Mbp) than in modern germplasm (1.8 Mbp) at r 2 = 0.5. ADMIXTURE analysis of modern germplasm defined a minimum of 13 distinct genetic clusters (k), which could be traced to the breeding program of origin. Chromosome regions putatively subjected to strong selection pressure were identified from fixation index (F st ) and diversity reduction index (DRI) metrics in pairwise comparisons among decades of release and breeding programs. Clusters of putative selection sweeps (PSW) were identified as co-localized with major loci controlling phenology (Ppd and Vrn), plant height (Rht) and quality (gliadins and glutenins), underlining the role of the corresponding genes as driving elements in modern breeding. Public seed availability and deep genetic characterization of the GDP make this collection a unique and ideal resource to identify and map useful genetic diversity at loci of interest to any breeding program