Items from Germany-The impact of Rht alleles on cross-pollination efficiency traits with relevance for hybrid breeding in wheat

Hybrid breeding and the ability to exploit heterosis is one of a few high-priority wheat breeding strategies that have the potential to rapidly improve yield and stability. Yield improvements associated with hybrid vigor were demonstrated to be in the order of a 10–25% increase in grain yield as well as improved resistance against biotic/abiotic stresses and grain quality. Faced with these scenarios, the identification of factors affecting the development of hybrid wheats is of fundamental importance in order to accelerate the rate of genetic gain of the crop. Due to the prevalence and usefulness of Rht ‘Green revolution’ dwarfing alleles, it is important to gain a better understanding of how these alleles affect those traits related to the development of hybrid wheat seed production. Up to now, the expected influence of these alleles/ genes on wheat flowering-related traits was evaluated based on mapping populations or genome-wide association studies, without taking into account the actual effect of each Rht allele in particular. In this project, we propose to explore the effect of different Rht alleles using many near-isogenic lines. The experiments were performed at the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben, Germany) and the Faculty of Agricultural Sciences and Forestry (National University of La Plata, Argentina) during three growing seasons. Four sets of NILs carrying the alleles of Rht genes: Rht1 (Rht-B1b/Rht-D1a), Rht2 (Rht-B1a/Rht-D1b), Rht3 (Rht-B1c/Rht-D1a), Rht 1+2 (Rht-B1b/ Rht-D1b), Rht 2+3 (Rht-B1c/Rht-D1b), and rht (tall; Rht-B1a/Rht-D1a) in the genetic backgrounds of the wheat cultivars April Bearded, Bersee, Maris Huntsman, and Maris Widgeon were evaluated. Traits associated with cross-pollination efficiency (flowering date, plant height, spike length, anther extrusion, anther and filament length, and spikelets/spike) were studied. Preliminary results showed that the extreme dwarf alleles Rht3, Rht1+2, and Rht2+3 presented the greatest effects in all the variables analyzed. Plant height showed reductions from 22–25% (Rht1 and Rht2), 50–57% (Rht3 and Rht1+2), and 66% (Rht2+3) compared to rht (tall). Spike length was increased up to 14% (Rht1+2 vs. rht) and 3–9% for the rest of Rht alleles compared to rht, whereas spikelets/spike were increased up to 6% (Rht2+3 vs. rht). In comparison to rht (tall), the floral organs were negatively influenced by Rht alleles; decreases from 8–13% (Rht 1, Rht2, and Rht3) to 17–25% (Rht1+2 and Rht2+3) in anther length, and reductions from 16–44% in filament length were observed. For their part, anthers extrusion decreased between 15–27% (Rht1, Rht2, and Rht3) to 32–35% for Rht1+2 and Rht2+3 compared with that of rht. No significant differences were detected for flowering time among the alleles evaluated. These preliminary results indicate that Rht alleles combination are involved in multiple traits of interest for hybrid wheat production in breeding programs. Moreover, the magnitude of the negative impact of Rht alleles on floral organs depends on the combination of the alleles involved.Fil: Schierenbeck, Matías. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Leibniz Institute Of Plant Genetics And Crop Plant Research.; AlemaniaFil: Börner, A.. Leibniz Institute Of Plant Genetics And Crop Plant Research.; AlemaniaFil: Aleksandrov, V.. No especifíca;Fil: Alqudah, A. M.. No especifíca;Fil: Chebatareva, M. V.. No especifíca;Fil: Esquisabel, E.. No especifíca;Fil: Golik, S. I.. No especifíca;Fil: Kartseva, T.. No especifíca;Fil: Klykov, A. G.. No especifíca;Fil: Pshenichnikova, M. S.. No especifíca;Fil: Röder, V. P.. No especifíca;Fil: Shamanin, L. V.. No especifíca;Fil: Shchukina, M. R.. No especifíca;Fil: Simón, V. I.. No especifíca;Fil: Yakubovskiy, K.. No especifíca;Fil: Zaynali, Nezhad. No especifíca

The National Early Warning Score and its subcomponents recorded within ±24 hours of emergency medical admission are poor predictors of hospital-acquired acute kidney injury

YesBackground: Hospital-acquired Acute Kidney Injury (H-AKI) is a common cause of avoidable morbidity and mortality. Aim: To determine if the patients’ vital signs data as defined by a National Early Warning Score (NEWS), can predict H-AKI following emergency admission to hospital. Methods: Analyses of emergency admissions to York hospital over 24-months with NEWS data. We report the area under the curve (AUC) for logistic regression models that used the index NEWS (model A0), plus age and sex (A1), plus subcomponents of NEWS (A2) and two-way interactions (A3). Likewise for maximum NEWS (models B0,B1,B2,B3). Results: 4.05% (1361/33608) of emergency admissions had H-AKI. Models using the index NEWS had the lower AUCs (0.59 to 0.68) than models using the maximum NEWS AUCs (0.75 to 0.77). The maximum NEWS model (B3) was more sensitivity than the index NEWS model (A0) (67.60% vs 19.84%) but identified twice as many cases as being at risk of H-AKI (9581 vs 4099) at a NEWS of 5. Conclusions: The index NEWS is a poor predictor of H-AKI. The maximum NEWS is a better predictor but seems unfeasible because it is only knowable in retrospect and is associated with a substantial increase in workload albeit with improved sensitivity.The Health Foundatio

APLICACIÓN DE FUNGICIDAS Y FERTILIZACIÓN NITROGENADA EN AVENA: EFECTOS SOBRE LA GENERACIÓN DE BIOMASA AÉREA Y RENDIMIENTO

El objetivo fue evaluar el efecto de la fertilización nitrogenada (N) y la aplicación de fungicidas sobre la severidad causada por enfermedades foliares, índice de área foliar, biomasa aérea y rendimiento en avena. Se condujo un ensayo en la Facultad de Ciencias Agrarias y Forestales (FCAyF), UNLP, con diseño experimental en parcela sub-sub-sub dividida y tres repeticiones, siendo la parcela principal: dos ambientes (2011-2014), la sub-parcela: los tratamientos con y sin fungicidas, la sub-sub-parcela: los tratamientos con 0 y 60 kg N.ha -1 ; y la sub-sub-sub-parcela: tres genotipos (Líneas 5 y 6 de la FCAyF, y Bonaerense INTA Calén). La aplicación de fungicida disminuyó la severidad y la fertilización N la aumentó en EC8.2, estadio en que la roya de la hoja incrementó sus valores. En dicho estadio, el fungicida ejerció un mejor control en el tratamiento sin N. Tanto la aplicación de fungicida como de N incrementaron el índice de área foliar, la biomasa aérea y el rendimiento. Las Líneas 5 y 6 presentaron un menor nivel de enfermedad, mayor biomasa y rendi- miento que Calén

Evolutionary dynamics of Waxy and the origin of hexaploid Spartina species (Poaceae)

International audienceWe investigated the evolutionary dynamics of duplicated copies of the granule-bound starch synthase I gene (GBSSI or Waxy) within polyploid Spartina species. Molecular cloning, sequencing, and phylogenetic analyses revealed incongruences between the expected species phylogeny and the inferred gene trees. Some genes within species were more divergent than expected from ploidy level alone, suggesting the existence of paralogous sets of Waxy loci in Spartina. Phylogenetic analyses indicate that this paralogy originated from a duplication that occurred prior to the divergence of Spartina from other Chloridoideae. Gene tree topologies revealed three divergent homoeologous sequences in the hexaploid S. alterniXora that are consistent with the proposal of an allopolyploid origin of the hexaploid clade. Waxy sequences diVer in insertion–deletion events in introns, which may be used to diagnose gene copies. Both paralogous and homoeologous coding regions appear to evolving under selective constraints

The enigmatic invasive Spartina densiflora: A history of hybridizations in a polyploidy context

International audienceThe aim of this study was to explore the origin of the invasive Spartina densiflora by analysing samples from the native region (South America) and from a recently colonized area (California). A combination of various molecular data (chloroplast and nuclear sequences, molecular fingerprint) and ploidy level estimations was used to answer the question whether the reticulate phylogenetic pattern previously detected in S. densiflora was restricted to California, or alternatively, whether a more ancient hybrid origin preceded formation of this species in its native area. We found that this species is heptaploid in both its native and introduced range. Identification of nuclear homeologous sequences indicate that this species has a reticulate origin in its native range, involving a lineage related to the hexaploid clade formed by S. alterniflora, S. foliosa, and S. maritima, and another lineage related to the sub-Antarctic endemic S. arundinacea that provided the chloroplast genome. The samples from California displayed similar multilocus patterns to the samples from Chile, supporting the hypothesis that this species originated on the southeast American coast (Argentina), from where it eventually spread to the west coast of South America (Chile) first and to the Northern Hemisphere (California) later