349 research outputs found
Interspecific somatic hybrids between Solanum bulbocastanum and S. tuberosum and their haploidization for potato breeding.
Protoplast fusion between incongruent Solanum bulbocastanum and S. tuberosum haploids was accomplished to produce hybrids combining elite traits from both parents. We identified 11 somatic hybrids out of 42 regenerants analyzed through ISSR markers. Some hybrids had loss or gain of fragments compared to the parents, likely due to rearrangements and deletions of chromosome segments after fusion, and/or to somaclonal variation during hybrid regeneration. Increased heterotic vigor for some traits as well as high diversity was observed as the effect of both ploidy and fusion combination. Microsporogenesis analysis indicated the occurrence of multivalent configurations and several meiotic abnormalities, such as chromosomes bridges and various spindle orientations. Since all hybrids were sterile, in vitro anther culture was employed for haploidization as a possible strategy to overcome barriers to hybridizations. Haploids were obtained from all the tetraploid S. bulbocastanum (+) S. tuberosum somatic hybrids tested, although with differences in both the number of embryos per 100 anthers cultured and the number of differentiated green plantlets. This is the first report on the successful production of haploid plants from S. bulbocastanum (+) S. tuberosum hybrids
Genome-wide SNP discovery and population structure analysis in pepper (Capsicum annuum) using genotyping by sequencing
BACKGROUND: Knowledge on population structure and genetic diversity in vegetable crops is essential for association mapping studies and genomic selection. Genotyping by sequencing (GBS) represents an innovative method for large scale SNP detection and genotyping of genetic resources. Herein we used the GBS approach for the genome-wide identification of SNPs in a collection of Capsicum spp. accessions and for the assessment of the level of genetic diversity in a subset of 222 cultivated pepper (Capsicum annum) genotypes. RESULTS: GBS analysis generated a total of 7,568,894 master tags, of which 43.4% uniquely aligned to the reference genome CM334. A total of 108,591 SNP markers were identified, of which 105,184 were in C. annuum accessions. In order to explore the genetic diversity of C. annuum and to select a minimal core set representing most of the total genetic variation with minimum redundancy, a subset of 222 C. annuum accessions were analysed using 32,950 high quality SNPs. Based on Bayesian and Hierarchical clustering it was possible to divide the collection into three clusters. Cluster I had the majority of varieties and landraces mainly from Southern and Northern Italy, and from Eastern Europe, whereas clusters II and III comprised accessions of different geographical origins. Considering the genome-wide genetic variation among the accessions included in cluster I, a second round of Bayesian (K = 3) and Hierarchical (K = 2) clustering was performed. These analysis showed that genotypes were grouped not only based on geographical origin, but also on fruit-related features. CONCLUSIONS: GBS data has proven useful to assess the genetic diversity in a collection of C. annuum accessions. The high number of SNP markers, uniformly distributed on the 12 chromosomes, allowed the accessions to be distinguished according to geographical origin and fruit-related features. SNP markers and information on population structure developed in this study will undoubtedly support genome-wide association mapping studies and marker-assisted selection programs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-016-3297-7) contains supplementary material, which is available to authorized users
Is heart failure misdiagnosed in hospitalized patients with preserved ejection fraction? From the European Society of Cardiology - Heart Failure Association EURObservational Research Programme Heart Failure Long-Term Registry.
AIMS: In hospitalized patients with a clinical diagnosis of acute heart failure (HF) with preserved ejection fraction (HFpEF), the aims of this study were (i) to assess the proportion meeting the 2016 European Society of Cardiology (ESC) HFpEF criteria and (ii) to compare patients with restrictive/pseudonormal mitral inflow pattern (MIP) vs. patients with MIP other than restrictive/pseudonormal. METHODS AND RESULTS: We included hospitalized participants of the ESC-Heart Failure Association (HFA) EURObservational Research Programme (EORP) HF Long-Term Registry who had echocardiogram with ejection fraction (EF) ≥ 50% during index hospitalization. As no data on e', E/e' and left ventricular (LV) mass index were gathered in the registry, the 2016 ESC HFpEF definition was modified as follows: elevated B-type natriuretic peptide (BNP) (≥100 pg/mL for acute HF) and/or N-terminal pro-BNP (≥300 pg/mL) and at least one of the echocardiographic criteria: (i) presence of LV hypertrophy (yes/no), (ii) left atrial volume index (LAVI) of >34 mL/m2 ), or (iii) restrictive/pseudonormal MIP. Next, all patients were divided into four groups: (i) patients with restrictive/pseudonormal MIP on echocardiography [i.e. with presumably elevated left atrial (LA) pressure], (ii) patients with MIP other than restrictive/pseudonormal (i.e. with presumably normal LA pressure), (iii) atrial fibrillation (AF) group, and (iv) 'grey area' (no consistent description of MIP despite no report of AF). Of 6365 hospitalized patients, 1848 (29%) had EF ≥ 50%. Natriuretic peptides were assessed in 28%, LV hypertrophy in 92%, LAVI in 13%, and MIP in 67%. The 2016 ESC HFpEF criteria could be assessed in 27% of the 1848 patients and, if assessed, were met in 52%. Of the 1848 patients, 19% had restrictive/pseudonormal MIP, 43% had MIP other than restrictive/pseudonormal, 18% had AF and 20% were grey area. There were no differences in long-term all-cause or cardiovascular mortality, or all-cause hospitalizations or HF rehospitalizations between the four groups. Despite fewer non-cardiac comorbidities reported at baseline, patients with MIP other than restrictive/pseudonormal (i.e. with presumably normal LA pressure) had more non-cardiovascular (14.0 vs. 6.7 per 100 patient-years, P < 0.001) and cardiovascular non-HF (13.2 vs. 8.0 per 100 patient-years, P = 0.016) hospitalizations in long-term follow-up than patients with restrictive/pseudonormal MIP. CONCLUSIONS: Acute HFpEF diagnosis could be assessed (based on the 2016 ESC criteria) in only a quarter of patients and confirmed in half of these. When assessed, only one in three patients had restrictive/pseudonormal MIP suggestive of elevated LA pressure. Patients with MIP other than restrictive/pseudonormal (suggestive of normal LA pressure) could have been misdiagnosed with acute HFpEF or had echocardiography performed after normalization of LA pressure. They were more often hospitalized for non-HF reasons during follow-up. Symptoms suggestive of acute HFpEF may in some patients represent non-HF comorbidities
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