Breeding Innovations in Underutilized Temperate Fruit Trees

The recent growing interest in minor species (i.e., fig, pomegranate, feijoa, etc.) has recently driven new research on breeding and genetics to address producer and consumer traits. Since these species have received little attention from the scientific community, they were less improved via conventional breeding, and lacked detailed genomic information on important traits. This lack of data, together with a general poor genetic knowledge of these species, has limited a wider cultivation of varieties with improved characteristics. For these reasons, and with the objective to increase the interest of scientists, farmers, and consumers for these fruits, this Research Topic “Breeding Innovations in Underutilized Temperate Fruit Trees” comprises biochemical, morphological, and genetic studies on some minor species regarding fruit trait variation, resistance, evolution, or sex determination. In this context, Marcotuli et al. examined the mechanisms behind the bud evolution toward breba or main crop in fig (Ficus carica L.), since this aspect remains unclear. The X-ray images of buds showed a great structural similarity between breba and the main crop during the initial stages of development, but breba inflorescence differentiation was completed in two seasons whereas that of main crop started at the end of winter and was completed within 2–3 months in the same season. The higher expression of floral homeotic protein AGAMOUS in breba compared to the main crop may indicate a role of these fruits on staminate flowers’ production for pollination of the main crop, as profichi act in the caprifig. Within the same species (Ficus carica L.) and for sexual determination, Ikegami et al. analyzed the FcRAN1 gene (during a breeding program for the selection of female plants) strongly associated with the sex phenotype. A male-biased segregation ratio distortion was obtained in 12 F1 populations, suggesting some genetic factor(s) affecting it. A comparison between the annotated genes and the genes required for normal embryo or gametophyte development and function identified several candidate genes responsible for the segregation distortion in fig. Following the same topic, Wang et al. hypothesized an early sex-identification method to improve breeding efficiency. The use of a deletion as a forward primer, a newly established AG-Marker, was as accurate as the RAN1-Marker, and provided the identification of male plants, giving new clues to understanding Ficus sex determination. Moving toward another attracting species, i.e., pomegranate (Punica granatum L.), Trainin et al. investigated the black peel color of some pomegranate varieties. Biochemical analysis revealed that delphinidin is highly abundant in the peel of black varieties and the pattern of anthocyanin accumulation is different from that of other pomegranates with red or pink colors of the peel. Genetic analysis of an F2 population segregating for the black phenotype revealed that it is determined by a single recessive gene. Pomegranate was also studied by Goudappa Patil et al. with regards to the SSR of “Tunisia” pomegranate variety. There was a positive trend in chromosome length and the SSR abundance, as marker density, enhanced with a shorter chromosome length. Examination of the distribution of SSR motif types within a chromosome suggested the abundance of hexanucleotide repeats in each chromosome followed by dinucleotides. A comprehensive set of highly polymorphic genome-wide SSRs was successively developed and tested. These chromosome-specific SSRs could serve as a powerful genomic tool to leverage future genetic studies, germplasm management, and genomics-assisted breeding in pomegranate varieties. Some evolutionary aspects of pear were investigated by Kumar et al. who put a light on runs of homozygosity (ROH) in self-incompatible plants, in particular Asian pears, European pears, and interspecific hybrids using genotyping-by-sequencing. The observed ROH patterns suggested that systematic breeding of European pears would have started earlier than Asian pears. Fruit trait variation in Persian walnut (Juglans regia L.) was addressed by Bernard et al. who conducted a genome-wide association study (GWAS) using multi-locus models in a panel of 170 accessions of J. regia to elucidate the genetic determinants of fruit quality traits in walnut toward the breeding of new varieties. The authors proposed several candidate genes involved in nut characteristics, such as a gene coding for a beta-galactosidase linked to several size-related traits and known to also be involved in fruit development in other species. With regards of fruit traits, Kyratzis et al. investigated the germplasm of an ancient species, the carob (Ceratonia siliqua L.), on the island of Cyprus. The domestic germplasm varies both in terms of pod morphology and composition, reflecting the genetic and physiological characteristics of both grafted and non-grafted accessions, and possibly the impact of agro-environmental conditions. Morphological traits, such as seeds-to-pod weight ratio, pod width, and thickness, were principally under genetic control. Contrarily, chemical compounds, particularly total phenolic content, including condensed tannins, in vitro antioxidant capacity, and to a lesser extent gallic acid, organic acids, sugars (glucose and fructose), and minerals were more under agro-environmental control. In the Southern Hemisphere, Quezada et al. worked on feijoa (Acca sellowiana Berg.), a fruit tree species native to Uruguay and Brazil. A high-density composite genetic linkage map of feijoa was constructed using two genetically populations. Genotyping by sequencing (GBS) approach was successfully applied for developing single nucleotide polymorphism (SNP) markers. They used both the reference genome of the closely related species Eucalyptus grandis and a de novo pipeline to construct a composite map. A novel approach for the construction of composite maps where the meiosis information of individuals of two connected populations is captured in a single estimator is described. The topic of resistance was carried out by Alves et al. in order to find sources of genetic resistance to Huanglongbing (HLB)-associated “Candidatus Liberibacter asiaticus” (Las), one of the most destructive diseases of citrus. Some genotypes from subtribe Citrinae, sexually incompatible but graft-compatible with Citrus, may provide new rootstocks able to restrict bacterial titer in the canopy. Authors tested for Las resistance a wide collection of graft-compatible Citrinae species using an aggressive and consistent challenge-inoculation and evaluation procedure. Eremocitrus glauca and Papua/New Guinea Microcitrus species as well as their hybrids resulted in full resistance, opening the way for using these underutilized genotypes as Las resistance sources in breeding programs

Regulatory circuits involving bud dormancy factor PpeDAM6

DORMANCY-ASSOCIATED MADS-BOX (DAM) genes have recently emerged as key potential regulators of the dormancy cycle and climate adaptation in perennial species. Particularly, PpeDAM6 has been proposed to act as a major repressor of bud dormancy release and bud break in peach (Prunus persica). PpeDAM6 expression is downregulated concomitantly with the perception of a given genotype-dependent accumulation of winter chilling time, and the coincident enrichment in H3K27me3 chromatin modification at a specific genomic region. We have identified three peach BASIC PENTACYSTEINE PROTEINs (PpeBPCs) interacting with two GA-repeat motifs present in this H3K27me3- enriched region. Moreover, PpeBPC1 represses PpeDAM6 promoter activity by transient expression experiments. On the other hand, the heterologous overexpression of PpeDAM6 in European plum (Prunus domestica) alters plant vegetative growth, resulting in dwarf plants tending toward shoot meristem collapse. These alterations in vegetative growth of transgenic lines associate with impaired hormone homeostasis due to the modulation of genes involved in jasmonic acid, cytokinin, abscisic acid, and gibberellin pathways, and the downregulation of shoot meristem factors, specifically in transgenic leaf and apical tissues. The expression of many of these genes is also modified in flower buds of peach concomitantly with PpeDAM6 downregulation, which suggests a role of hormone homeostasis mechanisms in PpeDAM6-dependent maintenance of floral bud dormancy and growth repression

A peach germplasm collection for increasing the genetic diversity in European breeding programs

Trabajo presentado al VIII International Peach Symposium, celebrado en Matera (Italia) del 17 al 20 de junio de 2013.European breeding programs are hampered by the low intraspecific genetic diversity, which is due to the self-compatibility of this homozygous species along with the low number of genotypes introduced and thus used for breeding. In 2009, four research institutions which carried out peach breeding programs in Aragon, Catalonia, Valencia and Murcia, started a new peach germplasm collection worldwide aimed at enlarging the peach genetic diversity available for breeding. The plant material was introduced from germplasm collections located in China, Central Asia, Iran and the USA (National Germplasm Repository of Davis). Sanitary status was assessed by molecular diagnosis of known diseases caused by virus, viroid, bacteria and phytoplasm pathogens. Healthy plant material was grafted and maintained in quarantine conditions. The new germplasm collection was established in two places: Zaragoza as high chilling and Murcia as low chilling requirements. Pomological and molecular data were gathered and a public database constructed. The descriptors used were from the National Center for Genetic Resources from the INIA. Introduced budwood and seeds resulted in more than 250 new genotypes from 15 countries. The molecular analysis of a subset of the collection with 21 SSR markers evenly distributed in the genome resulted in a high number of alleles per SSR (mean A=9.5) and low observed heterozygosity (mean Ho=0.38). Variability was further assessed by geographic origin. Population structure analysis revealed the existence of 8 subpopulations explained, in some cases, by the geographic origin of the genotypes. As a result of the project a new database containing 95 accessions and 38 variables is available.Peer reviewe

Traumatic brain injury: integrated approaches to improve prevention, clinical care, and research

No abstract available

Variation in neurosurgical management of traumatic brain injury

Background: Neurosurgical management of traumatic brain injury (TBI) is challenging, with only low-quality evidence. We aimed to explore differences in neurosurgical strategies for TBI across Europe. Methods: A survey was sent to 68 centers participating in the Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. The questionnaire contained 21 questions, including the decision when to operate (or not) on traumatic acute subdural hematoma (ASDH) and intracerebral hematoma (ICH), and when to perform a decompressive craniectomy (DC) in raised intracranial pressure (ICP). Results: The survey was completed by 68 centers (100%). On average, 10 neurosurgeons work in each trauma center. In all centers, a neurosurgeon was available within 30 min. Forty percent of responders reported a thickness or volume threshold for evacuation of an ASDH. Most responders (78%) decide on a primary DC in evacuating an ASDH during the operation, when swelling is present. For ICH, 3% would perform an evacuation directly to prevent secondary deterioration and 66% only in case of clinical deterioration. Most respondents (91%) reported to consider a DC for refractory high ICP. The reported cut-off ICP for DC in refractory high ICP, however, differed: 60% uses 25 mmHg, 18% 30 mmHg, and 17% 20 mmHg. Treatment strategies varied substantially between regions, specifically for the threshold for ASDH surgery and DC for refractory raised ICP. Also within center variation was present: 31% reported variation within the hospital for inserting an ICP monitor and 43% for evacuating mass lesions. Conclusion: Despite a homogeneous organization, considerable practice variation exists of neurosurgical strategies for TBI in Europe. These results provide an incentive for comparative effectiveness research to determine elements of effective neurosurgical care

Transcriptomic Analysis Reveals Salt Tolerance Mechanisms Present in Date-Plum Persimmon Rootstock (Diospyros lotus L.)

Agriculture needs solutions for adapting crops to increasing salinity globally. Research on physiological and molecular responses activated by salinity is needed to elucidate mechanisms of salinity tolerance. Transcriptome profiling (RNA-Seq) is a powerful tool to study the transcriptomic profile of genotypes under stress conditions. Persimmon species have different levels of tolerance to salinity, this variability may provide knowledge on persimmon species and development of salt--tolerant rootstocks. In this study, we conducted a physiological and transcriptomic profiling of roots and leaves in tolerant and sensitive plants of persimmon rootstock grown under saline and control conditions. Characterization of physiological responses along with gene expression changes in roots and leaves allowed the identification of several salt tolerance mechanisms related to ion transport and thermospermine synthesis. Differences were observed in putative H+/ATPases that allow transmembrane ionic transport and chloride channel protein-like genes. Furthermore, an overexpression of thermospermine synthase found in the roots of tolerant plants may indicate that alterations in root architecture could act as an additional mechanism of response to salt stress. These results indicate that Diospyros lotus L. exhibits genetically-controlled variability for salt tolerance traits which opens potential opportunities for breeding salt-tolerant persimmon rootstocks in a Mediterranean environment challenged by drought and salinity

Application of molecular markers in breeding for resistance to the Plum Pox Virus in Prunus spp.

National audienc

Application of molecular markers in breeding for resistance to the Plum Pox Virus in Prunus spp.

International audienc

Neurological outcomes and mortality of hyperoxaemia in patients with acute brain injury: protocol for a systematic review and meta-analysis

Introduction Oxygen is frequently prescribed in neurocritical care units. Avoiding hypoxaemia is a key objective in patients with acute brain injury (ABI). However, several studies suggest that hyperoxaemia may also be related to higher mortality and poor neurological outcomes in these patients. The evidence in this direction is still controversial due to the limited number of prospective studies, the lack of a common definition for hyperoxaemia, the heterogeneity in experimental designs and the different causes of ABI. To explore the correlation between hyperoxaemia and poor neurological outcomes and mortality in hospitalised adult patients with ABI, we will conduct a systematic review and meta-analysis of observational studies and RCTs.Methods and analysis The systematic review methods have been defined according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and follow the PRISMA-Protocols structure. Studies published until June 2024 will be identified in the electronic databases MEDLINE, Embase, Scopus, Web of Science, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature and ClinicalTrials.gov. Retrieved records will be independently screened by four authors working in pairs, and the selected variables will be extracted from studies reporting data on the effect of ‘hyperoxaemia’ versus ‘no hyperoxaemia on neurological outcomes and mortality in hospitalised patients with ABI. We will use covariate-adjusted ORs as outcome measures when reported since they account for potential cofounders and provide a more accurate estimate of the association between hyperoxaemia and outcomes; when not available, we will use univariate ORs. If the study presents the results as relative risks, it will be considered equivalent to the OR as long as the prevalence of the condition is close to 10%. Pooled estimates of both outcomes will be calculated applying random-effects meta-analysis. Interstudy heterogeneity will be assessed using the I2 statistic; risk of bias will be assessed through Risk Of Bias In Non-Randomised Studies of Interventions, Newcastle-Ottawa or RoB2 tools. Depending on data availability, we plan to conduct subgroup analyses by ABI type (traumatic brain injury, postcardiac arrest, subarachnoid haemorrhage, intracerebral haemorrhage and ischaemic stroke), arterial partial pressure of oxygen values, study quality, study time, neurological scores and other selected clinical variables of interest.Ethics and dissemination Specific ethics approval consent is not required as this is a review of previously published anonymised data. Results of the study will be shared with the scientific community via publication in a peer-reviewed journal and presentation at relevant conferences and workshops. It will also be shared key stakeholders, such as national or international health authorities, healthcare professionals and the general population, via scientific outreach journals and research institutes’ newsletters

A PEACH GERMPLASM COLLECTION FOR INCREASING THE GENETIC DIVERSITY IN EUROPEAN BREEDING PROGRAMS

Trabajo presentado al VIII International Peach Symposium, celebrado en Matera (Italia) del 17 al 20 de junio de 2013.European breeding programs are hampered by the low intraspecific genetic diversity, which is due to the self-compatibility of this homozygous species along with the low number of genotypes introduced and thus used for breeding. In 2009, four research institutions which carried out peach breeding programs in Aragon, Catalonia, Valencia and Murcia, started a new peach germplasm collection worldwide aimed at enlarging the peach genetic diversity available for breeding. The plant material was introduced from germplasm collections located in China, Central Asia, Iran and the USA (National Germplasm Repository of Davis). Sanitary status was assessed by molecular diagnosis of known diseases caused by virus, viroid, bacteria and phytoplasm pathogens. Healthy plant material was grafted and maintained in quarantine conditions. The new germplasm collection was established in two places: Zaragoza as high chilling and Murcia as low chilling requirements. Pomological and molecular data were gathered and a public database constructed. The descriptors used were from the National Center for Genetic Resources from the INIA. Introduced budwood and seeds resulted in more than 250 new genotypes from 15 countries. The molecular analysis of a subset of the collection with 21 SSR markers evenly distributed in the genome resulted in a high number of alleles per SSR (mean A=9.5) and low observed heterozygosity (mean Ho=0.38). Variability was further assessed by geographic origin. Population structure analysis revealed the existence of 8 subpopulations explained, in some cases, by the geographic origin of the genotypes. As a result of the project a new database containing 95 accessions and 38 variables is available.Peer reviewe