The identification of genes involved in variation of peach fruit quality would assist breeders to create new cultivars with improved fruit quality. Peach is a genetic and genomic model within the ...Rosaceae. A large quantity of useful data suitable for fine mapping using Single Nucleotide Polymorphisms (SNPs) from the peach genome sequence was used in this study. A set of 94 individuals from a peach germplasm collection was phenotyped and genotyped, including local Spanish and modern cultivars maintained at the Experimental Station of Aula Dei, Spain. Phenotypic evaluation based on agronomical, pomological and fruit quality traits was performed at least 3 years. A set of 4,558 out of a total of 8,144 SNPs markers developed by the Illumina Infinium BeadArray (v1.0) technology platform, covering the peach genome, were analyzed for population structure analysis and genome-wide association studies (GWAS). Population structure analysis identified two subpopulations, with admixture within them. While one subpopulation contains only modern cultivars, the other one is formed by local Spanish and several modern cultivars from international breeding programs. To test the marker trait associations between markers and phenotypic traits, four models comprising both general linear model (GLM) and mixed linear model (MLM) were selected. The MLM approach using co-ancestry values from population structure and kinship estimates (K model) identified a maximum of 347 significant associations between markers and traits. The associations found appeared to map within the interval where many candidate genes involved in different pathways are predicted in the peach genome. These results represent a promising situation for GWAS in the identification of SNP variants associated to fruit quality traits, potentially applicable in peach breeding programs.
Japanese plums are classified as climacteric; however, some economically important cultivars selected in California produce very little ethylene and require long ripening both "on" and "off" the tree ...to reach eating-ripe firmness. To unravel the ripening behavior of different Japanese plum cultivars, ripening was examined in the absence (air) or in the presence of ethylene or propylene (an ethylene analog) following a treatment or not with 1-methylcyclopropene (1-MCP, an ethylene action inhibitor). Detailed physiological studies revealed for the first time three distinct ripening types in plum fruit: climacteric, suppressed-climacteric, and non-climacteric. Responding to exogenous ethylene or propylene, the slow-softening supressed-climacteric cultivars produced detectable amounts of ethylene, in contrast to the novel non-climacteric cultivar that produced no ethylene and softened extremely slowly. Genetic analysis using microsatellite markers produced identical DNA profiles for the climacteric cultivars "Santa Rosa" and "July Santa Rosa," the suppressed-climacteric cultivars "Late Santa Rosa," "Casselman," and "Roysum" and the novel non-climacteric "Sweet Miriam," as expected since historic records present most of these cultivars as bud-sport mutations derived initially from "Santa Rosa." This present study provides a novel fruit system to address the molecular basis of ripening and to develop markers that assist breeders in providing high-quality stone fruit cultivars that can remain "on-tree," increasing fruit flavor, saving harvesting costs, and potentially reducing the need for low-temperature storage during postharvest handling.
Previous cross-sectional studies report that cognitive impairment is associated with poor psychosocial functioning in euthymic bipolar patients. There is a lack of long-term studies to determine the ...course of cognitive impairment and its impact on functional outcome. Method A total of 54 subjects were assessed at baseline and 6 years later; 28 had DSM-IV TR bipolar I or II disorder (recruited, at baseline, from a Lithium Clinic Program) and 26 were healthy matched controls. They were all assessed with a cognitive battery tapping into the main cognitive domains (executive function, attention, processing speed, verbal memory and visual memory) twice over a 6-year follow-up period. All patients were euthymic (Hamilton Rating Scale for Depression score lower than 8 and Young mania rating scale score lower than 6) for at least 3 months before both evaluations. At the end of follow-up, psychosocial functioning was also evaluated by means of the Functioning Assessment Short Test.
Repeated-measures multivariate analysis of covariance showed that there were main effects of group in the executive domain, in the inhibition domain, in the processing speed domain, and in the verbal memory domain (p<0.04). Among the clinical factors, only longer illness duration was significantly related to slow processing (p=0.01), whereas strong relationships were observed between impoverished cognition along time and poorer psychosocial functioning (p<0.05).
Executive functioning, inhibition, processing speed and verbal memory were impaired in euthymic bipolar out-patients. Although cognitive deficits remained stable on average throughout the follow-up, they had enduring negative effects on psychosocial adaptation of patients.
•‘Translocated’ incompatibility was only found on the Japanese plum cv. ‘Golden Japan’ budded on AP-45.•Plum cvs. exhibited good graft compatibility with all hexaploid plum rootstocks.•‘Reine Claude ...Verte’ showed ‘localized’ incompatibility budded on Myrobalan B and Myrobalan GF 3-1.•‘Stanley’ cv. showed ‘localized’ incompatibility with the six evaluated peach × almond hybrid rootstocks.•Peach-almond and P. cerasifera based rootstocks showed prune brownline disease symptoms with ‘Golden Japan’.
The introduction of some new rootstocks requires knowledge of the potential ‘translocated’ and ‘localized’ graft incompatibilities before releasing these rootstocks into the market. Trials were established at the Aula Dei Experimental Station (Zaragoza, Spain) to assess graft compatibility between five European plum (Prunus domestica L.) and six Japanese plum (Prunus salicina L.) cultivars with thirty-eight rootstocks belonging to peach × almond hybrids, as well as slow-growing, fast-growing and interspecific hybrid plum groups. Some of these rootstocks are under process of selection and others are commercial rootstocks already introduced into the European market. External visual diagnosis of the scion-rootstock graft combinations was performed by observing symptoms of the ‘translocated’ incompatibility in the nursery. Visual symptoms of ‘translocated’ incompatibility were only found on the Japanese plum cv. ‘Golden Japan’ budded on the plum-apricot hybrid AP-45. The ‘localized’ graft incompatibility was assessed after internal macroscopically examination of graft unions. In the case of the European plum cvs., ‘President’ and ‘Reine Claude Tardive of Chambourcy’ exhibited good graft compatibility with all the tested rootstocks, with the exception of ‘President’ budded on the pentaploid plum hybrid rootstock Damas GF 1869. ‘Reine Claude Verte’ cv. showed ‘localized’ incompatibility with Myrobalan B and Myrobalan GF 3-1 since the second year after budding. ‘Stanley’ cv. showed ‘localized’ incompatibility with the six evaluated peach × almond hybrid rootstocks, although it was compatible with all plum based rootstocks. In the case of Japanese plums, four cultivars (‘Angeleno’, ‘Black Amber’,’ Delbarazur’ and ‘Songold’) did not show any graft incompatibility, but ‘Friar’ showed ‘localized’ incompatibility on Myrobalan B. In the case of peach-almond and P. cerasifera based rootstocks (Adarcias, GF 677, Damas GF 1869, Myrobalan B, Myrobalan 29 C, Myrobalan GF 3-1 and Marianna GF 8-1), ‘Golden Japan’ trees showed similar symptoms to those caused by TomRV in Myrobalan and peach rootstocks and ‘localized’ incompatibility. Finally, this study confirmed the interest of P. insititia specie as well as several interspecific Prunus hybrids as a good source of rootstocks for the plum industry.
Grafting is an ancient plant propagation technique widely used in horticultural crops, particularly in fruit trees. However, the involvement of two different species in grafting may lead to lack of ...affinity and severe disorders between the graft components, known as graft-incompatibility. This complex agronomic trait is traditionally classified into two categories: "localized" (weak graft unions with breaks in cambial and vascular continuity at the graft interface and absence of visual symptoms in scion leaves and shoots) and "translocated" (degeneration of the sieve tubes and phloem companion cells at the graft interface causing translocation problems in neighboring tissues, and reddening/yellowing of scion leaves). Over the decades, more attention has been given to the different mechanisms underlying the "localized" type of graft-incompatibility; whereas the phenylpropanoid-derived compounds and the differential gene expression associated with the "translocated" graft-incompatibility remain unstudied. Therefore, the aim of this study was to shed light on the biochemical and molecular mechanisms involved in the typical "translocated" graft-incompatibility of peach/plum graft-combinations. In this study, the "Summergrand" (SG) nectarine cultivar was budded on two plum rootstocks: "Adara" and "Damas GF 1869". "Translocated" symptoms of incompatibility were shown and biochemically characterized in the case of "SG/Damas GF 1869" graft-combination, 3 years after grafting. Non-structural carbohydrates (soluble sugars and starch), phenolic compounds and antioxidant activity, were significantly enhanced in the incompatible graft-combination scion. Similarly, the enzymatic activities of the antioxidant enzyme peroxidase, the phenylalanine ammonia-lyase (PAL) and polyphenol oxidase involved in the phenylpropanoid pathway were significantly affected by the incompatible rootstock "Damas GF 1869", inducing higher activities in the scion than those induced by the compatible rootstock "Adara". In addition, a positive and strong correlation was obtained between total phenol content, antioxidant capacity and the expression of the key genes involved in the phenylpropanoid pathway,
and
. Regarding the "SG/Adara" graft-combination, there were neither external symptoms of "translocated" incompatibility nor significant differences in the biochemical and molecular parameters between scion and rootstock, proving it to be a compatible combination. The differential expression of
genes together with the biochemical factors cited above could be good markers for the "translocated" peach/plum graft-incompatibility.
To design an appropriate association study, we need to understand population structure and the structure of linkage disequilibrium within and among populations as well as in different regions of the ...genome in an organism. In this study, we have used a total of 98 almond accessions, from five continents located and maintained at the Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA; Spain), and 40 microsatellite markers. Population structure analysis performed in 'Structure' grouped the accessions into two principal groups; the Mediterranean (Western-Europe) and the non-Mediterranean, with K = 3, being the best fit for our data. There was a strong subpopulation structure with linkage disequilibrium decaying with increasing genetic distance resulting in lower levels of linkage disequilibrium between more distant markers. A significant impact of population structure on linkage disequilibrium in the almond cultivar groups was observed. The mean r2 value for all intra-chromosomal loci pairs was 0.040, whereas, the r2 for the inter-chromosomal loci pairs was 0.036. For analysis of association between the markers and phenotypic traits, five models comprising both general linear models and mixed linear models were selected to test the marker trait associations. The mixed linear model (MLM) approach using co-ancestry values from population structure and kinship estimates (K model) as covariates identified a maximum of 16 significant associations for chemical traits and 12 for physical traits. This study reports for the first time the use of association mapping for determining marker-locus trait associations in a world-wide almond germplasm collection. It is likely that association mapping will have the most immediate and largest impact on the tier of crops such as almond with the greatest economic value.
Apple is widely cultivated in temperate regions. The beneficial properties of apple for preventing several illnesses are widely known. Nevertheless, qualitative variables such as sweetness or ...sourness may influence consumer satisfaction; they are critical factors for fruit consumption and essential in plant breeding. In the present work, 155 apple accessions were assessed during five consecutive years (2014–2018). Four individual sugars and seven organic acids were analysed by HPLC. A mixed-effects model was fitted with accessions and the years’ climatic features as independent variables. A cluster analysis was applied on the mixed-effects model coefficients. Four groups were considered as optimum. Genetics seemed to have the strongest effect and showed clear differences between accession groups, while climate effects were strong only for certain compounds and had a more horizontal behaviour equally affecting the different accession groups. In fact, non-Spanish cultivars tended to concentrate, while autochthone accessions had a much wider spread. Individual sugars and acids concentrations correlated negatively with precipitation and positively with temperature range and solar radiation in all accession groups. The geographic region where the orchard is grown is thus very important in the resulting metabolites profiles. Moreover, apple genetics would also play a decisive role as highlighted in the cluster analysis.
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