23 research outputs found
Evaluation of novel peach cultivars in the European Union: the EUFRIN Peach and Apricot Working Group initiative
No full textPeach cultivars can undergo large performance variations when cultivated in different environmental conditions. As growers cannot afford the financial risk of choosing a cultivar unsuited to their specific conditions, information as comprehensive as possible on the marketed cultivars is useful and highly needed. Several organizations in the European Union (EU) are engaged in the performance assessment of the novel cultivars based on experimental trials. However, the exchange of information is overall poor, limiting the completeness of information on new releases that would derive from integrating the results obtained in various climatic and agronomical contexts. The Apricot and Peach working group established in 2014 within EUFRIN (European Fruit Research Institutes Network, www.eufrin.org) has recently embarked on a new initiative aiming to implement a collaborative varietal evaluation system in the EU countries. The first step was the establishment o fa common list of descriptors to assess the performance of peach cultivars in the testing trials. About 40 descriptors, related to different phenological traits as flowering or harvest period, productivity, fruit appearance and internal quality, susceptibility to physiological disorders and to some major diseases in peach were selected. The protocols to measure and score each trait are being set up, as well as the selection of a common set of cultivars to include as references in the various testing sites in order to homogenize the evaluation. Implementation of this network will allow a real-time information exchange on the new peach releases
Design and simulation of an integrated optical CMOS heart rate sensor
No full textAn optical CMOS heart rate sensor that processes the photoplethysmographic signal was designed and fabricated in Austriamicrosystems 0.35um CMOS process. The sensor consists of photodiode, transimpedance amplifier, analogue bandpass filters, analogue-to-digital converters, digital signal processor, and a timing circuit that is used to modulate the external light-emitting diodes. The mixed-signal simulation has been carried out to validate the system design. With modulated green light source and integrated lock-in detection the sensor is capable of extracting clean photoplethysmographic signal when it is operated in reflectance mode. The heart rate output was compared with commercial devices and they show a good agreement. The chip-level integration enables a small footprint of the design and makes it suitable for the applications of ambulatory monitoring
Protein and mineral nutrient contents in kernels from 72 sweet almond cultivars and accessions grown in France, Greece and Italy
No full textAlmond protein and potassium (K), phosphorus (P), calcium (Ca) and magnesium (Mg) contents were determined in 72 cultivars and accessions grown in France, Greece and Italy, as part of the networking of European SAFENUTAGRI GEN RES project, which aimed to explore and valorize the almond genetic resources in Europe. Great variation was found in the nutrient content and the amount of nutrient supplied when consuming the recommended daily amount of one serving of almond, among the different genotypes assayed. The variation among the different genotypes was greatest for Ca, followed by the protein content; the latter also exhibited the lowest variation considering the harvest year. Results from a principal component analysis showed that P and Mg were the most discriminant elements for categorizing samples. Cluster analysis showed groups of samples with interesting characteristics for breeding. There was no clear distinction among the different origins of samples. Correlation analyses between weather conditions and the nutrients assayed showed that the mean temperature recorded in the period between March and September was positively correlated with Ca and P only in France, a place where the greatest climatic difference between years was observed
Fruit Quality Traits and Genotypic Characterization in a Pomegranate Ex Situ (Punica granatum L.) Collection in Greece
No full textPomegranate is one of the oldest known fruit crops, well adapted to hot and dry areas and successfully grown in Mediterranean countries. During the last two decades, numerous publications have revealed the traditionally known associations between pomegranate consumption and health benefits, which led to increased demand by consumers and expansion in cultivation areas. Pomegranate is well adapted to areas with diverse pedoclimatic conditions and local cultivars could provide an essential source of genes for breeding. In this study, fruit phenotypic and genetic variability, and relationships, were studied in 26 Greek and foreign pomegranate cultivars/accessions grown in an ex situ collection located in Naoussa Greece, using Inter Simple Sequence Repeat (ISSR) and Start Codon Targeted (SCoT) molecular markers. Results from the principal component analysis made on fruit phenotypic characters revealed five components that accounted for 74.8% of the total variance, the first being related to skin color parameters and the second to juice antioxidant contents and aril color. Clustering from phenotypic data allocated individuals into four clusters. A total of 184 bands were generated for all markers applied across the 26 pomegranate cultivars/accessions, with an average of 77 bands per ISSR markers and 82 bands for SCoT markers. Low variability in the phenotypic and genotypic level was indicated; nevertheless, results from the association study between phenotypic traits and molecular markers that were obtained using Multiple Regression Analysis (MRA) could prove valuable for marker-assisted breeding programs, especially from SCoT markers that were found to be strongly or averagely associated with the morphological traits and chemical components
Estimation of chilling and heat requirements of peach and nectarine cultivars grown under different pedoclimatic conditions
No full text8 Pags.- 4 Tabls. Article published from a contribution by the Authors to X International Peach Symposium (Naoussa, Grecia. 30 mayo-3 junio, 2022)Climate change is already depicted as an increase in winter temperatures
resulting in lower chilling accumulation that is required for proper flowering and
subsequent fruit set in temperate fruit species. Since temperature requirements are
cultivar-specific, the knowledge of these requirements may be valuable for predicting
the adaptability of each cultivar to particular areas. The most widely used method for
estimating chilling requirements is the Tabuenca test. However, little is known on the
stability of results obtained from the above methodology in different years or
pedoclimatic conditions. To this aim, experiments were carried out in Lleida (Spain)
and Naoussa (Greece) on 14 different peach and nectarine cultivars, representing a
wide range of pomological and phenological characteristics, belonging to the EUFRIN
testing trial network. Chilling accumulation was similar in both locations, but the most
efficient chilling period was earlier in winter in Lleida, resulting to a mean of a 2-day
earlier end of dormancy (15 January vs 17 January). Following endodormancy, heat
accumulation was much higher in Naoussa resulting in a 12-day earlier beginning of
bloom, suggesting that blooming time was more regulated by heat rather than cold
accumulation in both locations. Chill requirements of the studied cultivars were
estimated using four models; low coefficient of variation (CV%) was observed using the
Dynamic, Utah and Positive Utah Models. Instead, high CV% was found with the Chilling
Hours model and no significant differences among cultivars, indicating for a low
suitability in the studied regions. Chilling requirements ranged from 48.3 to 68.7
Chilling Portions (CP); in the lowest range were ‘Carla’, ‘Patty’ and ‘Big Top’ (48.3, 51.0
and 55.8 CP, respectively) whereas ‘Catherina’ and ‘O’Henry’ (64.0 and 68.7 CP,
respectively) had the highest chilling requirements. No differences in heat
requirements among the examined cultivars was monitored. There was no effect of
location on chilling and heating requirements of the studied cultivars, apart from the
Positive Utah and Chilling Hours models; to this aim more studies under more
contrasting chilling regimes are needed to further elucidate the effect of pedoclimatic
conditions for a given cultivar.PD and GP were financed by the European Union and Greek national funds through the
Operational Program Competitiveness, Entrepreneurship and Innovation, under the call
RESEARCH – CREATE - INNOVATE (project code: Τ1EDK-05438).Peer reviewe
Over-expression of ascorbate oxidase in the apoplast of transgenic tobacco results in altered ascorbate and glutathione redox states and increased sensitivity to ozone
No full textTransgenic tobacco (Nicotiana tabacum L. cv. Xanthi) plants expressing cucumber ascorbate oxidase (EC.1.10.3.3) were used to examine the role of extracellular ascorbic acid in mediating tolerance to the ubiquitous air pollutant, ozone (O3). Three homozygous transgenic lines, chosen on the basis of a preliminary screen of AO activity in the leaves of 29 lines, revealed up to a 380-fold increase in AO activity, with expression predominantly associated with leaf cell walls. Overexpression of AO resulted in no change in the total ascorbate content recovered in apoplast washing fluid, but the redox state of ascorbate was reduced from 30% in wild-type leaves to below the threshold for detection in transgenic plants. Levels of ascorbic acid and glutathione in the symplast were not affected by AO overexpression, but the redox state of ascorbate was reduced, while that of glutathione was increased. AO overexpressing plants exposed to 100 nmol mol-1 ozone for 7 h day-1 exhibited a substantial increase in foliar injury, and a greater pollutant-induced reduction in both the light-saturated rate of CO2 assimilation and the maximum in vivo rate of ribulose-1,5-bisphosphate carboxylase/oxygenase carboxylation, compared with wild-type plants. Transgenic plants also exhibited a greater decline in CO2 assimilation rate when exposed to a brief ozone episode (300 nmol mol-1 for 8 h). Stomatal conductance, hence O3 uptake, was unaffected by AO over-expression. Our findings illustrate the important role played by ascorbate redox state and sub-cellular compartmentation in mediating the tolerance of plants to ozone-induced oxidative stress.</p
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Genetic assessment of the pomological classification of plum Prunus domestica L. accessions sampled across Europe
No full textThe genotyping of European fruit tree collections has helped to identify synonyms, determine parentage, reveal key specimens in the collections and provide information on the development of modern cultivars from one or several progenitors. However, studies on European plum Prunus domestica have been lagging behind, mainly because of the hexaploid chromosome number. In this co-operative study, 104 accessions conserved by 14 partners across Europe were phenotyped for 20 descriptors, and genotyped for 8 SSR loci together with 8 reference cultivars. Based on the descriptors as well as additional information supplied by the partners, as well as the scientific and horticultural literature, each accession was assigned to one of six pomological groups; (1) egg plums sensu lato (E), (2) prunes of the French d’Agen type (P/A), (3) prunes of the Central-Southeast European Zwetschen type (P/Z), (4) greengages (G), (5) mirabelles (M) and (6) bullaces, damsons and var. pomariorum (D/B). A MANOVA conducted on descriptor data revealed significant differentiation among the pomological groups as well as a geographic impact on the differentiation of local plum accessions in Europe. SSR data showed that two trios and seven pairs of genotypes had very similar allele profiles and possibly are genetically identical in spite of different accession names. An AMOVA indicated sparse genetic differentiation when accessions were grouped according to geographic origin whereas significant differences were obtained among pomological groups. A Bayesian analysis of genetic structure, as well as a discriminant analysis of principal components (DAPC), further revealed levels of similarity among and within the different pomological groups, suggesting that egg plums sensu lato (E) and greengages (G) can be referred to subsp. domestica while damsons and bullaces (D/B) but also Central-Southeast European prunes (P/Z) show more affinity to subsp. insititia. The small and possibly heterogeneous groups with mirabelles (M) and prunes of the d’Agen type (P/A) take an intermediate position suggesting a hybridogenic origin
