Pyrus Communis Research Articles

Mass Spectrometric Identification of Metabolites after Magnetic-Pulse Treatment of Infected Pyrus communis L. Microplants

The major goal of this study is to create a venue for further work on the effect of pulsed magnetic fields on plant metabolism. It deals with metabolite synthesis in the aforementioned conditions in microplants of Pyrus communis L. So far, there have been glimpses into the governing factors of plant biochemistry in vivo, and low-frequency pulsed magnestatic fields have been shown to induce additional electric currents in plant tissues, thus perturbing the value of cell membrane potential and causing the biosynthesis of new metabolites. In this study, sixty-seven metabolites synthesized in microplants within 3–72 h after treatment were identified and annotated. In total, thirty-one metabolites were produced. Magnetic-pulse treatment caused an 8.75-fold increase in the concentration of chlorogenic acid (RT = 8.33 ± 0.0197 min) in tissues and the perturbation of phenolic composition. Aucubin, which has antiviral and antistress biological activity, was identified as well. This study sheds light on the effect of magnetic fields on the biochemistry of low-molecular-weight metabolites of pear plants in vitro, thus providing in-depth metabolite analysis under optimized synthetic conditions. This study utilized high-resolution gas chromatography-mass spectrometry, metabolomics methods, stochastic dynamics mass spectrometry, quantum chemistry, and chemometrics, respectively. Stochastic dynamics uses the relationships between measurands and molecular structures of silylated carbohydrates, showing virtually identical mass spectra and comparable chemometrics parameters.

Changes of the antioxidant system in pear (Pyrus communis L.) fruits by foliar application of copper, selenium, iron, and zinc nanoparticles

Innovations in agricultural nanotechnology are a viable option for improving the antioxidant system in the pear crop helping to mitigate the different types of abiotic and biotic stresses whose effects have increased due to the advance of climate change. Therefore, foliar applications were made with nanoparticles (NPs) of copper (Cu), iron (Fe), and zinc (Zn) at 250 ppm, as well as applications with selenium (Se) at 50 ppm, and control with water in a commercial pear orchard (Bartlett variety), to evaluate its effect on the behavior of the enzymatic antioxidant system, the concentration of bioactive compounds, and the evaluation of damage by lipid peroxidation, hydrogen peroxide concentration, and activity of polyphenol oxidases (PPO) in the fruits. The results indicate that the Cu and Se NPs stimulated in the fruits a greater synthesis of total phenols, flavonoids, and ascorbic acid, achieving higher concentrations than the control fruits, and also exhibited greater antioxidant activity in vitro. An opposite effect was observed in the fruits of the treatment with Zn NPs, since the concentration of phenols and flavonoids was reduced by 33.14 and 34.24 %, respectively, as well as a decrease in antioxidant activity. On the other hand, the Cu and Fe NPs improved the activity of the enzymes superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase, additionally, the integrity of the membranes was maintained, thus avoiding enzymatic browning due to the activity of the PPOs in the fruits. The highest concentration of malondialdehyde and PPOs activity was observed in the fruits of the treatment with Se and Zn NPs. The results indicate that the application of Cu NPs at 250 ppm can improve the enzymatic and non-enzymatic antioxidant system in Bartlett cultivar pear fruits.

Usefulness of Living Mulch in Rows in a Dwarf Pear, Pyrus communis L., Orchard

The key problem in the cultivation of densely planted dwarf orchards is the removal of weeds—trees’ competitors for habitat resources. There is an urgent need to look for ecological methods of weed control as an alternative to herbicides that are harmful to the environment. The use of living mulch (LM) in tree rows additionally improves soil quality but usually weakens tree growth and may reduce yield. The aim of this 11-year experiment was to assess the impact of the use of two different LMs in rows (Trifolium repens—Tr and Agrostis capillaris—Ac) on the growth, yield, and fruit quality of three pear cultivars on Quince S1 rootstock compared to herbicide fallow. The presence of LM did not significantly affect tree growth. There was no significant effect of either mulch on the cumulative yield. However, for the first 4–6 years, the yield was clearly lower than in the control, which changed in the later years of the experiment. When LMs were used, pear trees showed a significantly lower tendency to alternate fruiting. The average fruit weight was significantly lower in Tr, but the other parameters of external fruit quality did not differ significantly. Furthermore, a smaller share of ultra-small fruit was found with LM compared to the control. The LM did not significantly affect such parameters as the content of soluble solids, vitamin C, Ca, Mg, and P. The use of Ac in dwarf pear orchards with sowing in tree rows is recommended in the 2nd or 3rd year after planting at the earliest.

Current state of trees and shrubs vegetation conditional references linden-ash oakwoods flood places of Dniprovsk Prisamarya

Natural oakwoods are considered one of the main centers of biodiversity of flora and fauna in Europe and an important agent of providing a wide range of ecosystem, sociocultural and economic services. But in the modern period, there is a decrease in the share of common oak natural forests in the forest reserves of European countries and various manifestations of their degradation. Floodplain forests form a particular value among natural oakwoods. They’re not only play an important role in the formation of vegetation and biogeocenotic cover, but also have a significant positive environment-transforming effect on soil-hydrological and mesoclimatic conditions. That helps to regulate the hydrological regime of river floods. An analysis of the current state of the tree-shrub vegetation of conditional reference linden-ash oakwoods of the central floodplain of the Samara River was conducted. They are a complex of forest vegetation component of Prysamary Dniprovskyi, the territory of which is reserved for the creation of a national nature park. The forest valuation indicators of stands of the main forest-forming tree species have been determined. According to the obtained data, the species composition of tree-shrub vegetation and the type of stand correspond to typical fresh central floodplain linden-ash forests. An increase in the share of participation in the tree stand of Acer campestre and a decrease of Tilia cordata are characteristic. Quercus robur and Fraxinus excelsior take a leading part in the formation of stocks of stem wood. It is determined that in the natural linden-ash oak centropopulation Fraxinus excelsior, Acer platanoides, Acer campestre, Ulmus laevis, Tilia cordata, Ulmus glabra, Pyrus communis, Ulmus minor belong to the normal type and are stable and capable of self-maintenance. The most active self-regeneration is recorded in Acer campestre. The population of Quercus robur is characterized as regressive with signs of disruption of natural regeneration processes and the absence of healthy undergrowth. Fraxinus excelsior, Acer platanoides, Ulmus laevis, Pyrus communis are distinguished by the highest indicators of vitality ((Ln) and according to the index of relative vitality their tree stands belong to the “healthy” categoty. The tree stand of Quercus robur belongs to the “weakend” category. Deterioration of the vitality of Quercus robur tree stands and disruption of its self-regeneration processes can potentially lead to a decrease in the edifying role of oak in fresh linden-ash forets of the valley complex of the Samara River. Also, it can lead to a transformation of their type of wood composition and a decrease in productivity. Major of environmental significance of the forest vegetation of this area requires systematic comprehensive monitoring studies to update current data on the state of unique natural oakwoods. The presented results are a continuation of the monitoring studies of natural reference central floodplain linden-ash forests and can become the basis for the development of differentiated methods of their preservation and restoration.

Gas Exchanges and Physiological Responses Differ Among ‘Pyrodwarf’ Clonal and ‘Dargazi’ Seedling Pear (Pyrus communis L.) Rootstocks in Response to Drought Stress

Gas Exchanges and Physiological Responses Differ Among ‘Pyrodwarf’ Clonal and ‘Dargazi’ Seedling Pear (Pyrus communis L.) Rootstocks in Response to Drought Stress

Discovery of microRNAs in Pyrus stigma exudates opens new research avenues in Horticulture.

In many plant species, flower stigma secretions are important in early stages of sexual reproduction. Previous chemical analysis and proteomic characterization of these exudates provided insights into their biological function. Nevertheless, the presence of nucleic acids in the stigma exudates has not been previously reported. Here, we studied the stigma exudates of Pyrus communis, Pyrus pyrifolia, and Pyrus syriaca and showed them to harbor extracellular RNAs of various sizes. RNA sequencing revealed, for the first time, the presence of known Rosaceae mature microRNAs (miRs), also abundant in the stigma source tissue. Predicted targets of the exudate miRs in the Arabidopsis thaliana genome include genes involved in various biological processes. Several of these genes are pollen transcribed, suggesting possible involvement of exudate miRs in transcriptional regulation of the pollen. Moreover, extracellular miRs can potentially act across kingdoms and target genes of stigma interacting organisms/microorganisms, thus opening novel applicative avenues in Horticulture.

Insights into the Evolution of Ohnologous Sequences and Their Epigenetic Marks Post-WGD in Malus Domestica.

A Whole Genome Duplication (WGD) event occurred several Ma in a Rosaceae ancestor, giving rise to the Maloideae subfamily which includes today many pome fruits such as pear (Pyrus communis) and apple (Malus domestica). This complete and well-conserved genome duplication makes the apple an organism of choice to study the early evolutionary events occurring to ohnologous chromosome fragments. In this study, we investigated gene sequence evolution and expression, transposable elements (TE) density, and DNA methylation level. Overall, we identified 16,779 ohnologous gene pairs in the apple genome, confirming the relatively recent WGD. We identified several imbalances in QTL localization among duplicated chromosomal fragments and characterized various biases in genome fractionation, gene transcription, TE densities, and DNA methylation. Our results suggest a particular chromosome dominance in this autopolyploid species, a phenomenon that displays similarities with subgenome dominance that has only been described so far in allopolyploids.

Genome-wide identification, comparative analysis and functional roles in flavonoid biosynthesis of cytochrome P450 superfamily in pear (Pyrus spp.)

BackgroundThe cytochrome P450 (CYP) superfamily is the largest enzyme metabolism family in plants identified to date, and it is involved in many biological processes, including secondary metabolite biosynthesis, hormone metabolism and stress resistance. However, the P450 gene superfamily has not been well studied in pear (Pyrus spp.).ResultsHere, the comprehensive identification and a comparative analysis of P450 superfamily members were conducted in cultivated and wild pear genomes. In total, 338, 299 and 419 P450 genes were identified in Chinese white pear, European pear and the wild pear, respectively. Based on the phylogenetic analyses, pear P450 genes were divided into ten clans, comprising 48 families. The motif and gene structure analyses further supported this classification. The expansion of the pear P450 gene family was attributed to whole-genome and single-gene duplication events. Several P450 gene clusters were detected, which have resulted from tandem and proximal duplications. Purifying selection was the major force imposed on the long-term evolution of P450 genes. Gene dosage balance, subfunctionalization and neofunctionalization jointly drove the retention and functional diversification of P450 gene pairs. Based on the association analysis between transcriptome expression profiles and flavonoid content during fruit development, three candidate genes were identified as being closely associated with the flavonoid biosynthesis, and the expression of one gene was further verified using qRT-PCR and its function was validated through transient transformation in pear fruit.ConclusionsThe study results provide insights into the evolution and biological functions of P450 genes in pear.

A MADS-box gene-induced early flowering pear (Pyrus communis L.) for accelerated pear breeding.

There have been a considerable number of studies that have successfully sped up the flowering cycle in woody perennial horticultural species. One particularly successful study in apple (Malus domestica) accelerated flowering using a silver birch (Betula pendula) APETALA1/FRUITFULL MADS-box gene BpMADS4, which yielded a good balance of vegetative growth to support subsequent flower and fruit development. In this study, BpMADS4 was constitutively expressed in European pear (Pyrus communis) to establish whether this could be used as a tool in a rapid pear breeding program. Transformed pear lines flowered within 6-18 months after grafting onto a quince (Cydonia oblonga) rootstock. Unlike the spindly habit of early flowering apples, the early flowering pear lines displayed a normal tree-like habit. Like apple, the flower appearance was normal, and the flowers were fertile, producing fruit and seed upon pollination. Seed from these transformed lines were germinated and 50% of the progeny flowered within 3 months of sowing, demonstrating a use for these in a fast breeding program.

Cover crops in pear (Pyrus communis) orchards: effects on soil nematode assemblage

Long-term vegetation cover can affect soil organic carbon content and carbon flow within the soil food web. Nematode trophic structure and soil properties were evaluated in pear rows (intra) maintained without weeds applying herbicide and in the inter-rows (between rows) covered with: Medicago+grasses (MG), fescue or spontaneous vegetation. Soil samples were taken at 0-20 and 20-40 cm depths from 2012 to 2014. Nematode assemblage was different in each inter-row and row, mainly in the topsoil. The inter-rows were reservoirs of omnivores-predators. The MG inter-row promoted the highest accumulation of organic carbon, total N and exchangeable K in the soil. The enrichment index was related to the quantity of dry matter produced by cover crops with the highest index observed in MG. Nematode biomass showed a positive correlation with intra and inter-rows soil organic carbon. Carbon flow through bacterivores prevailed in intra-rows, while bacterivores or herbivores canalized the inter-rows. Highlights: Each cover crop (Medicago+grasses, spontaneous vegetation and fescue) was associated with a different nematode assemblage, mainly in the topsoil. Omnivores-predators were higher in the inter-row than its associated row. Nematode Biomass showed a positive correlation with the content of SOC in the row and in the inter-row. Soil energy channels revealed higher carbon flow within the soil food web under Medicago+grasses and spontaneous vegetation than under fescue.

Quality attributes of dehydrated pear (Pyrus communis L.) as affected by conventional and novel blanching techniques

ABSTRACT A study was conducted to assess the impact of different blanching methods and blanching time on the quality of dried pear slices. Pears are only available seasonally, making the production of high-quality dried slices a valuable commodity. The pears were prepared and sliced before being blanched using three different methods: traditional blanching with hot water, blanching with steam, and microwave blanching for varying lengths of time. After blanching, the slices were cooled and then placed on filter papers to dry. The dried slices were then evaluated for chemical properties, such as sugars, total soluble solids, titratable acidity, ascorbic acid, Brix/acid ratio, ash content, and moisture content. Sensory properties such as color, taste, texture, and overall acceptability were also evaluated using a 9-point hedonic scale. The data generated were analyzed using a two-way analysis of variance (ANOVA) to determine the significant differences between variables. The results showed that the blanching method used had a non-significant effect (p < .05) on the chemical properties of the pear slices, such as total sugars (reducing and non-reducing), total soluble solids, titratable acidity, ascorbic acid, Brix/acid ratio, ash content, and moisture content. However, there was no significant effect on the sensory properties of color, texture, taste, and overall acceptability. In conclusion, blanching is an effective technique for preventing microbial growth and chemical and enzymatic reactions that can lead to the deterioration of dried pear slices. It also helps to remove moisture without adversely affecting the physicochemical and sensory quality attributes of the final product.

New Hosts, Distribution, and Color Trap Preferences of the Invasive Thrips Scirtothrips dorsalis (Thysanoptera: Thripidae) in Mexico

Abstract Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is an insect of Asian origin and is currently distributed in several countries around the world. It has highly polyphagous habits and has been reported as a primary pest of different fruit, horticultural, and ornamental crops. This species was reported in Mexico in 2020, however, due to its invasive nature and its rapid adaptation to new ecosystems, it is probably present in other regions of the country. The lack of information on this pest has resulted in misidentifications and misdiagnosis at the field level by phytosanitary technicians. In the present work, we found that S. dorsalis is distributed in the states of Veracruz, Sinaloa, Jalisco, and Michoacán in Mexico occupying sites with different climates (warm and temperate) and elevations from 6 to 1,721 m above sea level. Plant reproductive hosts were blackberry (Rubus sp.), blueberry (Vaccinium sp.), Persian lime (Citrus latifolia Tanaka), mango (Mangifera indica L.), and pear (Pyrus communis L.). Through an evaluation of the response of adults toward chromatic traps, we found that this species greatly prefers yellow (×5.40) compared with blue color. More studies are needed on detection and control measures in order to reduce the distribution and economic impact caused by this insect pest in Mexico.

Effect of Regulated Deficit Irrigation (RDI) on the Growth and Development of Pear Fruit (Pyrus communis L.), var. Triunfo de Viena

The irrigation of crops represents 70% of the world’s water use. For crops grown in high-altitude tropical climates, due to the decrease in rainfall with increasing altitude, along with the effects of global warming, it is necessary to propose alternatives for sustainable fruit production with reduced water consumption. This study was carried out in Sesquilé, Colombia (South America), at an altitude of 2595 m a.s.l. for two successive years with pear trees, var. Triunfo de Viena. The objective of this work was to determine the effect of regulated deficit irrigation (RDI) on the absolute and relative growth rates of the equatorial diameter of the fruits, the fresh and dry weights, the number of fruits, the yield per tree and the water potential of the fruits. In 2014, during the rapid growth phase of the fruit, one group of plants was irrigated at 100% of the crop evapotranspiration (ETc) (control), another at 74% and a third group at 60%. In 2015, the three groups were irrigated at 100%, 48% and 27% of the ETc. The use of RDI did not significantly affect the growth of the fruits. This study showed that the ‘Triunfo de Viena’ pear tree not only has sufficient adaptive reserves, but also has good ecological plasticity under water stress conditions in high-altitude tropical climates. In cases where water is a limiting factor for pear tree production, RDI can obtain production rates similar to those of a regularly irrigated crop, as long as this technique is used and implemented in phenological states of low sensitivity to water stress without exceeding the tolerance limits of the plants to the stressor.

First report of Didymella macrostoma causing calyx-end rot of pear (Pyrus communis) in The Netherlands.

Pear (Pyrus communis) is an important fruit crop in the Netherlands, with a total production of 400,000 tons in 2020, and 'Conference' is the main pear cultivar that comprises 80% of total pear production area. In the Netherlands, pears are kept in controlled atmosphere cold storage (-0.5°C) up to 11 months after harvest. Calyx-end rot incidences of 1% to 5% were observed on 'Conference' pears from different orchards in surveys from 2019-2021 in packing houses in the Netherlands. Infections showed 1 to 3 cm brown necrosis. Lesions were round, slightly sunken and next to or including part of the calyx. To isolate the causal agent, fruit were rinsed with sterile water, lesions were sprayed with 70% ethanol until droplet runoff, the skin was removed aseptically with a scalpel, and tissue under the lesion was isolated and placed onto Potato Dextrose Agar (PDA) (Oxoid, UK). The PDA plates were incubated at 20°C in the dark, and hyphal tip isolates were transferred to fresh PDA plates. Colonies on PDA were rosy-whitish to peach-colored. Colonies grown on oat meal agar (OA) under UV light were peach to red color, aerial mycelium sparse, and produced a pink to salmon colored conidial matrix. Conidia were irregular-ellipsoidal to allantoid, smooth, hyaline and usually with one or several gutulles. Conidia were sometimes one septate and measured 15.2±2.8 x 4.0±0.7 μm (n =14), but mostly aseptate and measured 7.9±1.7 x 3.2±0.6 μm (n =100). The fungus was morphologically identical to Didymella macrostoma (syn. Phoma macrostoma) (Boerema et al. 2004; Hou et al. 2020). The identity of four representative isolates, WURR-206, WURR-223, WURR-227 and WURR-308, from affected pears from four orchards in the Netherlands, was determined by multilocus gene sequencing. To this end, genomic DNA was extracted using the LGC Mag Plant Kit (Berlin, Germany) in combination with the Kingfisher method (Waltham, MA). Sequences of the internal transcribed spacer (ITS) region of ribosomal DNA, the large-subunit rRNA (LSU) region, partial sequences of beta-tubulin (TUB) and the translation elongation factor 1-alpha (TEF1) gene region were amplified with primers ITS1/ITS4 (White et al. 1990), LROR/LR5 (Vilgalys and Hester 1990), Btub2Fd/Btub4Rd (Woudenberg et al. 2009) and EF1-983F/EF1-1567R (Rehner and Buckley 2005), respectively. Sequences were deposited under GenBank accession numbers ON077588-ON077591 (ITS), ON113487-ON113490 (LSU), ON098515-ON098518 (TUB) and ON098519-ON098522 (TEF1). MegaBLAST analysis revealed that the ITS, LSU, TUB sequences matched with 100% identity to culture collection sequences of Didymella macrostoma in GenBank MH854841 (ITS), MH866341 (LSU), MN983895 (TUB). The TEF1 sequences matched with 99.7% identity to TEF sequence of Didymella macrostoma MT454020. Subsequently, Koch's postulates were performed on 10 'Conference' pears per isolate (WURR-206, WURR-223, WURR-227 and WURR-308). Fruits wiped with 70% ethanol were inoculated in pathogenicity tests with an agar disk (5 mm diameter) of D. macrostoma prepared from the actively growing edge of 14-day-old cultures grown on PDA. Inoculated fruits were sealed in plastic bags and were incubated in darkness at 20°C. Typical symptoms appeared 7-10 days after inoculation on all pears. PDA-only controls remained symptomless. Fungal colonies isolated from the lesions and cultured on PDA morphologically resembled the original isolate from the infected pears. The identity of the re-isolations was confirmed as D. macrostoma by sequencing, thus completing Koch's postulates. To the best of our knowledge, this is the first report of D. macrostoma causing calyx-end rot of pears. The identification of this causal agent is important knowledge necessary for developing control measures for postharvest diseases of pear.

Occurrence of Microplastics in Most Consumed Fruits and Vegetables from Turkey and Public Risk Assessment for Consumers.

Microplastics are transferred to humans through the food chain by consuming food contaminated with microplastics. However, the knowledge about the risks of dietary exposure for humans to these particles is very limited. Moreover, only a few studies on microplastic pollution in fruit and vegetables have been carried on. Thus, this study aims to investigate the presence of microplastics in some of the most consumed fruits and vegetables (pear (Pyrus communis), apple (Malus domestica), tomato (Solanum lycopersicum), onion (Allium cepa), potatoes (Solanum tuberosum), and cucumber (Cucumis sativus)) from Turkey and to evaluate the potential risk for consumers. Fruits and vegetable samples were purchased from different markets and fruiterer (two of each) in Muğla province, Southwest of Turkey. Microplastic extraction processes were carried out on the edible parts of the samples. According to the results obtained, a total of 210 particles (2.9 ± 1.6 particle g-1) were detected in all samples. Any significant difference occurred among the different markets. The maximum average amount of microplastic was determined in tomato samples (3.63 ± 1.39 particle g-1). The highest microplastic intake was with tomato (398,520 particles individual-1 year-1 for Estimated Annual Intake (EAI) and Estimated Daily Intake (EDI) for children 68.24 particles kg-1 day-1). The occurrence of microplastics of big size, that are not allowed to pass by plant xylem transport, suggests that fresh vegetables and fruits can be contaminated with plastic, especially during the production phase, during agricultural activities and during the marketing process (transport to the market and purchasing process).

Effect of Different Culture Conditions on Anthocyanins and Related Genes in Red Pear Callus

Red pears are appreciated for their abundant nutritional benefits and visually striking red hue, rendering them a favored option among consumers and stimulating substantial market demand. The present study employs the flesh of a red pear as the explant, subjecting the flesh callus to varying sugar sources, MS concentrations, light qualities, and temperatures to investigate the alterations in secondary metabolites, including anthocyanins, within the callus. It was found that sucrose can induce more anthocyanins, and its related metabolites and genes also increase as the sucrose and MS concentrations increase. Under the conditions of red-blue light and a temperature of 15 °C, it can further induce the production of more anthocyanins and secondary metabolites and can also upregulate the synthesis of anthocyanin-related genes. As such, this investigation serves to elucidate the factors that contribute to anthocyanin accumulation in red pears, thereby providing a theoretical foundation for understanding the mechanisms underlying color change.

Evaluation of Phenological and Morphological Properties of Some Asian Pear Varieties in the Climatic Conditions of South Moravia Therapeutic Interventions

The cultivation of Asian pear varieties in Czech climatic conditions, specifically South Moravian region, looks very promising. The introduction of new species and varieties can increase the biodiversity, what is an important factor in dealing with currentthreats in context with climatic changes. Asian pears are especially valuable due to their resistance to Erwinia amylovoraand Pear decline phytoplasma. They have also excellent tolerance to low temperatures and resistance to European pear scab (caused byVenturia pyrina). For this experiment, pomological and phenological properties were analysed on 32 pear varieties. The fruits were maturing from 9thof September (`Zao Su Li`) to the 20thof October (`Kieffer`). The heaviest fruits were determined at `Wu Jiu Xiang` (308 g on average). The lowest weight was detected at `Nanguo` (66 g on average). `Wu Jiu Xiang`, `Zao Su Li` and `Nanguo` have thin skin, which makes them ideal for direct consumption but also, they are prone to damage. `Baoshy` and `Dong guo` have thick skin, which provides good damage protection but decreases the organoleptic properties. The thick skin tends to be very bitter and overwhelms the taste of the fruit. The highest values of total soluble solids were measured in `Nanguo` (17.5%). The sourest was `Dong guo` (0.63 %) and `Nanguo` (0.54%of total titratable acids). Varieties of Asian pears and their fruits have very diverse characteristics and it is clear that their cultivation is worthwhile in the conditions of South Moravia (i.e. in the conditions of the Middle Europe).

Firmness prediction of 'Rocha' pear based on non-destructive methods and shelf-life using PLS-regression modeling

Knowledge of fruit firmness in the distribution chain is essential for stakeholders, including producers, agri-food industries, and consumers. In recent years, there has been a general interest in predicting ripening-related firmness with non-destructive techniques. The objective of this study was to create a model, based on non-destructive methods that assess directly critical physiological parameters and quality attributes related to ripening, along with shelf-life time, to predict firmness of 'Rocha' pear (Pyrus communis L.), a protected designation of origin (PDO) commodity. Hereto, pear firmness profile was assessed for ten days at room temperature, after removal from different storage periods at cold conditions. Ripening was evaluated based on color alterations, ethylene production, and respiration rate. Pear firmness decreased drastically over time, concomitant with the yellowing of the fruit skin and increased ethylene production and respiration rate. These characteristics and shelf-life time were correlated with firmness by applying the Partial Least Squares (PLS) procedure to develop a mathematical model for predicting pear firmness during ripening. The model explained 89 % of the firmness variance during ripening and, after validation, showed high accuracy (R2 = 0.87). To the best of our knowledge, this is the first time that these physiological parameters, directly related to ripening-firmness, have been used to predict pear firmness using non-destructive measurements of the samples.

Understanding the salt overly sensitive pathway in Prunus: Identification and characterization of NHX, CIPK, and CBL genes.

Salinity is a major abiotic stress factor that can significantly impact crop growth, and productivity. In response to salt stress, the plant Salt Overly Sensitive (SOS) signaling pathway regulates the homeostasis of intracellular sodium ion concentration. The SOS1, SOS2, and SOS3 genes play critical roles in the SOS pathway, which belongs to the members of Na+/H+ exchanger (NHX), CBL-interacting protein kinase (CIPK), and calcineurin B-like (CBL) gene families, respectively. In this study, we performed genome-wide identifications and phylogenetic analyses of NHX, CIPK, and CBL genes in six Rosaceae species: Prunus persica, Prunus dulcis, Prunus mume, Prunus armeniaca, Pyrus ussuriensis × Pyrus communis, and Rosa chinensis. NHX, CIPK, and CBL genes of Arabidopsis thaliana were used as controls for phylogenetic analyses. Our analysis revealed the lineage-specific and adaptive evolutions of Rosaceae genes. Our observations indicated the existence of two primary classes of CIPK genes: those that are intron-rich and those that are intron-less. Intron-rich CIPKs in Rosaceae and Arabidopsis can be traced back to algae CIPKs and CIPKs found in early plants, suggesting that intron-less CIPKs evolved from their intron-rich counterparts. This study identified one gene for each member of the SOS signaling pathway in P. persica: PpSOS1, PpSOS2, and PpSOS3. Gene expression analyses indicated that all three genes of P. persica were expressed in roots and leaves. Yeast two-hybrid-based protein-protein interaction analyses revealed a direct interaction between PpSOS3 and PpSOS2; and between PpSOS2 and PpSOS1C-terminus region. Our findings indicate that the SOS signaling pathway is highly conserved in P. persica.

Transcriptome analysis for key softening-related genes in 'Docteur Jules Guyot' pear (Pyrus communis L.)

The storage period of European pear (Pyrus communis L.) is prolonged at low temperature, but the pear softened quickly after shifting to room temperature. However, the molecular mechanisms that influence this process are unknown. In this study, 'Docteur Jules Guyot' pears were placed at room temperature (RT) and low temperature and then turned to room temperature (LR). The fruit firmness of 'Docteur Jules Guyot' under LR decreased faster than RT after moving from low temperature. The ethylene production rate, water-soluble pectin (WSP), ionic-soluble pectin (ISP) content, and pectin degradation enzyme activity of 'Docteur Jules Guyot' under LR increased faster than RT after moving from low temperature. RNA-seq of 'Docteur Jules Guyot' pear under different storage conditions was carried out, and 1018 genes were found to be negatively correlated with fruit firmness by the weighted gene coexpression network analysis (WGCNA) method. Then, 24 structural genes and transcription factors related to fruit softening were selected to verify the RNA-Seq results. The expression of all these selected genes increased significantly after LT storage. The fruit firmness, pectin content, and pectin degradation enzyme activity of ‘Laiyang’ pear did not change significantly under RT and LR storage conditions. The expression of LAX2, ARF19, EXP1, EXPA1, EXP3 and PG2 was upregulated in 'Docteur Jules Guyot' pear but downregulated in ‘Laiyang’ pear. These genes might play important roles in the softening process of European pear. This work laid the foundation for revealing the mechanisms of European pear fruit softening.