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Xanthine oxidase (XOD) is a key enzyme that promotes the oxidation of xanthine/hypoxanthine to form uric acid, and the accumulation of uric acid leads to hyperuricaemia. The prevalence of gout caused by hyperuricaemia is increasing year by year. TAOZHI (TZ) can be used for the treatment of rheumatic arthralgia due to qi stagnation and blood stasis and contains a large number of polyphenolic components. The aim of this study was to investigate the relationship between chromatograms and XOD inhibition of 21 batches of TZ total polyphenol extract samples. Chemometric methods such as grey correlation analysis, bivariate correlation analysis, and partial least squares regression were used to identify the active ingredient groups in the total polyphenol extracts of TZ, which were validated using molecular docking techniques. The total polyphenol content contained in the 21 batches did not differ significantly, and all batches showed inhibitory effects on XOD. Spectroeffect correlation analysis showed that the inhibitory effect of TZ on XOD activity was the result of the synergistic effect of multiple components, and the active component groups screened to inhibit XOD were F2 (4-O-Caffeoylquinic acid), F4, and F10 (naringenin). The molecular docking results showed that the binding energies of all nine dockings were lower than −7.5 kcal/mol, and the binding modes included hydrogen bonding, hydrophobic forces, salt bridges, and π-staking, and the small molecules might exert their pharmacological effects by binding to XOD through the residue sites of the amino acids, such as threonine, arginine, and leucine. This study provides some theoretical basis for the development and utilisation of TZ total polyphenols. [ABSTRACT FROM AUTHOR]

The brown marmorated stink bug (BMSB; Halyomorpha halys Stål.) is a highly destructive and polyphagous invasive pest that poses a serious threat to more than a hundred reported host plants. In the current study, the metabolic response of peach fruit of two cultivars—'Maria Marta' and 'Redhaven'—to BMSB infestation was studied using high-performance liquid chromatography (HPLC) and mass spectrometry (MS). In general, a strong phenolic response to BMSB infestation in peach flesh in the injury zone was observed, with flavanol content increasing by 2.4-fold, hydroxycinnamic acid content by 5.0-fold, flavonol content by 3.2-fold, flavanone content by 11.3-fold, and dihydrochalcones content by 3.2-fold compared with the undamaged tissue in the cultivar 'Maria Marta'. The phenolic response in the 'Redhaven' cultivar was even stronger. Consequently, the total phenolic content in the injured flesh also increased, 3.3-fold in 'Maria Marta' and 6.9-fold in 'Redhaven', compared with the uninjured flesh. Infestation with BMSB induced the synthesis of cyanidin-3-glucoside, which is not normally present in peach flesh. In comparison, the phenolic response was lower in peach peel, especially in the cultivar 'Maria Marta'. The study showed that both peach cultivars reacted to BMSB infestation with an increase in phenolic content in the peach flesh, but in a limited area of injury. [ABSTRACT FROM AUTHOR]

Xanthine oxidase (XOD) is a key enzyme that promotes the oxidation of xanthine/hypoxanthine to form uric acid, and the accumulation of uric acid leads to hyperuricaemia. The prevalence of gout caused by hyperuricaemia is increasing year by year. TAOZHI (TZ) can be used for the treatment of rheumatic arthralgia due to qi stagnation and blood stasis and contains a large number of polyphenolic components. The aim of this study was to investigate the relationship between chromatograms and XOD inhibition of 21 batches of TZ total polyphenol extract samples. Chemometric methods such as grey correlation analysis, bivariate correlation analysis, and partial least squares regression were used to identify the active ingredient groups in the total polyphenol extracts of TZ, which were validated using molecular docking techniques. The total polyphenol content contained in the 21 batches did not differ significantly, and all batches showed inhibitory effects on XOD. Spectroeffect correlation analysis showed that the inhibitory effect of TZ on XOD activity was the result of the synergistic effect of multiple components, and the active component groups screened to inhibit XOD were F2 (4-O-Caffeoylquinic acid), F4, and F10 (naringenin). The molecular docking results showed that the binding energies of all nine dockings were lower than −7.5 kcal/mol, and the binding modes included hydrogen bonding, hydrophobic forces, salt bridges, and π-staking, and the small molecules might exert their pharmacological effects by binding to XOD through the residue sites of the amino acids, such as threonine, arginine, and leucine. This study provides some theoretical basis for the development and utilisation of TZ total polyphenols.

The objective of this study was to evaluate the influence of the environment and the genetic factor on the the phenology of 16 advanced selections of peachtrees in the municipality of Urussanga, state of Santa Catarina. The experiment was conducted in two areas (360 m and 220 m above sea level) in 2017, 2018, and 2019 harvests. The selections are part of the EPAGRI fruit breeding program. The dates of beginning, full, and end of flowering and budding, percentage of flowering, budding and effective fructification were determined. The standard model (number of hours with temperatures below 7.2 °C) was not the most suitable. Full flowering was anticipated by five days, on average over three years, at the highest altitude due to the greater accumulation of cold. The 16 selections were classified into three groups: early (harvest in October), medium (harvest in November), and late (harvest in December). It is concluded that the environment and the genetic factor influence the phenology of advanced peach selections. Being the first, it influences the periods of flowering and budding and the percentages of flowering, budding and effective fruiting. The second with emphasis the maturation cycle and the harvest period. [ABSTRACT FROM AUTHOR]

Abstract. The present study tracks changes in the development of two native peach varieties (“Laskava” and “Evmolpiya”) from fruit formation to full ripening within five calendar weeks. In search for a non-destructive method for maturity assessment, the parameters firmness, color, size, weight, dry weight, ash content, and TSS values were evaluated. It was found that a 30% increase in size and a 1.8-2 times increase in weight occurred during the ripening period. The TSS data did not change radically, which shows that the main nutrients of the peach accumulate in the early stages of development. The color indicators change in the following trend: a decrease in the “L”, “h” and “b” values, and a tendency of increase in the “c” values. The stone size does not change drastically during the evaluation time. The moisture content also does not change significantly, although in the initial stage of fruit growth it cannot be characterized by juiciness. Firmness progressively decreases. The obtained results show grounds for the creation of a database of expected markers which may indicate the onset of maturity without the fruit being pulled from the tree or damaged.

ABSTRACT The objective of this study was to evaluate the influence of the environment and the genetic factor on the the phenology of 16 advanced selections of peachtrees in the municipality of Urussanga, state of Santa Catarina. The experiment was conducted in two areas (360 m and 220 m above sea level) in 2017, 2018, and 2019 harvests. The selections are part of the EPAGRI fruit breeding program. The dates of beginning, full, and end of flowering and budding, percentage of flowering, budding and effective fructification were determined. The standard model (number of hours with temperatures below 7.2 °C) was not the most suitable. Full flowering was anticipated by five days, on average over three years, at the highest altitude due to the greater accumulation of cold. The 16 selections were classified into three groups: early (harvest in October), medium (harvest in November), and late (harvest in December). It is concluded that the environment and the genetic factor influence the phenology of advanced peach selections. Being the first, it influences the periods of flowering and budding and the percentages of flowering, budding and effective fruiting. The second with emphasis the maturation cycle and the harvest period.

Abstract Brown rot and blossom blight caused by fungi of the genus Monilinia are the most important peach diseases. The increased concern with the environment and the health of workers and consumers, as well as the emergence of fungus isolates resistant to the main fungicide molecules favor control strategies such as genetic resistance. The objective of this study was to adjust a phenotyping protocol for evaluation of resistance/susceptibility to blossom blight in peach, as well as to quantify the antioxidant compounds present in the petals of these flowers and their correlation with the disease incidence and severity. The experiment was arranged in a randomized complete block split-split plot design, the plot being four concentrations of Monilinia fructicola conidia; the subplot two phenological flower stage; and the sub-subplot four peach genotypes. The quantification of antioxidant compounds and their correlation with susceptibility to blossom blight was performed in the four genotypes analyzed. Phenotyping was more efficient when concentrations between 400 and 4,000 conidia mL-1 were used, regardless of phenological flower stage. The phenolic compounds, anthocyanins and antioxidant activity are positively correlated among them, and negatively correlated with the blossom blight incidence and severity. In order to estimate the blossom blight susceptibility, it is recommended to use flowers at the pink or bloom stage, inoculum equivalent to 20-200 conidia per flower, and perform the evaluation at 96 hours after inoculation. This study suggests that more intense pink flowers have a higher content of antioxidant compounds and less blossom blight susceptibility.

The present study tracks changes in the development of two native peach varieties ("Laskava" and "Evmolpiya") from fruit formation to full ripening within five calendar weeks. In search for a non-destructive method for maturity assessment, the parameters firmness, color, size, weight, dry weight, ash content, and TSS values were evaluated. It was found that a 30% increase in size and a 1.8-2 times increase in weight occurred during the ripening period. The TSS data did not change radically, which shows that the main nutrients of the peach accumulate in the early stages of development. The color indicators change in the following trend: a decrease in the "L", "h" and "b" values, and a tendency of increase in the "c" values. The stone size does not change drastically during the evaluation time. The moisture content also does not change significantly, although in the initial stage of fruit growth it cannot be characterized by juiciness. Firmness progressively decreases. The obtained results show grounds for the creation of a database of expected markers which may indicate the onset of maturity without the fruit being pulled from the tree or damaged. [ABSTRACT FROM AUTHOR]

A reasonable main branch opening angle can improve the canopy light environment of a tree, change the direction of nutrient transport, and promote the formation of flower buds. In this experiment, 3-year-old 'Lu Hong 618' was used as the test material to study the effects of different main branch opening angles (three treatments: 45°, 65°, and 85°) on the canopy light distribution, canopy characteristics, fruit quality, and flower bud quality of 'Y'-shaped peach trees. The main findings were as follows: the solar energy utilization in the canopy varied greatly between different main branch opening angles, with the best relative light intensity of the canopy at 85°. In addition, the canopy light distribution on photosynthesis was more reasonable at 85°, and the daily variation range of CO2 concentration in the inner canopy was the greatest, which facilitated ventilation and light penetration in the inner canopy. With the increase in the main branch opening angle, the new growth of peach trees and the growth of the main branch trunk were inhibited. A reasonable branch opening angle results in good branch structure and leaf morphology. Leaf stomatal morphology and the soluble sugar and starch contents at different levels of the canopy are influenced by canopy light, and higher levels of canopy light can significantly increase the stomatal size and improve the leaf photosynthetic capacity, SPAD value, and soluble sugar and starch contents. With the increase in the main branch opening angle, C/N tended to increase. In addition, the distribution pattern of fruit quality in the canopy was similar to that of light distribution. In the same fruiting part, the fruit quality was higher at 85° and 45° than at 65° and slightly higher at 85° than at 45°, but the difference was not significant. The effects of different main branch opening angle treatments on the fruit weight, flesh firmness, soluble solids, and titratable acid were more significant. The 85° pulling angle effectively increased the light intensity of the different canopy layers of the peach trees and promoted the accumulation of nutrients. An 85° pulling angle can be used as a more suitable pulling angle for peach tree shaping cultivation. [ABSTRACT FROM AUTHOR]

Peach (Prunus persica (L.) Batsch) is a fruit tree of economic and nutritional importance, but it is very sensitive to drought stress, which affects its growth to a great extent. Lauric acid (LA) is a fatty acid produced in plants and associated with the response to abiotic stress, but the underlying mechanism remains unclear. In this study, physiological analysis showed that 50 ppm LA pretreatment under drought stress could alleviate the growth of peach seedlings. LA inhibits the degradation of photosynthetic pigments and the closing of pores under drought stress, increasing the photosynthetic rate. LA also reduces the content of O2−, H2O2, and MDA under drought stress; our results were confirmed by Evans Blue, nitroblue tetrazolium (NBT), and DAB(3,3-diaminobenzidine) staining experiments. It may be that, by directly removing reactive oxygen species (ROS) and improving enzyme activity, i.e., catalase (CAT) activity, peroxidase (POD) activity, superoxide dismutase (SOD) activity, and ascorbate peroxidase (APX) activity, the damage caused by reactive oxygen species to peach seedlings is reduced. Peach seedlings treated with LA showed a significant increase in osmoregulatory substances compared with those subjected to drought stress, thereby regulating osmoregulatory balance and reducing damage. RNA-Seq analysis identified 1876 DEGs (differentially expressed genes) in untreated and LA-pretreated plants under drought stress. In-depth analysis of these DEGs showed that, under drought stress, LA regulates the expression of genes related to plant–pathogen interaction, phenylpropanoid biosynthesis, the MAPK signaling pathway, cyanoamino acid metabolism, and sesquiterpenoid and triterpenoid biosynthesis. In addition, LA may activate the Ca2+ signaling pathway by increasing the expressions of CNGC, CAM/CML, and CPDK family genes, thereby improving the drought resistance of peaches. In summary, via physiological and transcriptome analyses, the mechanism of action of LA in drought resistance has been revealed. Our research results provide new insights into the molecular regulatory mechanism of the LA-mediated drought resistance of peach trees. [ABSTRACT FROM AUTHOR]

ABSTRACT The adaptation of temperate fruit crops is a challenge being increased by the global warming. Chilling requirement is a key factor for adaptation. The objective of this study was to estimate the chilling requirement of peach cultivars BRS Bonão, Esmeralda, Granada and Eragil, using the Tabuenca test. Chilling accumulation was computed using four different chilling hour (≤ 7.2 ºC and ≤ 11 ºC) models; and chill units using the Low Chill model and the Taiwan model. The fresh bud weight and bud water contents were also evaluated. The Tabuenca test (based on differences in bud´s dry weight) showed a fairly good efficiency for estimating the end of dormancy in peach. However, under mild winter conditions, it is better to use fresh bud weights. Either one of three chilling accumulation computation models (temperature ≤ 7.2 °C, ≤ 11°C, or Taiwan model) is suitable to classify comparatively different cultivars, but none is accurate enough to conclude on the adaptation of a given cultivar to a specific site. Using hours of temperatures ≤ 11 ºC: ‘BRS Bonão’ needed around 180 hours for dormancy release; ‘Esmeralda’ around 250 hours; ‘Granada’ between 300 and 400 hours, and ‘Eragil’ more than 500 hours.

One of the diseases that has the greatest negative effect on peach production is brown rot, produced by the fungus, Monilinia spp. The way to diminish this disease is the selection of genotypes with a high tolerance to Monilinia spp. while maintaining fruit quality. In this study, the tolerance to Monilinia laxa and agronomic and biochemical characteristics of forty-two hybrids derived from the 'Andross' × 'Calante' cross were studied under controlled conditions during two consecutive years, and compared with their parents. The assessment of tolerance to brown rot was estimated on inoculated fruit with M. laxa, recording the incidence of brown rot and colonization, lesion diameter and extent of colonization, to establish the severity of incidence and colonization. At harvest, physicochemical traits and antioxidant compounds (vitamin C, total phenolics, flavonoids and relative antioxidant capacity) were determined. We have found inverse relationships between fruit firmness, pH, titratable acidity and antioxidant contents with the disease symptoms in fruit. Our results confirm that the accumulation of antioxidants tends to reduce the lesion and colonization in inoculated fruit. Principal component analysis allowed the selection of two genotypes, AC-24 and AC-93, of 'Calanda'-type peaches with a known standard quality, high antioxidant content and minimal susceptibility to brown rot. [ABSTRACT FROM AUTHOR]

Water shortage is a key factor that can restrict peach tree growth. Plants produce fatty acids and the fatty acid derivatives lauric acid (LA) and 12-hydroxylauric acid (LA-OH), which are involved in abiotic stress responses, but the underlying stress response mechanisms remain unclear. In this study, physiological examination revealed that in Prunus persica (L.) Batsch, pretreatment with 50 ppm LA-OH and LA reduced drought stress, efficiently maintained the leaf relative water content, and controlled the relative conductivity increase. Under drought stress, LA-OH and LA treatments prevented the degradation of photosynthetic pigments, increased the degree of leaf stomatal opening and enhanced the net photosynthetic rate. Compared with drought stress, LA-OH and LA treatment effectively increased the net photosynthetic rate by 204.55% and 115.91%, respectively, while increasing the Fv/Fm by 2.75% and 7.75%, respectively, but NPQ decreased by 7.67% and 37.54%, respectively. In addition, the level of reactive oxygen species increased under drought stress. The content of O2 - in LA-OH and LA treatment decreased by 12.91% and 11.24% compared to CK-D, respectively, and the content of H2O2 decreased by 13.73% and 19.94%, respectively. At the same time, the content of malondialdehyde (MDA) decreased by 55.56% and 58.48%, respectively. We believe that the main reason is that LA-OH and LA treatment have improved the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). The application of exogenous LA increased the levels of soluble sugars, soluble proteins, proline and free amino acids under drought stress, and maintained the osmotic balance of cells. Compared with CK-D treatment, it increased by 24.11%, 16.89%, 29.3% and 15.04%, respectively. At the same time, the application of exogenous LA-OH also obtained similar results. In conclusion, exogenous LA-OH and LA can alleviate the damage to peach seedlings caused by drought stress by enhancing the photosynthetic and antioxidant capacities, increasing the activities of protective enzymes and regulating the contents of osmotic regulators, but the molecular mechanism is still in need of further exploration. [ABSTRACT FROM AUTHOR]

Brown rot, caused by Monilinia spp., is the main stone fruit disease. Major efforts to detect sources of resistance are being applied by several breeding programs worldwide. The main objective of this study was to seek sources of brown rot resistance, as well as to study the segregation, estimate the heritability, verify the possible existence of the maternal effect, and estimate the genetic advances. For this purpose, 20 parents and 303 seedlings, representing 16 breeding families, and 'Bolinha' (control) have been phenotyped for fruit reaction to brown rot using wounded and non-wounded inoculation procedures in 2015–2016, 2016–2017, and 2017–2018 growing seasons. Wounded fruits were very susceptible to brown rot incidence, however, the incidence and severity of non-wounded fruits showed high variability among the evaluated genotypes. Conserva 947 and Conserva 1600 and their progeny, had lower disease incidence and severity than most of the evaluated genotypes. Genetic gain estimation was −5.2 to −30.2% (wounded fruits) and between −15.0 to −25.0% (non-wounded fruits) for brown rot resistance. Selected genotypes were equal to or better than 'Bolinha' in relation to brown rot resistance, with several of them far superior in fruit quality than 'Bolinha', demonstrating the progress of the Embrapa Peach Breeding Program. [ABSTRACT FROM AUTHOR]

ABSTRACT Blossom blight and brown rot caused by Monilinia fructicola is the most important peach disease in Brazil. Genetic resistance is a control strategy that is gaining importance in breeding programs worldwide. This study aimed to identify genotypes with higher levels of blossom blight resistance to estimate the heritability of this character; study the frequency distribution in populations; and test the possibility of maternal effect. Blossom blight susceptibility was tested in reciprocal hybridizations seedlings, as well as their parents. The detached flower technique was used in a randomized complete block design, considering each genotype as a treatment. Flower inoculation was made by spraying a M. fructicola suspension and evaluations were carried out after 72 and 120 hours using a scale of five severity levels. The studied populations presented low phenotypic variability regarding the flower resistance/susceptibility to M. fructicola, being most of them susceptible or very susceptible. Among the tested genotypes, the cultivars Maciel and Cerrito showed less blossom blight susceptibility, transmitting this character to their progenies. Heritability estimates of the blossom blight resistance were medium to low. The low heritability and its distribution in the progenies suggest that the character has additive inheritance, without detecting deviations associated with maternal effects.

Abstract. The article presents a three-year traceability (2018, 2019, 2020) of biometric results of the fruits of eight peach and nectarine varieties. The study covers the fifth, sixth and seventh vegetation period from the period of full fruiting. Varieties included in this investigation were “Filina” (peach, clingstone), “Gergana” (nectarine, clingstone), “July Lady” (peach, semi-clingstone), “Ufo 4” (flat peach, semi-clingstone), “Laskava” (peach, freestone), “Morsiani 90” (nectarine, freestone), “Flat Queen” (flat peach, freestone), and “Evmolpiya” (peach, freestone). The experimental collection plantation was created in the spring of 2014 on the territory of the Fruit Growing Research Institute, Plovdiv, (lat. 42.10384828045957 and long. 24.72164848814686). The data analysis shows that the varieties “Laskava” and “Evmolpiya” produce fruits with the highest weight – 319.60 g and 303.60 g, respectively. Medium weight is registered in the “Morsiani 90” variety (226.07 g) and the “July Lady” variety (193.87 g). “UFO 4” is characterized with the smallest fruits – an average of 143.83 g and the highest flesh yield. Considering the fact that the “Filina” variety is very early ripening, its fruits can be treated as large for the season – 170.21 g. The stones of the “July Lady”, “Morsiani 90” and “Evmolpiya” varieties have the largest average mass

A reasonable main branch opening angle can improve the canopy light environment of a tree, change the direction of nutrient transport, and promote the formation of flower buds. In this experiment, 3-year-old ‘Lu Hong 618’ was used as the test material to study the effects of different main branch opening angles (three treatments: 45°, 65°, and 85°) on the canopy light distribution, canopy characteristics, fruit quality, and flower bud quality of ‘Y’-shaped peach trees. The main findings were as follows: the solar energy utilization in the canopy varied greatly between different main branch opening angles, with the best relative light intensity of the canopy at 85°. In addition, the canopy light distribution on photosynthesis was more reasonable at 85°, and the daily variation range of CO2 concentration in the inner canopy was the greatest, which facilitated ventilation and light penetration in the inner canopy. With the increase in the main branch opening angle, the new growth of peach trees and the growth of the main branch trunk were inhibited. A reasonable branch opening angle results in good branch structure and leaf morphology. Leaf stomatal morphology and the soluble sugar and starch contents at different levels of the canopy are influenced by canopy light, and higher levels of canopy light can significantly increase the stomatal size and improve the leaf photosynthetic capacity, SPAD value, and soluble sugar and starch contents. With the increase in the main branch opening angle, C/N tended to increase. In addition, the distribution pattern of fruit quality in the canopy was similar to that of light distribution. In the same fruiting part, the fruit quality was higher at 85° and 45° than at 65° and slightly higher at 85° than at 45°, but the difference was not significant. The effects of different main branch opening angle treatments on the fruit weight, flesh firmness, soluble solids, and titratable acid were more significant. The 85° pulling angle effectively increased the light intensity of the different canopy layers of the peach trees and promoted the accumulation of nutrients. An 85° pulling angle can be used as a more suitable pulling angle for peach tree shaping cultivation.

Bloom date (BD) in peach is determined by the dynamic relationship between chilling (CR) and heat requirement (HR) fulfilment during dormancy. Understanding these thermal requirements would enable breeders to adapt new cultivars to variable climates. Among the three traits, HR is the least investigated, with the genetic variability in peach germplasm and interaction between HR, CR and BD still mostly unknown. Therefore, we investigated the HR of 136 peach cultivars over 8 growing seasons (2014–2021) by calculating the growing degree hours (GDH) from the moment their CR was satisfied until full bloom. The HR ranged from 1362 to 10,348 GDH across years and cultivars, with cultivar HR eight-year having the best linear unbiased prediction (BLUP) values from 4808 to 7721 GDH. In addition, a high positive correlation between BD and CR, a negative correlation between CR and HR and a seasonal effect on the correlation between BD and HR were observed. Moreover, simulating HR with different threshold base temperatures (Tb) revealed different trends of GDH accumulation, suggesting that genotype-specific Tb should be determined to allow precise discrimination of this requirement. Peach germplasm showed high variation in HR that could be used in breeding for bloom delay to adapt to different environments and climate change. [ABSTRACT FROM AUTHOR]

The adaptation of temperate fruit crops is a challenge being increased by the global warming. Chilling requirement is a key factor for adaptation. The objective of this study was to estimate the chilling requirement of peach cultivars BRS Bonão, Esmeralda, Granada and Eragil, using the Tabuenca test. Chilling accumulation was computed using four different chilling hour (d+ 7.2 °C and d+ 11 °C) models; and chill units using the Low Chill model and the Taiwan model. The fresh bud weight and bud water contents were also evaluated. The Tabuenca test (based on differences in bud's dry weight) showed a fairly good efficiency for estimating the end of dormancy in peach. However, under mild winter conditions, it is better to use fresh bud weights. Either one of three chilling accumulation computation models (temperature d+ 7.2 °C, d+ 11°C, or Taiwan model) is suitable to classify comparatively different cultivars, but none is accurate enough to conclude on the adaptation of a given cultivar to a specific site. Using hours of temperatures d+ 11 °C: 'BRS Bonão' needed around 180 hours for dormancy release; 'Esmeralda' around 250 hours; 'Granada' between 300 and 400 hours, and 'Eragil' more than 500 hours. [ABSTRACT FROM AUTHOR]

Chill hour’s availability influence break dormancy, sprouting and production of temperate fruit trees in different regions. Chilling requirements for growing peaches in subtropical regions are limited during winter and some chemicals are necessary for overcoming dormancy and inducing budburst. Therefore, there is a necessity of more information about the use of these chemicals on inducing sprouting in peach trees. This study aimed to assess hydrogen cyanamide, nitrogen fertilizer and calcium nitrate to induce budburst in the ‘Douradão’ peach orchard, located in the subtropical region of São Paulo state, Brazil. Then, tree chemicals were evaluated: 0.6% hydrogen cyanamide; 2.5% nitrogen fertilizer + 4% calcium nitrate; 4% calcium nitrate and control to determine the budburst, flowering and fruit set percentage, flowering period, number of fruits, production per tree and yield. The experimental design was a randomized block, in a split plot arrangement. The plots were represented by inducing sprouting chemicals and subplots for two crop seasons. The hydrogen cyanamide increased, anticipated and concentrated the flowering of the plants; besides enhancing fruit set and production. Furthermore, nitrogen fertilizer + calcium nitrate also promoted budburst enhancing flowering, production per tree and yield. The spraying of the peach trees with only calcium nitrate presented a performance like the one observed in the control. The results allowed indicate the use of hydrogen cyanamide or nitrogen fertilizer + calcium nitrate, as an alternative for inducing budburst in peach trees of Douradão cultivar under subtropical conditions, depending on the adopting orchards system cultivation.

Peach (Prunus persica (L.) Batsch) is a fruit tree of economic and nutritional importance, but it is very sensitive to drought stress, which affects its growth to a great extent. Lauric acid (LA) is a fatty acid produced in plants and associated with the response to abiotic stress, but the underlying mechanism remains unclear. In this study, physiological analysis showed that 50 ppm LA pretreatment under drought stress could alleviate the growth of peach seedlings. LA inhibits the degradation of photosynthetic pigments and the closing of pores under drought stress, increasing the photosynthetic rate. LA also reduces the content of O2−, H2O2, and MDA under drought stress; our results were confirmed by Evans Blue, nitroblue tetrazolium (NBT), and DAB(3,3-diaminobenzidine) staining experiments. It may be that, by directly removing reactive oxygen species (ROS) and improving enzyme activity, i.e., catalase (CAT) activity, peroxidase (POD) activity, superoxide dismutase (SOD) activity, and ascorbate peroxidase (APX) activity, the damage caused by reactive oxygen species to peach seedlings is reduced. Peach seedlings treated with LA showed a significant increase in osmoregulatory substances compared with those subjected to drought stress, thereby regulating osmoregulatory balance and reducing damage. RNA-Seq analysis identified 1876 DEGs (differentially expressed genes) in untreated and LA-pretreated plants under drought stress. In-depth analysis of these DEGs showed that, under drought stress, LA regulates the expression of genes related to plant–pathogen interaction, phenylpropanoid biosynthesis, the MAPK signaling pathway, cyanoamino acid metabolism, and sesquiterpenoid and triterpenoid biosynthesis. In addition, LA may activate the Ca2+ signaling pathway by increasing the expressions of CNGC, CAM/CML, and CPDK family genes, thereby improving the drought resistance of peaches. In summary, via physiological and transcriptome analyses, the mechanism of action of LA in drought resistance has been revealed. Our research results provide new insights into the molecular regulatory mechanism of the LA-mediated drought resistance of peach trees.

Blossom blight and brown rot caused by Monilinia fructicola is the most important peach disease in Brazil. Genetic resistance is a control strategy that is gaining importance in breeding programs worldwide. This study aimed to identify genotypes with higher levels of blossom blight resistance to estimate the heritability of this character; study the frequency distribution in populations; and test the possibility of maternal effect. Blossom blight susceptibility was tested in reciprocal hybridizations seedlings, as well as their parents. The detached flower technique was used in a randomized complete block design, considering each genotype as a treatment. Flower inoculation was made by spraying a M. fructicola suspension and evaluations were carried out after 72 and 120 hours using a scale of five severity levels. The studied populations presented low phenotypic variability regarding the flower resistance/susceptibility to M. fructicola, being most of them susceptible or very susceptible. Among the tested genotypes, the cultivars Maciel and Cerrito showed less blossom blight susceptibility, transmitting this character to their progenies. Heritability estimates of the blossom blight resistance were medium to low. The low heritability and its distribution in the progenies suggest that the character has additive inheritance, without detecting deviations associated with maternal effects. [ABSTRACT FROM AUTHOR]

Brown rot caused by the pathogen of the genus Monilinia is the most destructive disease in peaches worldwide. It has seriously reduced the economic value of the peach (Prunus persica (L.) Batsch) in Nyingchi and Qamdo, Tibet, China. Monilinia fructicola, Monilia mumecola, and M. yunnanensis have been reported as the causal agents of brown rot disease on stone fruits in China. In this study, we report on the identification of M. yunnanensis in peach orchards in Nyingchi and Qamdo, Tibet. From twenty-three isolates with the same characteristics, we identified the representative single-spore isolates T8-1, T8-8, and T8-20 as M. yunnanensis and confirmed that the Tibet brown rot disease was caused by M. yunnanensis based on the morphological characteristics and molecular analyses. The phylogenetic analysis of the glyceraldehyde-3-phosphate dehydrogenase (G3PDH) and β-tubulin (TUB2) nucleotide sequences and the multiplex PCR identification revealed that the representative isolates T8-1, T8-8, and T8-20 were more closely related to M. yunnanensis than other Monilinia species. Furthermore, the biocontrol strain of Trichoderma T6 presented significant antagonistic activity on the M. yunnanensis T8-1 isolate (T8-1) among the five Trichoderma strains. The highest inhibitory rates for Trichoderma T6 and its fermentation product against T8-1 mycelial growth were 72.13% and 68.25%, respectively. The obvious inhibition zone displayed on the colony interaction area between the colony of T8-1 isolate and Trichoderma T6 and the morphological characterization of the T8-1 hyphae were enlarged and malformed after inoculation with the Trichoderma T6 fermentation product at 20-fold dilution. Our results indicate that the strain of Trichoderma T6 could be considered as a beneficial biocontrol agent in managing brown rot of peach fruit disease.

One of the diseases that has the greatest negative effect on peach production is brown rot, produced by the fungus, Monilinia spp. The way to diminish this disease is the selection of genotypes with a high tolerance to Monilinia spp. while maintaining fruit quality. In this study, the tolerance to Monilinia laxa and agronomic and biochemical characteristics of forty-two hybrids derived from the ‘Andross’ × ‘Calante’ cross were studied under controlled conditions during two consecutive years, and compared with their parents. The assessment of tolerance to brown rot was estimated on inoculated fruit with M. laxa, recording the incidence of brown rot and colonization, lesion diameter and extent of colonization, to establish the severity of incidence and colonization. At harvest, physicochemical traits and antioxidant compounds (vitamin C, total phenolics, flavonoids and relative antioxidant capacity) were determined. We have found inverse relationships between fruit firmness, pH, titratable acidity and antioxidant contents with the disease symptoms in fruit. Our results confirm that the accumulation of antioxidants tends to reduce the lesion and colonization in inoculated fruit. Principal component analysis allowed the selection of two genotypes, AC-24 and AC-93, of ‘Calanda’-type peaches with a known standard quality, high antioxidant content and minimal susceptibility to brown rot.

The article presents a three-year traceability (2018, 2019, 2020) of biometric results of the fruits of eight peach and nectarine varieties. The study covers the fifth, sixth and seventh vegetation period from the period of full fruiting. Varieties included in this investigation were "Filina" (peach, clingstone), "Gergana" (nectarine, clingstone), "July Lady" (peach, semi-clingstone), "Ufo 4" (flat peach, semi-clingstone), "Laskava" (peach, freestone), "Morsiani 90" (nectarine, freestone), "Flat Queen" (flat peach, freestone), and "Evmolpiya" (peach, freestone). The experimental collection plantation was created in the spring of 2014 on the territory of the Fruit Growing Research Institute, Plovdiv, (lat. 42.10384828045957 and long. 24.72164848814686). The data analysis shows that the varieties "Laskava" and "Evmolpiya" produce fruits with the highest weight - 319.60 g and 303.60 g, respectively. Medium weight is registered in the "Morsiani 90" variety (226.07 g) and the "July Lady" variety (193.87 g). "UFO 4" is characterized with the smallest fruits -- an average of 143.83 g and the highest flesh yield. Considering the fact that the "Filina" variety is very early ripening, its fruits can be treated as large for the season - 170.21 g. The stones of the "July Lady", "Morsiani 90" and "Evmolpiya" varieties have the largest average mass. [ABSTRACT FROM AUTHOR]

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Brown rot, caused by Monilinia spp., is the main stone fruit disease. Major efforts to detect sources of resistance are being applied by several breeding programs worldwide. The main objective of this study was to seek sources of brown rot resistance, as well as to study the segregation, estimate the heritability, verify the possible existence of the maternal effect, and estimate the genetic advances. For this purpose, 20 parents and 303 seedlings, representing 16 breeding families, and ‘Bolinha’ (control) have been phenotyped for fruit reaction to brown rot using wounded and non-wounded inoculation procedures in 2015–2016, 2016–2017, and 2017–2018 growing seasons. Wounded fruits were very susceptible to brown rot incidence, however, the incidence and severity of non-wounded fruits showed high variability among the evaluated genotypes. Conserva 947 and Conserva 1600 and their progeny, had lower disease incidence and severity than most of the evaluated genotypes. Genetic gain estimation was −5.2 to −30.2% (wounded fruits) and between −15.0 to −25.0% (non-wounded fruits) for brown rot resistance. Selected genotypes were equal to or better than ‘Bolinha’ in relation to brown rot resistance, with several of them far superior in fruit quality than ‘Bolinha’, demonstrating the progress of the Embrapa Peach Breeding Program.

Bloom date (BD) in peach is determined by the dynamic relationship between chilling (CR) and heat requirement (HR) fulfilment during dormancy. Understanding these thermal requirements would enable breeders to adapt new cultivars to variable climates. Among the three traits, HR is the least investigated, with the genetic variability in peach germplasm and interaction between HR, CR and BD still mostly unknown. Therefore, we investigated the HR of 136 peach cultivars over 8 growing seasons (2014–2021) by calculating the growing degree hours (GDH) from the moment their CR was satisfied until full bloom. The HR ranged from 1362 to 10,348 GDH across years and cultivars, with cultivar HR eight-year having the best linear unbiased prediction (BLUP) values from 4808 to 7721 GDH. In addition, a high positive correlation between BD and CR, a negative correlation between CR and HR and a seasonal effect on the correlation between BD and HR were observed. Moreover, simulating HR with different threshold base temperatures (Tb) revealed different trends of GDH accumulation, suggesting that genotype-specific Tb should be determined to allow precise discrimination of this requirement. Peach germplasm showed high variation in HR that could be used in breeding for bloom delay to adapt to different environments and climate change.

O presente trabalho tem por objetivo apresentar o novo cultivar de pessegueiro obtido pelo Programa de Melhoramento Genétco da Epagri/Estação Experimental de Urussanga, denominado SCS419 Mondardo. Esse cultivar tem como genitores os cultvares Aurora 1 (feminino) e Pampeano (masculino). Ele tem boa adaptação a regiões com aproximadamente 200 horas de frio hibernal abaixo de 7,2°C, porém sem ocorrência de geadas tardias. O grande diferencial desse cultivar é a precocidade na maturação dos frutos. É medianamente resistente a Xanthomonas pruni, apresenta frutos com polpa branca, baixa acidez e bom tamanho para a época de colheita. É recomendado para plantio na Região Sul de Santa Catarina, em altitudes acima de 200 metros, como também para outras regiões do Sul do Brasil, onde ocorrem 200 ou mais horas de frio hibernal abaixo de 7,2°C e não sujeitas a geadas tardias.

ABSTRACT This study aimed to use and validate a simple contact force model that describes the behavior of peaches stored in a wooden box, loaded cyclically, by using the discrete element method. The Kelvin-Voigt contact force model was used and the cyclic loading in the simulation was performed with an amplitude of 1 mm and frequency of 12 Hz for time intervals of 3600, 5400, and 7200 s. The laboratory test was performed with a peach box attached to a vibrating table by applying the same excitation conditions used in the simulation. For validation, model results were compared with those from the laboratory test by using deformation values of fruits in the contact regions. To measure this deformation, we adapted the methodology for determining the radius of curvature. The Kelvin-Voigt linear contact model, despite its simplicity in representing the viscoelastic behavior, adequately estimated the final deformation in peaches submitted to cyclic loading.

Zacatecas peach production currently faces low productivity and competitiveness due to multiple factors. Therefore, the objective of the study was to characterize peach genotypes with outstanding characteristics at harvest time and fruit quality. A group of 91 six-year-old genotypes from an improved population of 403 hybrids and peach segregates, planted at random at high densities in 2008, was selected and evaluated in 2014. Controls were ‘Victoria’ and a segregator from ‘Victoria’ (VicS). For the phenotyping of the fruit (n= 10), it was harvested at consumption maturity. The response variables of each fruit were: polar and equatorial diameter, fresh mass, endocarp and mesocarp mass, and dry matter concentration of each fruit; as well as the color of the epicarp and mesocarp, firmness and concentration of total soluble solids. The outstanding peach genotypes GD1, GD3, GD5, and GD7 matured in June, GD43 in July, GD45, GD47, and GD68 in August, while GD70, GD77, and GD87 matured in September, respectively. In addition, these genotypes had the best phenotypic characteristics of the fruit. The results suggest that the fresh fruit supply period and the diversification of peaches with competitive quality for Zacatecas and similar agroecological zones can be extended to improve the prospects for cultivation in these regions. [ABSTRACT FROM AUTHOR]

Mexican peach production [Prunus persica (L.) Batsch] faces an economic crisis, as a result of the gradual decrease the area planted, production, prices, and national consumption per capita. Therefore, the producers have a low income. The objective of the study was to assess whether or not organic peach production would contribute to the improvement of the income of producers in the Estado de Mexico. The economic viability of turning the conventional production system into the organic production system was evaluated using the real options theory, while the abandonment option was assessed through the binomial option pricing model. In contrast to traditional valuation methods, the real options theory considers flexibility in decisions when the profitability of investments faces volatility and uncertainty. The quantified value of the crop by-products and residues was added to the farmer’s final income to find out if the amount would help to improve his income, during and after the conversion process. Given the positive value of the options, investing in organic production is feasible, even when the project abandonment option was considered. The economic valuation of the by-products contributed to improve the income of the producers. [ABSTRACT FROM AUTHOR]

Peach [Prunus persica (L.) Batsch] is among the most demanded fruit crops in the world. Biotechnological methods help to originate new hybrid forms in order to increase the cultivar diversity and create new valuable genotypes. Cross combinations between the cultivars Clyde Wilson, Jerseyglo, Loadel, Summerglo and the promising cultivar ‘Nikitskiy Podarok’ have been done. The embryos of these hybrids germinated and formed plantlets after stratification at 4 °C for 45–60 days. The best regeneration rates in the hybrids ‘Loadel’ × ‘Nikitskiy Podarok’ and ‘Summerglo’ × ‘Nikitskiy Podarok’ (96.30% and 92.59%, respectively) were noted on hormone-free Monnier culture medium supplemented with 400.0 mg L−1 casein hydrolyzate. When the newly formed plantlets had necrosis of the shoot apex or immature roots, nodal shoot segments were used. At the same time, a high regeneration capacity was noted in the hybrids ‘Summerglo’ × ‘Nikitskiy Podarok’ and ‘Loadel’ × ‘Nikitskiy Podarok’ on B5 culture medium with 0.75 mg L−1 6–benzyl–aminopurine (BAP) + 0.1 mg L−1 indole–3–butyric acid (IBA). After the second subculture, the number of new adventitious shoots was 5.18 ± 0.18 and 4.95 ± 0.18 shoots per explant, respectively. The plants obtained from the hybrid embryos in a soil mixture soil: peat: sand (3:1:1) were adapted. The main morphological and anatomical features of the leaf blades in newly originated peach hybrids have been studied: the thickness of their tissues and the distribution of stomatal apparatus, as well as the physiological parameters of the photosystem II activity in regenerants cultured in vitro and during their in vivo acclimatization. The high capacity to post aseptic adaptation in the obtained hybrids has been shown.

Abstract In the peach nursery trees production, the use of rootstocks with unknown genetic identity obtained from peach seeds in the canning industry is frequent. The hypothesis tested was that there are rootstocks that express greater graft compatibility, enabling greater survival and growth, and that peroxidase activity can be used as indication of graft incompatibility. The aim of this study was to evaluate the survival and the peroxidase activity efficiency in identifying graft incompatibility and the trunk diameter growth of ‘Barbosa’ peach grafted onto 18 Prunus clonal rootstocks, propagated by herbaceous cuttings, compared to own-rooted scion trees. The experimental design was three randomized blocks, with one tree per plot. The first three vegetative cycles of trees conducted in double Y (5.0m x 2.0m) without irrigation were evaluated. The highest trunk diameter growth was provided by ‘Okinawa’, ‘Tsukuba-1’, ‘Tsukuba-2’, Mexico F1 and ‘Flordaguard’ rootstocks, without differing from own-rooted ‘Barbosa’ peach. Peroxidase activity differs by rootstock effect at the beginning of the dormancy period, and is higher than in vegetative growth, especially in interspecific graft combinations. Peroxidase activity is a biochemical indicator of stress, but should not be used alone and generalized to characterize graft incompatibility.

Continuous assessment of plant water status indicators provides the most precise information for irrigation management and automation, as plants represent an interface between soil and atmosphere. This study investigated the relationship of plant water status to continuous fruit diameter (FD) and inverse leaf turgor pressure rates (pp) in nectarine trees [Prunus persica (L.) Batsch] throughout fruit development. The influence of deficit irrigation treatments on stem (Ψstem) and leaf water potential, leaf relative water content, leaf stomatal conductance, and fruit growth was studied across the stages of double-sigmoidal fruit development in ‘September Bright’ nectarines. Fruit relative growth rate (RGR) and leaf relative pressure change rate (RPCR) were derived from FD and pp to represent rates of water in- and outflows in the organs, respectively. Continuous RGR and RPCR dynamics were independently and jointly related to plant water status and environmental variables. The independent use of RGR and RPCR yielded significant associations with midday Ψstem, the most representative index of tree water status in anisohydric species. However, a combination of nocturnal fruit and leaf parameters unveiled an even more significant relationship with Ψstem, suggesting a changing behavior of fruit and leaf water flows in response to pronounced water deficit. In conclusion, we highlight the suitability of a dual-organ sensing approach for improved prediction of tree water status.

Abstract The densification of orchards has become a viable alternative for producers seeking a greater use of current area, as well as greater profitability. In this sense, the spacing and training system to be used in the peach tree planting are extremely important to facilitate orchard management and, above all, to maximize tree yield. Based on this, the present research aimed to evaluate the possibility of orchard densification and the use of different numbers of main scaffolds to recommend the best way of training and spacing the ‘BRS Rubimel’ peach cultivar. The planting was carried out in 2010, in the city of Fraiburgo - SC, and eight treatments with different spacings between the plants in the rows and number of scaffolds were evaluated during four harvests (2013, 2014, 2015 and 2016): T1- 2 scaffolds and 0.75 m; T2- 2 scaffolds and 1.00 m; T3- 2 scaffolds and 1.25 m; T4- 2 scaffolds and 1.50 m; T5- 4 scaffolds and 1.00 m; T6- 4 scaffolds and 1.50 m; T7- 4 scaffolds and 1.75 m; T8- 4 scaffolds and 2.00 m, totaling a plant density of 2667, 2000, 1600, 1333, 2000, 1333, 1143 and 1000 per hectare, respectively. The analyzed variables were the number of fruits per plant, production per plant (kg); productivity (t ha-1); fresh fruit mass (g), total soluble solids content (ºBrix), total acidity (meq L-1), epidermal coloring and pulp firmness (pounds). The highest yields were found in the treatment with two scaffolds and 0.75m between plants, as well as that with 4 scaffolds in 1.0 m spacing in the 2014 and 2015 crops and two scaffolds in 1.0m in the 2015 harvest. The fresh mass, soluble solids, total acidity and fruit firmness were not influenced by the different treatments. It was concluded that the densification of orchards is feasible for peach trees of the ‘BRS Rubimel’ cultivar due to the increase in productivity, without decreasing the quality of the fruits, indicating a spacing of 0.75 cm between plants and two scaffolds in the “Y-shape” as ideal. Another option with good results is the use of the four-scaffold “Y-shaped” training system, indicated for the ‘BRS Rubimel’ peach trees, due to the maintenance of high yields and reduction in the number of plants per hectare when compared to treatments with two scaffolds.

Sterilization of nursery substrate materials decreases the beneficial microorganisms in the surrounding root media and may result in poor seedling growth; compost and arbuscular mycorrhizal fungi (AMF) may improve the plantlet development. This experiment aimed to analyze the effect of both AMF inoculation and vermicompost for the initial peach [Prunus persica (L.) Batsch.] seedling growth in sterilized substrate. Peach seedlings germinated in sterilized perlite were distributed into four resulting treatments from the combination of two factors and two levels each: with/without vermicompost in the growing media and with/without AMF inoculation at the transplanting time. Seedlings were arranged completely randomized inside a glasshouse throughout the study. Utilization of vermicompost in the growing media and AMF inoculation, and their combination, resulted in less total chlorophyll (p < 0.05) measured at 108 days after planting (DAP). At the end of the experiment (180 DAP), AMF inoculation resulted in root colonization greater than 70% of the total root length; however, this effect was eclipsed by adding vermicompost to the substrate. Root and shoot dry weights and also stem diameter were superior (p < 0.01) by adding vermicompost to the growing substrate, but AMF inoculation had no effect on these variables. It is concluded that vermicompost addition to the substrate is preferable to AMF inoculation in order to stimulate peach seedling growth during the initial six months in sterilized substrates.

Copyright of Informacion Tecnica Economica Agraria is the property of Asociacion Interprofesional para el Desarrollo Agrario (AIDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Continuous assessment of plant water status indicators provides the most precise information for irrigation management and automation, as plants represent an interface between soil and atmosphere. This study investigated the relationship of plant water status to continuous fruit diameter (FD) and inverse leaf turgor pressure rates (p p) in nectarine trees [ Prunus persica (L.) Batsch] throughout fruit development. The influence of deficit irrigation treatments on stem (Ψ stem) and leaf water potential, leaf relative water content, leaf stomatal conductance, and fruit growth was studied across the stages of double-sigmoidal fruit development in 'September Bright' nectarines. Fruit relative growth rate (RGR) and leaf relative pressure change rate (RPCR) were derived from FD and p p to represent rates of water in- and outflows in the organs, respectively. Continuous RGR and RPCR dynamics were independently and jointly related to plant water status and environmental variables. The independent use of RGR and RPCR yielded significant associations with midday Ψ stem, the most representative index of tree water status in anisohydric species. However, a combination of nocturnal fruit and leaf parameters unveiled an even more significant relationship with Ψ stem, suggesting a changing behavior of fruit and leaf water flows in response to pronounced water deficit. In conclusion, we highlight the suitability of a dual-organ sensing approach for improved prediction of tree water status. [ABSTRACT FROM AUTHOR]

• Pru p 1 and Pru p 3 are proteins found in peach (Prunus persica (L.) Batsch). • They are the principal allergens of the peach fruit. • An assay for Pru p 1 and Pru p 3 was developed using AQUA peptides and LC–MS/MS. • A linear relationship was found in the concentrations of 3.1–200 and 13–200 fmol/μL. • Coefficients of variation measured on five different days were 11.6–30.1%. Pru p 1 and Pru p 3 are proteins found in peach (Prunus persica (L.) Batsch), and they are members of the pathogenesis-related protein 10 (PR-10) and non-specific lipid transfer protein (nsLTP) families, respectively. They are the main allergens of peach. In this paper, we describe a quantitative method for these proteins based on protein absolute quantification with liquid chromatography–tandem mass spectrometry, and LVASPSGGSIIK[13C 6 ,15N 2 ] and ISASTNC[CAM]ATVK[13C 6 ,15N 2 ] (C[CAM]: carbamidomethyl-modified C), stable isotope-labelled internal standard peptides. We show that this method exhibits linearity with r 2 > 0.97 in a dose range of 3.1–200 fmol/μL for LVASPSGGSIIK[13C 6 ,15N 2 ] and 13–200 fmol/μL for ISASTNC[CAM]ATVK[13C 6 ,15N 2 ]), and overall coefficients of variation for multiple tests of 11.6–30.1%. This approach is therefore helpful for screening and breeding low allergenic peach cultivars. [ABSTRACT FROM AUTHOR]

The peach tree (Prunus persica (L.) Batsch) is very demanding in high demand for labor, especially for pruning and fruit thinning, but this labor is often scarce and reflecting higher costs in the production and fruit smaller caliber. In view of the above, the objective of this work was to evaluate the need for manual thinning after applying chemical products to the 'Della Nona' peach. The experiment was conducted in a commercial orchard of approximately 17 years, located in the municipality of Videira (Santa Catarina, Brazil), in the 2018/2019 harvest. The experimental design was a randomized block design with 6 treatments and 5 replicates per treatment, each experimental unit being composed of one plant. The treatments tested were: 1 - manual thinning (control); 2 - metamitron (MM) 154 mg L-1, falling petals (QP); 3 - MM 308 mg L-1, in QP; 4 - MM 308 mg L-1, fruits of 5 mm; 5 - gibberellins (GA4 + 7) 18.8 mg L-1 + benzyladenine (BA) 18.8 mg L-1, in QP; 6 - ethephon 360 mg L-1 in full bloom (PF). Were marked ten years of branches, located in two-thirds of each plant, in which they were counted: the number of flowers and fruits (before and after treatment application) as well as the need for manual transfer (manual thinning). The manual thinning occurred 30 days after the application of the treatments, as well as the count of fruits removed per plant. Ethephon 360 mg L-1, (PF) reduced on average by 58.5% the need for manual thinning compared to the control (manual thinning), 324.6 and 781.8 fruit being removed, respectively. GA4 + 7 18.8 mg L-1 + BA 18.8 mg L-1 and Ethephon 360 mg L-1 PF promote increase in mean fruit mass. The application of ethephon 360 mg L-1 (PF) is a viable alternative for reducing the need for manual thinning, and therefore reduced demand for hand labor. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the effects of pre-storage for 24h and 48h and different modified atmosphere packaging-MAP treatments (using low-density polyethylene - LDPE) on the antioxidant compounds and the postharvest quality of 'Douradão' peaches under cold storage. The peaches were submitted to the following treatments: a control (no packaging or pre-storage) and prestorage for 24h or 48h at 25°C combined with passive MAP (LDPE 60 µm or 80 µm). After the application of the treatments, the fruits were stored at 0°C for 30 days plus 3 days at 25°C to simulate marketing conditions. The results showed that on the simulated marketing period, all the treatments (except for the control) reduced woolliness and internal browning. Furthermore, both pre-storage and LDPE MAP enhanced the polygalacturonase (PG) activity, the levels of phenolic compounds and the antioxidant capacity. Thus, these results suggest that the pre-storage associated with LDPE packaging increases the shelf life of peaches by up to 30 days under cold storage. [ABSTRACT FROM AUTHOR]

One of the main problems of peach culture in Brazil is no standardization of the plants due to the sexual propagation of the rootstocks, which causes variation in the agronomic performance of the peach scion cultivar. This paper aimed to evaluate the vegetative growth, the productive performance and fruit quality of the own-rooted cultivar BRS Libra (without rootstock) and grafted on 23 clonal rootstocks under edaphoclimatic conditions in southern Minas Gerais. The study was developed in 2014 to 2017 at the Agricultural Research Company of Minas Gerais (EPAMIG). The experimental design was a randomized block design and the plants were conducted in a "Y" system with spacing of 5.0 x 1.5 m, without irrigation. The annual stem diameter growth rate in relation to grafting point, survival rates, yield efficiency, production and productivity, as well as the fruit weight, longitudinal and transversal diameter and soluble solids content of the fruits were evaluated. The rootstocks with the best agronomic performance and the possibility of use in southern Minas Gerais were "Okinawa", "Flordaguard", "Tsukuba-2", "De Guia" and "Rigitano", as well as own-rooted trees. [ABSTRACT FROM AUTHOR]

Phenolic compounds from natural products are considered effective enhancers of insulin secretion to prevent and treat type 2 diabetes (T2DM). The flowers of Prunus persica (L.) Batsch also contain many phenolic compounds. In this study, the extract of flowers of P. persica (PRPE) exhibited an insulin secretion effect in a glucose-stimulated insulin secretion (GSIS) assay, which led us to isolate and identify the bioactive compound(s) responsible for these effects. Compounds isolated from PRPE were screened for their efficacy in INS-1 rat pancreatic β-cells. Among them, caffeic acid (5), methyl caffeate (6), ferulic acid (7), chlorogenic acid (8), naringenin (11), nicotiflorin (12), and astragalin (13) isolated from PRPE increased GSIS without inducing cytotoxicity. Interestingly, the GSIS effect of methyl caffeate (6) as a phenolic compound was similar to gliclazide, an antidiabetic sulfonylurea drug. Western blot assay showed that methyl caffeate (6) enhanced the related signaling proteins of the activated pancreatic and duodenal homeobox-1 (PDX-1) and peroxisome proliferator-activated receptor-γ (PPAR-γ), but also the phosphorylation of the total insulin receptor substrate-2 (IRS-2), phosphatidylinositol 3-kinase (PI3K), and Akt, which influence β-cell function and insulin secretion. This study provides evidence that methyl caffeate (6) isolated from PRPE may aid in the management of T2DM.

The evaluation of dormancy break based on the number of flower buds in bloom was performed in years 2011-2013 (January-April) for 15 peach cultivars compared to the control cv. Redhaven. Based on the date of endogenous dormancy break the evaluated peach cultivars could be classified into three groups consisting of: (1) cultivars with an early break of dormancy, (2) cultivars with a medium-early break of dormancy and (3) cultivars with a late break of dormancy. For individual cultivars, the duration of the dormancy period was influenced by meteorological conditions existing in a given year.

The present study aimed to investigate the effects of pre-storage for 24h and 48h and different modified atmosphere packaging-MAP treatments (using low-density polyethylene – LDPE) on the antioxidant compounds and the postharvest quality of ‘Douradão’ peaches under cold storage. The peaches were submitted to the following treatments: a control (no packaging or pre-storage) and pre-storage for 24h or 48h at 25ºC combined with passive MAP (LDPE 60 µm or 80 µm). After the application of the treatments, the fruits were stored at 0ºC for 30 days plus 3 days at 25ºC to simulate marketing conditions. The results showed that on the simulated marketing period, all the treatments (except for the control) reduced woolliness and internal browning. Furthermore, both pre-storage and LDPE MAP enhanced the polygalacturonase (PG) activity, the levels of phenolic compounds and the antioxidant capacity. Thus, these results suggest that the pre-storage associated with LDPE packaging increases the shelf life of peaches by up to 30 days under cold storage.

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)