Peach Research Articles

RNA-Seq analysis reveals the mechanism in response to cold stress of peach cv ‘Dingjiaba’

BACKGROUND: ‘Dingjiaba’ is an important Prunus persica cultivar (cv) mainly grown in the Hexi corridor in northwest China, which has an inherited strong cold tolerance. OBJECTIVE: To compare the transcriptome and physiology data of leaves of cvs ‘Dingjiaba’ (D) and ‘Kanoiwa’ (K) following cold treatment at different time periods, in order to gain new insights into the mechanisms of cold adaptation in ‘Dingjiaba’. MATERIALS AND METHODS: We analyzed the transcriptomic and physiological data of leaves of D and K cvs exposed to 0 h (D0/K0), 2 h (D2/K2), 6 h (D6/K6) and 12h (D12/K12) cold stress. RESULTS: Low temperature stress caused membrane damage and led to increased rate of electrolyte leakage and increased MDA content. Cold stress induced the accumulation of soluble sugars, soluble proteins and proline in leaves of both cvs, with a lower increase in K compared to D. Transcriptome analysis identified 4,631, 5,069, 5,662 and 3,886 differentially expressed genes (DEGs) between D0 and K0, D2 and K2, D6 and K6 and D12 and K12, respectively. The differentially expressed genes significantly enriched in metabolic pathways and biosynthesis of secondary metabolites. We further validated the reliability of sequencing data of the RNA-Seq with Real-Time Quantitative PCR, which suggested that the expression trend of the RNASeq were same as RT-PCR. CONCLUSIONS: These results provide novel insights into a series of molecular mechanisms underlying physiological metabolism and defense.

Pest categorisation of Lepidosaphes malicola.

The EFSA Panel on Plant Health performed a pest categorisation of Lepidosaphes malicola (Hemiptera: Diaspididae), the Armenian mussel scale, for the territory of the European Union, following commodity risk assessments of Prunus persica and P. dulcis plants for planting from Türkiye, in which L. malicola was identified as a pest of possible concern. L. malicola is a polyphagous insect of temperate and arid areas, feeding on more than 60 plant species belonging to 26 families. Important crops significantly affected by L. malicola in parts of Asia include stone fruits (Prunus armeniaca, P. persica), pome fruits (Malus domestica, Pyrus communis), grapes (Vitis vinifera), pomegranate (Punica granatum), walnuts (Juglans regia) and ornamental plants (Berberis spp., Cornus spp., Jasminum spp., Ligustrum spp.). L. malicola has two generations annually. The overwintered eggs hatch from late May to early June. First-instar nymphs crawl on the host plant for a short period, then settle to feed. Nymphs reach maturity in late summer or early autumn. Plants for planting, fruits and cut flowers provide potential pathways for entry into the EU. Host availability and climate suitability suggest that southern, central and some parts of northern EU countries would be suitable for the establishment of L. malicola. Despite being a pest in Armenia, Iran and Tajikistan, there is no evidence of it being a pest in Türkiye. L. malicola was detected in Bulgaria and Greece over 30 years ago, but there have been no records since, and its status is uncertain. Its ability to cause an impact in the EU is also uncertain. It is not listed in Annex II of the Commission Implementing Regulation (EU) 2019/2072. Phytosanitary measures are available to reduce the likelihood of entry. Except for the criterion of having an economic or environmental impact, for which there is great uncertainty, L. malicola satisfies all other criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Analysis of flavonoid metabolism of compounds in succulent fruits and leaves of three different colors of Rosaceae

Red flesh apple (Malus pumila var. medzwetzkyana Dieck), purple leaf plum (Prunus cerasifera Ehrhar f), and purple leaf peach (Prunus persica ‘Atropurpurea’) are significant ornamental plants within the Rosaceae family. The coloration of their fruits and leaves is crucial in their appearance and nutritional quality. However, qualitative and quantitative studies on flavonoids in the succulent fruits and leaves of multicolored Rosaceae plants are lacking. To unveil the diversity and variety-specificity of flavonoids in these three varieties, we conducted a comparative analysis of flavonoid metabolic components using ultra-high-performance liquid phase mass spectrometry (UPLC-MS/MS). The results revealed the detection of 311 metabolites, including 47 flavonoids, 105 flavonols, 16 chalcones, 37 dihydroflavonoids, 8 dihydroflavonols, 30 anthocyanins, 14 flavonoid carbon glycosides, 23 flavanols, 8 isoflavones, 11 tannins, and 12 proanthocyanidins. Notably, although the purple plum and peach leaves exhibited distinct anthocyanin compounds, paeoniflorin and corythrin glycosides were common but displayed varying glycosylation levels. While the green purple leaf peach fruit (PEF) and red flesh apple leaf (AL) possessed the lowest anthocyanin content, they exhibited the highest total flavonoid content. Conversely, the red flesh apple fruit (AF) displayed the highest anthocyanin content and a diverse range of anthocyanin glycosylation modifications, indicating that anthocyanins predominantly influenced the fruit's color. Purple PLF, PLL, and PEL showcased varying concentrations of anthocyanins, suggesting that their colors result from the co-color interaction between specific types of anthocyanins and secondary metabolites, such as flavonols, flavonoids, and dihydroflavonoids. This study provides novel insights into the variations in tissue metabolites among Rosaceae plants with distinct fruit and leaf colors.

Combined analysis of mRNA and miRNA transcriptomes reveals the regulatory mechanism of Xanthomonas arboricola pv pruni resistance in Prunus persica

BackgroundPeach bacterial shot hole, caused by Xanthomonas arboricola pv pruni (Xap), is a global bacterial disease that poses a threat to the yield and quality of cultivated peach trees (Prunus persica).ResultsThis study compared the mRNA and miRNA profiles of two peach varieties, ‘Yanbao’ (resistant) and ‘Yingzui’ (susceptible), after inoculation with Xap to identify miRNAs and target genes associated with peach tree resistance. mRNA sequencing results revealed that in the S0-vs-S3 comparison group, 1574 genes were upregulated and 3975 genes were downregulated. In the R0-vs-R3 comparison group, 1575 genes were upregulated and 3726 genes were downregulated. Through miRNA sequencing, a total of 112 known miRNAs belonging to 70 miRNA families and 111 new miRNAs were identified. Notably, some miRNAs were exclusively expressed in either resistant or susceptible varieties. Additionally, 59 miRNAs were downregulated and 69 miRNAs were upregulated in the R0-vs-R3 comparison group, while 46 miRNAs were downregulated and 52 miRNAs were upregulated in the S0-vs-S3 comparison group. Joint analysis of mRNA and miRNA identified 79 relationship pairs in the S0-vs-S3 comparison group, consisting of 48 miRNAs and 51 target genes. In the R0-vs-R3 comparison group, there were 58 relationship pairs, comprising 28 miRNAs and 20 target genes. Several target genes related to resistance, such as SPL6, TIFY6B, and Prupe.4G041800_v2.0.a1 (PPO), were identified through literature reports and GO/KEGG enrichment analysis.ConclusionIn conclusion, this study discovered several candidate genes involved in peach tree resistance by analyzing differential expression of mRNA and miRNA. These findings provide valuable insights into the mechanisms underlying resistance to Xap in peach trees.

Impact of Deficit Irrigation Strategies Using Saline Water on Soil and Peach Tree Yield in an Arid Region of Tunisia

Sustainable fruit orchard development in arid areas is severely affected by the scarcity of fresh water. To mitigate the lack of fresh water, the use of low-quality water for irrigation is becoming a common practice in several margin areas. However, salinity is considered one of the most important environmental constraints limiting the successful crop production. Therefore, the effects of deficit irrigation strategies using saline water (3.1 dS m−1) on soil water content, soil salinity, and yield of commercial peach orchard were investigated. Three irrigation treatments were considered: a Control, full irrigated (FI); and partial root-zone drying (PRD50); and deficit irrigation (DI) strategies irrigated at 50% ETc. These levels of water supply allowed for contrasting watering conditions with clear distinction between irrigation treatments. The differential pattern in soil moisture was accompanied by that of soil salinity with an increase in all FI treatments (16–25%). The results indicated that soil salinity increased with increasing water supply and evaporative demand during the growing season from January (3.2 dS m−1) to August (6.6 dS m−1). Deficit irrigation strategies (DI, PRD50) induced more soil salinity along the row emitter compared to the Control due to insufficient leaching fractions. By the end of the growing season, the soil salinity under long-term saline drip irrigation remained stable (5.3–5.7 dS m−1). An efficient leaching action seemed to be guaranteed by rainfall and facilitated by sandy soil texture, as well as the high evaporative demand and the important salt quantity supplied, which maintain the deficit irrigation strategies as valuable tools for water saving and improving water productivity. The significant water saving of 50% of water requirements induced a fruit yield loss of 20%. For this reason, DI and PRD50 could be reasonable irrigation management tools for saving water and controlling soil salinity in arid areas and on deep sandy soil.

Rootstock vigor dictates the canopy light environment that regulates metabolite profile and internal fruit quality development in peach

Five rootstock cultivars of differing vigor: vigorous (‘Atlas™’ and ‘Bright's Hybrid® 5’), standard (‘Krymsk® 86’ and ‘Lovell’) and dwarfing (‘Krymsk® 1’) grafted with ‘Redhaven’ as the scion were studied for their impact on productivity, mid-canopy photosynthetic active radiation transmission (i.e., light availability) and internal fruit quality. Αverage yield (kg per tree) and fruit count increased significantly with increasing vigor (trunk cross sectional area, TCSA). Α detailed peach fruit quality analysis on fruit of equal maturity (based on the index of absorbance difference, IAD) coming from trees with equal crop load (no. of fruit cm−2 of TCSA) characterized the direct impact of rootstock vigor on peach internal quality [dry matter content (DMC) and soluble solids concentration (SSC)]. DMC and SSC increased significantly with decreasing vigor and increasing light availability, potentially due to reduced intra-tree shading and better light distribution within the canopy. Physiologically characterized peach fruit mesocarp was further analyzed by non-targeted metabolite profiling using gas chromatography mass spectrometry (GC-MS). Metabolite distribution was associated with rootstock vigor class, mid-canopy light availability and fruit quality characteristics. Fructose, glucose, sorbose, neochlorogenic and quinic acids, catechin and sorbitol were associated with high light environments and enhanced quality traits, while sucrose, butanoic and malic acids related to low light conditions and inferior fruit quality. These outcomes show that while rootstock genotype and vigor are influencing peach tree productivity and yield, their effect on manipulating the light environment within the canopy also plays a significant role in fruit quality development.

Effect of Municipal Mulch and Poultry Litter Amendments on Soil and Tree Parameters of a Mature Peach Orchard in a Humid Subtropical Climate

Applying organic matter (OM) amendments in mature peach orchards with low organic matter content (Prunus persica (L.) Batsch.) may improve tree nutrient and water status during the growing season and enable growers to reduce synthetic fertilizer inputs. Three treatments were applied to “Juneprince” and “Scarletprince” peach trees: (1) grower standard of bare soil (GS), (2) municipal mulch (M), and (3) poultry litter with municipal mulch (PLM). Synthetic fertilizer was reduced within the M and PLM treatments each year. Soil samples were taken from under the amendments, and the nutrient and water status of the soil and trees were monitored over 3 years. Fruit yield and tree growth measurements were also recorded. Soil OM did not increase, but soil P increased in all three treatments over time. Soil Cu was reduced by adding OM amendments, while PLM increased soil Na and increased leaf K in “Scarletprince” trees. The PLM and M treatments buffered soil water compared to GS, but tree water status between treatments was largely similar. The elevated N status over time from the PLM and M treatments delayed fruit maturity and reduced cumulative yield in “Juneprince” trees. The PLM treatment increased “Scarletprince” fruit size and mass over 3 years, as well as tree size compared to GS. Covering the soil with mulch allowed for reduced synthetic fertilizer use, but further reduction of supplemental synthetic fertilizer or adjustment of amendment rates is needed to limit N and ensure desired fruit harvest windows and long-term production.

Global Transcriptome Analysis of the Peach (Prunus persica) in the Interaction System of Fruit-Chitosan-Monilinia fructicola.

The peach (Prunus persica L.) is one of the most important stone-fruit crops worldwide. Nevertheless, successful peach fruit production is seriously reduced by losses due to Monilinia fructicola the causal agent of brown rot. Chitosan has a broad spectrum of antimicrobial properties and may also act as an elicitor that activate defense responses in plants. As little is known about the elicitation potential of chitosan in peach fruits and its impact at their transcriptional-level profiles, the aim of this study was to uncover using RNA-seq the induced responses regulated by the action of chitosan in fruit-chitosan-M. fructicola interaction. Samples were obtained from fruits treated with chitosan or inoculated with M. fructicola, as well from fruits pre-treated with chitosan and thereafter inoculated with the fungus. Chitosan was found to delay the postharvest decay of fruits, and expression profiles showed that its defense-priming effects were mainly evident after the pathogen challenge, driven particularly by modulations of differentially expressed genes (DEGs) related to cell-wall modifications, pathogen perception, and signal transduction, preventing the spread of fungus. In contrast, as the compatible interaction of fruits with M. fructicola was challenged, a shift towards defense responses was triggered with a delay, which was insufficient to limit fungal expansion, whereas DEGs involved in particular processes have facilitated early pathogen colonization. Physiological indicators of peach fruits were also measured. Additionally, expression profiles of particular M. fructicola genes highlight the direct antimicrobial activity of chitosan against the fungus. Overall, the results clarify the possible mechanisms of chitosan-mediated tolerance to M. fructicola and set new foundations for the potential employment of chitosan in the control of brown rot in peaches.

Defying gravity: WEEP promotes negative gravitropism in peach trees by establishing asymmetric auxin gradients.

Trees with weeping shoot architectures are valued for their beauty and are a resource for understanding how plants regulate posture control. The peach (Prunus persica) weeping phenotype, which has elliptical downward arching branches, is caused by a homozygous mutation in the WEEP gene. Little is known about the function of WEEP despite its high conservation throughout Plantae. Here, we present the results of anatomical, biochemical, biomechanical, physiological, and molecular experiments that provide insight into WEEP function. Our data suggest that weeping peach trees do not have defects in branch structure. Rather, transcriptomes from the adaxial (upper) and abaxial (lower) sides of standard and weeping branch shoot tips revealed flipped expression patterns for genes associated with early auxin response, tissue patterning, cell elongation, and tension wood development. This suggests that WEEP promotes polar auxin transport toward the lower side during shoot gravitropic response, leading to cell elongation and tension wood development. In addition, weeping peach trees exhibited steeper root systems and faster lateral root gravitropic response. This suggests that WEEP moderates root gravitropism and is essential to establishing the set-point angle of lateral roots from the gravity vector. Additionally, size exclusion chromatography indicated that WEEP proteins self-oligomerize, like other proteins with sterile alpha motif domains. Collectively, our results from weeping peach provide insight into polar auxin transport mechanisms associated with gravitropism and lateral shoot and root orientation.

First Report of Apiospora arundinis Causing Leaf Spot on Polygonatum cyrtonema Hua in China.

Polygonatum cyrtonema Hua, which is a perennial herb of Liliaceae, can be used as clinical Chinese medicine for treating diabetes and asthma. It is widely cultivated in China, with 700 ha planted in Tonggu County, Jiangxi province (Chen et al. 2022). In June 2022, leaf spot symptoms were observed on P. cyrtonema in Tonggu county (28°71'42″N, 114°56'19″E), and the disease incidence was estimated to be above 35%. In the early stages of infection, small brown spots appear on the edge or tip of the leaves. As the lesion matures, the spots gradually expand to form wedge-shaped or elliptic to irregular lesions with brown edges and yellow halos. To identify the pathogen species, leaf pieces (5 × 5 mm) from the lesion borders were surface sterilized in 75% ethanol for 30 s, followed by 2% NaClO for 2 min, then rinsed with sterile distilled water for 3 times and dried with sterile filter paper. The tissues were placed on potato dextrose agar (PDA) and incubated at 25°C. Pure cultures were obtained by monosporic isolation, and the representative isolates, HJYB2-1, HJYB2-2 were used for morphological studies and phylogenetic analyses. Colonies on PDA of the two isolates were white with fluffy aerial mycelia. The hyphae were smooth, hyaline, and branched. The conidiophores were hyaline or pale brown and produced conidiogenous cells. The conidiogenous cells were pale brown, smooth, and ampulliform, 5.8-11.7 × 3.0-4.9 μm (n=50). The conidia were brown, smooth, and ellipsoidal to spherical, 4.7-7.3 × 2.3-4.5 μm (n=50). Morphological features were similar to Apiospora arundinis species complex (Crous et al. 2013, Pintos et al. 2021). For molecular identification, the ITS, TUB2 and TEF 1-α genes were amplified with the primer pairs ITS1/ITS4, T1/Bt-2b and EF1-728F/EF-2 (White et al. 1990), respectively. The generated sequences were deposited in GenBank with accession numbers OR229623, OR229624 (ITS), OR260104, OR260105 (TUB2), and OR290789, OR290790 (TEF1-α). Maximum likelihood and Bayesian posterior probability analyses using IQtree v. 1.6.8 and Mr. Bayes v. 3.2.6 with the concatenated sequences placed HJYB2-1 and HJYB2-2 in the clade of A. arundinis. The two isolates were identified as A. arundinis based on morphological and multilocus phylogenetic analyses. For pathogenicity testing, healthy leaves of six P. cyrtonema plants (five leaves each, n=30) in the field were pin-pricked with a sterile needle and inoculated with 100 µL spore suspension on the wound (1×106 conidia per mL). Healthy leaves of another three P. cyrtonema plants (five leaves each, n=15) in the field were pin-pricked with a sterile needle, inoculated with sterile distilled water and served as the control. All the inoculated leaves were covered with plastic bags to keep a high-humidity environment with a temperature of about 28℃. The test was repeated three times. More than 90% of inoculated leaves showed similar symptoms to those observed in the field, whereas control leaves were asymptomatic for 7 days. Apiospora arundinis was reisolated from the leaf lesions on the inoculated plants. No pathogenic fungus was isolated from the control leaves. A. arundinis has been reported causing disease on Camellia sinensis (Thangaraj et al. 2019), Prunus persica (Ji et al. 2020), Saccharum officinarum (Liao et al. 2022) but has not previously been reported causing disease on P. cyrtonema. To our knowledge, this is the first report that A. arundinis can cause leaf spot on P. cyrtonema in China. Our result should help with future monitoring and control of this disease.

PpAmy1 Plays a Role in Fruit-Cracking by Regulating Mesocarp Starch Hydrolysis of Nectarines.

Nectarine [Prunus persica (L.) Batsch var.] fruits are highly susceptible to cracking during the ripening process, which significantly decreases their commercial value. In this study, we investigated the underlying mechanism of nectarine fruit-cracking using two nectarine varieties, namely, "Qiannianhong" (cracking-susceptible) and "CR1012" (cracking-resistant). Our findings indicate that nectarine fruit-cracking occurs during the second stage of fruit expansion. Despite no differences in epicarp cell size between "Qiannianhong" and "CR1012", the mesocarp cells of "Qiannianhong" were larger than those of "CR1012". Moreover, a comparison of starch hydrolysis between the two varieties revealed that "CR1012" had higher starch content in the mesocarp but lower soluble sugar content compared to "Qiannianhong". Additionally, by testing the α-amylase and β-amylase activity of the mesocarp, our results showed a difference only in α-amylase activity between the two varieties. Furthermore, qRT-PCR detection indicated a higher expression level of the PpAmy1 (α-amylase synthesis gene) in "Qiannianhong" compared to "CR1012". To further investigate the role of PpAmy1, we employed RNAi technology to suppress its expression in "Qiannianhong" fruits. The results showed a significant reduction in α-amylase activity, starch hydrolysis, soluble sugar content, cell size of the mesocarp, and fruit-cracking. These findings underscore the pivotal role of PpAmy1 in the occurrence of nectarine fruit cracking.

Preparation, Characterization, and Antioxidant Activities of Extracts from Amygdalus persica L. Flowers.

A novel water-soluble Amygdalus persica L. flowers polysaccharide (APL) was successfully isolated and purified from Amygdalus persica L. flowers by hot water extraction. Its chemical components and structure were analyzed by IR, GC-MS, and HPLC. APL consisted of rhamnose, arabinose, mannose and glucose in a molar ratio of 0.17:0.034:1.0:0.17 with an average molecular weight of approximately 208.53 kDa and 15.19 kDa. The antioxidant activity of APL was evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 3-ethylbenzthiazoline-6-sulfonic acid (ABTS), Hydroxyl radical scavenging, Superoxide radical scavenging, and the reducing power activity was also determined in vitro. Besides, in vivo antioxidant experiment, zebrafish (Danio rerio) embryos were treated with different concentrations of APL and then exposed to LPS to induce oxidative stress. Treatment with APL at 50 or 100 µg/mL significantly reduced LPS-induced oxidative stress in the zebrafish, demonstrating the strong antioxidant activity of APL. Moreover, the effect of APL on zebrafish depigmentation was tested by analyzing the tyrosinase activity and melanin content of zebrafish embryos. APL showed a potential reduction in the total melanin content and tyrosinase activity after treatment. This work provided important information for developing a potential natural antioxidant in the field of cosmetics and food.

Evaluation of lethal and sublethal effects of laminarin on the green peach aphid,Myzus persicae, under extended laboratory conditions

AbstractRecent studies have opened the way for using elicitor‐induced resistance in plants as a method to control arthropod pests. In this study, 1,3‐β‐glucan laminarin, an elicitor of disease resistance in plants, was tested on the green peach aphid,Myzus persicae(Sulzer) (Hemiptera: Aphididae), on peach [Prunus persica(L.) Batsch, Rosaceae] plantlets and evaluated its effects on short‐term mortality and population growth. Laminarin exposure did not affect aphid survival in the short term; however, laminarin‐treated peach plants sustained fewer nymphs and adults in comparison with the control. Aphid populations on plants treated with laminarin declined significantly over the sampling period compared to the control. Moreover, the demographic parameters net reproductive rate (R0), finite rate of increase (λ), and intrinsic rate of increase (rm), all showed decreasing trends in aphid populations reared on laminarin‐treated plants. The decline in aphid populations exposed to laminarin seemed to mainly be linked to reduced adult survival, slower nymph development, and lower nymph survival and only marginally to changes in reproduction outcome. Changes in gene expression causing the final production of defence chemicals by peach plants may contribute to explaining the results. However, potential direct effects of laminarin onM. persicaefeeding activity and probing behaviour cannot be ruled out. This study provides evidence that, although laminarin did not display insecticidal activity in the short term, this elicitor caused sublethal effects, significantly reducing aphid populations.

Optimizing water use and crop yield with deficit irrigation techniques: A comprehensive overview and case study from Morocco

Water scarcity is a global challenge that threatens agricultural productivity and food security. Irrigation agriculture consumes most of the world’s freshwater resources and often suffers from low water use efficiency. To address water shortages, deficit irrigation techniques have been developed to minimize water inputs while sustaining or enhancing crop yields and quality. Deficit irrigation consists of allocating a minimum amount of water to the crop. It can be applied either for the entire growing season (sustained deficit irrigation) or for specific crop stages (regulated deficit irrigation). Another technique is partial root zone drying, which involves alternately irrigating different parts of the root system. This causes partial water stress and increases the water uptake efficiency. These techniques aim to maximize net water use efficiency by exploiting the physiological responses of crops to water stress. This paper provides a theoretical background on deficit irrigation, a review of recent studies on its effects on different crops and environments, and a case study in Morocco where sustained deficit irrigation was applied to peach trees in a semiarid region. The findings showed that sustained deficit irrigation reduced water use by 20% without affecting fruit yield or quality and increased water productivity by 33%. This paper also discusses the challenges and opportunities for implementing deficit irrigation in different contexts and provides some recommendations for future research and development.

Investigation of Xinomavro Red Wine Aging with Various Wood Chips Using Pulsed Electric Field

This study explored the potential of pulsed electric field (PEF) as an alternative wine-aging method in four Xinomavro red wines with the implementation of several wood chips (apricot, peach, apple, cherry, acacia, and oak trees). The evolution of total polyphenol content (TPC) and sensory properties of the wines were investigated. Sensory evaluation revealed that PEF treatment increased volatile compound extraction from each wood chip, thereby enhancing the overall quality of the wines. The utilization of acacia tree wood chips in Goumenissa wine led to a notable increase of 10.84% in TPC from the control sample, reaching 2334.74 mg gallic acid equivalents/L. A notable outcome was that PEF decreased TPC, a trend that was also verified through correlation analyses. The highest positive impact of PEF was observed in peach tree wood chips in Goumenissa wine, with a significant increase of 11.05% in TPC. The results from the volatile compound analysis revealed an increase in alcohols and esters from 0.24% to 23.82%, with the highest proportion found in 2-phenylethanol (16.92 mg/L) when utilizing peach tree wood chips in the production of Amyndeo wine. This study could provide a benchmark for rapid, efficient, and cost-effective wine aging through the implementation of the PEF process.

Classification of cultivars of common peach (Persica vulgaris Mill.)

The existing classifications of peach cultivars are based on the morphological characteristics of vegetative and generative organs, and are of economic importance. The classification by N. I. Ryabov (1939) gained the greatest popularity. The entire cultural assortment of Persica vulgaris Mill. was divided by him into two varieties distinguished by the type of flower. A variety with a rose-shaped flower, P. vulgaris var. rosaeflora Rjab., is divided into 4 groups: 1. American early ripers; 2. Northern Chinese peaches of the ‘Chinese Cling’ type (with cartilage-like flesh texture); 3. cultivars of the Turkestan-Transcaucasian type; 4. South Chinese ‘Honey’ type peaches (honey peaches). A variety with a bell-shaped flower, P. vulgaris var. campanuliflora Rjab., is divided into two groups: 1. Iranian, the ‘Phillips Cling’ type (with cartilage-like flesh texture); 2. Iranian, the ‘Crawford’ type (with a fibrous flesh texture). The work was carried out in the collection orchard of the Research Institute of Plant Genetic Resources of Uzbekistan.Research has shown that the groups do not have a specific geographical area and consist of cultivars from all around the world. Peach cultivars are grouped according to a set of morphological characteristics, therefore, the average values of basic biological properties within a group are very close and the differences are insignificant, which complicates the use of the classification for scientific purposes.The proposed classification of peach cultivars is based on the botanical-geographical principle (Vavilov, 1935). It is proposed to divide all common peach cultivars into groups according to their geographical origin: 1. Chinese; 2. Transcaucasian; 3. European; 4. American; and 5. Central Asian. Each of these groups has its own distribution area. The biological properties of cultivars were formed under the influence of various soil and climatic conditions. Chinese peaches are frost and winter hardy and have a long dormancy period. However, in terms of commercial and taste qualities they are inferior to modern cultivars. They can be used in breeding for creating large-fruited, frostresistant, late flowering varieties. European cultivars were forming under different conditions and they should be used differentially; they are good source material for breeding cultivars with high commercial and taste qualities of fruits. Transcaucasian varieties are superior to other groups in terms of transportability. These are cultivars for canning and high quality processed products. They are relatively resistant to fungous diseases. American cultivars are distinguished by high commercial and taste qualities of fruits. Most cultivars are highly frost-resistant, but they are poorly winterhardy. They can be used for breeding highly productive cultivars with high commercial and taste qualities of fruits, with different ripening periods. Central Asian varieties have a long dormancy period, they are frost-, drought-, and soil salinity resistant. However, they are weakly resistant to fungous diseases. They can be used in breeding according to the indicated characteristics

Long‐term compost use and high frequency low concentration fertigation reduce N2O emissions from a California almond orchard

AbstractUsing compost as an agricultural amendment offers a means to reduce organic waste, as mandated in the US state of California (SB 1383). Compost can improve soil physical characteristics and soil carbon content by increasing soil organic matter. We examined the effect of compost application (7‐year duration) on soil nitrous oxide (N2O) emissions, inorganic nitrogen (N) pools, soil temperature and water content, bulk density, and total carbon (C) and N content. The orchard was composed of Nonpareil cultivars interplanted with Aldrich and Carmel cultivars, all grafted on Nemaguard peach rootstock [Prunus persica (L.) Bratsch]. Its soil was Oakdale sandy loam (coarse‐loamy, mixed, active, thermic Mollic Haploxeralf). Delivering nutrients through the irrigation system, the orchard was fertigated 14 times with urea ammonium nitrate or calcium ammonium nitrate, using high frequency and low concentration (HFLC) fertigation applications (total 195 kg N ha−1). Soil without compost (No Compost) tended to have higher N2O fluxes (up to 2.75‐fold) than soil with compost (Compost). Cumulative measured N2O emissions (i.e., sum of nine sampling events) from Compost were half that from No Compost. Soil pH, electrical conductivity, total C, and N tended to be greater in Compost, and bulk density tended to be lower in Compost than No Compost. No relationships between N2O emissions and soil temperature, volumetric water content, water‐filled pore space, and inorganic N pools occurred in either treatment. Our findings indicate that long‐term applications of compost in perennial crops, in combination with an HFLC nutrient management program, could reduce losses of N as N2O to the atmosphere.

The Population Dynamics and Parasitism Rates of Ceratitis capitata, Anastrepha fraterculus, and Drosophila suzukii in Non-Crop Hosts: Implications for the Management of Pest Fruit Flies.

Understanding the seasonal dynamics inherent to non-crop host-fruit fly-parasitoid interactions is vitally important for implementing eco-friendly pest control strategies. This study assessed the abundance and seasonal infestation levels of three pest fly species, Ceratitis capitata (Wiedemann), Anastrepha fraterculus (Wiedemann), Drosophila suzukii (Matsumura), as well as the related saprophytic drosophilids, and their natural parasitism in a disturbed wild habitat characterized by non-crop hosts in northwestern Argentina over 40 months. Juglans australis Griseb (walnut), Citrus aurantium L. (sour orange), Eriobotrya japonica (Thunb.) Lindley (loquat), Prunus persica (L.) Batsch (peach), and Psydium guajava L. (guava) were sampled throughout their fruiting seasons. Fruits were collected from both the tree canopies and the ground. The most abundant puparia was A. fraterculus, followed by C. capitata and D. suzukii. Drosophila species from the D. melanogaster group were highly abundant only in fallen fruits. Spatiotemporal overlaps of different host fruit availability provided suitable sources for pest proliferation throughout the year. The populations of both invasive pests peaked from December to January, and were related to the highest ripe peach availability, whereas the A. fraterculus population peaked from February to April, overlapping with the guava fruiting period. The three pest fly species were parasitized mainly by three generalist resident parasitoids, which are potential biocontrol agents to use within an integrated pest management approach.

Transcription factor LBD16 targets cell wall modification/ion transport genes in peach lateral root formation.

LATERAL ORGAN BOUNDARIES DOMAIN/ASYMMETRIC LEAVES2-LIKEs (LBDs/ASLs) are plant-specific transcription factors that function downstream of auxin-regulated lateral root (LR) formation. Our previous research found that PpLBD16 positively regulates peach (Prunus persica) LR formation. However, the downstream regulatory network and target genes of PpLBD16 are still largely unknown. Here, we constructed a PpLBD16 homologous overexpression line and a PpLBD16 silenced line. We found that overexpressing PpLBD16 promoted peach root initiation, while silencing PpLBD16 inhibited peach root formation. Through RNA sequencing (RNA-seq) analysis of roots from PpLBD16 overexpression and silenced lines, we discovered that genes positively regulated by PpLBD16 were closely related to cell wall synthesis and degradation, ion/substance transport, and ion binding and homeostasis. To further detect the binding motifs and potential target genes of PpLBD16, we performed DNA-affinity purification sequencing (DAP-seq) analysis in vitro. PpLBD16 preferentially bound to CCNGAAANNNNGG (MEME-1), [C/T]TTCT[C/T][T/C] (MEME-2), and GCGGCGG (ABR1) motifs. By combined analysis of RNA-seq and DAP-seq data, we screened candidate target genes for PpLBD16. We demonstrated that PpLBD16 bound and activated the cell wall modification-related genes EXPANSIN-B2 (PpEXPB2) and SUBTILISIN-LIKE PROTEASE 1.7 (PpSBT1.7), the ion transport-related gene CYCLIC NUCLEOTIDE-GATED ION CHANNEL 1 (PpCNGC1) and the polyphenol oxidase (PPO)-encoding gene PpPPO, thereby controlling peach root organogenesis and promoting LR formation. Moreover, our results displayed that PpLBD16 and its target genes are involved in peach LR primordia development. Overall, this work reveals the downstream regulatory network and target genes of PpLBD16, providing insights into the molecular network of LBD16-mediated LR development.

PbRbohH/J mediates ROS generation to regulate the growth of pollen tube in pear

Respiratory burst oxidase homolog (Rboh) family genes play crucial functions in development and growth. However, comprehensive and systematic investigation of Rboh family members in Rosaceae and their specific functions during pear pollen development are still limited. In the study, 63 Rboh genes were identified from eight Rosaceae genomes (Malus domestica, Pyrus bretschneideri, Pyrus communis, Prunus persica, Rubus occidentalis, Fragaria vesca, Prunus mume and Prunus avium) and divided into seven main subfamilies (I-VII) according to phylogenetic and structural features. Different modes of gene duplication led to the expansion of Rboh family, with purifying selection playing a vital role in the evolution of Rboh genes. In addition, RNA sequencing and qRT-PCR results indicated that PbRbohH and PbRbohJ were specifically high-expressed in pear pollen. Subsequently, subcellular localization revealed that PbRbohH/J distributed at the plasma membrane. Furthermore, by pharmacological analysis and antisense oligodeoxynucleotide assay, PbRbohH/J were demonstrated to mediate the formation of reactive oxygen species (ROS) to manage pollen tube growth. In conclusion, our results provide useful insights into the functions, expression patterns, evolutionary history of the Rboh genes in pear and other Rosaceae species.