Search

AbstractPeat and perlite are considered traditional growing substrates in soilless culture. The high cost of both and the urgent need for agricultural waste recycling prompted scientists and soilless culture growers to find alternative growing substrates provide optimal growth conditions and help dispose waste safely. In this study, corn cobs (CB) were tested as growing media and compared with peat moss (PM) and perlite (P). The organic wastes tested: CB, PM, and P were examined with washed sand (WS) at five treatments (WS, CB, CB + peat, CB + P and CB + sand). Cucumber (Cucumis sativus L.) plants were cultivated using 5 kg pots that contained the investigated substrates. Vegetative growth parameters, early fruiting stage, photosynthetic pigments, and cucumber yield had the highest values with CB and CB + P substrates, while the lowest ones were found in WS and CB + WS. CB resulted in greater flowering with the number of fruits per plant and yield being 39.70%, 37.33%, and 33.67%, 29.88 in both seasons, higher than the lowest substrate (WS). Although adding P to CB showed the highest values of measured growth characteristics, its high cost decreased net profit. Furthermore, CB characteristics as a growing media qualify it for use in cucumber soilless culture production. The use of this replacement media, which contains crushed CB, could reduce (but not eliminate) the need for PM and P in soilless culture. Also, using pyrolyzed biomass in growing media provides another way to convert biomass residues into valuable products. [ABSTRACT FROM AUTHOR]

Nitrogen-fixing cyanobacterial consortia are an alternative to the indiscriminate use of chemical fertilizers that affect the environment, fix atmospheric nitrogen, and can therefore be used as plant growth promoters, synthesize various substances such as auxins, vitamins, and total proteins, and fix atmospheric biofertilizers and soil conditioners. The present study aimed to obtain and develop, by biotechnological means, two consortia of cyanobacteria isolated from the root and rhizosphere of Carica papaya grown in sandy loam soil. The culture was carried out in Blue Green Medium without modified nitrogen (BG110), with aeration of 0.32 L min−1, at a light intensity of 48.83 μEm−2s−1, and a temperature of 22 ± 2 °C. Two consortia consisting of Nostoc commune, Aphanothece minutissima, Planktothrix sp. (C1), Nostoc commune, Calothrix sp., and Aphanothece minutissima (C2) were isolated and morphologically identified. The effective development of these consortia was verified at the laboratory level by obtaining biomass in dry weight as well as photosynthetic pigments, proteins, carbohydrates, and lipids. Germination parameters were determined in seeds of Cucumis sativus L. var. Market plus treated with the nitrogen-fixing cyanobacteria consortia, obtaining a higher germination percentage (>90%), greater root length (>6 cm), and higher vigour index I (513), II (13.02) for the C2 consortium. This broadens the spectrum of rhizosphere-derived microorganisms with potential as growth biostimulators. [ABSTRACT FROM AUTHOR]

Abstract Background BAK1 (Brassinosteroid insensitive 1-associated receptor kinase 1) plays an important role in disease resistance in plants. However, the function of BAK1 family in cucumber and the decisive genes for disease-resistance remain elusive. Results Here, we identified 27 CsBAK1s in cucumber, and classified them into five subgroups based on phylogenetic analysis and gene structure. CsBAK1s in the same subgroup shared the similar motifs, but different gene structures. Cis-elements analysis revealed that CsBAK1s might respond to various stress and growth regulation. Three segmentally duplicated pairwise genes were identified in cucumber. In addition, Ka/Ks analysis indicated that CsBAK1s were under positive selection during evolution. Tissue expression profile showed that most CsBAK1s in Subgroup II and IV showed constitutive expression, members in other subgroups showed tissue-specific expression. To further explore whether CsBAK1s were involved in the resistance to pathogens, the expression patterns of CsBAK1s to five pathogens (gummy stem blight, powdery mildew, downy mildew, grey mildew, and fusarium wilt) reveled that different CsBAK1s had specific roles in different pathogen infections. The expression of CsBAK1-14 was induced/repressed significantly by five pathogens, CsBAK1-14 might play an important role in disease resistance in cucumber. Conclusions 27 BAK1 genes were identified in cucumber from a full perspective, which have important functions in pathogen infection. Our study provided a theoretical basis to further clarify the function of BAK1s to disease resistance in cucumber.

Drought, one of the most frequent natural disasters, is a devastating abiotic stress that arises unpredictably, develops gradually, and carries long-lasting repercussions even after it ceases. The duration and severity of drought markedly impact plant growth, development, and yield by disrupting normal morpho-physio-biochemical processes. Silicon (Si) is regarded as a crucial element for mitigating the detrimental effects of abiotic stress, including drought. The objective of this study was to evaluate the effect of Si application method on morpho-physio-biochemical traits of cucumber plants under drought stress. Two independent polyhouse experiments were conducted where cucumber (Cucumis sativus L.) plants were grown under four levels of soil moisture that included 40%, 60%, 80%, and 100% field capacity (FC) and Si was applied either in the form of seed priming (Experiment 1) or as soil drench (Experiment 2). For the seed priming study, four doses of Si (in the form of monosilicic acid with 20% Si content) applied were 0.25, 0.5, 1.0, and 2.0 mM along with a control in which seeds were sown directly without any priming. For the soil application study, four doses of Si (in the form of monosilicic acid with 20% Si content) applied were 15, 30, 60, and 120 kg ha–1 along with a control. The minimal soil moisture level (40% FC) resulted in 55–68% and 53–76% reduction in root dry matter in Experiment 1 and Experiment 2, respectively, in comparison to that at 100% FC throughout Si doses. Fruit yield, irrigation water productivity, and net photosynthetic rate exhibited a respective reduction of 77–84% and 78–84%, 25–52% and 13–47%, and 37–46% and 26–33% in Experiment 1 and Experiment 2, respectively, at 40% FC than those at 100% FC throughout Si doses. The exogenous application of Si was equally efficient irrespective of application methods. Seed priming with 0.5 mM Si outperformed all other doses and resulted in an increase of 199–284%, 169–263%, and 20–59% in fruit yield, irrigation water productivity, and net photosynthetic rate, respectively, in comparison to the control throughout soil moisture levels. Among different soil application doses of Si, 60 kg ha–1 was the most efficient, which resulted in 217–293%, 198–307%, and 11–33% enhancement in fruit yield, irrigation water productivity, and net photosynthetic rate, respectively, in comparison to the control throughout soil moisture levels. Exogenous incorporation of Si as seed priming at 0.5 mM and as soil drench at 60 kg ha–1 is recommended for cucumber cultivation in drought-affected areas. [ABSTRACT FROM AUTHOR]

Cucumber is an important member of Cucurbitaceae family which is grown and consumed globally. It is consumed in the form of salads or pickles and has abundant supply of minerals and vitamins. It has been a focus of extensive research due to its publically available genome sequences. Marker assisted breeding has been employed to generate improved varieties of cucumber with resistance to various diseases besides desirable horticultural traits. One such trait is the production of parthenocarpic fruits i.e. seedless fruits developed in the absence of pollination. Naturally, parthenocarpy occurs under unfavourable environmental conditions. However, it is possible to artificially induce parthenocarpy by applying plant growth regulators. At molecular level, parthenocarpy is a result of complex role-play of genes and hormones with tight regulation. Many researchers aim at developing parthenocarpic varieties by either transferring the trait into existing varieties with resistance to specific diseases or by knocking off genes controlling parthenocarpy. A comprehensive knowledge of background and genetics of parthenocarpy is required in both cases. This review includes an-inclusive study of the molecular basis of parthenocarpy. The genes and hormones involved and their functions, inheritance of parthenocarpy and markers associated with it have been given in detail. [ABSTRACT FROM AUTHOR]

SUMMARY: The target of rapamycin (TOR) kinase serves as a central regulator that integrates nutrient and energy signals to orchestrate cellular and organismal physiology in both animals and plants. Despite significant advancements having been made in understanding the molecular and cellular functions of plant TOR kinases, the upstream regulators that modulate TOR activity are not yet fully elucidated. In animals, the translationally controlled tumor protein (TCTP) is recognized as a key player in TOR signaling. This study reveals that two TCTP isoforms from Cucumis sativus, when introduced into Arabidopsis, are instrumental in balancing growth and defense mechanisms against the fungal pathogen Golovinomyces cichoracearum. We hypothesize that plant TCTPs act as upstream regulators of TOR in response to powdery mildew caused by Podosphaera xanthii in Cucumis. Our research further uncovers a stable interaction between CsTCTP and a small GTPase, CsRab11A. Transient transformation assays indicate that CsRab11A is involved in the defense against P. xanthii and promotes the activation of TOR signaling through CsTCTP. Moreover, our findings demonstrate that the critical role of TOR in plant disease resistance is contingent upon its regulated activity; pretreatment with a TOR inhibitor (AZD‐8055) enhances cucumber plant resistance to P. xanthii, while pretreatment with a TOR activator (MHY‐1485) increases susceptibility. These results suggest a sophisticated adaptive response mechanism in which upstream regulators, CsTCTP and CsRab11A, coordinate to modulate TOR function in response to P. xanthii, highlighting a novel aspect of plant–pathogen interactions. Significance Statement: Target of rapamycin (TOR) signaling pathway serves as a central integrator of diverse nutrient, energy, hormone, and environmental signals, playing a pivotal role in the precise regulation of cellular and organismal physiology. In this study, we reveal a novel mechanism involving the TCTP‐Rab11A module, which significantly contributes to plant stress responses by positively regulating the TOR signaling pathway. This discovery not only enhances our understanding of the complex regulatory networks in plants but also provides potential targets for improving plant resistance to biotic and abiotic stresses. [ABSTRACT FROM AUTHOR]

【Objective】In order to provide favorable genes for the analysis of the grafting healing mechanism of Cucumis sativus L. or Cucurbita moschata Duch. grafted seedlings and the molecular breeding of resistance of the cucumber and pumpkin vegetables, we conducted the analysis of the expression patterns of Bcl-2 associated athanogene（BAG）family proteins in the cucumber and pumpkin in response to abiotic stress and in response to light during cucumber or pumpkin grafting healing.【Method】Based on the genome information of the cucumber and pumpkin, the BAG gene family in the cucumber and pumpkin was identified through bioinformatics methods, and its physicochemical characteristics, chromosome mapping, gene structure, phylogeny and collinearity were analyzed. The expression patterns of BAG family proteins in the cucumber and pumpkin in response to abiotic stress and in response to light during cucumber or pumpkin grafting healing were analyzed. These data were based on the public database and the transcriptome sequencing data of the cucumber or pumpkin grafted seedlings in the process of grafting and healing.【Result】A total of 12 and 18 members of the BAG family were identified in the cucumber and pumpkin, respectively and they were all divided into two subfamilies and the gene members were highly conserved. The BAG of subfamily I was mainly involved in gene regulation and stress response, while the BAG of subfamily II was mainly involved in plant development. The BAG genes of cucumber and pumpkin had multiple linear relationships with Arabidopsis, Oryza sativa L. and Solanum lycopersicum L., respectively, but the CsaV3_1G017210 was relatively conservative and there was no collinearity with the BAG genes in Arabidopsis, rice, tomato and pumpkin. Different BAG genes possessed tissue-specific expression patterns. CsaV3_6G000970 and CmoCh08G008520 belonged to the BAG family molecular chaperone regulator 6. In both cucumber and pumpkin, they were upregulated during the grafting healing process and in response to abiotic stress.【Conclusion】BAG family genes respond differently to abiotic stress and light during the grafting healing process of the cucumber or pumpkin. These genes synergistically regulate the growth, development and grafting healing of the cucumber and pumpkin. BAGs play an important role in the process of the cucumber and pumpkin abiotic stress and cucumber or pumpkin grafting healing. [ABSTRACT FROM AUTHOR]

Drought stress limits cucumber germination and initial growth. Decreases cucumber germination and initial growth cause uneven plant stands and decrease crop productivity. Identifying drought-tolerant cultivars and drought stress attenuators can improve cucumber germination and initial growth. Therefore, we evaluated the drought stress tolerance of cucumber cultivars and the action of drought-stress attenuators on cucumber germination, initial growth, osmotic adjustment, and antioxidant activity. The research was carried out in two stages. In the first one, we evaluated five levels of osmotic potential and seven cucumber cultivars. In the second stage, we evaluated two cultivars—one sensitive and one tolerant to drought stress—subjected to six combinations of osmotic potential and attenuator. The osmotic potential of − 0.4 MPa is critical for cucumber seedlings—the cultivars Compadre, Campeiro, Sliced Max, and Prêmio are sensitive, and cultivars Diplomat, Runner, and Safira are tolerant at the − 0.4 MPa level. Sensitive cultivar seeds treated with hydropriming, salicylic acid, and hydrogen peroxide showed better growth, osmotic adjustment, and higher antioxidant activity than seeds not treated under drought stress. Gibberellic acid was beneficial only in the drought-stress tolerant cultivar and can increase the vigor of drought-tolerant cultivars. Our results reveal that Diplomat, Runner, and Safira cucumber cultivars are drought-tolerant and that hydropriming, salicylic acid, and hydrogen peroxide improve the tolerance of drought-sensitive cucumber cultivars. [ABSTRACT FROM AUTHOR]

Nanofertilizers represent an efficient method for fertilizing crops, with a positive impact on plant development. This work aimed to determine the impact of Nubiotek Ultra Ca and Nubiotek Hyper Fe +Mg nanofertilizers on the yield and quality of cucumber fruits in 2020. Two doses of Nubiotek Ultra Ca (0 and 20 L ha-1) and four doses of Nubiotek Hyper Fe+Mg (0, 2, 4, and 8 ml L-1) were evaluated. An experimental design of randomized complete blocks was used with a factorial arrangement (2x4), with four repetitions. The results showed that the nanofertilizers evaluated did not improve internode distance, dry weight of each organ, root length, total soluble solids, vitamin C, titratable acidity, and fruit color parameters compared to the values obtained with the control. On the other hand, with the treatments of 0 L ha-1 Nubiotek Ultra Ca + 8 ml L-1 Nubiotek Hyper Fe+Mg and 20 L ha-1 Nubiotek Ultra Ca + 2 ml L-1 Nubiotek Hyper Fe+Mg, the fruit yield increased by 111 and 123%, respectively, compared to the control. Likewise, a greater firmness of fruits was observed when applying Nubiotek Ultra Ca and Nubiotek Hyper Fe+Mg in doses of 20 L ha-1 + 8 ml L-1; on the other hand, the highest content of chlorophyll a, b and total was achieved with doses of 20 L ha-1 + 4 ml L-1 and 20 L ha-1 + 8 ml L-1. [ABSTRACT FROM AUTHOR]

Due to the widespread use of intensive cropping patterns, the problem of continuous cropping obstacle, which is dominated by autotoxicity, has been becoming more and more prominent. Although many methods have been proposed to overcome the continuous cropping obstacle of cucumber, no study has reported the screening and evaluation of cucumber germplasm resistant to autotoxicity. In this study, 28 physiological indices related to the cucumber bud stage under cinnamic acid (CA) treatment were determined. In total, 45 cucumber cultivars were classified into three groups using principal component analysis and cluster analysis, and a model for evaluating cucumber resistance to autotoxicity was developed. The evaluation model was validated using autotoxicity-tolerant and non-autotoxicity-tolerant cultivars. The results showed that the growth of non-autotoxicity-tolerant cultivars was significantly inhibited compared to autotoxicity-tolerant cultivars. This indicated that the evaluation model of cucumber autotoxicity tolerance is reliable. The results of this study provide a valuable reference for the application of cucumber autotoxicity-tolerant germplasm resources and the development of autotoxicity-tolerant genes. [ABSTRACT FROM AUTHOR]

Smart horticulture aims to use the emerging technologies to modernise industrial applications and address issues such as productivity, environmental sustainability, and food security. In recent years, scientists have made significant efforts to design the novel methods for horticultural applications with using nanoparticles (NPs) and their composites. The use of silver nanoparticles (Ag-NPs) as growth-modulating and antipathogen agents in horticulture is a promising area of research. However, the current state of knowledge in these fields is still insufficient.The study aimed to assess the impact of alginate gels containing Ag-NPs on the germination of cucumber (Cucumis sativus L.) seeds and the initial growth stage of seedlings. Composites with Ag-NPs were prepared using chemical synthesis, with maltose as the reducing substance and biodegradable polymer, sodium alginate, as the stabilizer. Blotting paper was used to place cucumber seeds on dishes. The seeds were then soaked with diluted test solutions containing Ag-NPs (10 ppm and 20 ppm), as well as treatments with deionized water (negative control) and aqueous sodium alginate solutions (1:5 and 1:10) without silver nanoparticles (positive control). After 8 days, the germination, morphological and biochemical parameters were determined. Seed germination percentage was not affected by alginate gels and 10 ppm Ag-NPs. At a concentration of 20 ppm, Ag-NPs reduced the germination index,as well as length and weight of the root, stem, seedling, when compared to the positive and negative control. The inhibition coefficients for root, stem, and seedling were significantly higher in the treatment group. The application of Ag-NPs at concentrations of 10 and 20 ppm resulted in a decrease in the total antioxidant capacity (TAC), total phenolics (TP), and malondialdehyde (MDA) content in seedling roots compared to the negative control. However, there was an increase in TAC and TP in shoots, but not in MDA. In the roots of the seedlings, the application of Ag-NPs resulted in an increase in catalase (CAT) activity, while ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and superoxide dismutase (SOD) activity was decreased compared to the negative control. In the shoots of the seedlings, CAT, GPX, and SOD activity was higher than in the plant material from the positive control. The application of Ag-NPs had a significant, dose-dependent effect on the investigated parameters of cucumber seedlings. However, it was also observed that sodium alginate without NPs had an impact. Ag-NPs elicit a stronger response in shoot tissues, as reflected by higher TAC and content of TP and MDA, although CAT, GPX, and SOD activity was lower than in roots Composites of sodium alginate with Ag-NPs can be used to shape of cucumber seedling germination performance.

Objectives: Cucumis sativus L. (C. sativus) is vegetable commonly used for managing blood pressure and often consumed in combination with standard antihypertensive therapy, despite lack of scientific evidence supporting their use. Combination of herbs and standard medication could have positive or negative effects. Therefore, this study aimed to evaluate the antihypertensive activity of C. sativus and the combined effect with losartan in the hypertensive rat model induced by angiotensin II. Angiotensin II is a component of the renin-angiotensin-aldosterone system that, upon binding to its receptor, constricts blood vessels leading to elevation of blood pressure. Methods: In an antihypertensive study, rats received C. sativus orally at doses of 9, 18, 27, and 36 mg/kg (full dose); while in a combination study, animals received losartan 2.25 mg/kg combined by either with C. sativus 9 or 18 mg/kg. The standards group received losartan 2.25 mg/kg or 4.5 mg/kg (full dose). Results: Blood pressure was measured using the tail-cuff method. C. sativus significantly attenuated angiotensin II-induced hypertension as observed in groups receiving C. sativus at 9, 18, 27, and 36 mg/kg at 30 minutes after induction showed the average change (Δ) of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with respect to time zero were 28.8/18.3, 24.8/15.8, 22.8/15.5, and 11.5/9.0 mmHg, respectively. Whereas the average change (Δ) of SBP and DBP in the rats receiving the combination of half doses of C. sativus and losartan were 8.8/9.0 mmHg, respectively. These diminished effects were better than a full dose of C. sativus and comparable with a full dose of losartan (6.5/7.8 mmHg). Conclusion: The present findings indicate that C. sativus dose-dependently blocks blood pressure elevation induced by angiotensin II. The combination of half dose of C. sativus and losartan has an additive effect in lowering blood pressure.

Nitrogen-fixing cyanobacterial consortia are an alternative to the indiscriminate use of chemical fertilizers that affect the environment, fix atmospheric nitrogen, and can therefore be used as plant growth promoters, synthesize various substances such as auxins, vitamins, and total proteins, and fix atmospheric biofertilizers and soil conditioners. The present study aimed to obtain and develop, by biotechnological means, two consortia of cyanobacteria isolated from the root and rhizosphere of Carica papaya grown in sandy loam soil. The culture was carried out in Blue Green Medium without modified nitrogen (BG110), with aeration of 0.32 L min−1, at a light intensity of 48.83 μEm−2s−1, and a temperature of 22 ± 2 °C. Two consortia consisting of Nostoc commune, Aphanothece minutissima, Planktothrix sp. (C1), Nostoc commune, Calothrix sp., and Aphanothece minutissima (C2) were isolated and morphologically identified. The effective development of these consortia was verified at the laboratory level by obtaining biomass in dry weight as well as photosynthetic pigments, proteins, carbohydrates, and lipids. Germination parameters were determined in seeds of Cucumis sativus L. var. Market plus treated with the nitrogen-fixing cyanobacteria consortia, obtaining a higher germination percentage (>90%), greater root length (>6 cm), and higher vigour index I (513), II (13.02) for the C2 consortium. This broadens the spectrum of rhizosphere-derived microorganisms with potential as growth biostimulators.

Haploidization technique is the modern and advanced breeding technique used to enhance economically essential crops, including cucumber, to meet consumers' preferences and needs worldwide. This study aimed to evaluate the effects of factors such as genotype, thermal pre-treatments, and nutrient medium combinations that are considered in haploid production via ovary culture in four commercial cucumber varieties. Four different induction media with four distinct maturation medium combinations and three F1 and one open-pollinated (Beith Alpha) cucumber varieties were used. All explants (cucumber ovaries' slices) were inoculated in induction media and remained at 35 °C/3 d in the dark, then were transferred at 25 ± 1 °C 16-/8-h light/dark photoperiod for a further 9 d. The results of the study demonstrated that the embryo-like structure (ELS) formation rate was high in induction medium 2 which was successful in all varieties of Ptk40 (20%), Botanik (20%), Beith Alpha (16%), and Sardes (13.3%), respectively, compared to other induction medium combinations used in this study. Callus formation rates obtained from regeneration of medium 2 supplemented with 2.0 mg L−1 6-benzylaminopurine (BAP) and 0.5 mg L−1 1-naphthaleneacetic acid (NAA) were Ptk40 (65%), Sardes (60%), and Botanik (40%), and no callus was formed in Beith Alpha. Due to the findings of this study, the nutrient medium containing KIN and 2,4-D seems to be successful during induction of haploid embryo formation in cucumbers. One plantlet germinated but perished at early stage. The plantlet regeneration was observed to be low. Further studies are required to optimize the embryo regeneration medium composition due to the cucumber growing seasons, genotypes, and nutrient medium. [ABSTRACT FROM AUTHOR]

Cytochrome P450s are a large family of protein-encoding genes in plant genomes, many of which have not yet been comprehensively characterized. Here, a novel P450 gene, CYP82D47, was isolated and functionally characterized from cucumber (Cucumis sativus L.). Quantitative real-time reverse-transcription polymerase chain reaction analysis revealed that CYP82D47 expression was triggered by salicylic acid (SA) and ethephon (ETH). Expression analysis revealed a correlation between CYP82D47 transcript levels and plant defense responses against powdery mildew (PM) and Fusarium oxysporum f. sp. cucumerinum (Foc). Although no significant differences were observed in disease resistance between CYP82D47-RNAi and wild-type cucumber, overexpression (OE) of CYP82D47 enhanced PM and Foc resistance in cucumber. Furthermore, the expression levels of SA-related genes (PR1, PR2, PR4, and PR5) increased in CYP82D47-overexpressing plants 7 days post fungal inoculation. The levels of ETH-related genes (EIN3 and EBF2) were similarly upregulated. The observed enhanced resistance was associated with the upregulation of SA/ETH-signaling-dependent defense genes. These findings indicate the crucial role of CYP82D47 in pathogen defense in cucumber. CYP82D47-overexpressing cucumber plants exhibited heightened susceptibility to both diseases. The study results offer important insights that could aid in the development of disease-resistant cucumber cultivars and elucidate the molecular mechanisms associated with the functions of CYP82D47. [ABSTRACT FROM AUTHOR]

Countries in arid climates, such as Qatar, require efficient water-saving strategies and nitrogen treatment for vegetable production. Vegetable importation constituted approximately USD 352 million of Qatar's 2019 GDP; hence, enhancing local production is essential. This study investigated the effect of varying nitrogen and water levels on cucumber (Cucumis sativus L.) fruit yield. Various water management strategies were also evaluated. A split plot design was employed with two water levels (W1: 50% deficit irrigation, W2: 100% full irrigation) and three nitrogen levels (N1: 50 kg N ha−1, N2: 70 kg N ha−1, N3: 100 kg N ha−1) to examine cucumber yield and physiological response. Our findings revealed that using minimal drip irrigation and reducing nitrogen levels significantly enhanced the growth, SPAD index, fruit characteristics, and yield components of cucumber. Drip irrigation had a greater influence on cucumber production than nitrogen levels. Shoot height increased by 4% from W2N1 (T1) to W1N3 (T6) and 4.93% from W2N2 (T2) to W1N2 (T5). Fruit length and width increased by 10.63% and 13.41% from T2 and T1 to T5, respectively. The highest total yield occurred at T5, followed by T6, T2, W2N3 (T3), W1N1 (T4), and T1 at 34.5, 29.1, 27.6, 25.8, 25.2, and 20.4 t/ha, respectively. The optimal combination comprised 50% deficit irrigation (W1) and 70 kg N ha−1 (N2) nitrogen. These results suggest the importance of optimizing drip irrigation for achieving maximum cucumber fruit yield in arid climates. [ABSTRACT FROM AUTHOR]

Gummy stem blight (GSB), caused by Didymella bryoniae, is one of the most devastating diseases that severely reduces cucumber production. Developing resistant varieties would be an effective strategy to control GSB. Although several GSB-resistant QTLs have been reported, causal genes for GSB resistance have not yet been identified in cucumber. A novel loci gsb3.1 for seedling GSB resistance from the "PI 183967" genotype was previously identified in a 1.7-Mb interval on chromosome 3. In this study, we developed a residual heterozygous line-derived strategy from Recombinant Inbred Lines to perform fine mapping, and with this approach, the gsb3.1 locus was narrowed to a 38 kb interval. There were six predicted genes at the gsb3.1 locus, four of which differed in expression in the GSB-resistant compared to the susceptible lines after fungal inoculation. These candidate genes (Csa3G020050, Csa3G020060, Csa3G020090, and Csa3G020590) within the gsb3.1 locus could be helpful for the genetic study of GSB resistance and marker-assisted selection in cucumber. Phylogenetic analyses indicated that the resistant gsb3.1 allele may uniquely exist in the wild species present in the Indian group, and that nucleotide diversity was significantly reduced in cultivated accessions. Therefore, the gsb3.1 allele could be introgressed into existing commercial cultivars and combined with other resistance QTLs to provide broad-spectrum and robust GSB resistance in cucumber.

Cucumber green mottle mosaic virus (CGMMV), as a typical seed-borne virus, causes costly and devastating diseases in the vegetable trade worldwide. Genetic sources for resistance to CGMMV in cucurbits are limited, and environmentally safe approaches for curbing the accumulation and spread of seed-transmitted viruses and cultivating completely resistant plants are needed. Here, we describe the design and application of RNA interference-based technologies, containing artificial microRNA (amiRNA) and synthetic trans-acting small interfering RNA (syn-tasiRNA), against conserved regions of different strains of the CGMMV genome. We used a rapid transient sensor system to identify effective anti-CGMMV amiRNAs. A virus seed transmission assay was developed, showing that the externally added polycistronic amiRNA and syn-tasiRNA can successfully block the accumulation of CGMMV in cucumber, but different virulent strains exhibited distinct influences on the expression of amiRNA due to the activity of the RNA-silencing suppressor. We also established stable transgenic cucumber plants expressing polycistronic amiRNA, which conferred disease resistance against CGMMV, and no sequence mutation was observed in CGMMV. This study demonstrates that RNA interference-based technologies can effectively prevent the occurrence and accumulation of CGMMV. The results provide a basis to establish and fine-tune approaches to prevent and treat seed-based transmission viral infections.

Compost has a broad application in terms of the improvement of the soil properties. This research work was conducted to present the molecular implications of using compost obtained from different substrates to improve soil parameters for cucumber seedlings cultivation. In the experiment, the following compost mixtures were used: sewage sludge (80%) + sawdust (20%); sewage sludge (40%) + sawdust (10%) + biodegradable garden and park waste (50%); biodegradable garden and park waste (90%) + sawdust (10%); sewage sludge (80%) + sawdust (20%) + Eisenia fetida; sewage sludge (40%) + sawdust (10%) + biodegradable garden and park waste (50%) + Eisenia fetida; biodegradable garden and park waste (90%) + sawdust (10%) + Eisenia fetida. The final substrate compositions consisted of compost mixtures and deacidified peat(O) (pH 6.97; Corg content—55%, N content—2.3%), serving as a structural additive, in different mass ratios (mass %). The produced plants underwent biometric and physiological measurements as well as enzymatic analyses of stress markers. Based on the conducted studies, it has been found that the substrate productivity depends not only on the content of nutrient components but also on their structure, which is moderated by the proportion of peat in the substrate. The most effective and promising substrate for cucumber seedling production was variant 2 (I), which consisted of 25% compost from sewage sludge (40%) + sawdust (10%) + biodegradable garden and park waste (50%) and 75% deacidified peat. Despite the richness of the other substrates, inferior parameters of the produced seedlings were observed. The analysis of the enzymatic activity of stress markers showed that these substrates caused stress in the plants produced. The study's results showed that this stress was caused by the presence of Eisenia fetida, which damaged the developing root system of plants in the limited volume of substrate (production containers). The adverse influence of Eisenia fetida on the plants produced could possibly be eliminated by thermal treatment of the compost, although this could lead to significant changes in composition. [ABSTRACT FROM AUTHOR]

Plant endophytic fungi and rhizosphere soil fungi are often reported as biocontrol agents against plant pathogens or with plant growth promotion potential. Four treatments were performed in field and greenhouse experiments where cucumber plants were inoculated with Trichoderma harzianum and Fusarium oxysporum in 2022. The roots, stems and leaves of cucumber plants and their rhizosphere soil were collected twice individually from the field and greenhouse for isolation of cucumber endophytic and rhizosphere soil fungi. All fungal strains were identified through sequence similarity of the ITS1-5.8s-ITS2 rDNA region. The potato dextrose agar (PDA) media yielded the highest number of genera isolated from cucumber plants, rhizosphere soil and both compared to other media. There were no significant differences among the four media for the isolation of all cucumber endophytic fungi. However, in the roots, the number of endophytic fungi isolated by MRBA was significantly higher than that isolated on malt extract agar (MEA), while in the stems, the number of fungi isolated with PDA was significantly higher than that isolated with Martin's rose bengal agar medium (MRBA). PDA had significantly higher isolation efficiency for the rhizosphere soil fungi than MRBA. The 28 fungal genera had high isolation efficiency, and the endophytic Trichoderma strains were significantly more isolated by MEA than those of MRBA. It is suggested that PDA can be used as a basic medium, and different cultural media can be considered for specific fungal genera. [ABSTRACT FROM AUTHOR]

Due to the widespread use of intensive cropping patterns, the problem of continuous cropping obstacle, which is dominated by autotoxicity, has been becoming more and more prominent. Although many methods have been proposed to overcome the continuous cropping obstacle of cucumber, no study has reported the screening and evaluation of cucumber germplasm resistant to autotoxicity. In this study, 28 physiological indices related to the cucumber bud stage under cinnamic acid (CA) treatment were determined. In total, 45 cucumber cultivars were classified into three groups using principal component analysis and cluster analysis, and a model for evaluating cucumber resistance to autotoxicity was developed. The evaluation model was validated using autotoxicity-tolerant and non-autotoxicity-tolerant cultivars. The results showed that the growth of non-autotoxicity-tolerant cultivars was significantly inhibited compared to autotoxicity-tolerant cultivars. This indicated that the evaluation model of cucumber autotoxicity tolerance is reliable. The results of this study provide a valuable reference for the application of cucumber autotoxicity-tolerant germplasm resources and the development of autotoxicity-tolerant genes.

Background: Calcium nitrate is a widely used fertilizer in the preparation of nutrient solutions. However, there is still a need to determine the effects of different levels of calcium nitrate on the Persian cucumber crop to optimize fertilization practices and improve crop yield. Objective: To determine the effects of two levels of calcium nitrate in the nutrient solution on the growth, yield, and nutrient content of two Persian cucumber hybrids (Bereket and Cruz). Methodology: The experiment was carried out in a completely randomized design in a factorial arrangement (two hybrids and two nutrient solutions) under greenhouse conditions. Results: The nutrient solution with 11 meq L-1 of calcium nitrate increased the concentration of nitrate and calcium in the petiole sap of the Cruz hybrid in the flowering stage; however, the yield of both hybrids decreased. On the other hand, the nutrient solution with 9 meq L-1 of calcium nitrate increased the number of fruits of both hybrids and the yield per plant of the Cruz hybrid. Implications: The Cruz hybrid showed to be more efficient in calcium uptake than the Bereket hybrid, which is interesting since it could require less calcium application without affecting yield. However, other studies are necessary to expand this information. Conclusion: The nutrient solution containing 9 meq L-1 of calcium nitrate showed a significant increase in the number of fruits per plant for both the Cruz and Bereket hybrids. This highlights the importance of appropriate calcium nitrate supplementation in the nutrient solution, as it enhances the production of hydroponically grown Persian cucumbers.

Cucumber is an important vegetable crop, and grafts often affect the quality and wax loss in cucumber fruit and affect its value. However, their metabolites and molecular mechanisms of action remain unclear. Metabolome and transcriptome analyses were conducted on the fruit peels of self-rooted plants (SR) grafted with white seed pumpkin (WG). The results showed that there were 352 differential metabolites in the fruit peels of the SR and WG. The transcriptome analysis showed 1371 differentially expressed genes (DEGs) between the WG and SR. These differentially expressed genes were significantly enriched in plant hormone signal transduction, cutin, suberin, wax biosynthesis, phenylpropanoid biosynthesis, and zeatin biosynthesis. By analyzing the correlation between differential metabolites and differentially expressed genes, six candidate genes related to the synthesis of glycitein, kaempferol, and homoeriodictyol were identified as being potentially important. Key transcription factors belonging to the TCP and WRKY families may be the main drivers of transcriptional changes in the peel between the SR and WG. The results of this study have provided a basis for the biosynthesis and regulation of wax loss and quality in grafted cucumbers and represents an important step toward identifying the molecular mechanisms of grafting onto cucumber fruit. [ABSTRACT FROM AUTHOR]

Salinity stress prominently limits cucumber growth and productivity. However, the mechanism underlying salinity response mediated by the C-TERMINALLY ENCODED PEPTIDE (CEP) peptide in cucumber primary root remains largely unclear. In this study, we show that salinity prominently inhibits cucumber primary root growth, and CsCEP gene expression is differentially induced by salinity. We further demonstrate that the exogenous application of synthetic CsCEP3 peptide partially suppresses salinity-triggered growth inhibition in cucumber primary root, although CsCEP3 peptide itself shows no obvious effect on cucumber primary root growth under normal conditions. Our transcriptomic and qRT-PCR data further reveal that CsCEP3 peptide may modulate gene expression related to abscisic acid (ABA) signaling pathway, reactive oxygen species (ROS) production, and slat-responsive transcription factors to attenuate the inhibitory effect of salinity on cucumber primary root growth. Taken together, our work provides a fundamental insight into CEP peptide-mediated cucumber salinity adaptation. [ABSTRACT FROM AUTHOR]

The application of oligosaccharides can promote plant growth by increasing photosynthesis or inducing plant innate immunity. However, the mechanisms by which oligosaccharides affect bacterial community diversity and abundance remain unclear. In this study, a mixed oligosaccharide was applied to the growth of cucumbers. The findings of the present study suggest that the application of MixOS has significant effects on the bacterial communities in the phyllosphere, rhizosphere, and bulk soil of cucumber plants. The treatment with MixOS resulted in delayed senescence of leaves, well-developed roots, and higher fruit production. The bacterial diversity and composition varied among the different ecological niches, and MixOS application caused significant shifts in the bacterial microbiome composition, particularly in the phyllosphere. Moreover, mixed oligosaccharides increased the abundance of potential growth-promoting bacteria such as Methylorubrum spp. and Lechevalieria spp., and more zOTUs were shared between the WM and MixOS treatments. Furthermore, the bacterial cooccurrence network analysis suggested that the modularity of the phyllosphere networks was the highest among all samples. The bacterial co-occurrence networks were altered because of the application of MixOS, indicating a greater complexity of the bacterial interactions in the rhizosphere and bulk soil. These findings suggest that mixed oligosaccharides has the potential to improve plant growth and yield by modulating the bacterial communities within and outside the plants and could provide a theoretical basis for future agricultural production. [ABSTRACT FROM AUTHOR]

A wide range of soilless cultivation techniques have been developed and introduced for intensive cropping systems and for boosting the crop yield of many vegetables, mainly in greenhouses. Adoption of some local natural byproducts to be utilized as a substrate growing medium to overcome soil-related problems appeared to be a promising project. Therefore, greenhouse experiments were conducted at the Baloza Experimental Station of the Desert Research Center (DRC), North Sinai Governorate, Egypt, during the two consecutive winter growing seasons of 2016-2017 and 2017-2018. These experiments aimed to investigate the effects of seven growing substrate culture treatments of separated or mixed sand obtained from sand dunes and date palm tree residues (Karenna) on plant vegetative growth, flowering, fruit yield and quality traits, and fruit nutritional values of cucumber plants (Cucumis sativus L.) Filial-1 hybrid 1101. Crop evapotranspiration reference (ETc) and water use efficiency (WUE), as well as treatment feasibility, were also studied. The experiment was set up in a complete randomized block design with three replicates. The obtained results strongly indicated that growing substrate media containing 25% sand (S) from sand dunes mixed with 75% grinded Karenna (Kg) of date palm (1 S + 3 Kg) significantly recorded the superiority of all studied characters of plant vegetative growth, number of flowers, fruit set, yield and its components, as well as fruit N, P and K contents, compared with other growing substrate medium treatments. On the contrary, the worst values of all studied parameters were achieved when sand was used alone (100% S) as a growing media. Furthermore, the highest water use efficiency and net income values were also attained by the 1 S + 3 Kg media treatment relative to the other growing substrate medium treatments. [ABSTRACT FROM AUTHOR]

Soluciones nutritivas con balance en las relaciones, proporciones y concentraciones de los iones optimizan la eficiencia en el uso de nutrimentos y el rendimiento de los cultivos. El objetivo de este trabajo fue evaluar, en invernadero, tres relaciones porcentuales Mg2+/cationes (20, 40 y 60/100) y tres de NO3-/aniones (40, 60 y 80/100) y su combinación sobre la composición mineral, la eficiencia de uso de nutrimentos (EUN) y el rendimiento de pepino (Cucumis sativus cv. Poinsett 76) desarrollado en hidroponía en circuito cerrado. El diseño experimental fue completamente al azar con arreglo factorial de tratamientos 32 y seis repeticiones. Las variables evaluadas fueron la composición mineral de hojas, tallos y frutos, EUN, peso, diámetro, longitud, número, y rendimiento de fruto. Los resultados se analizaron con ANDEVA y los promedios se compararon con la prueba de Tukey (P ≤ 0.05). El rendimiento superior fue con la combinación 20/100 Mg2+ y 60/100 NO3-, relaciones mayores de Mg2+ (40 y 60/100) y de NO3- (80/100) redujeron el rendimiento 33.4%, 30.7% y 20.6%, respectivamente, y disminuyeron la eficiencia de Mg y N, respecto a 20/100 Mg2+ y 60/100 NO3-. La relación 60/100 Mg2+ aumentó la concentración nutrimental de Mg en los frutos, pero disminuyó el rendimiento.

[Objective] The paper aims to explore whether calmodulin-like CMLs participate in the sexual differentiation process in Cucumis sativus L., so as to provide reference for improving the regulatory network of sexual differentiation furtherly. [Method] In the study, CMLS, ACSIG, ACS2 and ACS11 genes of cucumber were cloned, qPCR was used to detect the expressions of CMLS gene in different types of the flowers, and the interactions between CMLS and proteins encoded by major genes of cucumber sex differentiation were detected by the method of yeast two-hybrid. [Result】 CML8 was cloned from cucumber which contained a complete ORF of 441 bp, encoding 146 aa without signal peptide. It was an extracellular protein without transmembrane domain and introns, and contained 4 EF-hand domains with Ca2+ binding ca- pacity, and subcellular was located in cell membrane and cytoplasm. ACSIG, ACS2 and ACSII, three key genes of cucumber sexual differ- entiation were cloned, and sequence alignment showed that the nucleotide sequences and encoded protein sequences of the three genes were consistent with those in the cucumber database. There were significant differences in the expression levels of three genes in the female flow- ers, male flowers and bisexual flowers, and extremely significant differences in male flowers. The yeast two-hybrid experiment showed that CMLS could interact with ACSIG and ACS2, but not with ACS11. [Conclusion] Calmodulin-like 8 (CMLS) was cloned, and CMLS could interact with ACSIG and ACS2, which might participate in the sexual differentiation of cucumber, and the study was the first time to explore the involvement of calmodulin in the process of plant sexual differentiation, and expect to provide reference for calcium signaling system to participate in the process of plant sexual differentiation. [ABSTRACT FROM AUTHOR]

Soil biofumigation is a widely used farming practice for soil-borne disease management in vegetable crops. Soil biofumigation is the practice of the incorporation of fresh plant materials from the members of the Brassicaceae family into the soil which release antimicrobial volatile organic compounds (VOCs), namely glucosinolates and their hydrolysis products. However, the VOCs may affect non-target beneficial soil biota including microbial biocontrol agents (MBAs) due to their broad-spectrum toxicity. In this study, native antagonistic rhizobacteria were isolated from cabbage plants grown in biofumigated fields and their potential in the management of Pythium aphanidermatum cucumber damping-off was evaluated with and also without biofumigation using cabbage leaf residue. A total of 20 morphologically distinct, culturable bacterial strains were recovered from the rhizosphere soil of cabbage cultivated in a biofumigated field, with the largest fraction of the isolates belonging to the genus Bacillus. The other bacterial genera isolated were Pseudomonas, Serratia, Stenotrophomonas, Microbacterium and Priestia. Of the 20 bacterial isolates, Pseudomonas aeruginosa B1-SQU, Pseudomonas indica B2-SQU, Serratia marcescens B3-SQU and Pseudomonas brenneri B4-SQU exhibited inhibitory activity against P. aphanidermatum in a co-culture assay. The deformation and shrinkage of P. aphanidermatum hyphae due to diffusible antimicrobial compounds from these bacterial strains were witnessed through scanning electron microscopy. A biofilm was formed by these bacterial strains in vitro and they exhibited compatibility with each other; however, they had no significant plant growth promotion effect on cucumber. These bacterial strains significantly reduced damping-off in cucumber under greenhouse conditions when applied to soil singly, but failed to show a significant effect when combined with biofumigation treatment, though the bacterial population in the soil was maintained at higher levels. Soil biofumigation alone was also not effective in suppressing the damping-off of cucumber. Gas chromatography–mass spectrometry analysis revealed that 1-butanol, n-butyl butyrate and butyl acetate were the predominant VOCs in the soil amended with cabbage leaf residue. The results suggest that soil biofumigation with cabbage leaf residue has no significant effect on P. aphanidermatum under high inoculum levels; furthermore, it affects the efficiency of the bacterial antagonists in controlling damping-off in cucumber. [ABSTRACT FROM AUTHOR]

Countries in arid climates, such as Qatar, require efficient water-saving strategies and nitrogen treatment for vegetable production. Vegetable importation constituted approximately USD 352 million of Qatar’s 2019 GDP; hence, enhancing local production is essential. This study investigated the effect of varying nitrogen and water levels on cucumber (Cucumis sativus L.) fruit yield. Various water management strategies were also evaluated. A split plot design was employed with two water levels (W1: 50% deficit irrigation, W2: 100% full irrigation) and three nitrogen levels (N1: 50 kg N ha−1, N2: 70 kg N ha−1, N3: 100 kg N ha−1) to examine cucumber yield and physiological response. Our findings revealed that using minimal drip irrigation and reducing nitrogen levels significantly enhanced the growth, SPAD index, fruit characteristics, and yield components of cucumber. Drip irrigation had a greater influence on cucumber production than nitrogen levels. Shoot height increased by 4% from W2N1 (T1) to W1N3 (T6) and 4.93% from W2N2 (T2) to W1N2 (T5). Fruit length and width increased by 10.63% and 13.41% from T2 and T1 to T5, respectively. The highest total yield occurred at T5, followed by T6, T2, W2N3 (T3), W1N1 (T4), and T1 at 34.5, 29.1, 27.6, 25.8, 25.2, and 20.4 t/ha, respectively. The optimal combination comprised 50% deficit irrigation (W1) and 70 kg N ha−1 (N2) nitrogen. These results suggest the importance of optimizing drip irrigation for achieving maximum cucumber fruit yield in arid climates.

Salicylic acid (SA) is a phenolic compound capable of inducing physiological and metabolic changes that enhance the tolerance of plants to saline stress associated with using a hydroponic system and enable the use of saline water in semi-arid regions. In this context, this assay aimed to evaluate the impact of the foliar application of SA on mitigating salt stress effects on Japanese cucumber cultivated in a hydroponic system. The experiment was carried out in a protected ambient (greenhouse), using the Nutrient Film Technique—NFT hydroponic system. A completely randomized design was performed in a 4 × 4 split-plot scheme, with four levels of electrical conductivity of the nutrient solution—ECns (2.1, 3.6, 5.1, and 6.6 dS m−1)—considered as plots and four SA concentrations (0, 1.8, 3.6, and 5.4 mM), regarded as subplots, with four replicates and two plants per plot. An increase in the ECns negatively affected the physiology, production components, and post-harvest quality of cucumber. However, the application of SA to leaves at concentrations between 1.4 and 2.0 mM reduced the deleterious effects of saline stress and promoted an increase in the production of and improvement in the post-harvest quality of cucumber fruits. [ABSTRACT FROM AUTHOR]

Horticulture is now revolutionized by advancements in light-emitting diode (LED) lighting. New technologies enable knowledge expansion on how plants require different spectral illumination for optimal growth and development. The aim of this study was to evaluate the quality of cucumber (Cucumis sativus L. ‘Parys F1’) and tomato (Solanum lycopersicum L. ‘Poranek’) seedlings produced in indoor controlled conditions, using three different types of LED tubes emitting warm light (AP67, AP673L, and G2). The photosynthetic photon flux density was set at 50–65 μmol m−2 s −1 and a 16-hour light regime was used. The results were compared to the cool daylight-emitting fluorescent (FL) control (tube lamp TLD 36W/54). A detailed analysis of the biometrical parameters of the aboveground and underground parts of seedlings was performed. Moreover, the content of chlorophyll in the leaves was measured. No effect of light spectra on the underground part of cucumber was found. On the other hand, the type of lamp affected the number of leaves and chlorophyll content in this species. Lamps AP673L and FL can be recommended in the production of cucumber seedlings. The obtained seedling had characteristics desired for horticultural production, i.e., compact habit with a fair number of leaves and chlorophyll content. As for tomato, the FL lamp had the best effect on the development of seedlings. Due to the high share of far red light, the tested LEDs stimulated the elongated growth of flaccid plants, unsuitable for commercial producers. Our findings not only described the effect of various light spectra on plant development but can also be useful for producers of popular vegetable crops. [ABSTRACT FROM AUTHOR]

The downy mildew disease of cucurbits is considered the most economically damaging disease of Cucurbitaceae worldwide. The causal agent, Pseudoperonospora cubensis (Berkeley & Curtis), may cause complete crop losses of cucurbits. Few commercial cucurbit cultivars are resistant to this disease. Commercially, P. cubensis is controlled primarily with synthetic fungicides that inhibit or eliminate the pathogen. Several biological agents have also been identified that provide some level of control. In our study, foliar applications of three strains of Trichoderma harzianum and two native strains of Bacillus subtilis were evaluated for the control of the disease on cucumber plants grown under commercial greenhouse conditions. The study was conducted using a completely randomized design with six individual treatments during two production cycles: fall 2015 and spring 2016. The response variables included disease incidence and severity, plant height, total yield, fruit quality, and weight. B. subtilis provided the best control over the incidence and severity of the disease in both production cycles. Interestingly, while T. harzianum was less effective at controlling the disease, it enhanced plant growth and productivity, and produced a higher number of better-quality fruits per plot. This increased yield with higher quality fruits may result in higher profit for the growers. [ABSTRACT FROM AUTHOR]

Low temperature (LT) is an important environmental factor affecting the growth and yield of plants. Melatonin (MT) can effectively enhance the LT tolerance of cucumber. This study found that LT stress induced the expression of Comt1 (caffeic acid O-methyltransferase 1), with the highest expression being about 2-times that of the control. Meanwhile, the content of MT was found to be roughly 63.16% of that in the control samples. Compared with LT treatment alone, exogenous MT pretreatment upregulated the expression levels of TOR (Target of rapamycin), PIN1 (Pin-formed 1), and YUC4 (YUCCA 4) , with maximum upregulations reaching approximately 66.67%, 79.32%, and 42.86%, respectively. These results suggest that MT may modulate the tolerance of cucumber seedlings to LT stress by regulating the expression of TOR , PIN1 , and YUC4. In addition, co-treatment with AZD-8055 (a TOR inhibitor) or NPA (N-1-naphthylphthalamic acid, an auxin polar transport inhibitor) and MT attenuated MT-induced resistance to LT stress, leading to higher levels of reactive oxygen species (ROS), reduced antioxidant defense capacity, and increased damage to the membrane system in cucumber seedlings. Concurrently, the content of osmoregulatory substances and the photosynthesis decreased. These results demonstrate that both TOR and auxin were required for MT to alleviate LT-induced damage in cucumber. In summary, the present study demonstrates that TOR and auxin signaling synergistically contribute to alleviating LT damage in cucumber seedlings by exogenous MT. These findings help us understand the function of MT and provide insights into the regulatory network of MT that regulates the LT tolerance of plants. • Melatonin (MT) responds positively to low temperature (LT) stress and enhances LT tolerance in cucumber seedlings. • Under LT stress, MT induces the expression of target of rapamycin (TOR) and auxin signaling related genes. • MT pretreatment enhances LT stress tolerance through interaction with TOR and auxin signaling. [ABSTRACT FROM AUTHOR]

Plant endophytic fungi and rhizosphere soil fungi are often reported as biocontrol agents against plant pathogens or with plant growth promotion potential. Four treatments were performed in field and greenhouse experiments where cucumber plants were inoculated with Trichoderma harzianum and Fusarium oxysporum in 2022. The roots, stems and leaves of cucumber plants and their rhizosphere soil were collected twice individually from the field and greenhouse for isolation of cucumber endophytic and rhizosphere soil fungi. All fungal strains were identified through sequence similarity of the ITS1-5.8s-ITS2 rDNA region. The potato dextrose agar (PDA) media yielded the highest number of genera isolated from cucumber plants, rhizosphere soil and both compared to other media. There were no significant differences among the four media for the isolation of all cucumber endophytic fungi. However, in the roots, the number of endophytic fungi isolated by MRBA was significantly higher than that isolated on malt extract agar (MEA), while in the stems, the number of fungi isolated with PDA was significantly higher than that isolated with Martin’s rose bengal agar medium (MRBA). PDA had significantly higher isolation efficiency for the rhizosphere soil fungi than MRBA. The 28 fungal genera had high isolation efficiency, and the endophytic Trichoderma strains were significantly more isolated by MEA than those of MRBA. It is suggested that PDA can be used as a basic medium, and different cultural media can be considered for specific fungal genera.

The use of high-quality seedlings is a key factor for the success of the vegetable production system, and the use of plant growth-promoting bacteria (PGPB) can be decisive for the production of quality cucumber seedlings. Seeds from two cucumber cultivars (Aodai Melhorado and Marketmore76) were used to investigate the effectiveness of applying inoculant rates containing Azospirillum brasilense to improve germination rate and initial seedling growth. Seeds previously inoculated with inoculant containing the strains AbV5 and AbV6 of A. brasilense [0 (control), 4, 8, and 16 mL kg-1 of seed] were placed to germinate in a germination chamber at 25°C for 8 days. The experimental design used was completely randomized in a 2 x 4 factorial scheme, with four replications of 50 seeds. The results reported that the inoculant application containing the strains AbV5 and AbV6 of A. brasilense reduced germination percentage and germination rate index, whereas the inoculation of A. brasilense resulted in an increase in the mean germination time, especially for the Marketmore76 cultivar. The inoculation of seeds with A. brasilense has little effect on the shoot and root growth of cucumber seedlings. The negative and positive effects of the application of A. brasilense on the growth of cucumber seedlings are dependent on the genotype used. These results indicate that further studies should be conducted to investigate other application methods and use of other strains of A. brasilense to prove the beneficial effects of using these PGPB in improving the quality of cucumber seedlings. [ABSTRACT FROM AUTHOR]

Microclimate modification patterns are about the mimicking of natural systems to control the environment to achieve several benefits. Cucumbers (Cucumis sativus L.) are high yielding summer vegetables but are extremely sensitive to sudden weather changes. So, the changes in microclimatic parameters under polyhouse by using plastic mulching has evaluated on cucumber to improve the production of fruits and also to identify the optimum microclimatic situation of the crop. Research was conducted to study the performance of cucumber under protected conditions with different plastic mulches. This experiment was conducted in a split plot design, having irrigation levels as main plot and mulches as subplots. The study revealed that there was an increase in RH and air temperature inside the poly house. RH was increased by 8-12% that of outside. Temperature showed 5-7% increase in morning time and 7-10% in afternoon. Mulching helped to maintain the soil moisture higher than the bare soil and black mulch showed higher soil temperature and soil moisture (23.3%) under 100% irrigation. Black mulch with 100% irrigation attained maximum plant height (174.05cm). Yield of crop was also influenced by mulching. Black mulch with 100% irrigation attained maximum yield (36.1t/ha) followed by white (33.6t/ha) and silver (32.1t/ha) at same level of irrigation. Yield decreased in correspondence with reduction in irrigation level. Red and yellow mulches performed on par and maintained soil moisture greater than control plot. In conclusion, Black mulch with 100% irrigation performed well among the treatments because of higher moisture and favourable soil temperature. [ABSTRACT FROM AUTHOR]

A hydroponic experiment was carried out to study the ameliorative effects of exogenous glycinebetaine (GB) upon cadmium (Cd) toxicity in cucumber seedlings. The results indicated that 50 μmol/L Cd stress decreased soil plant analysis development (SPAD) value, plant height, root length, seedling biomass, activities of ascorbate peroxidase (APX) and ATPase in leaves, stems and roots; however, increased peroxidase (POD) and superoxide dismutase (SOD) activities in all tissues, catalase (CAT) activities in stems/roots. Moreover, Cd stress also elevated leaf/root malondialdehyde (MDA), proline, phenols and flavonoid content in all cucumber tissues over the control. The supplementation of GB (Cd + GB) prominently alleviated Cd-induced growth inhibition and oxidative stress, increased SPAD value and stem ATPase, and improved photosynthetic performance compared with Cd treatment alone. Furthermore, external GB diminished leaf/root MDA accumulation and decreased leaf/root proline contents as well as phenols and flavonoid contents in all tissues. Meanwhile, exogenous GB counteracted Cd-induced alterations of certain antioxidant enzymes. For example, it brought all tissue POD and SOD activities and stem/root CAT activities down towards the control level and significantly increased APX activities, especially in leaves and stems. These data suggested the principal protective mechanism for the exogenous GB against Cd toxicity in cucumber seedlings is closely related to improved photosynthesis, diminished Cd-induced proline and MDA accumulation, enhanced ATPase as well as modulation of antioxidant enzymes. [ABSTRACT FROM AUTHOR]

Gummy stem blight (GSB), caused by Didymella bryoniae, is one of the most devastating diseases that severely reduces cucumber production. Developing resistant varieties would be an effective strategy to control GSB. Although several GSB-resistant QTLs have been reported, causal genes for GSB resistance have not yet been identified in cucumber. A novel loci gsb3.1 for seedling GSB resistance from the "PI 183967" genotype was previously identified in a 1.7-Mb interval on chromosome 3. In this study, we developed a residual heterozygous line-derived strategy from Recombinant Inbred Lines to perform fine mapping, and with this approach, the gsb3.1 locus was narrowed to a 38 kb interval. There were six predicted genes at the gsb3.1 locus, four of which differed in expression in the GSB-resistant compared to the susceptible lines after fungal inoculation. These candidate genes (Csa3G020050, Csa3G020060, Csa3G020090, and Csa3G020590) within the gsb3.1 locus could be helpful for the genetic study of GSB resistance and marker-assisted selection in cucumber. Phylogenetic analyses indicated that the resistant gsb3.1 allele may uniquely exist in the wild species present in the Indian group, and that nucleotide diversity was significantly reduced in cultivated accessions. Therefore, the gsb3.1 allele could be introgressed into existing commercial cultivars and combined with other resistance QTLs to provide broad-spectrum and robust GSB resistance in cucumber. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias 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.)

This study aimed to evaluate the effects of the protein hydrolysate Naturamin WSP on the antioxidant defense system and oxidation-related damage of young cucumber plants exposed to chilling stress. Low positive temperatures have a negative effect on plant growth and performance, and besides visible alterations, such as inhibited growth, significant changes occur at the cellular level. Plants grown at low temperature typically suffer from oxidative damage, which leads to increased lipid peroxidation. Moreover, chilling-stressed plants accumulate more proline to protect their cell membranes. The application of biostimulants such as the protein hydrolysate Naturamin WSP can alleviate some of the adverse effects caused by low temperature. Our results indicated an increased activity of guaiacol peroxidase (GPOD) in all plants treated with the biostimulant regardless of the temperature of cultivation. The mitigation of damages caused by chilling stress might be explained by an enhanced anti-oxidative defense, as demonstrated by the activity of guaiacol peroxidases and increased proline concentrations in Naturamin WSP-treated plants.

Salinity stress prominently limits cucumber growth and productivity. However, the mechanism underlying salinity response mediated by the C-TERMINALLY ENCODED PEPTIDE (CEP) peptide in cucumber primary root remains largely unclear. In this study, we show that salinity prominently inhibits cucumber primary root growth, and CsCEP gene expression is differentially induced by salinity. We further demonstrate that the exogenous application of synthetic CsCEP3 peptide partially suppresses salinity-triggered growth inhibition in cucumber primary root, although CsCEP3 peptide itself shows no obvious effect on cucumber primary root growth under normal conditions. Our transcriptomic and qRT-PCR data further reveal that CsCEP3 peptide may modulate gene expression related to abscisic acid (ABA) signaling pathway, reactive oxygen species (ROS) production, and slat-responsive transcription factors to attenuate the inhibitory effect of salinity on cucumber primary root growth. Taken together, our work provides a fundamental insight into CEP peptide-mediated cucumber salinity adaptation.

Population-specific, positive selection promotes the diversity of populations and drives local adaptations in the population. However, little is known about population-specific, recent positive selection in the populations of cultivated cucumber (Cucumis sativus L.). Based on a genomic variation map of individuals worldwide, we implemented a Fisher's combination method by combining 4 haplotype-based approaches: integrated haplotype score (iHS), number of segregating sites by length (nSL), cross-population extended haplotype homozygosity (XP-EHH), and Rsb. Overall, we detected 331, 2,147, and 3,772 population-specific, recent positive selective sites in the East Asian, Eurasian, and Xishuangbanna populations, respectively. Moreover, we found that these sites were related to processes for reproduction, response to abiotic and biotic stress, and regulation of developmental processes, indicating adaptations to their microenvironments. Meanwhile, the selective genes associated with traits of fruits were also observed, such as the gene related to the shorter fruit length in the Eurasian population and the gene controlling flesh thickness in the Xishuangbanna population. In addition, we noticed that soft sweeps were common in the East Asian and Xishuangbanna populations. Genes involved in hard or soft sweeps were related to developmental regulation and abiotic and biotic stress resistance. Our study offers a comprehensive candidate dataset of population-specific, selective signatures in cultivated cucumber populations. Our methods provide guidance for the analysis of population-specific, positive selection. These findings will help explore the biological mechanisms of adaptation and domestication of cucumber. [ABSTRACT FROM AUTHOR]

Background: Cucumber is a species that breeding studies for variety development are carried out intensively. However, double haploidy technology, which aims to shorten the breeding process, has not yet reached the desired level. Methods and results: Three induction (M1: Murashige and Skoog (MS), 0.04 mg L−1 Thidiazuron (TDZ); M2: MS, 0.15 mg L−1 2,4-Dichlorophenoxyacetic acid (2,4-D), 1.5 mg L−1 Kinetin; M3: MS, 0.1 mg L−1 2,4-D, 1 mg L−1 6-Benzylaminopurine (BAP) and one regeneration (MS, 0.2 mg L−1 BAP, 0.05 mg L−1 1-Naphthaleneacetic acid (NAA) media and 31 cucumber genotypes were used. At the end of study, in terms of embryo formation, M3 (33.41 embryos per 100 cultured ovaria, 99.61 embryos per 100 developed ovaria) and M2 (30.70 embryos per 100 cultured ovaria, 122.05 embryos per 100 developed ovaria) were found to be better than M1 (17.54 embryos per 100 cultured ovaria, 68.34 embryos per 100 developed ovaria). For plant formation, M1 (13.23 plants per 100 embryos) and M2 were found to be more succesful than M3. Ploidy analyses performed on 72 of 98 plants through flow cytrometry showed that obtained plants were various ploidy level (34.72% haploid, 37.5% diploid, 22.22% mixoploid, and 5.55% tetraploid). Conclusions: According to the results of the research, 2,4-D added to the nutrient media seems to be successful in induction of ovary culture in cucumber. In plants determined as diploid according to ploidy analysis, doubled haploid situation should be checked by molecular analysis. [ABSTRACT FROM AUTHOR]