Search Results (56)

Water scarcity is a major constraint to sustainable horticultural production, particularly in arid and semi-arid regions. This study evaluated the effectiveness of two natural foliar biostimulants, chitosan and Spirulina extract, in improving water productivity, growth performance, biomass production, and drought tolerance of passion fruit (Passiflora edulis Sims) seedlings under deficit irrigation. A factorial experiment was conducted using three irrigation regimes (100%, 85%, and 70% of field capacity, FC) combined with three foliar spray treatments: distilled water (control), chitosan (1 g L⁻¹), and Spirulina extract (1 g L⁻¹). Deficit irrigation significantly reduced chlorophyll content, vegetative growth, biomass production, and water productivity, with the greatest reductions observed at 70% FC. Foliar application of both biostimulants effectively alleviated these adverse effects by enhancing plant growth, biomass production, chlorophyll retention, and water productivity under water-limited conditions. Chitosan consistently outperformed Spirulina, particularly under moderate water deficit, by reducing irrigation water requirements while maintaining seedling growth and physiological performance comparable to those under full irrigation. Multivariate analyses, including Pearson correlation, principal component analysis, and response surface methodology, revealed strong positive relationships among biomass production, chlorophyll content, vegetative growth traits, and water productivity. Among all treatments, foliar application of chitosan at 1 g L⁻¹ combined with 85% FC was identified as the optimum strategy, providing substantial irrigation water savings while maintaining vigorous seedling growth, high biomass production, and superior water productivity. These findings demonstrate that integrating moderate deficit irrigation with chitosan application is an effective and sustainable strategy for improving passion fruit nursery production under conditions of limited water availability. Full article

This study evaluated the effects of two silicon sources (silicic acid and Agrisil) and increasing Si concentrations on physiological responses, total polyphenol content, photochemical performance, nutrient uptake, and phenolic metabolism in sour passion fruit (Passiflora edulis Sims) grown under soilless culture conditions. The experiment was conducted in a greenhouse using increasing concentrations of Si applied through the nutrient solution. Gas exchange parameters, chlorophyll index (SPAD), chlorophyll fluorescence variables, leaf temperature, and the contents of Si, nitrogen, and total polyphenols in leaves and roots were evaluated. Moderate Si concentrations enhanced stomatal conductance and transpiration, improving intrinsic water use efficiency, and maintaining higher chlorophyll levels and photochemical performance. In contrast, higher Si concentrations increased Si deposition in leaf tissues, reduced stomatal regulation and transpiration, and increased leaf temperature. These changes were associated with reductions in chlorophyll index and photochemical performance index (PI), as well as increased F₀/Fm. Net CO₂ assimilation remained relatively stable. Silicon uptake differed between sources, with silicic acid showing faster absorption and Agrisil a more gradual release. Silicon fertilization also increased nitrogen uptake and stimulated the accumulation of phenolic compounds in roots. Overall, moderate silicon supplies enhanced physiological stability, whereas excessive accumulation imposed photochemical constraints. Full article

The availability of water is a limiting factor for the growth and productivity of yellow passion fruit (Passiflora edulis Sims). The use of bioregulators has been investigated as a strategy to mitigate the effects of abiotic stress. Different concentrations of SNP were evaluated on growth, gas exchange, photosynthetic pigments, chlorophyll fluorescence, and enzymatic activity in Passiflora edulis seedlings under different water conditions. The experiment was conducted in a randomized block design, in a 2 × 4 factorial scheme, with two irrigation conditions (80 and 30% of field capacity), combined with three concentrations of SNP (50, 100 and 250 µM) and water (control), with five replications. Water deficit reduced morphological, physiological, and enzymatic parameters. The application of SNP increased root fresh mass (23.56 g at the 100 µM dose) and leaf dry mass (8.21 g at 250 µM SNP), with increases of 24.52% and 30.52% compared to the values obtained under the 50 µM dose, respectively. The highest number of leaves (14) and leaf area (1183.3 cm²) was observed at 250 µM SNP, corresponding to increases of 7.70% and 17.27%, respectively, compared to plants without SNP application. Water deficit reduced growth, gas exchange, chlorophyll fluorescence, and enzymatic activity. SNP promotes improvements in growth; however, it does not mitigate water deficit effects in Passiflora edulis seedlings. Full article

Temperature extremes represent a major constraint for the cultivation of yellow passion fruit (Passiflora edulis Sims f. flavicarpa), a tropical crop increasingly exposed to heat waves and chilling events under climate change. Glycine betaine (GB) is a widely studied osmoprotectant in plants, yet its influence on metabolic responses of passion fruit under contrasting temperature stresses remains poorly characterized. This study investigated the effects of exogenous GB on primary metabolite profiles of passion fruit seedlings subjected to heat (25, 35, and 45 °C) and cold (25, 15, and 5 °C) conditions. Seedlings were treated with GB (100 mM) or left untreated, and leaf metabolites were quantified using GC–MS-based metabolomics. Heat exposure was associated with pronounced changes in amino acids, organic acids, sugars, polyamines, and γ-aminobutyric acid (GABA), while GB-treated plants showed altered levels of proline, GABA, polyamines, and selected tricarboxylic acid intermediates. Under cold conditions, several amino acids and organic acids decreased, whereas soluble sugars accumulated, particularly in GB-treated plants. Principal component analysis revealed distinct metabolic configurations under heat and cold treatments and indicated that GB modified metabolite profiles in a stress-dependent manner rather than restoring control-like states. These findings describe how GB is associated with shifts in central carbon and nitrogen metabolism under contrasting temperature regimes, providing a metabolomic perspective on stress-related metabolic adjustments in passion fruit. Full article

This study aimed to evaluate the effects of high-intensity ultrasound (40 W/5 min), applied with and without mild heating (59 °C and 23 °C), and of pasteurization (63 °C/30 min), on the physicochemical, rheological, and microbiological parameters, as well as on ascorbate oxidase activity, total carotenoid content, phenolic compound profile, and antioxidant capacity of passion fruit (Passiflora edulis Sims.) pulps. Ultrasound processing induced changes in color (L*, a*, and b*), resulting in high ∆E values. Following ultrasound treatment, an increase in apparent viscosity at 100 s⁻¹ was observed. Ultrasound also promoted partial inactivation of ascorbate oxidase and a significant reduction in mold and yeast counts. Moreover, the application of ultrasound without heating (US-20) promoted the retention of 55% of ascorbic acid after 63 days of storage. The condition with heating (US-60) led to an increase in catechin content in both bright red passion fruit pulp (173.96%) and yellow passion fruit pulp (5.89%), demonstrating a balance between the retention of bioactive compounds, microbial inactivation, and reduction in ascorbate oxidase activity. Therefore, these results highlight ultrasound as a non-thermal and sustainable technology capable of extending shelf life, maximizing the preservation of bioactive compounds, and enhancing the functional properties of fruit pulps. Full article

Passion fruit (Passiflora edulis Sims) is an important economic fruit crop in Rwanda grown for both domestic consumption and export markets. However, viral diseases pose a significant threat to passion fruit production. Among these, passion fruit woodiness disease (PWD) is the most destructive, causing yield losses of up to 100%. A survey was carried out to assess the distribution of Ugandan passiflora virus (UPV; Potyvirus passiflorafricanse) in major passion fruit growing areas. UPV is one of the major viruses known to cause PWD. The incidence of viral symptoms observed in the field did not differ significantly among districts, ranging from 81% in Rusizi to 100% in Rwamagana. However, mean symptom severity scores varied significantly between districts, with the highest severity recorded in Kayonza (3.1) and the lowest in Rulindo (1.9). Serological analysis detected potyviruses in 44% of the total samples (n = 216), including 43% of symptomatic (n = 144) and 47% of asymptomatic (n = 72) leaf samples collected from passion fruit fields. Further analysis using Reverse-Transcription Polymerase Chain Reaction (RT-PCR) detected UPV in 56% of symptomatic (n = 126) and 53% of asymptomatic (n = 60) samples, corresponding to 55% of the total samples tested (n = 186). The virus was present in all surveyed districts, with UPV infection prevalence of 89% in Rusizi, 75% in Rwamagana, 74% in Karongi, 59% in Nyamagabe, 44% in Nyaruguru, 38% in Kayonza, and 30% in both Gakenke and Rulindo. Fifteen partial coat-protein gene sequences for the Rwandan isolates were obtained. The newly described Rwandan isolates shared 97–99% nucleotide (nt) identity with one another, 89–94% with previously reported Rwandan isolates, 81–97% with Ugandan isolates, and 80–82% with Kenyan UPV isolates, suggesting that the Rwandan virus population is relatively homogenous. Genetic distances among the 15 new UPV isolates and previously reported Rwandan, Ugandan, and Kenyan isolates were very short (0.01–0.03), indicating high sequence similarity. All Rwandan isolates clustered into a single major clade, together with some Ugandan and Kenyan isolates. This close genetic relationship suggests a common ancestry and the regional spread of a single dominant UPV lineage. These findings highlight the need to reinforce seed and planting-material certification systems, as well as the need to enhance farmer capacity through targeted training on viral disease identification and management practices. This is vital to limiting the spread of viral diseases that threaten income security among smallholder passion fruit farmers. Full article

As a tropical fruit of considerable economic importance, passionfruit (Passiflora edulis Sims) is extensively cultivated in the tropical and subtropical regions of China; however, the widespread incidence of viral diseases has significantly hampered the safety of its production. Rapid, sensitive, and visual detection of plant viruses is essential to effectively prevent and manage these viral diseases. In this study, we developed a visual detection system (displaying under blue light or UV) utilizing reverse transcription recombinase-aided amplification (RT-RAA) in conjunction with CRISPR/Cas12a to detect three viruses harmful to passionfruit production: telosma mosaic virus (TelMV), East Asian passiflora virus (EAPV), and passiflora mottle virus (PaMoV). Within this system, the optimal primer concentration for the RT-RAA reaction was determined to be 0.4 μM for all three viruses, with an optimal reaction temperature of 37 °C. The optimal reaction times were established as 20 min for TelMV, 15 min for EAPV, and 30 min for PaMoV. The entire detection process could be completed within 30 min without the need for sophisticated equipment or instruments. For TelMV and EAPV, the detection system demonstrated the capability to detect samples at a dilution of 10⁶, representing an approximately 10⁴-fold improvement over RT-PCR, while for PaMoV, it could identify samples at a dilution of 10⁶, representing an approximately 10²-fold improvement over traditional RT-PCR methods. These results confirm the successful development of the CRISPR/Cas12a-based detection systems. Subsequently, the system was applied for in situ detection of the three target viruses in field settings, yielding results that were fully consistent with laboratory-based RT-PCR assays, a consistency which underscores the system’s strong potential for field application in detecting important crop viruses. Full article

Nitrogen is the nutrient most required by plants and plays a central role in agricultural productivity due to its involvement in essential nutrients. This study evaluated the effects of different nitrogen sources on the physiological and morphological development of yellow passion fruit (Passiflora edulis Sims) seedlings. The experiment followed a randomized block design with six treatments (water, urea, ammonium sulfate, potassium nitrate, calcium nitrate, and magnesium nitrate), six replicates per treatment, and two plants per plot. An equal amount of nitrogen was supplied to all treatments, while the urea treatment excluded the additional macronutrients present in the other fertilizers (S, K, Ca, and Mg), allowing us to assess whether the benefits were exclusively attributable to the nitrogen source. The results indicated that ammonium sulfate and calcium nitrate promoted better root system development, while ammonium sulfate also improved shoot growth and physiological characteristics. Multivariate analysis revealed that CP1 explained most of the variability between treatments, highlighting the contribution of these sources compared to the control. Overall, fertilization with ammonium sulfate produced the best results, indicating that it is a more efficient nitrogen source for seedling development. Full article

Heat stress caused a stagnation in the growth and development of Passiflora edulis Sims. To investigate the effects of high-temperature stress, this study subjected P. edulis to 40 °C treatment for different durations; the changes in chlorophyll content, chlorophyll fluorescence parameters, photosynthetic parameters, transcriptome profiles, and photosynthesis-related genes of P. edulis under high-temperature stress were analyzed. The results showed that after 5 h of heat stress, the chlorophyll content of the leaves decreased by 31%, variable fluorescence/maximum fluorescence (Fv/Fm) decreased by 26.91%, photochemical performance index (PI_abs) by 99.28%, comprehensive performance index (PI_total) by 94.20%, light energy absorbed per unit area (ABS/CSm) by 13.56%, light energy captured per unit area (TRo/CSm) by 17.90% and quantum yield of electron transfer per unit area (ETo/CSm) by 92.61%. The net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) decreased by 47%, 41% and 38%, respectively, while intercellular CO₂ concentration (Ci) increased by 1.34 times. Transcriptome sequencing results of P. edulis under heat stress identified 2336 differentially expressed genes (DEGs), which were significantly enriched in pathways including chloroplast function and plant hormone signal transduction. GO enrichment analysis demonstrated that DEGs were significantly enriched in terms related to catalytic activity and chloroplast components. Concurrently, KEGG pathway analysis revealed that carbon fixation in photosynthetic organisms was among the key pathways showing significant enrichment of these DEGs. The expression levels of photosynthesis-related genes, including PePSAE, PeMADs, PebHLH, PeFAR1, PePSBS, PePnsB4, PebZIP and PeC2H2, exhibited a significant increase after 3 h of high-temperature stress and rapidly declined following 5 h. These findings lay a foundation for further research on the high-temperature stress response mechanism and photosynthetic regulation of heat tolerance in P. edulis. Full article

Practices that mitigate the deleterious effects of water deficit are of great importance for agricultural production in the semi-arid region of Northeastern Brazil. The objective of this study was to evaluate the effect of foliar application of salicylic acid on mitigating water deficit in the morphophysiology and yield components of sour passion fruit during different phenological stages. Treatments were arranged in a randomized block design in a 6 × 2 factorial scheme, consisting of six irrigation strategies under water deficit, based on reference evapotranspiration (ETr) [irrigation with 100% ETr throughout the entire cultivation cycle—IS1; irrigation with 50% ETr during the vegetative stage—IS2; flowering—IS3; fruiting—IS4; vegetative/flowering—IS5; and vegetative/fruiting—IS6], combined with or without salicylic acid (SA) application (0 and 1 mM). The application of 1.0 mM salicylic acid alleviated the effects of water deficit during the flowering stage, improving gas exchange, photochemical efficiency, relative water content, growth, and yield of sour passion fruit. In addition, it contributed to reducing electrolyte leakage in the leaf blade. Therefore, foliar application of salicylic acid represents a promising strategy to maintain the integrity of the photosynthetic apparatus and the productive performance of sour passion fruit under water deficit conditions. Full article

Glycine betaine (GB) is a compatible solute that enhances plant tolerance to abiotic stresses, yet its role in fruit crops remains insufficiently explored. This study assessed whether GB improves drought tolerance in Passiflora edulis Sims f. flavicarpa, a crop sensitive to irregular rainfall. A 3 × 2 × 2 factorial design was employed, combining three drought levels (control, mild, and severe), two propagation methods (seedlings and cuttings), and two GB treatments (0 and 100 mM), with 60 plants and five replicates. Plants were grown under controlled conditions, and irrigation was adjusted to maintain target field capacities. Chlorophyll content was monitored daily, and agronomic and physiological traits were measured after 45 days. GB application influenced leaf water dynamics and stress responses. Cuttings generally showed clearer improvements in drought tolerance when treated with GB, while seedlings exhibited more variable outcomes. These differences appear linked to the propagation method and developmental stage as cuttings were at a more advanced phase, whereas seedlings remained vegetative. Overall, the results demonstrate that exogenous GB can enhance drought tolerance in passion fruit, although its effectiveness is propagation-dependent and context-specific, highlighting the need to tailor its application to cultivation practices. Full article

Passion fruit (Passiflora edulis Sims), belonging to the Passifloraceae family, is an economically important plant in tropical and subtropical regions. The advances in functional genomics research of passion fruit have been significantly hindered by its recalcitrance to regeneration and stable transformation. This study establishes the first efficient Agrobacterium rhizogenes-mediated hairy root transformation system for passion fruit. Utilizing the eGFP marker gene, transformation efficiencies of 11.3% were initially achieved with strains K599, MSU440, and C58C1, with K599 proving most effective. Key transformation parameters were systematically optimized to achieve the following: OD₆₀₀ = 0.6, infection duration 30 min, acetosyringone concentration 100 μM, and a dark co-cultivation period of 2 days. The system’s utility was further enhanced by incorporating the red visual marker RUBY, enabling direct, instrument-free identification of transgenic roots via betaxanthin accumulation. Finally, this system was applied for functional analysis using PeMYB123, which may be involved in proanthocyanidin accumulation. Overexpression of PeMYB123 produced a higher content of proanthocyanidin in hairy roots. Additionally, the PeANR gene involved in the proanthocyanidin pathway was strongly activated in the transgenic hairy roots. This rapid and efficient visually simplified hairy root transformation system provides a powerful tool for functional gene studies in passion fruit. Full article

This study evaluated the effects of reduced glutathione (GSH) application on the production and quality of sour passion fruit irrigated with brackish water in the semi-arid region of Paraíba, Brazil. The experiment was conducted in drainage lysimeters under greenhouse conditions at the Center of Technology and Natural Resources of the Federal University of Campina Grande (UFCG). Treatments combined five levels of electrical conductivity of brackish irrigation water (Bw: 0.4, 1.2, 2.0, 2.8, and 3.6 dS m⁻¹) and four GSH concentrations (0, 40, 80, and 120 mg L⁻¹), arranged in a randomized block design with three replicates. Salinity levels above 0.4 dS m⁻¹ negatively affected fruit production and post-harvest quality of ‘BRS GA1’ sour passion fruit. Foliar application of 120 mg L⁻¹ GSH increased fruit yield, while 74 mg L⁻¹ GSH mitigated salt stress effects on production and pulp chemical quality. The ‘BRS GA1’ cultivar was highly sensitive to salinity, showing a 26.9% yield reduction per unit increase in Bw electrical conductivity above 0.4 dS m⁻¹. The results suggest that GSH can alleviate salt stress damage, improving crop productivity and fruit quality under semi-arid conditions. Full article

Passion fruit is an underutilised fruit in Northeastern India, known for its unique flavour and health benefits. This study analysed 15 genotypes (P1 to P15) to explore their morphological and biochemical traits related to fruit quality and yield. P. quadrangularis L. (P15) exhibited maximum flower length, fruit size, weight, juice content, shelf-life, and yield. P. edulis f. flavicarpa (P3, P5, and P2) had the highest seed count per fruit and antioxidant activity, along with greater chlorophyll and anthocyanin levels. Passiflora edulis Sims (P8 and P11) showed superior total soluble solids, carotenoids, and vitamin C. The study found that fruit shelf life positively correlated with seed weight, while the number of fruits per vine negatively correlated with seed traits and peel weight. Additionally, certain traits, such as total carotenoids, had strong positive correlations with reducing sugar and flavonoids. Principal component analysis revealed distinct trait relationships, particularly for genotypes P7 and P10. SDS-PAGE protein profiling indicated a significant distance between P3 and P14, emphasising genetic diversity. In conclusion, this research highlights the diverse morphological and biochemical characteristics of passion fruit genotypes, paving the way for the region’s improved fruit quality, yield, and breeding strategies. Full article

Heat stress severely inhibited the flower bud growth and development of passion fruit (Passiflora edulis Sims) in summer, resulting in severe production damage. Protein phosphorylation plays a key role in plant protein regulatory networks in response to abiotic stress, while the mechanism of phosphorylation regulation response to heat stress in passion fruit is still unknown. In this study, 97.62% of passion fruit floral buds withered and fell off after 2 h of heat stress, compared to 3.33% after 0.5 h. A total of 10,614 phosphorylation sites across 2906 proteins were identified by phosphoproteomic analysis. Among them, 1343 differentially regulated phosphoproteins (DRPPs) were mainly located in the nucleus, cytoplasm, and chloroplast. The DRPPs whose phosphorylation sites were induced by heat stress were mainly involved in the ‘ABC transporters’, ‘Plant hormone signal transduction’, and ‘MAPK signaling’ pathways. In addition, the accumulations of ABA and H₂O₂ were induced under heat stress for 0.5 h. Through protein interaction prediction and qRT-PCR analyses, we identified a key protein PePP2C1, in which the levels of gene expression, protein expression, and phosphorylation were induced by heat stress. The transient assays showed that the overexpression of PePP2C1 inhibited the accumulation of H₂O₂. Our results suggested the potential role of phosphoproteins under heat stress in the floral buds of passion fruit. The findings in this study contribute to a better understanding of the molecular mechanism of phosphoproteins in response to heat stress. Full article