Search Results (58)

Despite the recognized social and economic importance of common beans (Phaseolus vulgaris L.), the average grain yield is far below the productive potential of cultivars. This situation is explained by several factors, such as the large number of diseases and pests that affect the crop, some of which cause significant damage. It is estimated that approximately 200 diseases can significantly affect common beans. These can be bacterial, viral, fungal, and nematode-induced. The main bean fungal diseases include anthracnose, angular leaf spot, powdery mildew, gray mold, Fusarium wilt, dry root rot, Pythium root rot, southern blight, white mold, charcoal rot and rust. This review provides a comprehensive overview of eleven major fungal diseases affecting common bean, describing their associated damage, characteristic symptomatology, and the epidemiological factors that favor disease development. It further synthesizes current knowledge on host resistance mechanisms that can be exploited to develop molecularly informed resistant genotypes. The compilation includes characterized resistance genes and mapped quantitative trait loci (QTLs), with details on their chromosomal locations, genetic effects, and potential for use in breeding. Moreover, the review highlights successful applications of molecular breeding approaches targeting fungal resistance. Finally, it discusses conclusions and future perspectives for integrating advanced genetic improvement strategies—such as marker-assisted selection, genomic selection, gene editing, and pyramiding—to enhance durable resistance to fungal pathogens in common bean. This work serves as both a reference for forthcoming resistance-mapping studies and a guide for the strategic selection of resistance loci in breeding programs aimed at developing cultivars with stable and long-lasting fungal resistance. Full article

Pythium schmitthenneri, a soilborne pathogen responsible for root rot in olive trees, poses a significant threat to olive production. Managing this pathogen remains challenging due to its aggressive root colonization and the limited efficacy of conventional control methods. Given the concerns associated with chemical treatments, this study evaluated the resistance of eight olive varieties to P. schmitthenneri-induced root rot under controlled greenhouse conditions by assessing structural and biochemical defense mechanisms. Greenhouse trials revealed that Arbequina, Koroneiki, and Haouziya exhibited strong resistance, with 0% disease severity, while Picholine Marocaine and Picholine Languedoc were highly susceptible, reaching 100% disease severity. Growth parameters varied significantly, with susceptible varieties showing severe reductions in root length (RL), root fresh weight (RFW), and root dry weight (RDW), whereas resistant varieties maintained these parameters unchanged. While shoot length (SL) remained unaffected across all varieties, shoot fresh weight (SFW) and shoot dry weight (SDW) were significantly reduced in susceptible ones. Fourier-transform infrared (FTIR) spectroscopy revealed that resistant varieties maintained stable levels of lignin, cellulose, and polysaccharides, while susceptible ones exhibited extensive cell wall degradation. Additionally, total polyphenol content (TPC) and total flavonoid content (TFC) significantly increased in resistant varieties upon infection, whereas susceptible varieties experienced a substantial decline. These findings highlight the crucial role of structural and biochemical defenses in olive resistance to P. schmitthenneri and suggest that selecting resistant varieties could serve as a sustainable strategy for managing root rot in olive production. Full article

Atriplex hortensis var. rubra (red orache, RO) is a halotolerant species rich in nutraceutical compounds, which makes it a valuable crop for human nutrition. This plant could also be exploited for phytoremediation of contaminated soil and wastewater, and for saline aquaponics. A root rot disease was observed on hydroponically grown RO plants, caused by Pythium deliense and Pythium Cluster B2a sp. Identification was based on morphology, molecular analysis (ITS and COI), and phylogenetic analysis. We assessed disease severity in plants grown in a growth chamber with nutrient solutions containing different NaCl concentrations (0, 7, and 14 g L⁻¹ NaCl). In vitro growth at different salinity levels and temperatures was also evaluated. Both Pythium species were pathogenic but showed different responses. Pythium deliense was significantly more virulent than Pythium Cluster B2a sp., causing a steady reduction in root dry weight (RDW) of 70% across all salinity levels. Pythium Cluster B2a sp. reduced RDW by 50% at 0 and 7 g L⁻¹ NaCl while no symptoms were observed at 14 g L⁻¹ NaCl. Pythium deliense grew best at 7 and 14 g L⁻¹ NaCl, while Pythium Cluster B2a sp. growth was reduced at 14 g L⁻¹ NaCl. Both pathogens had an optimum temperature of 30 °C. This is the first report of Pythium spp. causing root rot on RO grown hydroponically. The effective use of halophytic crops must consider pathogen occurrence and fitness in saline conditions. Full article

Burkholderia gladioli is a multifaceted bacterium with both pathogenic and beneficial strains, and nonpathogenic Burkholderia species have shown potential as plant growth-promoting rhizobacteria (PGPRs) and biocontrol agents. However, the molecular mechanisms underlying their beneficial functions remain poorly characterized. This study systematically investigated the antimicrobial mechanisms and plant growth-promoting properties of B. gladioli strain ZBSF BH07, isolated from the grape rhizosphere, by combining genomic and functional analyses, including whole-genome sequencing, gene annotation, phylogenetic and comparative genomics, in vitro antifungal assays, and plant growth promotion evaluations. The results showed that ZBSF BH07 exhibited broad-spectrum antifungal activity, inhibiting 14 grape pathogens with an average inhibition rate of 56.58% and showing dual preventive/curative effects against grape white rot, while also significantly promoting grape seedling growth with increases of 54.9% in plant height, 172.9% in root fresh weight, and 231.34% in root dry weight. Genomic analysis revealed an 8.56-Mb genome (two chromosomes and one plasmid) encoding 7431 genes and 26 secondary metabolite biosynthesis clusters (predominantly nonribosomal peptide synthetases), supporting its capacity for antifungal metabolite secretion, and functional analysis confirmed genes for indole-3-acetic acid (IAA) synthesis, phosphate solubilization, and siderophore production. These results demonstrate that ZBSF BH07 suppresses pathogens via antifungal metabolites and enhances grape growth through phytohormone regulation and nutrient acquisition, providing novel insights into the dual mechanisms of B. gladioli as a biocontrol and growth-promoting agent and laying a scientific foundation for developing sustainable grapevine disease management strategies. Full article

Wheat (Triticum aestivum L.) is a major cereal crop globally, but its production is increasingly threatened by fungal pathogens, particularly Fusarium culmorum (Wm. G. Sm.) Sacc., which causes seedling blight and root rot, leading to yield losses and mycotoxin contamination. Conventional control strategies, such as crop rotation and the use of fungicides, are often inadequate and contribute to the development of resistance, particularly with the overuse of similar modes of action. This study investigated quaternary pyridinium salts—nicotinamide and isonicotinamide derivatives—as potential sustainable antifungal agents. In vivo tests involved treating sterilized wheat seeds grown in sterile sand that had been inoculated with F. culmorum, using compounds previously confirmed to be active in vitro. Disease index, shoot and root length, and fresh and dry biomass were measured. Among the tested compounds, nicotinamide derivatives (2) and (3) showed the lowest disease index (0.9) at a concentration of 10 µg/mL. Most compounds promoted plant and root growth. Isonicotinamide derivatives (6) and (7) at 100 µg/mL increased root dry weight, while compound (6) at 10 µg/mL resulted in the most significant increase in plant length. These findings highlight the dual antifungal and growth-promoting potential of certain eco-friendly derivatives for managing F. culmorum and supporting wheat seedling development. Full article

Potassium has been identified as a vital nutrient for plant growth and functions. Studies have demonstrated its capacity to mitigate the severity of diseases by accelerating seed maturation and promoting robust root system development. In this study, we aimed to determine how increasing potassium doses affect the nutrient content, dry weight, root weight, and resistance to Rhizoctonia rot of the pepper plant. Pepper seedlings were used as plant material, and potassium sulfate was employed as the potassium fertilizer in this study. The experiment involved applying four different potassium doses (0, 50, 100, and 150 kg ha⁻¹) to pepper seedlings, along with RS0 (control) and RS1 (diseased plant) in four replicates. At the end of the study, analyses of the plants’ nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), and boron (B) content, dry weights, and root weights were performed, in addition to disease assessments. An increase in N, P, K, Fe, and B content was observed with applied potassium doses, while a decrease in Mg content was noted. No significant change was detected in Cu content in pepper leaves, and the change in Mn content was not found to be statistically significant. An increase in plant dry weights was determined based on the applied treatments. The results indicated that plants subjected to potassium exhibited resistance to disease, an increase in root weights, and overall better conditions compared to samples without potassium. The best results in the experiments were achieved with the application of 150 kg ha⁻¹ K₂SO₄. It was observed that certain rates of potassium had positive effects on disease factors by suppressing Rhizoctonia rot and can be used for biological control. Full article

Recently, Fusarium root rot (FRR)-like symptoms were observed in Uganda’s agroecology zones, prompting the National Agricultural Organisation (NARO) to conduct a disease survey. The survey reports indicated FRR as the second most prevalent root rot disease of common bean in Uganda after Southern blight. Ninety nine Fusarium spp. strains were obtained from samples collected during the surveys. The strains were morphologically and pathogenically characterised and confirmed to cause Fusarium root rot as observed in the field. However, molecular characterization of the strains was not conducted. In this study, therefore, 80 of the strains were characterized using partial sequences of translation elongation factor 1-alpha (TEF-1α) gene, beta tubulin (β tubulin) gene and internal transcribed spacers (ITS) region of ribosomal RNA to determine species diversity. High-quality Sanger sequences from the target genes were compared to the sequences from Fusarium species available in the National Centre for Biotechnology Information coding sequences (NCBI-CDS) database to determine the most likely species the strains belonged. The sequences from our strains were deposited into the NCBI gene bank under ID#288420, 2883276, 2873058 for TEF-1α, β tubulin and ITS respectively. The Fusarium species identified included; F. oxysporum, F. solani, F. equiseti F. delphinoides, F. commune, F. subflagellisporum, F. fabacearum, F. falciforme, F. brevicaudatum, F. serpentimum, F. fredkrugeri and F. brachygibbosum. The diversity of these Fusarium species needs to be taken into consideration when developing breeding programs for management of the disease since currently there is no variety of common bean resistant to FRR in Uganda. Full article

The citrus industry contributes to the cultivation of one of the most important fruit crops globally. However, citrus trees are susceptible to numerous Bisifusarium, Fusarium, and Neocosmospora-linked diseases, with dry root rot posing a serious threat to citrus orchards worldwide. These infections are exacerbated by biotic and abiotic stresses, leading to increased disease incidence. Healthy trees unexpectedly wilt and fall, exhibiting symptoms such as chlorosis, dieback, necrotic roots, root rot, wood discolouration, and eventual decline. Research indicates that the disease is caused by a complex of species from the Nectriaceae family, with Neocosmospora solani being the most prominent. To improve treatment and management strategies, further studies are needed to definitively identify these phytopathogens and understand the conditions and factors associated with Bisifusarium, Fusarium, and Neocosmospora-related diseases in citrus. This review focuses on the epidemiology and symptomatology of Fusarium and Neocosmospora species, recent advances in molecular techniques for accurate phytopathogen identification, and the molecular mechanisms of pathogenicity and resistance underlying Fusarium and Neocosmospora–citrus interactions. Additionally, the review highlights novel alternative methods, including biological control agents, for disease control to promote environmentally friendly and sustainable agricultural practices. Full article

This study explores the impact of different temperature and humidity conditions on Mulberry cutting rooting and transplanting survival rates in an aeroponically rapid propagation system. It investigates the relationship between droplet adhesion and mortality based on mildew and rot distribution in cuttings. The regulating strategies were divided into three groups: humidity, temperature, and combined humidity and temperature. The humidity group included a fixed spray frequency (H3) and fixed-range humidity conditions (H1: 90% ≤ Humidity ≤ 100% and H2: 95% ≤ Humidity ≤ 100%). The temperature group comprised room temperature (T2) and fixed-range temperature circumstances (T1: 25 °C < Temperature < 27 °C). The non-regulation group (THCK) made no particular modifications, whereas the combined temperature and humidity group (TH) maintained both temperature and humidity within a set range (90% ≤ Humidity ≤ 100% and 25 °C < Temperature < 27 °C). Moreover, the humidity control group (HCK) and the temperature control group (TCK) integrated a soil cultivation system. Then, the transplantation experiment and the droplet adhesion amount experiment were carried out. The results demonstrate that faster callus formation and rooting with aeroponic propagation, temperature and humidity regulation significantly improves root growth and survival rate. The temperature and humidity regulation group outperforms, increased callus rate, rooting rate, average root length, average root number, fresh weight, and dry weight by 30%, 25%, 4.54 mm, 1.09, 0.12 g, and 0.012 g, while reducing mortality by 20%. Conversely, soil culture showed no callus formation or rooting throughout the same timeframe. Significant (p < 0.01) differences between regulation and non-regulation groups exist in growth parameters, mortality, and transplant survival rates. All groups achieved 80–100% transplant survival, with temperature regulation enhancing hardening effects. Excessive droplet adhesion heightens the risk of mortality, with an optimal adhesion threshold of approximately 0.06444 g. This study offers valuable insights into aeroponically rapid propagation and intelligent nurseries. Full article

Orange trees (Citrus × sinensis (L.) Osbeck) are the third-most cultivated citrus fruit species in Chile. In recent years, several trees in three orange orchards of ‘Lane late’ and ‘Fukumoto’ cultivars grafted on ‘Robidoux’ trifoliate orange (Poncirus trifoliata (L.) Raf.) have shown chlorosis, canopy reduction, wilting, root necrosis, defoliation, and plant death symptoms. This study aims to characterize the morphological symptoms observed in diseased orange trees in central Chile and identify the fungal pathogens that are involved. Isolation and morphological characterization of the pathogens were conducted by using different culture media. A total of 53 isolates were obtained, morphologically characterized and 12 isolates were selected for molecular identification. The isolates were identified using ITS, TEF-1α, and RPB2 regions. Two Fusarium species complexes were identified, Neocosmospora (Fusarium) solani (FSSC) and F. oxysporum (FOSC), based on >99% identity. Pathogenicity tests were conducted on young orange seedlings under greenhouse conditions. Results indicated that two months post inoculation, trifoliate orange seedlings displayed root rot symptoms such as necrosis, vascular discoloration, and wilting. FSSC and FOSC were re-isolated from necrotic seedling roots and identified through a combination of morphological traits and molecular techniques. This is the first detailed report of this disease, attributed to FSSC and FOSC, in orange orchards in Chile. These diagnostic results represent the first step in developing adequate phytosanitary programs for managing this disease. Full article

In order to sustain control over soybean root rot, wheat-straw-fiber-based mulch film (WFM) coated with carbendazim (C) and chitosan (CS) mixture (C-CS-WFM) were prepared through bar coating technology. The Box–Behnken design method was employed to investigate the effects of chitosan concentration, wet film thickness, and carbendazim loading on the dry tensile strength (DTS), wet tensile strength (WTS), and air permeance (AP) of C-CS-WFM. Eventually, the optimization process parameters were determined as follows: a chitosan concentration of 1.83–2.39%, a wet film thickness of 18–24 μm, and a carbendazim loading of 0.05–0.12 g/m². These parameters achieved the desired physical properties of C-CS-WFM, i.e., the DTS is not less than 3.5 kN/m, the WTS is not less than 0.8 kN/m, and the AP does not exceed 2.1 μm/(Pa·s). The results showed that after the introduction of the C-CS coating, the DTS and WTS of C-CS-WFM were enhanced by 11.4% and 14.9%, respectively. In contrast, the AP was reduced by 15.6%. FT-IR analysis indicated that carbendazim was embedded in the C-CS composite material without any chemical interaction. Through SEM and sustained-release kinetic analysis, it was found that the sustained-release mechanism of C-CS-WFM conformed to the Ritger–Peppas kinetic model, and its release mechanism was the physical diffusion and matrix erosion. The results of the in vitro antifungal test and pot experiment demonstrated that C-CS-WFM could effectively inhibit the growth of Fusarium solani and promote the growth of plants. This study provided new ideas for the comprehensive prevention and control of soybean root rot. Full article

Black root rot is a dangerous disease affecting many crops. It is caused by pathogens formerly known as Thielaviopsis basicola and then reclassified as two cryptic species, Berkeleyomyces basicola and B. rouxiae. The aim of this study was to perform species identification, morphological characterization, and pathogenicity tests for fungal isolates obtained from tobacco roots with black root rot symptoms in Poland. DNA sequences of the three regions (ITS, ACT, MCM7) were highly similar to the sequences of B. rouxiae deposited in the NCBI database. Phylogenetic analysis confirmed the assignment of the obtained isolates to this species. The cultures of four representative isolates (namely OT2, OT3, WPT7, WPT8) showed a similar structure and gray/brown color of the mycelium, although their growth rate varied from 3.8 to 5.1 mm/day depending on the isolate. The sizes of the endoconidia and chlamydospores showed a considerable variation, although they fit within ranges previously described for B. rouxiae. Pathogenicity tests performed on young tobacco plants grown in the inoculated peat substrate revealed differences among the four isolates. WPT7 demonstrated the lowest level of aggressiveness for tobacco. In contrast, the remaining three isolates caused severe disease symptoms and significantly reduced shoot and root dry weights of the susceptible cultivar Virginia Joyner. A parallel pathogenicity test performed on cultivar VRG 10TL confirmed the effectiveness of black root rot resistance derived from Nicotiana debneyi. Full article

The development and standardization of an effective inoculation technique are essential for reliable screening of crop genotypes. In this study, three inoculation methods—in vitro paper towel, in vitro agar, and soil inoculation in pots—were tested to evaluate the pathogenic potential of Macrophomina phaseolina, the causative agent of dry root rot (DRR). Since the pathogenicity of M. phaseolina is influenced by environmental factors, identifying a robust inoculation method is critical. Among the three techniques, the paper towel inoculation method resulted in the highest seedling mortality of 66.66% in cluster beans and 86.67% in cowpeas within just ten days, demonstrating its effectiveness. The agar inoculation technique, while successful, required 15 days to confirm pathogenicity, with seedling mortality rates of 63.33% for cowpeas and 53.33% for cluster beans. In contrast, the soil inoculation method showed comparatively lower mortality rates, with 36.66% for cluster beans and 26.67% for cowpeas. Based on these findings, the paper towel method emerged as the most efficient technique for inducing rapid pathogenicity in M. phaseolina in both cowpeas and cluster beans. Its suitability was further validated through the screening of released varieties of these crops compared against the soil inoculation method. Notably, genotypes that appeared moderately resistant under the soil inoculation method were found to range from susceptible to highly susceptible when evaluated using the paper towel technique. These results underscore the reliability of the paper towel method as a rapid and robust screening tool for identifying resistant genotypes of cowpea and cluster bean on a larger scale. Full article

Potatoes are a staple food crop consumed worldwide, with their significance extending from household kitchens to large-scale food processing industries. Their market value and quality are often compromised by various internal defects such as pythium, bruising, internal browning, hollow heart, gangrene, blackheart, internal sprouting, and dry rot. This study aimed to classify internal-based defects and investigate the quantification of internal defective areas in potatoes using visible and short-wavelength near-infrared spectroscopy. The acquisition of the spectral data of potato tubers was performed using a spectrometer with a wavelength range of 400–1100 nm. The classification of internal-based defects was performed using partial least squares discriminant analysis (PLS-DA), while the quantification of the internal defective area was based on partial least squares regression (PLSR). The PLS-DA double cross-validation accuracy for the distinction between non-defective and all internally defective potatoes was 90.78%. The double cross-validation classification accuracy achieved for pythium, bruising, and non-defective categories was 91.03%. The internal defective area model based on PLSR achieved a correlation coefficient of double cross-validation of 0.91 and a root mean square error of double cross-validation of 0.85 cm². This study makes a valuable contribution to advancing nondestructive techniques for evaluating internal defects in potatoes. Full article

Tomato production faces challenges such as high input costs, pests, diseases, and climate change. Biostimulants like Nurspray^®, based on hydroxycinnamic acid oligomers, offer a promising solution. This study evaluated the impact of different application timings of Nurspray^® on tomato yield and fruit quality under open-field conditions. Four treatments were tested: T1 (control), T2 (Nurspray^® at BBCH 19–51), T3 (Nurspray^® at BBCH 19–51–61), and T4 (Nurspray^® at BBCH 19–23–51). The results showed significant improvements in root development, canopy cover, and flowering for T3 and T4, with root systems increasing by up to 103% in T4 compared to the control. Fruit yield and quality were enhanced, with a reduction in blossom-end rot (BER) incidence to 0% in T3 and T4, compared to 5% in the control. Additionally, T4 produced the highest dry matter content in fruits. The optimal application strategy was three doses of Nurspray^® at BBCH 19–23–51, enhancing both yield and fruit quality. This study highlights the potential of Nurspray^® as an organic biostimulant in sustainable tomato farming. Full article