Search Results (137)

Chickpea is a legume that grows in most parts of the world. It is negatively affected by abiotic and biotic factors like drought and fungal diseases, respectively. One of the most important soil-borne pathogens affecting chickpeas is Fusarium oxysporum f.sp. ciceris (Foc). Its population dynamics in the soil are affected by fluctuations in soil water content and host characteristics. For the last three decades, drought has been common in most areas of the world due to global warming. Drought stress decreases the quality and quantity of the chickpeas, particularly where soil-borne pathogens are the main stress factor for plants. The use of both drought-tolerant and disease-resistant cultivars may be the only option for cost-effective yield production. In this study, we screened the seeds of twelve chickpea genotypes WR-315, JG-62, C-104, JG-74, CPS-1, BG-212, ANNIGERI, CHAFFA, BG-215, UC-27, ILC-82, and K-850 for drought tolerance at increasing polyethylene glycol (PEG) concentrations (0-, 5-, 7.5-, 10-, 15-, 20-, 25-, 30- and 50%) to create drought stress conditions at different severities. The performances of genotypes that were previously tested in Foc resistance/susceptibility studies were assessed in terms of percentage of germination, radicle and hypocotyl length, germination energy, germination rate index, mean germination time, and vigor index in drought conditions. We determined the genotypes of C-104, CPS-1, and WR-315 as drought-susceptible, moderately drought-tolerant, and drought-tolerant, respectively. We then elucidated the stress levels of selected genotypes (20-day-old seedlings) at 0–15% PEG conditions via measuring proline and malondialdehyde (MDA) contents. Our findings showed that genotypes that were resistant to Foc also exhibited drought tolerance. The responses of chickpea genotypes infected with Foc under drought conditions are the next step to assess the combined stress on chickpea genotypes. Full article

Rice bakanae disease (RBD), a major threat in rice-cropping nations, can reduce rice yield and quality. As it is a seed-borne disease, effective seed detection is crucial. Loop-mediated isothermal amplification (LAMP) can rapidly and specifically amplify DNA at a constant temperature with high sensitivity. This research uses LAMP to develop rapid RBD pathogen detection systems. Primers were designed targeting the NRPS31 gene of Fusarium fujikuroi and conserved TEF1α sequences of Fusarium asiaticum, Fusarium proliferatum, and Fusarium andiyazi. These reactions at 60 °C for 60 min had a detection limit of 100 pg·μL⁻¹, and LAMP proved applicable in field trials. Full article

Here, research on seed-borne virus diseases of cool-season pulses caused by bean yellow mosaic virus (BYMV) in Australia’s grain cropping regions since the 1940s is reviewed. A historical approach is taken towards all past studies involving the main cool-season pulse crops grown, lupin, faba bean, field pea, lentil and chickpea, and the minor ones, narbon bean, vetches and Lathyrus species. The main emphasis adopted is on describing what these studies revealed concerning BYMV biology, epidemiology and management. The field and glasshouse experimentation that enabled the development of effective phytosanitary, cultural and host resistance control strategies, supported by many image illustrations from past investigations, is emphasized. This review commences by providing brief background information and describing past studies on BYMV symptom and sequence variants, and alternative BYMV hosts. Next, as the lupin/BYMV pathosystem has been investigated in much greater depth than any other cool season pulse/BYMV pathosystem combination in Australia, what past studies using it have found is covered considerable detail under a series of nine different sub-headings. Finally, what is known about the less thoroughly investigated cool-season pulse/BYMV pathosystems, especially those involving faba bean, field pea and lentil, is reviewed under seven different sub-headings. Recommendations are provided concerning future research priorities. Full article

Soil-borne diseases lead to high risk in crop production by diminishing the productivity and general health of the affected plants. Brassica plants are known to produce glucosinolates, which, upon decomposition, release bioactive isothiocyanates (ITCs). ITCs have attracted attention because of their biofumigation properties, effectively suppressing soil-borne pathogens and pests, promising natural solutions for managing soil-borne diseases. ITCs produced by Brassica plants or seed meal additives to soil have the ability to reduce soil-borne pests and diseases while increasing beneficial soil microbiota. Several researchers have indicated that ITCs can interfere with the life cycles of soil-borne pathogens and, at the same time, strengthen plant defense systems, which makes them a more environmentally friendly option than chemical pesticides. The breakdown of Brassica biomass has also been shown to stimulate beneficial microbial communities, which play a key role in nutrient availability and pathogen suppression. Studies indicate that this process enhances the availability of essential nutrients like sulfur and nitrogen in the soil, both of which are critical for plant growth and development. This review provides a comprehensive exploration of the role of Brassica ITCs in mitigating soil-borne diseases. We aim to consolidate current knowledge on ITC-mediated biofumigation, recommend strategies for enhancing its efficiency in practical applications, and highlight the need for future research to optimize its long-term effectiveness in sustainable agriculture. Full article

Fusarium root rot, a destructive soil-borne fungal disease, necessitates eco-friendly biocontrol strategies. This study developed a microbial seed-coating approach using the antagonistic strain Paenibacillus polymyxa ZF129, formulated into a microencapsulated powder (10⁸ CFU/g) and a suspension (CS-ZF129). CS-ZF129 application enhanced cucumber resistance, achieving 46.30 ± 0.02% disease suppression while promoting root growth. The maximum increase in the fresh weight of the root in the promotion of rectangular growth was 47.16%. The colonization dynamics of ZF129 in the rhizosphere were systematically tracked, revealing its antagonistic correlation with Fusarium proliferation. An enzymatic activity analysis further uncovered the underlying regulatory mechanisms, demonstrating induced defense responses through pathogenesis-related protein activation. These findings highlight ZF129’s dual functionality as a biocontrol agent and a plant growth promoter, offering a sustainable strategy against soil-borne pathogens. Full article

Bacterial fruit blotch (BFB) is a highly destructive seed-borne and seed-transmitted disease caused by the Gram-negative bacterium Acidovorax citrulli that has caused substantial economic losses for the cucurbit industry in China. Despite its potential for economic damage, little is known about the bacterium’s molecular mechanisms of pathogenicity. Toxin–antitoxin (TA) systems are critical for the bacterial stress response. These systems are composed of two genes, toxin and antitoxin, that encode a stable toxin protein and a labile antitoxin protein, respectively. In this study, the genes for the putative HipBA TA system were identified in A. citrulli genomes through bioinformatic analysis. A series of molecular biology experiments have demonstrated that the HipBA TA system exists in A. citrulli Aac5. Furthermore, the transcription of hipA and hipB in A. citrulli Aac5 were induced by pH stress, chloramphenicol stress, and during plant infection. Overall, our results have revealed an active type II TA system, HipBA, in A. citrulli Aac5, and provided insights into its biological functions. These findings contribute to a better understanding of TA systems in plant pathogens. Full article

Fusarium stalk rot (FSR), a devastating soil-borne disease caused by Fusarium species, severely threatens global maize production through yield losses and mycotoxin contamination. Bacillus subtilis, a plant growth-promoting rhizobacterium (PGPR), has shown potential as a biocontrol agent against soil-borne pathogens, but its efficacy and mechanisms against maize FSR remain poorly understood. In this study, an identified strain of B. subtilis A3 was introduced to study its biological control potential against corn stalk rot. The bacteriostatic stability of the biocontrol strain was assessed, revealing that its inhibitory activity against F. graminearum remained consistent over five consecutive generations, indicating robust bacteriostatic stability. The strain also exhibited inhibitory effects on F. verticilliodes, F. proliferalum, and other pathogenic fungi, demonstrating it has broad-spectrum antibacterial activity. Indoor experiments showed that treatment with the biocontrol strain significantly increased plant height, stem diameter, and fresh weight, indicating a positive impact on corn growth. Additionally, the biocontrol strain A3 markedly reduced the lesion length of corn stalk rot, confirming its efficacy in controlling the disease. Field trials demonstrated that the growth of the A3-coated corn seeds was better than the control seeds, the control effect of FSR disease was 45.75%, and the yield increase was 3.6%. Microscopic observations revealed that the biocontrol strain A3 caused the hyphal tips of F. graminearum to swell and exhibit a beaded morphology, inhibiting normal growth. The volatile substances produced by A3 also showed significant antibacterial activity, with the antibacterial spectrum aligning with that of the biocontrol strain. Using headspace solid-phase microextraction and GC-MS, various antibacterial compounds were identified in the volatile substances. Analysis of root-associated microorganisms indicated that A3 significantly changed the microbial community composition. Co-occurrence network analysis revealed that A3-treated plants had fewer edges and lower negative correlations among bacterial communities. This study establishes the strong biocontrol potential of B. subtilis A3 against Fusarium stalk rot in corn, demonstrating its robust bacteriostatic stability, broad-spectrum antibacterial activity, positive impact on plant growth, and significant disease control efficacy, while also revealing its ability to alter root-associated microbial communities. These findings provide a foundation for further research into the mechanism of B. subtilis and its application in field biological control. Full article

Smallholder potato farmers in Ethiopia do not realize the theoretical yield potential of the crop because they do not benefit from the advantages of using quality seed potato of improved varieties. The high disease incidence in seed potatoes has large implications on the potato farming system since the country lacks appropriate seed quality assurance mechanisms. Seed potato quality assurance relies more on the technical support provided by the national research and extension systems than the official seed certification agency. This paper elaborates systematic challenges and opportunities within the potato seed system and poses two research questions: (1) What type of seed quality assurance mechanisms (informal, quality declared, certified) are under implementation in Ethiopia? (2) How does the current seed quality assurance system operate in terms of reliability, accessibility, and quality standards to deliver quality seed potato? The data were collected through face-to-face in-depth key informant interviews with various seed regulatory laboratory managers and technicians in the Oromia, SNNP, and SWEP regions in the main seed- and ware-producing areas of Ethiopia. This was complemented by a comprehensive analysis of relevant documents. The findings show that currently there is no established procedure in place to officially certify early-generation seed potatoes. Two out of six seed quality control laboratories assessed for this study inspected seed potato fields in 2021 but as quality declared seed (QDS), and approved the fields inspected based on visual inspection alone. Our study revealed a weak linkage between early-generation seed (EGS) potato producers, commercial, and QDS seed potato producers, and seed quality control laboratories. Seed potato quality assurance operations were carried out by only a few seed regulatory laboratories with several concerns raised over the effectiveness of quality standards since seed-borne diseases, such as bacterial wilt, have been found at high frequency in the country’s seed potato system. Hence, the current procedures and challenges call for the necessity of upgrading current quality assurance in seed potato certification. Our study underlines the need for policymakers, development partners, and researchers to collaborate and pool efforts to consider transforming the quality declared system to appropriate seed certification. We recommended that institutionalizing novel plant disease diagnostics into seed regulatory frameworks is needed for sustainable potato production and food security in Ethiopia. Full article

Soybean vein necrosis orthotospovirus (SVNV: Tospoviridae: Orthotospovirus) is a well-recognized thrips-vectored and seed-borne virus common in the United States (U.S.), Canada, and Egypt. Pakistan started the commercial cultivation of soybeans in the 1970s, when some soybean cultivars were imported from the U.S. to meet the country’s domestic requirement of oil, poultry, animal feed, and forage. A survey of farmers and scientists was conducted in the Punjab and Khyber Pakhtunkhwa provinces of Pakistan to understand perceptions of SVNV in the indigenous Pakistani community. Concurrently, soybean fields were sampled for SVNV presence at the National Agricultural Research Institute in Islamabad, Pakistan. Based upon survey and SVNV detection results through ELISA and qRT-PCR, a policy was developed. Overall, we found that SVNV was present in Islamabad, Pakistan in USDA-approved soybean cultivars. Although scientists knew about general thrips biology and insecticides, knowledge about identification of vectors (Thrips species) was not significantly different between the scientists and the farmers. Scientists at the Islamabad location were more aware of crop production technology and pests. This study reports that Pakistan needs to strengthen its research institutes, scientists’ and farmers’ capacity building, and extension programs to understand the disease complex in soybean crops. Full article

A wide range of seed-borne and soil-borne plant pathogens belonging to various fungal and fungal-like species cause pre-emergence seed decay and post-emergence seedling blights of wheat and other small-grain cereal crops. To prevent the death of the seedlings, poor establishment and reduced stand of the crops, extensive crop rotations, planting good-quality seeds and seed treatments with fungicides are used on regular basis. This study is aimed at assessing the efficacy of pre-sowing seed treatments with cold atmospheric plasma for the disinfestation of winter wheat seed from economically important fungal and fungal-like pathogens. Uninoculated or surface-inoculated with Fusarium culmorum, Bipolaris sorokiniana or Pythium ultimum wheat seeds, the cultivar Madara was treated by cold plasma produced either by microwave torch (MW) or underwater diaphragm discharge (UW) with low power at very short treatment times, or remained untreated controls. As per the treatments, the seeds were sown in a ready-to-use growing medium comprising a mixture of light and dark moss peat (w:w) 90–95%, 5–10% perlite and 3–5 kg/m³ CaCO₃, having an electrical conductivity of 40 mS/m, pH (H₂O) of 5.5–6.5 and moisture content of 60–70%, filling in 250 × 250 × 70 mm aluminum flat seed trays (40 grains per tray, four trays per treatment). The plants were cultivated for 45 days in a growth chamber held at (20 ± 2) °C, set to a cycle of 8 h/night and 16 h/day under fluorescent light of 2000–3000 lux intensity. For each replicate, disease incidence (DI) was determined as the total percentage of missing, dead and apparently symptomatic plants. Seed treatment with a microwave plasma torch with a power of 16 W for 40 s significantly (p < 0.001) reduced seedling blights caused by F. culmorum, B. sorokiniana and P. ultimum by 46.8%, 51.0% and 77.3%, respectively, but limited the emergence of wheat seedlings by 15.9% on average. Simultaneously, the effectiveness of underwater discharge seed treatments reached an average of about a 60% reduction of seedling blight caused by F. culmorum and B. sorokiniana and about 37% of the disease caused by P. ultimum. Pre-sowing treatments with a MW plasma torch with an input power of 11 W and treatment time of 60, 90 or 120 s exposure also showed significant (p < 0.001) effects in controlling winter wheat seedling blights caused by the three pathogens. The effectiveness of the treatment increased with increasing the time period of exposure and reached full disease control (>80% reduction) for B. sorokiniana and P. ultimum seedling blights. This study demonstrated that pre-sowing treatment with a microwave plasma torch and underwater diaphragm discharge at a relatively low input power and short exposure time can be used for disinfestation and the effective control of seedling blights in winter wheat caused by seed-borne fungal pathogens, such as Fusarium culmorum and Bipolaris sorokiniana, and fungal-like oomycetes, such as Pythium ultimum. Full article

Soil-borne diseases, including charcoal rot (Macrophomina phaseolina) and collar rot (Sclerotium rolfsii), threaten global soybean production. Four fungicide combinations were tested as seed treatments at three concentrations (1, 1.5, and 2 g or ml per kg of seed) under controlled conditions to address the challenges posed by these diseases. Under controlled conditions, the combination of thiophanate methyl + pyraclostrobin at a rate of 2 mL/kg of seed significantly alleviated disease symptoms caused by both pathogens. Additionally, it enhanced shoot and root weights by over 50% in plants affected by S. rolfsii. Field trials were conducted for two years at two distinct locations to assess the efficacy of three selected combination seed treatment fungicides against M. phaseolina and S. rolfsii. Both inoculated and uninoculated controls were included for the comparison. Among the fungicides, thiophanate-methyl + pyraclostrobin and trifloxystrobin + penflufen proved the most effective for suppressing both diseases under epiphytotic field conditions across the years and locations. This study also highlighted the benefits of these chemical combinations in enhancing agronomic traits, maintaining yield, and ensuring the economic viability of soybeans. Full article

The global demand for legumes has grown significantly since the 1960s, due to their high protein content and environmental benefits. However, this growth could also facilitate the spread of seed-borne pathogens like Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff). Cff is a Gram-positive bacterium causing bacterial wilt in common beans and poses substantial challenges in regard to its detection and management, due to its long latent period and xylemic nature. Traditional diagnostic methods have proven insufficient, highlighting the need for innovative approaches. This study explores the potential of volatile organic compounds (VOCs) produced by Cff to be used as diagnostic markers to prevent the spread of seed-borne pathogens. First, we analyzed the VOCs emitted by different Cff strains in vitro, identifying a unique blend of five major VOCs. Subsequently, we verified the presence of these VOCs in vivo in artificially infected Cannellino beans. Phenylmethanol and 2-methoxy-4-vinylphenol emerged as key diagnostic markers, differentiating Cff from other bacterial pathogens of beans, such as Pseudomonas savastanoi pv. phaseolicola and Xanthomonas phaseoli pv. phaseoli. Our findings suggest that VOC fingerprinting offers a non-invasive, effective method for the early detection of Cff, even in asymptomatic seeds. This innovative approach holds significant promise for improving seed-borne disease management and supporting the development of practical diagnostic tools for field applications. Further research should aim to enhance the sensitivity and specificity of VOC-based diagnostics, facilitating the rapid and accurate screening of plant materials at ports of entry. This would contribute to the sustainability and health of leguminous crop production. Full article

Potato Fusarium dry rot and wilt are the most important soil- and seed-borne diseases in potatoes. They cause high economic losses during potato growth and storage across the world. Previous observations have shown that dryocrassin ABBA can induce resistance in potatoes. However, little is known about whether dryocrassin ABBA can suppress Fusarium oxysporum. In this research, we determined that exogenous dryocrassin ABBA significantly inhibited the mycelial growth, changed the cell ultrastructure, increased the MDA content, and decreased the antioxidant enzyme activity of F. oxysporum. The transcriptome analysis of F. oxysporum with or without dryocrassin ABBA indicated that 1244 differentially expressed genes (DEGs) were identified, of which 594 were upregulated and 650 were downregulated. GO term analysis showed that the DEGs were mostly related to biological processes. The KEGG pathway was mainly related to carbohydrate, amino acid, and lipid metabolism. Moreover, most of the expressions of PCWDEs, HSPs, and MFS were downregulated, decreasing the stress capacity and weakening the pathogenicity of F. oxysporum with dryocrassin ABBA treatment. These findings contribute to a new understanding of the direct functions of dryocrassin ABBA on F. oxysporum and provide a potential ecofriendly biocontrol approach for potato Fusarium dry rot and wilt. Full article

Soybean, an essential oil crop in China, has witnessed accelerated seed transfer domestically and abroad in recent years. Seed carriage has emerged as a major route for the dissemination of soybean diseases. In this study, 14 soybean cultivars from three northeastern provinces were collected and examined for seed-borne microorganisms using traditional detection technology and high-throughput sequencing technology. Through traditional detection techniques, a total of six genera of bacteria and seventeen genera of fungi were isolated from the test varieties. The quantity and types of microorganisms on the seed surface were greater than those on the seed coat and within the seed, while the seed coat and internal seed contained fewer microorganisms. The dominant fungal genera were Cladosporium, Fusarium, Aspergillus, and Alternaria, accounting for 21.23%, 17.45%, 15.57%, and 11.56% of the genera, respectively. The dominant bacterial genera were Pseudomonas, Sphingomonas, and Pantoea, accounting for 37.46%, 17.29%, and 15.27% of the genera, respectively. The dominant genera obtained through traditional seed-carrying assay techniques were also dominant in high-throughput sequencing. However, some dominant genera obtained through high-throughput sequencing were not isolated by traditional methods. High-throughput sequencing analysis revealed that soybean seeds from Jilin Province had the highest abundance of seed-borne fungi, followed by seeds from Liaoning Province and Heilongjiang Province. Jilin Province also had the highest abundance of seed-borne bacteria, followed by Heilongjiang Province and Liaoning Province. The isolation and identification of microorganisms on soybean seeds provide a scientific basis for seed quarantine treatment and disease control, which is of great significance for soybean production in China. Full article

Leaf stripe disease, caused by Pyrenophora graminea, is a seed-borne fungal disease that significantly impacts hulless barley (Hordeum vulgare var. nudum) production on the Qinghai-Tibet Plateau. This study aimed to identify genetic factors conferring resistance to the leaf stripe by analyzing an F₃ population derived from a cross between the resistant landrace Teliteqingke and the susceptible landrace Dulihuang. Genetic analysis revealed that resistance in Teliteqingke was governed by two dominant genes. Using bulked segregant analysis combined with an SNP array (BSA-SNP) and RNA-seq, we identified two candidate regions on chromosomes 3H and 7H. Further analysis focused on chromosome 3H, which revealed a candidate genomic region containing seven potential disease-resistance genes. Among these, RT-qPCR experiments demonstrated significant expression induction of HORVU.MOREX.r3.3HG0232110.1 (encoding a RING/U-box superfamily protein) and HORVU.MOREX.r3.3HG0232410.1 (encoding a bZIP transcription factor) showed significant expression induction following inoculation with P. graminea. These genes are strong candidates for the resistance mechanism against leaf stripes in Teliteqingke. These results provide a foundation for functional validation of these genes and offer valuable insights for breeding disease-resistant hulless barley. Full article