Erlvejunzuo, a gallic acid-derived thiadiazole, inhibits glucose biosynthesis and confers broad-spectrum antifungal activity.

Polygonatum kingianum (dian huang jing), a perennial herb valued in traditional Chinese medicine for its bioactive polysaccharides and steroidal saponins, is increasingly threatened by stem rot disease across major cultivation regions in China (Tan et al., 2021). In August 2024, severe stem rot symptoms were observed in commercial fields in Panzhou County, Liupanshui, Guizhou Province, China (25°82′N, 104°53′E; elevation 2,113 meters). Initial symptoms included water-soaked, orange-red lesions on rhizomes, progressing to extensive soft rot, vascular browning, and tissue maceration. Aboveground symptoms featured progressive wilting, chlorosis, stunted growth, and eventual plant death. Five diseased underground stem tissues were surface-sterilized with 2% NaClO for 60 second, followed by three sterile-water rinses, then plated on potato dextrose agar (PDA) and incubated at 25°C in darkness. Three morphologically similar isolates (GF-1 to GF-3) were purified via mono-spore culturing. Colonies developed dense, cottony white aerial mycelia transitioning to pale gray after 7 days, with profuse salmon-orange conidial masses. Conidia were hyaline, aseptate, cylindrical with obtuse ends, measuring 13.2-16.8 × 4.5-5.7 µm (15.1 ± 0.9 × 5.0 ± 0.3 µm). Appressoria were dark brown, clavate to irregular, measuring 6.5-10.2 × 4.8-7.1 µm. For molecular identification, genomic DNA was extracted from the isolates (Zhao et al., 2020). Five loci were amplified: act, chs1, gapdh, his3, ITS, and tub2. PCR conditions followed standard protocols (Liu et al., 2022). A maximum-likelihood phylogeny (1,000 bootstraps) of concatenated sequences (act-chs1-gapdh-his3-ITS-tub2) constructed using MEGA-X version 10.1.6 (Kumar et al., 2018) showed that the isolates (GF-1 to GF-3) form a monophyletic clade, which was denoted as a new species (Colletotrichum panzhouensis). Pathogenicity tests used 2-year-old healthy P. kingianum plants grown in autoclaved soil in a pot (8.7 cm height, 9.7 cm upper diameter, and 6.7 cm bottom diameter). Each pot was irrigated with 5 ml of conidial suspension (10⁶ conidia/ml). Control plants received sterile water. Plants were maintained in a greenhouse (25°C; 85% RH; 12-h photoperiod). All inoculated plants underground stem developed water-soaked lesions within 9 days, progressing to severe necrotic rot and wilting at 17 days post-inoculation, matching field symptoms. Controls remained asymptomatic. The pathogens were reisolated from lesions and identified by morphological and molecular data, fulfilling Koch’s postulates. To our knowledge, this is the first global report of C. panzhouensis causing stem rot on P. kingianum. This finding underscores that C. panzhouensis may pose a significant threat to the sustainable cultivation of Polygonatum kingianum. Urgent research on host resistance, fungicide efficacy, and cultural controls is warranted.

In September 2022, a severe outbreak of stem rot disease occurred on Nicotiana tabacum cultivar Yunxue 1 in Lujiang Town, Baoshan City, Yunnan Province of China (98°45′-98°57′ E, 24°48′-25°17′ N). Symptoms included water-soaked lesions on stems and leaves that turned brown and rotted inward. Infected plants gradually wilted, defoliated, emitted a foul odor, and eventually died (Figure 1). Statistically, in a field of 0.8 ha,the disease incidence was 30% and the affected cultivar with Yunxue 1. Ten typical samples of cigar tobacco blackleg were collected from the Baoshan tobacco plantation, rinsed with sterile water, soaked in 75% ethanol for 30 seconds, and then rinsed with sterile water three times. The samples were then plated onto nutrient agar (NA) and incubated at 28°C. A total of 10 pathogenic strains were isolated. After 24 hours of incubation at 28°C ± 1°C in nutrient agar (NA) medium, the purification culture was carried out, and the most pathogenic strain, numbered BS113, was obtained.Pathogenicity tests were conducted using the capillary tube method. The purified bacterial strain was inoculated into NA liquid medium and cultured at 28°C for 18-24 h. The bacterial concenration was adjusted to 108 CFU/mL with sterile water, and 20 μL was injected into the stem base of 60-day-old tobacco plants (Yunxue 1), with sterile water as the control. The plants were grown under conditions of 28°C and 80% humidity, and disease symptoms were observed, with the color, size, location, and severity of lesions recorded at different stages of disease development. Symptoms appeared on the second day after inoculation, with initial lesions appearing brown. By the third day, the entire plant had rotted and withered, while the control group showed no symptoms (Figure 2). Pathogenic bacteria was reisolated from the infected plants, confirming Koch’s postulates and the pathogenicity on tobacco. The Biolog system was used to test carbon source utilization and chemical sensitivity (Bochner B R. 1989). The pathogenic bacterium Biolog GEN III identification result showed 52 positive reactions, 25 negative reactions, and 17 borderline reactions. Among these, 36 carbon sources were utilized, including D-mannitol. Chemical sensitivity testing yielded 16 positive reactions and 2 negative reactions. According to the symptoms and morphological characteristics (Figure 3), the pathogen was tentatively identifed as Pectobacterium brasiliense. The molecular identification was performed by 16S rRNA primers (27F,5'-AGAGTTTGATCCTGGCTCAG-3';1492R,5'-GGTTACCTTGTTACGACTT-3') and gapA primers (gapA-7-F and gapA-938-R) (Yang et al. 2008) region sequencing. Sequences of 1506 and 932bp, respectively, were deposited in GenBank (accession numbers 16S: OQ519692; gapA: PV820694 ),The results showed that the similarity between the pathogen and P.brasiliense (16S: KY021041; gapA: OP793232) was 99.73% and 99.57%, respectively. A multigene phylogenetic tree was constructed based on 16S rRNA, repoS and gapA gene fragments using MEGA 7.0 Neighbor-Joining (NJ) with the sequences of homologous genes as well as Dickeya solani as an outgroup (Fig. 4),Based on plant disease symptoms, biochemical tests, and molecular sequencing, we conclude that this bacterial strain is P. brasiliense. To our knowledge, this is the frst report of P. brasiliense infecting tobacco in China. Reports indicate that this pathogen can infect 19 different plant species from 10 different families (Oulghazi et al. 2021). Occurrence of P. brasiliense on tobacco poses a potential threat to the health and yield of tobacco and other plants.

Rapeseed-Mustard are usually called as “Oilseed brassica”, is the world’s third most important source of edible oil after soybean and oil palm. India is the third largest producer of rapeseed-mustard after Canada, China and contributing to around 14% of world’s total production. Now in India, rapeseed-mustard rank 1st in oilseed production and is an important Rabi oilseed crop contributing 11.3% of world’s edible oil supply. It is grown all over India covering 918.32lakh ha of area producing 131.16 lakh tonnes with 1444 kg/ha average productivity contributing 33.24% of total oilseed production. Bihar produces 122.48 thousand tonnes from an acreage of 96.98 thousand ha with average productivity of 1263 kg/ha. Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a persistent and devastating disease of rapeseed-mustard in Bihar, leading to substantial yield losses under high humidity and low temperature conditions. This study evaluated the efficacy of newer fungicidal molecules manage stem rot disease and enhance the yield. Field experiments were conducted during the 2021-22 and 2022-23 Rabi season and result showed that all tested fungicides significantly suppressed disease incidence and severity compared to the untreated control. Foliar application of Tebuconazole 50% + Trifloxystrobin 25% WG @ 0.1% (T1) at the time of flowering was the most effective treatment in reducing disease incidence and lesion length, and in enhancing yield compared to other fungicidal treatments and the untreated control. The treatment recorded the lowest pooled disease incidence (4.1%) and lesion length (3.2 cm), along with the highest pooled yield (1670.5 kg ha⁻¹) and maximum yield increase over control (750.9 kg ha⁻¹).

Background: Since peanut fields are often treated with fungicides during the growing season to control stem rot disease (caused by Sclerotium rolfsii Sacc.) and early and late leaf spot disease [caused by Cercospora arachidicola Hori) and Cercosporidium personatum (Berk. & M.A. Curtis) Deighton, respectively], weeds can also interfere with the uniform deposition of fungicides and therefore reduce disease control. Aims: The present study evaluates weed control and peanut response with the premix of carfentrazone plus pyroxasulfone (C + P). Study Design: Randomized complete block design with 3 to 4 reps depending on location. Place and Duration of Study: During the 2022 through 2024 growing seasons in the Texas Rolling Plains near Vernon and in south Texas near Yoakum. Methodology: Plots at Yoakum consisted of two rows spaced 97 cm apart and 7.6 m long while at Vernon plots were 2 rows spaced 102 cm apart by 7.6 m long in 2022 and 2024 and 4 rows spaced 102 cm apart by 18.2 m long in 2023. Preemergence (PRE) treatments were applied 2 to 10 days after planting (DAP). Peanut cracking (CRACK) treatments were applied 4 to 10 DAP. Postemergence (POST) treatments were applied 30 to 40 DAP. Weed control and peanut injury data were arcsine transformed prior to analysis of variance. Means were compared with Fisher’s Protected LSD test at the 5% probability level. The untreated control was not included in the weed control analysis but was included in the yield analysis. Results: In south Texas, Palmer amaranth (Amaranthus palmeri S. Wats.) control was > 90% with either pendimethalin applied PRE followed by (fb) S-metolachlor applied at CRACK fb C + P plus clethodim applied POST or S-metolachlor plus paraquat applied at CRACK fb S-metolachlor plus clethodim applied POST. All herbicide systems which contained C + P controlled Texas millet [Urochloa texana (Buckl.)] 87 to 98% while Smellmelon (Cucumis melo L. var. Dudaim Naud.) control with C + P systems ranged from 58 to 100%. In the Rolling Plains, A. palmeri and U. texana control was most consistent (76 to 91%) with C + P applied both at CRACK and POST. Under moderate A. palmeri pressure (4 to 5 plants/m2), all herbicide systems increased peanut yield over the untreated check (65%), while with no weed pressure, no differences in yield were noted with any herbicide treatment from the untreated check. Conclusion: The premix of C + P can help peanut producers manage their annual broadleaf weed problems. Broadleaf weeds cause Texas peanut growers considerable problems and can be hard-to-control with many of the presently used herbicides. Oftentimes, the premix of C + P does not effectively control large-seeded annual grasses such as Texas millet and requires the use of a graminicide such as fluazifop-P-butyl, clethodim, or sethoxydim (WSSA Group 1 herbicides) to improve season-long control.

The curative potential of an organic fungicide against Ganoderma boninense was previously assessed in vitro and yielded promising results. This organic fungicide was formulated using a combination of organosulfur compounds and polyphenols (OSC-P) as active ingredients. This study aimed to evaluate the effectiveness of OSC-P application in controlling basal stem rot (BSR) disease in infected oil palm seedlings of different varieties and to determine the optimum application dose. Two oil palm varieties were used: a G. boninense-susceptible variety and a moderately tolerant variety. The seedlings were artificially infected with G. boninense using inoculated rubber wood blocks (RWB). OSC-P was applied to 16-week-old seedlings by soil drenching at a volume of 200 mL per plant at 2-week intervals for 24 weeks. A total of six treatments, including controls, were arranged with four replications and observed at 4-week intervals. Each replication consisted of 10 seedlings. Observed parameters included disease incidence, disease severity, and vegetative growth parameters. The results showed that OSC-P application significantly reduced the incidence and severity of BSR disease in infected oil palm seedlings. BSR symptoms were less severe in the moderately tolerant variety than in the susceptible variety; however, disease incidence did not differ significantly between the two varieties. The optimum application dose of OSC-P was 0.8% (v/v), and variations in application dose did not significantly affect disease incidence or severity at 24 weeks after application. These findings are expected to complement existing preventive strategies for BSR management.

Groundnut (Arachis hypogaea L.) is one of the most important oilseed crops, but its production is severely affected by stem rot disease caused by Sclerotium rolfsii. The present study investigates the potential of a chitinase-producing Bacillus amyloliquefaciens strain GR16 for biological control of S. rolfsii. The isolate was obtained from rhizospheric soil of healthy groundnut plants and identified through morphological, biochemical, and molecular characterization. B. amyloliquefaciens RRR16 exhibited strong chitinolytic activity on colloidal chitin agar plate and significantly inhibited the mycelial growth of S. rolfsii in a dual culture assay with 92.86 % inhibition. The results indicate that B. amyloliquefaciens RRR16, through its chitinolytic mechanism, can serve as an efficient biocontrol agent for sustainable management of groundnut stem rot disease.

Forsythia suspensa is an important ornamental horticultural plant, and its fruit is a traditional Chinese medicine used for treating inflammation and pyrexia. Phomopsis velata is a pathogen causing stem rot disease in F. suspensa. In this study, we investigated the host-response mechanism of healthy forsythia plants inoculated with P. velata by evaluating physiological indexes, hormone content, and gene expression levels 5, 10, and 15 days postinoculation. After inoculation with P. velata on forsythia branches, the symptoms of stem rot disease appeared. The activity of physiological indexes and hormone content were significantly changed. Compared with the control groups, 1,112 genes were significantly changed at transcriptional levels in treatment groups. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that differently expressed genes were mainly enriched in plant-pathogen interaction, plant hormone signal transduction, the MAPK signaling pathway, and the peroxidase pathway. The plant-pathogen interaction pathway exhibited the most enriched differentially expressed genes. Our study has identified CaMCML, FLS2, EIX1/2, BAK1, and other related protein receptors. This study elucidates the molecular defense mechanisms of F. suspensa in response to P. velata infection, providing a theoretical foundation for the effective management of stem rot disease in this species.

Ganoderma boninense is a fungus that causes basal stem rot disease in oil palm plants. This fungus disrupts the transport of water and nutrients from the soil, leaf chlorosis, stem decay, fruitlessness, and ultimately death. This study is one of the first to specifically explore the bark of Senna multijuga as a source of antifungal compounds against Ganoderma boninense. Previous studies have focused more on leaf extracts from other Senna species, so the use of S. multijuga bark provides a new contribution to the search for biological agents to control G. boninense. This study aims to extract and isolate the active fraction from S. multijuga bark as antifungal agents against G. boninense. The study was conducted in three stages. The extraction and isolation of the active fraction from S. multijuga bark as antifungal agents against G. boninense, the determination of the chemical composition of the S. multijuga bark, and the antifungal activity of the active fraction against G. boninense in vitro. Based on the GC-MS results for fraction-1 from S. multijuga bark showed the main compounds of 1-hexadecene (5.51%), 1-octadecene (8.29%), hexadecanoid acid (10.46%), 2-ethoxycyclohexanol (5.53%), 9,12-octadecadienoic acid (8.91%), 9,12,15-octadecatrienoic acid (7.70%), 2-hexadecen-1-ol (5.48%), 1-docosene (3.33%), 2-pyridol (6.28%), and calotropenol acetate (6.52%). A concentration of fraction-1 at 1.50 ppm can inhibit the growth of G. boninense (0.32 cm/day), inhibition of G. boninense (67,46%), and produce thin white mycelium that collects in the middle of the medium.

During the rainy season of September-October 2022, rice plants (cv. Swarna; MTU7029) in Pedapudi village, East Godavari district, Andhra Pradesh, exhibited brown to black, water-soaked lesions with irregular margins on the outer leaf sheaths near the waterline. The causal fungus was isolated on potato dextrose agar and produced abundant, initially white, round sclerotia that turned brown to black upon maturity. Microscopic examination revealed right-angled branching hyphae with slight constriction at the branch points; hyphal width ranged from 3.04 to 6.68 mm (mean 4.80 mm). Sclerotial diameter ranged from 0.26 to 0.49 mm (mean 0.39 mm). The internal transcribed spacer (ITS) region of the isolate was amplified and sequenced (GenBank accession ON514170), showing 99.83% nucleotide identity with Sclerotium hydrophilum strain SH1 (GenBank accession KX181457.1). Pathogenicity was confirmed on rice cultivar Prabhat (MTU3626) under glasshouse conditions, fulfilling Koch's postulates. Based on cultural, morphological, pathogenic, and molecular characteristics, the pathogen was identified as Sclerotium hydrophilum. According to existing literature, this constitutes the first confirmed report of S. hydrophilum causing stem rot of rice in the Godavari delta zone of Andhra Pradesh.

Ganoderma sp. is a fungal pathogen that causes basal stem rot in oil palm, leading to production losses of up to 80%. One potential method to inhibit fungal growth is the use of plant-based fungicides derived from bintaro fruit (Cerbera manghas L.) extract. This study aims to determine the effective concentration of C. manghas fruit extract for controlling Ganoderma sp., the causal agent of basal stem rot disease in oil palm, under in vitro conditions. The extract was tested at concentrations of 0%, 4%, 6%, 8%, and 10% using a Completely Randomized Design with five treatments and five replications. The extract was prepared using distilled water (simple extraction) and incorporated into PDA medium. Observed parameters included fungal colony area, mycelial dry weight, and mycelial fresh weight. Data were analyzed using analysis of variance (ANOVA), followed by the Least Significant Difference (LSD) test at the 5% significance level. The results indicated that C. manghas fruit extract inhibited the growth of Ganoderma sp. The 6% extract concentration exhibited the highest inhibitory effect, reducing colony area by 15.49%, dry weight by 31.30%, and fresh weight by 30.77%.

Mung bean is Indonesia's important legume crop after soybean and peanut, and it can be grown as a primary crop or an intercrop. The purpose of this study was to compare disease development and yield on mung bean fields grown under a spreading and dibbling cropping system in Kedungwringin Village, Jatilawang District, Banyumas Regency, Central Java. Data was collected from farmers through interviews and weekly disease observation in six mung bean fields. The type of disease, disease incidence, and severity were also determined using data obtained directly from the field. The study discovered five fungi and virus: powdery mildew (Erysiphe sp.), stem rot (Sclerotium rolfsii), leaf rust (Uromyces sp.), leaf spot (Cercospora sp.), and yellow mosaic disease (Begomovirus). The incidence of such diseases was ranging from 1% up to 85%, with the yellow mosaic disease having a very low incidence. There is no significant difference of disease intensity on both system. Leaf spot was the major disease with severity increasing gradually from 11.11% to 43.17%. Several insect pests and predators were discovered in fields. Considering the higher pod production in response to the disease occurrence, the dibble cropping system is recommended as the better mung bean farming strategy.

BackgroundAnoectochilus formosanus Hayata, a valuable medicinal herb. However, its quality and yield are severely compromised by stem rot disease caused by Fusarium oxysporum. Although this disease is commonly controlled with synthetic fungicides, their application poses environmental and health risks. Botanical fungicides, particularly plant extracts, offer safer alternatives.ResultsIn this study, the extracts from Rosmarinus officinalis L. ‘Severn Sea’ and ‘Majorca Pink’ significantly inhibited F. oxysporum growth in vitro and mitigated stem rot symptoms in vivo. In addition, in vivo experiments showed that rosemary EEs increased stem weight and significantly reduced MDA and POD levels in susceptible plants. This is likely through upregulation of cathepsin F, calmodulin, and MAPK gene expression at the mRNA level. ConclusionsThis study confirmed the in vitro antifungal activity of R. officinalis ethanolic extracts (EEs) against F. oxysporum as well as their in vivo immunoregulatory effects in A. formosanus. These findings highlight the potential of R. officinalis EEs for the development of botanical fungicides.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-025-07894-9.

Aloe vera is a perennial evergreen herb belonging to Liliaceae Aloe, which is widely used in beauty, food, healthcare, and medicine (Kumar et al. 2019) and extensively cultivated worldwide due to its enormous commercial value. However, a stem rot disease severely restricts the development of A.vera cultivation in China (Ji et al. 2007). In 2023, the average disease incidence of A.vera Mill. with basal stem rot in Dajie Town, Daming County, Handan City, Hebei Province, was 20％. The disease initially appeared as translucent, water-soaked patches on the epidermis of basal stems. These lesions progressed from light brown to dark brown, with vascular bundles turning brown. Internal tissues softened into a soggy decay and emitted a foul odor. Nine diseased plants showing representative symptoms were collected from three greenhouses. The pathogen was isolated from diseased stems using a tissue separation method. The stem tissues were surface sterilized with 75% ethanol for 30 s, then rinsed three times with sterile distilled water, dried, transferred to potato dextrose agar (PDA) supplemented with 100 μg/ml of streptomycin sulfate, and incubated at 25℃ for 2 days. A total of six isolates with similar morphology on PDA were consistently isolated, and purified by single-spore isolation (Qiu et al. 2011). Colonies showed round, flat surfaces, white downy or powdery mycelium, clear on the reverse side. Hyphae were hyaline, septate and branched microscopically. Arthrospores were hyaline, cylindrical or oval-shaped, ranging in size from 2.5 to 7.2 μm × 0.1 to 6.2 μm (n=50). These morphological features matched those of Geotrichum candidum (Kai et al. 2021). To further confirm the identification, the internal transcribed spacer (ITS) and translation elongation factor 1 -alpha (TEF1-α) regions were amplified and sequenced from two randomly selected isolates (BAI, BAI2) using the primers ITS1/ITS4 (White et al. 1990), EF1-1018/EF1-1620R (Stielow et al. 2015). BLAST analysis revealed that the ITS sequences (PV018630, PV168341) had 100% identity to that of G. candidum and TEF1-α sequences (PV469904, PV469905) had 100% and 99% identity to that of G. candidum. A neighbor-joining phylogenetic tree based on ITS and TEF1-α indicated that BAI and BAI2 clustered with G. candidum (Saitou and Nei, 1987). BAI and BAI2 were deposited in the Life Sciences Experimental and Practical Training Center. For pathogenicity testing, healthy 1.5-year-old A.vera Mill. plants were surface disinfected with 75% ethanol, and then two 2-mm-depth wounds were punctured on each basal stem using a sterilized toothpick. Ten plants were inoculated with 10 μl of a conidial suspension (5 × 10 5 conidia per ml) obtained from 7-day-old PDA cultures and eluted with sterile distilled water (Ding et al. 2015). Ten control plants were inoculated with 10 μl of sterile distilled water. All plants were incubated at 25℃ under a 12/12-h light/dark cycle. After 10 days, all plants inoculated with BAI and BAI2 developed basal stem rot symptoms that were similar to those observed in the greenhouses. While control plants remained healthy, G. candidum was reisolated from the inoculated stems and confirmed by morphological and molecular analysis, fulfilling Koch’s postulates. Tests were repeated with consistent results. To the best of our knowledge, this is the first report of G. candidum causing basal stem rot on A. vera in China. These findings will aid the cultivation of this economically important crop by enabling early diagnosis and targeted control strategies.

Abstract Stem rot disease in citrus is one of the most detrimental diseases in Indonesia. Controlling this disease is difficult because the symptoms only appear when the fungus infection is severe. Currently, disease control is mainly technical and chemical culture with synthetic fungicides. This research aims to obtain the kind of essential oils that have the potential to supress the fungus that causes citrus stem rot disease. Samples of diseased plants were isolated and characterized by morphology and molecular analysis. The study uses three types of essential oils, namely nutmeg, cloves, and lemongrass oil with synthetic fungicide as a comparison. The efficacy of essential oils on inhibiting the growth of fungal colonies was tested by food poisoning technique with concentration of 0 ppm, 50 ppm, 100 ppm, 150 ppm, 200 ppm, 250 ppm, and 300 ppm. Based on molecular analysis, this fungus has a high similarity to Lasiodiplodia theobromae from Mangifera indica (GenBank: MK530065.1) with a similarity level reaching 98%. The study showed that essential oils have the ability to inhibit L. theobromae. Clove oils are known to inhibit the growth of fungal colonies at the concentration 200 ppm. The LC50 value of clove oil against L. theobromae is 149,64 ppm. These findings highlight the efficacy of clove oil as a natural alternative to synthetic fungicides. Therefore, further evaluation under field conditions is required for practical application.

In vitro evaluation of fungicides and chemicals against Fusarium fujikuroi associated with stem rot disease of dragon fruit in Kerala

Basal stem rot (BSR) is a major disease of oil palm. One approach to control the pathogen is by using organic fungicides. This study aims to assess the efficacy of two kinds of fungicides, organosulfur and polyphenol, in suppressing Ganoderma boninense and their impact on seedlings. Poisoned agar media were used in the in vitro assay with organosulfur at concentrations of 0.8% and 0.125%, polyphenol at 1.6% and 0.125%, and two combinations: 0.8% organosulfur + 0.125% polyphenol and 1.6% organosulfur + 0.125% polyphenol (v/v), with a 3-replication test. In vivo trials were conducted on 4-month-old oil palm seedlings inoculated with G. boninense. Two treatments were tested: Combination 1 (0.8% organosulfur + 0.125% polyphenol, v/v) and Combination 2 (1.6% organosulfur + 0.125% polyphenol, v/v). The solution was applied by soil drenching, 200 mL per plant, at the stem base every 14 days, totalling four applications within a 3-month period. The treatments were evaluated under three levels of disease severity: Group 1 (asymptomatic plants with fungal fruiting bodies), Group 2 (leaf necrosis ≤ 50%), and Group 3 (leaf necrosis ≥ 50%). The first result demonstrated a full inhibition of fungal growth in treatments with 1.6% polyphenol and the combination of 1.6% organosulfur + 0.125% polyphenol (v/v). In vivo assay results showed that an increase in resistance (measured by prolonged survival) was observed in Groups 1 and 2. These findings indicate that combining organosulfur and polyphenol fungicides can improve seedling resistance to BSR, particularly at early and moderate disease stages.

Adzuki bean [Vigna angularis (Willd.) Ohwi & H. Ohashi] is a high-value legume crop widely cultivated globally, primarily in Asia, for its nutritional benefits and economic importance. In 2023, an epidemic outbreak of stem rot disease was observed in commercial adzuki bean fields in Shangzhi City, Heilongjiang Province, China. Through tissue isolation and fulfillment of Koch's postulates, nine pathogenic fungal isolates were obtained from diseased stems. Morphological, molecular, and phylogenetic analyses identifiedFusarium graminearumSchwabe andF. oxysporum f. sp.glycinesas the causal agents,representing the first report of these fungi causing stem rot on adzuki bean in China. Pathogenicity testingof nine plant species (seven legumes and two cereals: corn and wheat)revealed thatall tested crops commonly cultivated in Northeast China were susceptible to infection byF. graminearumandF. oxysporum.In vitro screening identified high sensitivity ofF. graminearumto tebuconazole, with 80.0% mycelial growth inhibition at 4.3 × 10⁻⁴ g·mL⁻¹, and high sensitivity ofF. oxysporumto ethylicin, with 82.7% inhibition at 8.0 × 10⁻⁴ g·mL⁻¹. This study provides a comprehensive characterization of the pathogens, defines their host range, and identifies tebuconazole and ethylicin as effective candidates for field control, offering management strategies to protect adzuki bean production in Heilongjiang Province.

Ranunculi ternati Radix is a perennial herb of Ranunculaceae Ranunculus plant Ranunculus ternatus Thunb.. It is the only medicinal plant of the buttercup genus included in the 1977 edition of the Chinese Pharmacopoeia. As an important traditional medicinal plant,Ranunculus ternatus Thunb. is rich in organic acids, sugars, esters, sterols, volatile oils,alkaloids, flavonoids, triterpenoids, total saponins and other components. It is mainly distributed in Guangxi, Taiwan, Jiangsu, Zhejiang, Jiangxi, Hunan, Anhui, Hubei, Henan another provinces in China. In November of 2024, a severe outbreak of Ranunculus ternatus Thunb. soft rot disease occurred in Lichun Town, Pengzhou City, Sichuan Province of China (103°10′-103°40′ E, 30°54′-31°26′ N), causing symptoms such as water-soaked lesions on stems and leaves that turn brown and rot inward. Affected plants gradually wilt, defoliate, emit a foul odor, and eventually die (Figure 1). In a field of 0.8 ha,the disease incidence was 30% . Symptomatic samples were surface sterilized in 75% ethanol for 30 seconds and then in 2% NaClO for 60 seconds. After sterilization, the samples were rinsed three times with sterile water and dried on sterilized filter paper. The samples were then cut into pieces and suspended in sterile water. Finally, the suspension was spread onto culture plates containing nutrient agar medium (NA) and incubated for 2 days at 28 °C in the dark. Representative strain (fy02-1) was convex, circular with smooth margins on NA medium. The bacteria were gram-negative, short straight rods, 0.5 to 0.9 × 1.5 to 3.0 μm, single polar flagellum. The bacterium grew at temperatures up to 42 °C. The purified bacterial strain was inoculated into NA liquid medium and cultured at 28°C for 18-24 h. The bacterial concentration was adjusted to 108 CFU/mL with sterile water, and 20 μL was injected into the stem base of Ranunculus ternatus Thunb., with sterile water as the control. The plants were grown under conditions of 28°C and 70% humidity, and disease symptoms were observed, with the color, size, location, and severity of lesions recorded at different stages of disease development. Symptoms appeared on the second day after inoculation, with initial lesions appearing brown. By the third day, the entire plant had rotted and withered, while the control group showed no symptoms (Figure 2). Pathogenic bacteria was reisolated from the infected plants, confirming Koch’s postulates and the pathogenicity on Ranunculus ternatus Thunb. For bacterial species identification, a single-colony culture was subjected to genomic DNA extraction, gene amplification, and sequencing of 16S rRNA, rpoD, and gyrB. The universal primers 27F/1492R (Lane 1991) were used to amplify the 16S rRNA gene, and the specific primers 70F/70R and UP-1E/APrU (Hwang et al. 2005) were used to amplify the rpoD and gyrB genes, respectively. In the BLAST analysis, the 16S rRNA sequence (GenBank PV926360.1) of the isolate shared 99% similarity (1428/1527 bp) with the Pseudomonas fluorescens strain MFAF76a (KT350501.1), and the rpoD ( PV963828.1) and gyrB (PV963827.1) sequences showed >98% identity to rpoD (695/1260 bp; KT350504.1) and gyrB (657/940 bp; KT350502.1) of the P. fluorescens strain MFAF76a. Based on the multigene phylogeny, the isolated bacterium was identified as P. fluorescens. P. fluorescens has also been shown to cause certain plant diseases, such as stem rot disease on melon (Zhang et al. 2016), bacterial head rot on broccoli (Li et al. 2009), and head rot on Brassica oleracea convar. botrytis var. italica (Catore et al. 2007). As far as we know, this is the first report of P. fluorescens causing Ranunculus ternatus Thunb. soft rot disease in China. Soft rot caused by P. fluorescens may be a threat to Ranunculus ternatus Thunb. cultivation,and this report of its occurrence is the first step in determining potential spread and effective control measures.

ABSTRACTSclerotinia Stem Rot (SSR) disease is one of the most serious diseases affecting the yield and quality of oilseed rape (Brassica napus). Understanding the genetic basis of the resistance trait in oilseed rape to SSR and microbiome composition for enhanced resistance is crucial for developing resistant varieties and sustainably mitigating the impact of the disease. In this study, in a panel of 168 oilseed rape accessions, the most resistant (NGB 13503 and NGB 13834) and susceptible (NGB 13497 and NGB 13897) accessions are identified. A Genome‐wide association study (GWAS) identified 47 SNPs linked to the SSR lesion length, lesion area, and lesion relative to the leaf area. Among the SNPs significantly linked to lesion length were Bn‐A04‐p10555408, Bn‐A07‐p12487549, Bn‐A09‐p4652268, Bn‐A09‐p4916858 and, to our knowledge, these SNPs have not been previously linked to SSR resistance in oilseed rape. Moreover, the study identified 24 SNPs linked with chlorophyll content before SSR inoculation (SPADH), after the SSR inoculation (SPADI), and chlorophyll index (CI). Maintaining the chlorophyll level is correlated with SSR resistance. Furthermore, bacterial taxa (e.g., Pseudomonas, Methylobacterium, and Aquabacterium) and fungal taxa (e.g., Mycosphaerellales, Thelebolales, and Akanthomyces) were enriched in the resistant compared to the susceptible oilseed rape accessions. The SNPs linked to lesion length showed consistent haplotype variation between these selected accessions. Given the absence of complete resistance against SSR, the study provides insights into the significance of maintaining chlorophyll levels and considering microbiome composition for enhancing the level of existing partial resistance to SSR in oilseed rape.