Diseased Plants Research Articles

First report of strawberry root rot caused by Monosporascus eutypoides in China.

Strawberry (Fragaria × ananassa) is an important economic crop in Hebei, China. In May 2023, root rot was observed in strawberry plantations (cultivar 'Benihoppe') in Shijiazhuang (37°57'23″N, 115°16'34″E), Hebei, China. The incidence of the disease reached up to 30% in the field. The infected plants displayed symptoms of reduced vigor and stunted growth, yellowing leaves, blackened roots, and eventual rotting. Ten diseased strawberry plants were collected for pathogen isolation. Root tissues of symptomatic plants were surface sterilized sequentially in 70% ethanol (1 min), 3.125% NaOCl (6 min), and 70% ethanol (30 s), then they were rinsed in sterile water three times (Sahu et al. 2022). The sterilized roots were then cut into 3.0 × 3.0 mm pieces and placed on potato dextrose agar (PDA) medium supplemented with chloramphenicol (100 μg/mL). After 2 to 3 days incubated at 25℃ in darkness, single colonies from the initial isolates were streaked onto PDA agar plates to obtain pure cultures. The fungal colonies appeared milky white on PDA medium and exhibited only hyphae growth. Globose perithecia were observed on V8-juice medium after 30 days of incubation, with black, smooth, spherical ascospores 13.9 to 19.1 μm in diameter (n=50). For molecular analysis, the representative isolates ME10-2 and ME10-3 from different strawberry plants were selected for the amplification of internal transcribed spacer (ITS) and elongation factor 1-alpha (EF-1α) sequences using the primer sets ITS1/ITS4 (Bellemain et al. 2010) and EF1-688F/EF1-1251R (Alves et al. 2008). The sequences were deposited in GenBank (accession no. PP990210 and PP990211 for ITS, and PQ001579 and PQ001580 for EF-1α). BLASTn analysis revealed that the sequences of ITS had above 99% (504/511 bp and 503/506 bp) similarity to Monosporascus eutypoides (MK183805.1), the sequences of EF-1α had 94% (625/661 bp and 619/656 bp) similarity to Monosporascus eutypoides (JQ958959.1). Phylogenetic analysis based on concatenated sequences of ITS and EF-1α using the Maximum Likelihood method with IQ-TREE version 2.2.3 (Nguyen et al. 2015) also indicated that the two isolates clustered with M. eutypoides. To fulfill Koch's postulates, pathogenicity tests were performed (Chen et al. 2024). Due to challenges in ascospore production, an improved wheat grain medium (wheat grain with 2% dextrose) was used for fungal culture (Sainos et al. 2006). After 14 days of inoculation at 25℃, the medium was crushed and mixed into sterilized soil with a 10% ratio by weight. Four-week-old strawberry plants were transplanted into the inoculated soil and grown in a growth chamber at 25℃ (16 h light/8 h dark). Strawberry plants transplanted into sterilized uninoculated soil served as a negative control. Three weeks post-inoculation, the inoculated strawberry plants exhibited symptoms similar to those observed in field-infected, whereas no symptoms were observed on the control plants. The pathogen was reisolated from the symptomatic plants and identified as M. eutypoides based on colony morphology on a PDA plate and ITS sequences information. M. eutypoides has been found to cause Monosporascus root rot and vine decline on muskmelon, watermelon and cucumber (Martyn and Miller 1996; Salem I. B. et al. 2013). To our knowledge, this is the first report of M. eutypoides causing root rot on strawberry. This finding suggests a potential risk of strawberry root rot when planting subsequent to cucurbit crops and assists strawberry growers in the region in adjusting their planting and disease management decisions.

Digital framework for georeferenced multiplatform surveillance of banana wilt using human in the loop AI and YOLO foundation models

Bananas (Musa spp.) are a critical global food crop, providing a primary source of nutrition for millions of people. Traditional methods for disease monitoring and detection are often time-consuming, labor-intensive, and prone to inaccuracies. This study introduces an AI-powered multiplatform georeferenced surveillance system designed to enhance the detection and management of banana wilt diseases. We developed and evaluated several deep learning foundation models, including YOLO-NAS, YOLOv8, YOLOv9, and Faster-RCNN to perform accurate disease detection on both platforms. Our results demonstrate the superior performance of YOLOv9 in detecting healthy, Fusarium Wilt and Xanthomonas Wilt diseased plants in aerial images, achieving high mAP@50, precision and recall metrics ranging from 55 to 86%. In terms of ground level images, we organized the dataset based on disease occurrence in Africa, Latin America, India, Asia and Australia. For this platform, YOLOv8 outperforms the rest and achieves mAP@50, precision and recall between 65 and 99% depending on the plant part and region. Additionally, we incorporated Explainable AI techniques, such as Gradient-weighted Class Activation Mapping, to enhance model transparency and trustworthiness. Human in the Loop Artificial Intelligence was also utilized to enhance the ground level model’s predictions.

Identification of Pratylenchus coffeae as a causal agent of root rot disease in Sorghum bicolor in China

Sorghum (Sorghum bicolor) is an important food and feed crop. Root-lesion nematodes (Pratylenchus spp.) are a group of pathogenic nematodes that cause severe economic losses in various food and cash crops. This study identified diseased sorghum plants with stunted growth and brown, rotting roots in sorghum fields in Shanxi Province, China. A species of root-lesion nematode was isolated by modified Baermann funnel method and named the GL-1 population. Afterward, the GL-1 population of root-lesion nematodes was identified as P. coffeae through a combination of morphological, rDNA-ITS and rDNA-28 S D2-D3 region techniques for molecular biological identification. We also conducted greenhouse experiments to assess the parasitism and pathogenicity of GL-1 and four other P. coffeae populations on sorghum through pot inoculation. At 60 days after inoculation, the results indicated that all five populations of P. coffeae were capable of infecting and causing damage to the sorghum plants. Sorghum is a suitable host for P. coffeae (with a reproduction factor > 1). Moreover, compared with those in the control group, the aboveground fresh weights and root fresh weights of sorghum in the five inoculation groups were significantly lower, and brown spots or even necrotic rot appeared on the roots. All five populations were highly pathogenic to sorghum, but there were significant differences in pathogenicity among the populations. This study provides a scientific basis for identifying and detecting root-lesion nematodes in sorghum.

Utilizing Convolutional Neural Networks for Accurate Detection of Leaf Diseases in Fava Beans

Background: Worldwide, people appreciate the variety of faba beans, also referred to as broad beans. They have many health advantages and are rich in protein and other vital nutrients. One can enhance the immune system, help manage your weight and improve your general well-being by including fava beans in your diet. This crop has been grown in several countries, including northern Europe, the Mediterranean region, central Asia, East Asia and Latin America, in addition to China, Ethiopia and Egypt. It is also grown in India as a minor crop. Many diseases, such as fusarium wilt, ascochyta blight, chocolate spot, bean rust, alternaria leaf blight, powdery mildew and root rot, can affect the production of faba beans and create a global threat. Methods: In this paper, A Sequential Convolutional Neural Network is trained for the detection of diseases present in the leaves of faba bean. Jupiter notebook with Anaconda environment is used for extraction and classification of healthy and diseased plant leaves. The dataset is collected with the help of agriculture experts. Before training and testing, the dataset is preprocessed to enhance the performance of the model. Result: The outcomes achieved after training and testing of datasets show remarkable performance matrices. The overall accuracy of the model is 98.92%. The confusion matrix, precision, recall and F1-score show the effectiveness of the proposed model. This work can be utilized as a reference for the enhancement of faba bean production.

First Report of Phytophthora inundata causing crown rot on Olea europaea (Olive) in Pakistan.

Crown rot impacted olive plants (cv. Koroneiki) in an orchard in Chakwal, Punjab, Pakistan (32° N, 72° E), with a prevalence of 60%. Observable symptoms included leaf chlorosis, defoliation, wilting, and twig dieback in 6-8-year-old plants, ultimately resulting in their demise (Fig. 1 A, B). It was initially observed in June 2020. In September 2020, 48 samples (3 root and 3 crown stem part sample per plant) of diseased olive plants were randomly chosen from the orchard for detailed analysis. Bark pieces from the diseases portion were sectioned into smaller pieces and placed on corn meal agar supplemented with PARP. The culture was maintained at 22°C in the dark. Within 4 days, coenocytic white fluffy mycelium emerged. Hyphae were subsequently transferred to carrot agar medium supplemented with beta-sitosterol. A total of 15 isolates were obtained and characterized, yet a particular two isolates consistently stood out. These isolates did not show sexual reproduction in culture (Ann 1988). Instead, they reproduced asexually through sporangia borne on aerial sporangiophores, originating directly from the internal mycelium. Each branch of the sporangiophore featured a sporangium at its tip, with sporangia varying in shape from pyriform to ellipsoid and being non-papillate and non-caducous (Fig. 2B, C, D). After morphological study, the isolates were identified as Phytophthora species and named BPK-01 and BPK-02. For the molecular identification, we amplified and sequenced their internal transcribed spacer and beta-tubulin regions using universal primer pairs ITS1 and ITS-4, as well as TUB-F and TUB-R primer pairs (Safaiefarahani et al. 2013). Sequences of 816 bp and 940 bp were obtained for the ITS and beta-tubulin regions, respectively. These sequences were deposited in NCBI GenBank, resulting in accession numbers OL423596 and OL423597 for the ITS region of BPK-01 and BPK-02, and OL771190 and OL771191 for the beta-tubulin region of BPK-01 and BPK-02, respectively. BLAST analysis revealed 99.88% identity (816bp out of 837bp) for ITS and 100% (940bp out of 940bp) for TUB between our isolate and P. inundata reference isolates (GenBank Accessions MK326518.1 and EF210202). Phylogenetic analysis using MEGA X software further confirmed the identity of the olive crown rot isolate as P. inundata, aligning it with reference isolates from various Phytophthora species (Fig. 3) (Tamura et al. 2013). The fungal isolates have been officially deposited as living cultures at the Barani Agricultural Research Institute's fungal culture collection center under the designations BAPI.3550 and BAPI.3551. The pathogenicity test involved inoculating isolated strains on 2.5-year-old olive trees. Each isolate was used to inoculate five Koroneiki plants, while five plants served as controls. Inoculation, performed on the stem, included surface disinfection, wounding, and placement of a mycelium plug, with all plants maintained in controlled conditions (25°C, 12h light). After 15 days, symptoms such as leaf chlorosis, collar rot, and stem rot began to appear, and data was recorded up to 45 days. Symptoms were assessed at the conclusion of the experiments using a 0-4 scale, with the following criteria: 0: No symptoms observed (0%), 1: Symptoms present on 1-33% of the plant (1-33% affected), 2: Symptoms present on 34-66% of the plant (34-66% affected), 3: Symptoms present on more than 67% of the plant (more than 67% affected), 4: Complete root death observed (González et al. 2017). Notably, the symptoms induced by strain BPK-02 were more severe than those caused by BPK-01, ultimately resulting in plant wilting and death (Fig. 4)(Santilli et al. 2020). Control plants inoculated with sterile CA plugs remained healthy. Reisolation and morphological identification of P. inundata from diseased tissues fulfilled Koch's postulates. To the best of our knowledge, this is the first report of P. inundata infecting olive plants in Chakwal region of Pakistan, and it is a serious threat to the olive plantation in Pakistan, posing a significant threat to the olive plantations throughout the country.

Toxicity of standing milkvetch infected with Alternaria gansuense in white mice.

Standing milkvetch (Astragalus adsurgens) is widely distributed in the wild in Eurasia and North America and has been bred for cultivated forage in China. Yellow stunt and root rot disease caused by Alternaria gansuense is the primary disease of standing milkvetch. A. gansuense promotes the production of swainsonine in the plant. This study aimed to determine the safety of standing milkvetch that is infected with A. gansuense as forage for animals. Two-week-old specific pathogen-free (SPF) male white mice were fed a commercial mouse feed (CMF), healthy plant feed (HPF) and diseased plant feed (DPF) for 3 or 6 weeks. We observed histological changes in the liver and kidney tissues of the mice and measured their daily feed intake, daily water intake, body weight, feed utilization, organ coefficients, and activities of serum enzymes. The results showed that the daily feed intake of the mice that were fed DPF and HPF was significantly higher (p < 0.05) than those fed CMF at 3 and 6 weeks. The highest increase was observed in the daily water intake of the mice fed HPF (p < 0.05) followed by DPF and CMF. However, the mice fed DPF gained the least weight (p < 0.05). There was a significantly higher percentage of liver weight to body weight of the mice fed DPF (p < 0.05) than those fed HPF for 3 weeks and those fed CMF for 3 and 6 weeks. There were significantly higher levels of concentrations of alanine aminotransferase in the mice fed DPF and HPF than those fed CMF for 3 weeks (p < 0.05) and 6 weeks (p < 0.01). However, there was no significant difference in the mice fed HPF than those fed DPF. There were significantly higher of lactate dehydrogenase concentration (p < 0.001), while the blood urea nitrogen was lower in the mice fed DPF than those fed HPF and CMF at 3 weeks. There was a significantly higher percentage of numbers of lymphocytes in the blood of the mice fed DPF (p < 0.05) than those fed HPF, but the percentages of monocytes and eosinophils were significantly lower. Comparatively, there were more apparent pathological changes in the liver and kidney tissues of the mice fed with DPF than in those fed with HPF. These findings indicate that standing milkvetch was toxic to white mice, and infection with A. gansuense increased its toxicity. Therefore, we conclude that standing milkvetch plants infected by A. gansuense must never be used as animal feed under any circumstances. Additionally, the amount of healthy standing milkvetch fed to animals should be appropriate, avoiding long-term or excessive feeding.

First Report of Bacterial Wilt Caused by Clavibacter michiganensis subsp. michiganensis Affecting Tomato in Iğdır

Tomato wilt disease caused by Clavibacter michiganensis subsp. michiganensis (Cmm) is one of the most destructive tomato diseases and causes significant crop loss in both greenhouse and field tomato production areas worldwide. In this study, the presence of the causal agent of bacterial wilt disease in tomato plants was investigated in Aras Valley. Isolation was made from diseased plant samples and it was determined whether the strains were pathogenic by cellulase activity and HR test. The virulence, morphological and biochemical characteristics of the strains were determined. Strains that fatty acid methyl ester extraction, isolation and purification were performed were identified at species and subspecies level with % similarity index using gas chromatography system. The diagnosis was confirmed with the Biolog Gen III System and all strains were identified at the subspecies level with a % similarity index. As a result of this study, 57 strains were obtained in the isolation, and 39 of the strains were determined not to be pathogenic. Strain 18 was determined as the pathogen causing the most damage to tomato plants with 100 % disease severity. Strains were identified as Cmm at subspecies level with a similarity index of 71-87 % using gas chromatography system and 54-75 % similarity index with Biolog Gen III System. According to the heat map created, it was determined that the strains consisted of two main clusters. The presence of pathogen in Aras Valley was proven for the first time by this study.

Identification of Fusarium species in vegetable greenhouses in Kumluca district, Antalya

Kumluca is an important district where many kinds of vegetables are produced and exported to other countries in Turkey. The main purpose of the current investigation was to diagnose the Fusarium species in different crop plants including tomato, pepper, eggplant, cucumber and melon in Kumluca district, Antalya. A total of 272 samples were gathered from diseased plants in greenhouses. In this work, eight Fusarium species were diagnosed according to morphological characteristics. Considering the pathogenicity test under climate chamber conditions, the disease severity of these species ranged from 48 to 92%. Among these species, Fusarium verticillioides (92%) was the most virulent species in pepper plants.

First report of hop stunt viroid infecting luffa and cantaloupe in Taiwan

Luffa (Luffa cylindrica (L.) M. Roem.) and cantaloupe (Cucumis melo L.) are economically important cucurbitaceous crops in Taiwan. In August 2018, luffa samples displaying leaf chlorosis and deformation were collected in Nantou while cantaloupe samples exhibiting the above suspected systemic viral-like symptoms were collected in Chiayi in October 2019, respectively. Reverse transcription (RT)-PCR tests were conducted to investigate potential viral infections in leaf samples from 12 luffa and nine cantaloupe plants. Total nucleic acids were extracted from symptomatic cucurbit tissues using the taco™ DNA/RNA extraction kit (GeneReach Biotechnology, Taiwan), followed by PCR or RT-PCR tests for virus detection. Seven sets of degenerate primers targeting viral genera reported in local cucurbit crops, including genera Begomovirus, Crinivirus, Cucumovirus, Polerovirus, Potyvirus, Orthotospovirus and Tobamovirus, were utilized. However, all tests yielded negative results. Consequently, degenerate primers targeting genus Pospiviroid or hop stunt viroid (HSVd)-specific primers were employed. Among these tests, only HSVd-specific primers HSVd-RTR_F/R (5’-GGAATTCTCGAGTTGCCGCA-3’/5’-CCGCGGCCCTCTCT-3’) (van Dorst and Peters 1974) successfully amplified DNA fragments of approximately 130 bp from 19 symptomatic samples (12 from luffa and 9 from cantaloupe), while normal leaf samples of luffa and cantaloupe tested negative. Based on known nucleotide sequences, primers were designed to amplify and obtain the full-length 303-nucleotide sequences of the HSVd genome derived from luffa (accession no. OP331278) and cantaloupe (accession no. OP331279). The two sequences exhibit a 98.7% nucleotide identity with each other while exhibiting 99.3% nucleotide identity with a cucumber isolate from Japan (X00524) (Sano et al. 1984) and 98.0% nucleotide identity with another isolate (X07405) from the Netherlands (Puchta et al. 1988). Comparisons with 13 HSVd citrus isolates from Taiwan revealed nucleotide similarities ranging from 96.1% to 99.0%. To confirm pathogenicity, Nicotiana benthamiana was chosen as the experimental isolation host. Mechanical inoculation of N. benthamiana with diluted sap (20 W/V) from diseased plants consistently produced leaf wrinkling and stunting symptoms in 10–60% of inoculated plants by 12 days post-inoculation (DPI). RT-PCR tests confirmed viroid infection. Additionally, luffa seedlings at the cotyledon stage back-inoculated with the purified HSVd luffa isolate developed leaf deformation symptoms 15–25 DPI, and the infection was confirmed by RT-PCR, fulfilling Koch’s postulates. HSVd infections have previously been reported in citrus and grapes in Taiwan (Lin et al. 2015). To our knowledge, this is the first report of HSVd infecting luffa and cantaloupe in Taiwan. The newly identified HSVd cucumber isolates represent a potential threat to cucurbit production and warrant further investigation.

First Report of Root Rot in Aralia elata Caused by Phytophthora cactorum in China

Aralia elata (Miq.) Seem, is an important cash crop in northeastern China. The tender shoots are rich in amino acids, vitamins, and trace elements, and the saponins of leaves and roots have antioxidant and immune-boosting properties. In August of 2023, root rot disease was observed in 4-year-old A. elata plants in Dongzhou County (41.79 °N, 124.11 °E), Liaoning Province, China, with an overall incidence of approximately 40%. While previous studies have described root rot in A. elata caused by Fusarium oxysporum (Zheng et al. 2024), this new root rot showed different symptoms. The leaves of the diseased plants were water-soaked and wilted but not chlorotic. The internal tissue of the roots was disintegrated and soft, while the xylem appeared brown and empty with only the epidermis remaining. Diseased root tissues were sterilized with 75% ethanol for 30 s, treated with 2% sodium hypochlorite for 2 min, and rinsed twice in sterile distilled water. Twelve isolates with similar morphological characteristics were obtained (isolation frequency of 80%), the isolates were plated on PDA medium and incubated at 25℃. Single-zoospore cultures were obtained and transferred to soybean agar medium (SA). After growth on SA for 7 days, the formation of rounded colonies of white aerial mycelia was observed. The sporangia were ovoid or ellipsoid, papillate, terminally borne, with an average length and width of 30.24 (18.35 to 45.39) × 24.16 (14.55 to 37.64) μm. The isolates were homothallic, produced plerotic oogonia with smooth walls with an average diameter of 27.97 (21.06 to 35.90 μm), and yielded one paragynous or anohiginous antheridium, sized 12.21 (10.11 to 14.72) μm × 9.75 (8.39 to 11.31) μm. Based on these morphological characteristics, the isolates were identified as part of the Phytophthora genus (Montealegre et al. 2016). The internal transcribed spacer (ITS) region and cytochrome oxidase subunit Ⅱ (COXⅡ) gene were amplified using the respective primers ITS1/ITS4 and FM66/FM58 (Wiseman et al. 2018). The ITS and COXⅡ sequences were compared with sequences in GenBank, showing 99.83% to 100% sequence identity with Phytophthora cactorum (accession nos. OR347848 and OR351295, respectively). The sequences have been deposited in GenBank with the accession numbers PP479774 (ITS) and PP489221 (COXⅡ). Construction of a maximum-likelihood phylogenetic tree of the identified sequences using MEGA-X indicated that the isolate could be identified as P. cactorum. To confirm pathogenicity, shallow wounds were made in the taproots of 10 one-year-old A. elata and were inoculated with four 9-mm diameter agar plugs from one-week-old oomycete cultures on SA agar per root, and the pathogenicity test was repeated twice. Another 10 wounded plants inoculated with agar plugs without oomycete served as the controls. The plants were planted in flowerpots filled with sterilized forest soil and cultured in a greenhouse at 25℃ with 14 h of light per day. After 20 days, the inoculated plants showed similar symptoms to those initially observed in the field. No symptoms of root rot were observed in the controls. The P. cactorum was re-isolated from the inoculated plants, and identified based on the morphology and ITS and COXⅡ sequence, fulfilling Koch’s postulates. P. cactorum has been reported to cause root rot in A. elata in Korea and Japan (Lee et al. 2005; Uchida et al. 1984). To our knowledge, this is the first report of P. cactorum causing root rot in A. elata in China. P. cactorum is a serious threat to A. elata cultivation, and disease management strategies need to be developed.

MORPHOLOGY, MOLECULAR IDENTIFICATION, PATHOGENICITY AND FIRST REPORT OF FUSARIUM EQUISETI ASSOCIATED WITH ROOT ROT AND WILT DISEASE OF CATHARANTHUS ROSEUS IN BAGHDAD, IRAQ

This study was conducted in the Plant Protection Department-College of Agricultural Engineering Sciences - University of Baghdad for the period 2021-2022 with the aim of isolating and identification the pathogens that cause root rot and wilt disease on the Catharanthus roseus plant in different regions of Baghdad by morphological and molecular methods using PCR technique dependence on the ITS region. The results of sampling collection showed the spread of root rot and wilt disease on C. roseus plant in all the regions covered by the study in Baghdad (Al-Gurayat, Al-Sidiyah, Al-Khadhra, Al-Ghazaliya and Al-Dura) and the incidence rate between 15-85%.The results of isolation and identification showed the presence of 4 types of fungi associated with diseased plant: Fusarium oxysporum, F. solani, F. equiseti and Rhizoctonia solani. All the isolates were differed in their pathogenicity on the dwarf and shrub cultivars of C. roseus, the FeL1 isolate recorded the highest incidence &amp; diseases severity 100 &amp; 65% respectively both cultivars of C. roseus, meaning that there are no significant differences between two cultivars, also the infection intensity of FeL2 isolate was 75% in shrub cultivar, while the control treatment recorded the lowest infection rate and infection intensity reaching 0%. Also, these fungi were diagnosed based on the microscopic and molecular characteristics. The results of the molecular identification showed that the three isolates FeL1, FeL2 and FeL9 belong to the F. equiseti and they showed a conformity ratio of 99.60, 99.39 and 95.97 respectively when compared with the nucleotide sequences of isolates of F. equiseti gene bank of Brazil JQ936262, Ghana OL998428 and China GU586830 respectively. All isolates were recorded in the gene bank and the bank code was given for each isolate. Also, the results confirmed that the sequences belonging to the two isolates (FsL8 and FsL10) gave a conformity ratio of 99.62 and 99.63 respectively when compared with the sequences of KU528858 from Tunis and OM936032 from Pakistan and confirmed their identification as F. solani, while the results of the FoL7 isolation, its identification was confirmed to be related to the F. oxysporum after it showed an conformity ratio of 99.98 with the isolate from China with the number MN96002.

Occurrence and Impact of Papaya Ring Spot Virus in the Marathwada Region of Maharashtra, India

Papaya ring spot virus (PRSV) is a major challenge to global papaya cultivation, including in the Marathwada region of Maharashtra, India. This study aimed to survey the prevalence of PRSV disease across three agroclimatic zones of Marathwada during, 2022. Infected plants exhibited various symptoms on leaves such as vein clearing, chlorosis, mosaic, blistering, leaf curling, puckering and shoestring appearance. Other symptoms such as, ringspots on leaves, fruits and stems, oily streaks on petioles and stems, malformed fruits, stunted growth of plants. Depending on the stage of infection, diseased plants produced few or no fruits. The survey revealed that, an average PRSV incidence ranging from 0.03% to 100%. Further analysis examined the influence of PRSV incidence on papaya cultivar, crop age and agroclimatic zones. Results indicated that older plants were more susceptible to PRSV than younger ones. Among the cultivars studied, the Red Lady cultivar demonstrated high susceptibility to the virus. However, there were no significant differences in the percent disease index (PDI) across the agroclimatic zones. These findings highlight the need for targeted management strategies, including the development of resistant cultivars and region wise disease control measures, to reduce the impact of PRSV on papaya production.

Development of A Novel Multiplex TaqMan Probe qPCR Assay Distinguishing Dikaryotic ITS rDNA Types of Sclerotium rolfsii (=Agroathelia rolfsii) and S. delphinii.

Sclerotium rolfsii (=Agroathelia rolfsii) and S. delphinii are globally ubiquitous and prevalent soil-borne pathogens. These species are distinguishable by the morphology of their sclerotia formed on artificial media. However, this distinction requires prior pure isolation, complicating direct identification from diseased plants or soil samples. Additionally, each species contains two distinct ITS ribosomal DNA types in a dikaryotic cell, further complicating their identification through sequence analysis. To address this issue, we developed a novel multiplex qPCR method utilizing TaqMan probes and primers. This method specifically targets the two ITS types unique to each species, effectively distinguishing between these pathogens and differentiating them from non-target soil-borne fungal and oomycete pathogens. Its efficiency and sensitivity were confirmed through their detections in artificially inoculated plants and soil samples. Our multiplex qPCR technique offers a precise and reliable approach for the simultaneous detection and differentiation of S. rolfsii and S. delphinii, significantly improving disease surveillance and facilitating timely, effective disease management.

Mycovirome of Diaporthe helianthi and D. gulyae, causal agents of Phomopsis stem canker of sunflower (Helianthus annuus L.).

Diaporthe gulyae and D. helianthi cause Phomopsis stem canker, which is a yield-limiting fungal disease of sunflower (Helianthus annuus L.) in the United States. In this study, the mycovirus population was characterized in D. gulyae and D. helianthi using 52 and 42 isolates, respectively, that were recovered from diseased sunflower plants randomly sampled from commercial sunflower fields in the U.S. states of Minnesota, Nebraska, North Dakota, and South Dakota. Total RNA extracts depleted of rRNA from each fungus were pooled to construct one library for sequencing to obtain 20 GB per library of raw reads using a metatranscriptomics approach. Only the family Mitoviridae was present in both Diaporthe species. Twelve and nine novel viral contigs were discovered infecting D. gulyae and D. helianthi, respectively. Additionally, we detected two of the same viruses infecting D. helianthi, Helianthus annuus leaf-associated partitivirus 3 and 5, that were detected in a direct sunflower metatranscriptome reported before. Interestingly, Qinvirus, which is mostly known as a group of insect viruses, was found in a contig. An ambivirus that is rarely reported in the phylum Ascomycota was also discovered in this study. Besides an understanding of virome diversity, the mycovirome survey provides the first clue of biological molecules that can be further developed for antifungal purposes.

First Report of Root Rot of Tobacco Caused by Fusarium concentricum in China.

Tobacco Fusarium root rot is caused by various Fusarium species, with eleven species reported, among which F. oxysporum and F. solani are main responsible in China (Yang et al., 2024). Notably, Fusarium concentricum has not been previously reported until now at a global level in tobacco. In June 2022, tobacco (Nicotiana tabacum L.) root rot symptoms were observed in tobacco fields (approximately 1500 m2) in Xuanen County, Enshi City, Hubei Province (29.99°N, 109.44°E). About 20% of tobacco plants showed symptoms including dwarfing of plants, chlorosis in the lower leaves and black roots or root rot, and some plants had died. The roots of twenty diseased tobacco plants were randomly collected from this field and subjected to surface sterilization with 75% ethanol for 5 min and 1% sodium hypochlorite for 5 min, followed by rinsing with sterile distilled water. The roots were then cut into small pieces (around 0.5 cm), placed onto potato dextrose agar (PDA) medium, and incubated at 28℃ in darkness for 3 to 5 days. Three representative isolates 40-LD, 41-LD and 42-LD with typical Fusarium spp. characters were obtained using single-spore purification method (Xiao et al. 2023). After 4 days of culture at 28°C on PDA, the colonies were circular, and by the next day, they began to produce red pigment. On the seventh day, the pigment turned purple, and the mycelium appeared cottony and wool-like. On PDA, microconidia were obovate to fusoid, with the size of 4.6 to 8.7×1.6 to 2.9 μm (n=50), 0 or 1 septate. Macroconidia observed on synthetic low nutrient medium (SNA) were falcate, with the size of 13.6 to 41.7×2.9to 4.8 μm (n=50), 3 to 5 septa. The morphological characteristics of the fungi were consistent with the description of Fusarium species(Liu et al. 1998). The internal transcribed spacer region (ITS) of rDNA, the elongation factor 1α (TEF-1α), and RNA polymerase II second largest subunit (RPB2) of the isolates were amplified using primers ITS1/ITS4(Kim and Choi 2020), EF-1H/EF-2T (Wang et al. 2013) and RPB2-5F/RPB2-7CR(Qiu et al. 2023). The obtained ITS (PQ056894), TEF-1α (PQ118393), and RPB2 (PQ329359) sequences showed 99.6% (490/514 bp), 99.7% (667/667 bp), and 100% (940/940 bp) similarity to F. concentricum NFMJ-1 (GenBank accession nos. ON184033, ON212051 and ON212052, respectively)(Xiao et al. 2023). A maximum likelihood phylogenetic tree, constructed by concatenating ITS, TEF1-α and RPB2 sequences using ACOPTools v2 software, showed the three isolates and F. concentricum were clustered into one branch. Pathogenicity was assessed by coculturing potted tobacco plants with 42-LD-infected wheat grains (Shen et al. 2023). Strain 42-LD was inoculated onto sterilized wheat grains and cultured at 28℃ for 7 days. Subsequently, the roots of ten healthy seedlings of Yunyan 87 at the 4-leaf stage were wounded with sterile scissors and then transplanted into sterile soil containing 30 wheat grains infected with 42-LD. In contrast, the wheat grains without 42-LD inoculation were used as controls. All seedlings were placed in a greenhouse at 25°C with 16 h of light and 8 h of darkness. Seven days later, all seedlings inoculated with 42-LD showed symptoms of yellowing and wilting of leaves, blackening of roots, and slow plant growth, while control plants showed no symptoms. The pathogenicity test was repeated three times. The pathogens reisolated from the root and stem of the infected plants were morphologically and molecularly identified as F. concentricum. This is the first report on F. concentricum inducing tobacco root rot in China. This finding implies that F. concentricum may pose a potential threat to tobacco production and thus reduce the income of tobacco farmers. Consequently, it is essential to develop appropriate prevention and control measures for this pathogen to ensure the sustainability of cultivation in our region.

Interaction of Meloidogyne incognita and Pseudomonas syringae pv. aptata in different types of soil on plant growth, photosynthetic pigments and proline contents of beetroot (Beta vulgaris L.).

Effect of Meloidogyne incognita and Pseudomonas syringae pv. aptata (Psa) was observed singly, together and pre and post inoculations in 4 soil types on plant growth, parameters, chlorophyll, carotenoid and proline contents of beetroot (Beta vulgaris L). Plant growth, chlorophyll and carotenoid contents were greater in loam soil followed by 20% fly ash soil, 10% fly ash plus 10% sand amended soil and least in 20 % sand mix soil. However, proline contents were high in 20% sand mix soil and least in loam soil. Plant growth (root dry weight), chlorophyll and carotenoid contents were reduced in plants inoculated with any test pathogen while proline contents were increased in plants inoculated with pathogens under study. Inoculation of both pathogens together caused a greater reduction of plant growth, chlorophyll and carotenoid contents than their individual inoculation. Inoculation of M. incognita 20 days prior to Psa resulted in greatest reduction in plant growth, chlorophyll and carotenoid and maximum proline contents. Inoculation of Psa with M. incognita reduced galling and nematode multiplication while prior inoculation of Psa caused maximum reduction in galling and nematode multiplication. Galling and nematode multiplication was high in 20% sand mix soil followed by loam soil and least in 20% fly ash amended soil. Bacterial leaf spot indices by Psa was 3 when alone. Disease indices were 5 when Psa was inoculated with M. incognita. Prior inoculation of M. incognita predisposed beetroots to Psa and aggravates the disease. Influence of M. incognita, Psa and their interactions in different soil types on various studied parameters in diseased plants was demonstrated by Principal component analysis.

First Report of Rust Caused by Cerotelium fici on Ficus carica L. in Korea.

Fig (Ficus carica L.) belonging to the Moraceae family is cultivated worldwide, with its primary production areas located in the Mediterranean region (Tous and Fergusen 1996). Yeongam-gun is a significant region for fig cultivation in Korea, accounting for 42% of the country's total fig cultivation area with approximately 1,400 fields (453ha, production yield 6000 tons). In July to November 2023, we observed severe rust disease in four fig orchards in Yeongam-gun (34°42'52.2"N, 126°31'32.16"E). The disease had affected 70% of the fig cultivation area (cv. Masui Dauphine). The area of each field is approximately 0.33~0.66ha, and 5 samples were collected from each field. Pustules of the pathogen were found in all samples. The diseased plants were deposited in the herbarium of the National Institute of Agricultural Sciences, Wanju, Korea (Specimen No. Cero_001). The initial symptoms were observed as chlorotic spots on the adaxial surface of the leaves, which developed into necrotic areas surrounded by chlorotic halos. Over time, dark brown spots were observed on the adaxial surface of the leaves, and abundant reddish-brown pustules were visible on the abaxial surface. Almost all leaves with these symptoms fell prematurely. Microscopic observation revealed that the urediniospores (n>50) were ellipsoidal, globose, obovoidal, or angular in shape, yellowish to faintly orange in color, sized 19.5-39.9 × 10.1-27.5 μm and had a wall thickness of 0.6-1.5 μm (average 1 μm). Telia were not observed. These morphological characteristics were comparable with that of Cerotelium fici (Gardner, 1997; Latinovic et al., 2015). For molecular analysis, genomic DNA was extracted from 3 to 5 samples, and the internal transcribed spacer region 2 (ITS2) and the large subunit (LSU) were amplified and sequenced using primer set: Rust2inv (Aime, 2006) and LR6 (Vilgalys and Hester, 1990). Furthermore, approximately 660 bp of the cytochrome c oxidase subunit III (COX3) gene was amplified and sequenced with CO3_F1 and CO3_R1 primers (Vialle et al., 2009). The obtained sequences were deposited in NCBI GenBank (GenBank accession no. PP491072 to PP491074 and PP491079 to PP491081). Phylogenetic tree analysis using the maximum likelihood method identified the isolate as Cerotelium fici. Pathogenicity test was conducted either by placing or by rubbing symptomatic leaf pieces on healthy leaves (5 leaves/plant) of three-year-olds fig plants (cv. Masui Dauphine) in a greenhouse in Wanju-gun, Jeonbuk special self-governing province. Healthy and symptom free leaf pieces were used for control. Two plants per treatment were used and the experiment repeated twice. The typical symptoms of fig rust disease were observed two weeks after inoculation in both methods. Control leaves were symptomless. C. fici was successfully reidentified from symptomatic tissues of inoculated leaves, fulfilling Koch's postulates and confirmed as a causal agent of fig rust. Fig rust caused by C. fici has been reported in New Zealand, Montenegro, Hawaii and other tropical regions (McKenzie, 1986). To our knowledge, this is the first report of fig rust in Korea caused by Cerotelium fici. It is believed that this will be helpful in research on the management of fig rust disease.

Advancements in Plant Protection Technologies and Mechanization in the Russian Federation

The paper highlights the achievements of domestic scientists, engineers and designers in pesticide application in agriculture. (Research purpose) The study provides a retrospective analysis of the evolution of plant protection technologies and mechanization tools in the Russian Federation. (Materials and methods) The research draws on a variety of sources, including publications in scientific journals, monographs, conference proceedings, archival photographs, and exhibits from the scientific and methodological office (museum) of the All-Russian Research Institute for Plant Protection. (Results and discussion) The paper details the development of domestic horse-drawn, mounted tractor, automobile field and portal garden sprayers in 1931-1941. In the 1960s, research focused on determining the optimal droplet size and phytocidal action radius for low-volume spraying of plant protection products. Aerosol technologies were developed. The paper highlights the contribution of Dr.Sc. V.F. Dunsky in establishing the theoretical foundations of fine-droplet and low-volume spraying physics and technology. It also emphasizes the development and enhancement of plant protection technologies by creating a comprehensive system of machines for agricultural mechanization. This progress was achieved under the scientific and methodological guidance of experts from the All-Russian Institute of Agricultural Mechanization. As the consumption rates of the working fluid decreased, rotary (disk) sprayers became essential for both ground and aerial spraying equipment. To enhance environmental safety, more eco-friendly sprayers were developed with systems for small droplet separation or forced sedimentation, and a method for electrically charging droplets was introduced. Modern approaches to the development of new plant protection technologies are based on the principles of precision farming. These approaches include differentiated crop treatment that considers the spatial heterogeneity in the distribution of harmful organisms within field areas. (Conclusions) Plant protection technologies and mechanization tools evolved and improved with the introduction of new chemical agents. Notably, spectrometry is used to create spectral image libraries of cultivated and weedy, healthy and diseased plants, facilitating the automatic decoding of data collected from field through neural networks (artificial intelligence). Additionally, unmanned aerial vehicles are utilized for the application of plant protection products.

Identification of Leaf Diseases from Figs Using Deep Learning Methods

Early detection of plant diseases is of great importance for agricultural production and plant health. Early detection is important to prevent the spread of diseases and reduce agricultural losses. The aim of this study is to use artificial intelligence technologies for the early detection of diseased fig plants and reduce agricultural losses. The fig leaf dataset used in the study has two classes: healthy and diseased leaves. There are a total of 2321 images in the dataset. Among these images, there are 1350 images representing diseased leaves and 971 images representing healthy leaves. The dataset is divided into 80% training data and 20% test data. DarkNet-19, ResNet50, VGG-19, VGG-16, ShuffleNet, GoogLeNet, MobileNet-v2, EfficientNet-b0, and DarkNet-53 algorithms were used to analyze the fig leaves dataset using a MATLAB graphical user interface (GUI). The classification accuracy values of each algorithm are as follows: DarkNet-19 90.3%, ResNet50 90.95%, VGG-19 93.32%, VGG-16 92.89%, ShuffleNet 89.44%, GoogLeNet 87.5%, MobileNet-v2 87.5%, EfficientNet-b0 85.56%, and DarkNet53 91.59%. These results evaluate the usability and performance of different algorithms for the early detection of plant diseases. The research emphasizes the importance of the effective use of artificial intelligence technologies in the agricultural industry.

Evaluating the biocontrol efficacy of beneficial soil microbes against the Fusarium wilt disease of tomato

Tomato is one of the most important agricultural crops in the world as it is a rich source of vitamins A and C. The quality and the quantity of tomato fruits is severely affected by the fungal plant pathogens. Fungal diseases are among the most dangerous biological stresses that cause severe damage to tomato crops in many countries. Fusarium wilt disease in tomato caused by Fusarium oxysporum f. sp. lycopersici, become a major concern of yield loss worldwide. This study evaluated the efficacy of multiple antagonistic biocontrol agents, including Trichoderma species and non-pathogenic F. oxysporum, in mitigating Fusarium wilt. Pathogenic F. oxysporum strains were isolated from diseased tomato plants, while biocontrol agents were cultured from rhizosphere soil of healthy tomato plants. In vitro dual-culture assays demonstrated that non-pathogenic F. oxysporum inhibited pathogenic strains by 86.8% (±4.8) at 7 days post-inoculation (dpi), significantly higher than T. harzianum, which achieved 62.8% (±6.2) inhibition (p &lt; 0.01). Other Trichoderma strains, such as T. viride and T. asperellum, showed moderate inhibition levels of 54.3% (±2.3) and 51.9% (±5.9), respectively. Greenhouse pot trials reinforced these in vitro results, with non-pathogenic F. oxysporum achieving a significant disease reduction of 77.0% (±3.0) in Fusarium wilt incidence, followed by T. harzianum at 64.8% (±2.7) (p &lt; 0.01). Statistically significant improvements in plant growth were also recorded in treated plants. T. harzianum increased shoot length by 25.6% (±3.1) and root weight by 22.4% (±2.9) compared to control plants, while non-pathogenic Fusarium enhanced root length by 30.2% (±3.4) and overall biomass by 28.7% (±3.8) (p &lt; 0.01). Data were analyzed using ANOVA, followed by LSD for pairwise comparisons, confirming the efficacy of these biocontrol agents in reducing disease incidence and promoting plant growth. These findings underscore the potential of antagonistic biocontrol agents as viable, sustainable alternatives to chemical fungicides for managing Fusarium wilt in tomato production systems, supporting both plant health and environmental resilience.