Int J Syst Evol Microbiol
December 2024
Six strains isolated from muskmelon and watermelon seedlings affected by stem rot and wilting in Serbia were reported as based on pathogenicity, LOPAT and cell wall fatty acid analyses. Recent bacterial isolates from cucurbit crops displaying -like symptoms in Alabama, USA, were identified as , prompting polyphasic re-evaluation of the Serbian strains. All six strains were found to cause severe disease in watermelon and squash seedlings under greenhouse conditions.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
December 2024
Three fluorescent bacterial strains, K1, K13 and K18, were obtained from watermelon () foliage symptomatic of bacterial leaf spot of cucurbits in Florida. The strains underwent phenotypic characterization, including LOPAT (levan production, oxidase activity, pectolytic activity on potato, arginine dihydrolase production and hypersensitive response (HR) on both tobacco and tomato) and pathogenicity testing on watermelon and squash seedlings. Whole-genome sequencing of the isolates was performed, and multi-locus sequence analysis (MLSA) utilizing housekeeping genes , , and placed the isolates into two distinct clades within the genus.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
August 2024
In Florida, angular leaf spot, caused by , was the only known bacterial disease in strawberry, which is sporadic and affects the foliage and calyx. However, from the 2019-2020 to 2023-2024 Florida strawberry seasons, unusual bacterial-like symptoms were observed in commercial farms, with reports of up to 30 % disease incidence. Typical lesions were water-soaked and angular in early stages that later became necrotic with a circular-ellipsoidal purple halo, and consistently yielded colonies resembling on culture media.
View Article and Find Full Text PDFWhiteflies () are a significant pest of cucurbits and vector many viruses, leading to substantial economic losses. Modern diagnostic tools offer the potential for early detection of viruses in the whiteflies before crop production. One such tool is the multiplex reverse transcriptase quantitative PCR (RT-qPCR) probe-based technique, which can detect multiple targets in a single reaction and simultaneously quantify the levels of each target, with a detection limit of 100 copies per target.
View Article and Find Full Text PDFBacterial spot caused by spp. is an economically important disease of pepper causing significant yield losses in Taiwan. Monitoring the pathogen population on a continuous basis is necessary for developing disease management strategies.
View Article and Find Full Text PDFThe widespread presence of tolerance to copper in species has resulted in the need to develop alternative approaches to control plant diseases caused by xanthomonads. In recent years, nanotechnological approaches have resulted in the identification of novel materials to control plant pathogens. With many metal-based nanomaterials having shown promise for disease control, an important question relates to the mode of action of these new materials.
View Article and Find Full Text PDFPlant disease classification is quite complex and, in most cases, requires trained plant pathologists and sophisticated labs to accurately determine the cause. Our group for the first time used microscopic images (×30) of tomato plant diseases, for which representative plant samples were diagnostically validated to classify disease symptoms using non-coding deep learning platforms (NCDL). The mean F1 scores (SD) of the NCDL platforms were 98.
View Article and Find Full Text PDFBacterial spot of tomato (BST), predominantly caused by () in Florida, is one of the most devastating diseases in hot, humid environments. Bacterial resistance to copper-based bactericides and antibiotics makes disease management extremely challenging. This necessitates alternative new solutions to manage the disease.
View Article and Find Full Text PDFBacterial leaf spot of cucurbits (BLS) is an emerging disease in the southeastern United States that is capable of causing widespread outbreaks under conducive conditions. Historically attributed solely to the bacterium pv. , recent studies have identified additional pathovars as causal agents of the disease.
View Article and Find Full Text PDFspp. infect a wide range of annual and perennial plants. Bacterial blight in young seedlings of spp.
View Article and Find Full Text PDFBegomoviruses and criniviruses, vectored by whiteflies (Bemisia tabaci), are important threats to crops worldwide. In recent years, the spread of cucurbit leaf crumple virus (CuLCrV), cucurbit yellow stunting disorder virus (CYSDV) and cucurbit chlorotic yellows virus (CCYV) on cucurbit crops has been reported to cause devastating crop losses in many regions of the world. In this study, a multiplex recombinase polymerase amplification (RPA) assay, an isothermal technique for rapid and simultaneous detection of DNA and RNA viruses CuLCrV, CYSDV and CCYV was developed.
View Article and Find Full Text PDFBacteriophages are biocontrol agents used to manage bacterial diseases. They have long been used against plant pathogenic bacteria; however, several factors impede their use as a reliable disease management strategy. Short-lived persistence on plant surfaces under field conditions results mainly from rapid degradation by exposure to ultraviolet (UV) light.
View Article and Find Full Text PDFBacterial spot of tomato is among the most economically relevant diseases affecting tomato plants globally. In previous studies, non-formulated magnesium oxide nanoparticles (nano-MgOs) significantly reduced the disease severity in greenhouse and field conditions. However, the aggregation of nano-MgO in liquid suspension makes it challenging to use in field applications.
View Article and Find Full Text PDFStraightneck squash (Cucurbita pepo var. recticollis) is an important cucurbit crop in Florida. In early fall 2022, straightneck squash showing severe virus-like symptoms of yellowing, mild leaf crinkling (Supplementary Figure 1), unusual mosaic patterns and deformation on the surface of the fruit (Supplementary Figure 2), were observed in a ~15-ha straightneck squash field in Northwest FL with a disease incidence of ~ 30%.
View Article and Find Full Text PDFThe pathogen that causes stem gall in was first identified in Florida and Alabama in 2018 and named pv. . We report the genome sequence of the pathotype strain of this pathogen, pv.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
November 2022
Five bacterial strains were isolated from symptomatic leaves of , sp. and sp. in California.
View Article and Find Full Text PDFBacterial diseases are a constant threat to crop production globally. Current management strategies rely on an array of tactics, including improved cultural practices; application of bactericides, plant activators, and biocontrol agents; and use of resistant varieties when available. However, effective management remains a challenge, as the longevity of deployed tactics is threatened by constantly changing bacterial populations.
View Article and Find Full Text PDFKeifer (Acari: Eriophyidae) is the vector of rose rosette virus (RRV), which causes rose rosette disease (RRD) in North America. The RRD symptoms, such as witches' broom, flower, and leaf deformation, disrupt the aesthetic appearance of plants and cause plant mortality. Because there is no cure for RRV, it is critical to manage the vector and reduce the spread of the virus.
View Article and Find Full Text PDFRose rosette disease (RRD) caused by rose rosette emaravirus (RRV) is a major issue in the U.S. rose industry with no effective method for its management.
View Article and Find Full Text PDFDisease Symptoms: Symptoms include water-soaked areas surrounded by chlorosis turning into necrotic spots on all aerial parts of plants. On tomato fruits, small, water-soaked, or slightly raised pale-green spots with greenish-white halos are formed, ultimately becoming dark brown and slightly sunken with a scabby or wart-like surface.
Host Range: Main and economically important hosts include different types of tomatoes and peppers.
Copper (Cu) is the most extensively used bactericide worldwide in many agricultural production systems. However, intensive application of Cu bactericide have increased the selection pressure toward Cu-tolerant pathogens, including , the causal agent of tomato bacterial spot. However, alternatives for Cu bactericides are limited and have many drawbacks including plant damage and inconsistent effectiveness under field conditions.
View Article and Find Full Text PDFFusarium wilt of watermelon (Citrullus lanatus) caused by Fusarium oxysporum f. sp. niveum (Fon), has become an increasing concern of farmers in the southeastern USA, especially in Florida.
View Article and Find Full Text PDFThe development of bacterial tolerance against pesticides poses a serious threat to the sustainability of food production. Widespread use of copper (Cu)-based products for plant disease management has led to the emergence of copper-tolerant pathogens such as () strains in Florida, which is very destructive to the tomato () industry. In this study, we report a hybrid nanoparticle (NP)-based system, coined Locally Systemic Pesticide (LSP), which has been designed for improved efficacy compared to conventional Cu-based bactericides against Cu-tolerant .
View Article and Find Full Text PDFTomato (Solanum lycopersicum), pepper (Capsicum annum), and gboma (Solanum macrocarpon) are major vegetables in Togo, with many people depending on these crops for their livelihood. In December 2018, during the dry season with temperatures between 21°C to 35°C, tomato ('Petomech'), pepper ('Gboyebesse') and gboma (local landrace) showing wilt symptoms without foliar yellowing were collected from two locations, Tchouloum and CECO-AGRO sites in the Sotouboua Prefecture of Togo, ~300 km from the capital city of Lome. Disease incidence ranged between 10% to 50% in multiple fields.
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