While BYDV-PAV is a prevalent wheat virus (as described by Chay et al., 1996), BWYV has not been observed to infect wheat. The polerovirus BWYV, transmitted by aphids, possesses a broad host range, encompassing more than 150 plant species from 23 dicotyledonous families, including Beta vulgaris, Spinacia oleracea, Lactuca sativa, and Brassica oleracea var. The study of italica, according to Duffus (1964, 1973), Russell (1965), and Beuve et al. (2008), merits further attention. The scientific literature (Zheng et al., 2018) detailed that a monocotyledonous plant, Crocus sativus (Iridaceae), was identified as a host for BWYV. Our research suggests this is the first time BWYV has been noted in wheat or any other grass species. The results demonstrate a possible hazard of BWYV to cereal crops planted in the field.
Stevia rebaudiana Bertoni, a medicinal crop of global significance, is widely grown. Within the stevia plant's leaves, stevioside, a non-caloric sweetener, is employed in place of artificial sweeteners as a substitute. In August 2022, symptoms of chlorosis, wilting, and root rot were observed in about 30 % of stevia plants growing at the Agricultural Station at Yuma Agricultural Center, Yuma, AZ, USA (327125 N, 1147067 W). Initially showing chlorosis and wilting, the infected plants ultimately succumbed, leaving their foliage intact on the plant. In cross-sections of affected stevia plant crowns, necrotic tissue and a dark brown discoloration were evident within the vascular and cortical regions. Dark brown microsclerotia were detected on the infected plant's stem bases, where necrotic roots were also present. Samples of five symptomatic plants were taken to isolate the causative pathogen. To disinfect root and crown tissues, measuring 0.5 to 1 cm, a 1% sodium hypochlorite solution was used for 2 minutes. Three sterile water rinses followed, before the disinfected samples were placed on potato dextrose agar (PDA). At 28°C, under a 12-hour photoperiod, all five isolates exhibited swift mycelial growth on PDA. The mycelia, starting as hyaline, changed from a gray tone to black seven days later. Following 3 days of incubation on PDA, substantial masses of dark microsclerotia, ranging from spherical to oblong shapes, were evident, having an average dimension of 75 micrometers in width and 114 micrometers in length (n=30). For the purpose of molecular identification, genomic DNA was extracted from the representative isolate Yuma's mycelia and microsclerotia using the DNeasy Plant Pro kit (Qiagen, Hilden, Germany). Primer sets ITS1/ITS4 (White et al., 1990), EF1-728F/EF1-986R (Carbone and Kohn, 1999), MpCalF/MpCalR (Santos et al., 2020), and T1/T22 (O'Donnell and Cigelink, 1997), respectively, were used to amplify the internal transcribed spacer (ITS), translation elongation factor-1 (TEF-1), calmodulin (CAL), and -tubulin (-TUB) regions. Comparative BLAST analysis of the sequences indicated 987 to 100 percent identity with Macrophomina phaseolina sequences, including MK757624, KT261797, MK447823, and MK447918. Molecular and morphological characteristics pointed to the fungus being M. phaseolina (Holliday and Punithaligam 1970). Among the submitted sequences, those associated with GenBank accession numbers OP599770 (ITS), OP690156 (TEF-1), OP612814 (CAL), and OP690157 (-TUB) were included. An investigation into pathogenicity was conducted on 9-week-old stevia plants (varieties unspecified). Planters, 4 inches in size, held the SW2267 specimens grown within the greenhouse. A 14-day-old culture of M. phaseolina, cultivated in potato dextrose broth (250 ml flasks) at a temperature of 28 degrees Celsius, was used to prepare the inoculum. The fungus's mycelial mats were combined with 250 milliliters of sterile distilled water, then strained through four layers of cheesecloth before being adjusted to a concentration of 105 microsclerotia per milliliter using a hemocytometer. Using 50 ml of inoculum per pot, twenty healthy plants were inoculated via soil drenching. viral immune response Five non-inoculated control plants underwent a soil drenching treatment using sterile distilled water. selleck At 28.3°C and with a 12-hour photoperiod, the greenhouse housed the plants. Twenty inoculated plants showed necrosis at the base of their petioles, along with leaf chlorosis and wilting, after six weeks, in stark contrast to the five un-inoculated control plants, which remained healthy throughout the trial. M. phaseolina was identified through reisolation of the fungus, utilizing morphological characteristics and DNA sequences from the ITS, TEF-1, CAL, and TUB regions. Biokinetic model North Carolina, USA, has previously seen reports of M. phaseolina on stevia (Koehler and Shew 2018), unlike the present report which constitutes the initial discovery of this organism in Arizona, USA. Future stevia production in Arizona, USA, could be negatively impacted by M. phaseolina's preference for warm soil conditions, as reported by Zveibil et al. (2011).
The initial report of tomato mottled mosaic virus (ToMMV) in tomatoes, from Mexico, was published by Li et al. (2013). This positive-sense, single-stranded RNA virus is classified within the Virgaviridae family, specifically under the genus Tobamovirus. A viral genome, containing approximately 6400 nucleotides, generates the production of four proteins, namely the 126 K protein, the 183 K protein, the movement protein (MP) and the coat protein (CP). Tu et al. (2021) report this finding. Solanaceous produce is at high risk for ToMMV-related harm. The virus infection in tomato plants manifests as stunted growth, top necrosis, and mottled, shrunken, necrotic leaves. A corresponding substantial reduction in tomato fruit yield and quality is observed, as documented by Li et al. (2017) and Tu et al. (2021). A perennial climbing herb, the Chinese snake gourd (Trichosanthes kirilowii Maxim) of the Cucurbitaceae family, makes use of its fruit, seeds, peel, and root in traditional Chinese medicine. From a Fengyang, Anhui Province nursery, twenty-seven asymptomatic seedlings, derived from tissue culture plantlets, were randomly selected in the month of May, 2021. Using degenerate tobamovirus primers Tob-Uni1 (5'-ATTTAAGTGGASGGAAAAVCACT-3') and Tob-Uni2 (5'-GTYGTTGATGAGTTCRTGGA-3'), RT-PCR was executed on total RNA extracted from each sample, according to the method outlined by Letschert et al. (2002). Following amplification, six out of twenty-seven samples produced amplicons of the expected size, which were then sequenced. Analysis of aligned nucleotide sequences across all ToMMV isolates in the NCBI GenBank repository showed a range of nucleotide sequence identities from 98.7% to 100%. The amplification of the ToMMV coat protein (CP) gene was conducted using primers CP-F (5'-ATGTCTTACGCTATTACTTCTCCG-3') and CP-R (5'-TTAGGACGCTGGCGCAGAAG-3'). Having been obtained, the sequence of the CP fragment was determined. Analysis of sequence alignments pointed to a distinctive CP sequence in isolate FY, which is further identified through its GenBank accession number. There was a 100% identical genetic match between the ON924176 sequence and the ToMMV isolate LN (MN8535921). S.L. prepared the anti-ToMMV polyclonal antibody (PAb) by immunizing a rabbit with purified Nicotiana benthamiana virus. Subsequently, serological tests (dot-enzyme linked immunosorbent assay, Dot-ELISA) of RNA-positive T. kirilowii leaf samples using the anti-ToMMV PAb proved positive. Using a pure culture of ToMMV derived from an infectious cDNA clone in N. benthamiana (Tu et al., 2021), Koch's postulates were fulfilled. Healthy T. kirilowii plants were then mechanically inoculated with the prepared inoculum from the infected N. benthamiana, employing the protocol previously described by Sui et al. (2017). Symptomatic T. kirilowii seedlings, presenting chlorosis at 10 days and leaf tip necrosis at 20 days post-inoculation, had their ToMMV infection confirmed using RT-PCR analysis, employing the primers CP-F and CP-R. These experimental results indicate T. kirilowii's role as a host for ToMMV in natural environments, which could compromise the production of this medicinal plant. While the seedlings from the nursery seemed healthy, chlorosis and necrosis became evident in the plants after inoculation in a controlled indoor environment. Using qRT-PCR, the viral accumulation in greenhouse-inoculated plants was found to be 256 times greater than that in field-collected plants. This difference likely accounts for the variation in symptom expressions observed in the two groups. Recent findings, published by Li et al. (2014), Ambros et al. (2017), and Zhang et al. (2022), indicate ToMMV presence in solanaceous (tomato, pepper, and eggplant) and leguminous (pea) crops within the field. Our findings suggest this is the first documented case of a naturally acquired ToMMV infection in T. kirilowii, and its natural infection within Cucurbitaceae botanical specimens.
Cultivating safflower is of immense socioeconomic importance on a global scale. To extract oil, the production of the seeds is planned. The SIAP (2021) report shows Mexico holding the fifth position in global agricultural production in 2021, with approximately 52,553.28 tons. Disease-ridden safflower plants were noted in fields situated in the north-central zone of Sinaloa, Mexico, specifically during April 2022. The plants exhibited a range of symptoms including chlorosis, necrosis of vascular bundles, rot, dwarfism, and the bending of the plant stems towards the ground. The disease, affecting the surveyed safflower fields, caused an estimated 15% reduction in seed production, compared to the yield of the previous year. Twenty-five plants exhibiting the signs of illness were sampled to isolate the pathogen. To prepare the plant material, the stems were trimmed close to the roots and the roots themselves were sectioned into 5 mm square segments. Following standard protocols, tissue specimens were treated with 70% ethyl alcohol for 10 seconds, then exposed to 2% sodium hypochlorite for 1 minute. The specimens were then rinsed in sterile water and placed on potato dextrose agar (PDA) plates kept at 28 degrees Celsius for 7 days in complete darkness. Twelve PDA-cultured monosporic isolates were evaluated for their morphological characteristics.