BYDV-PAV, a prevalent wheat virus, was noted by Chay et al. (1996), whereas BWYV has not been documented as a wheat pathogen. BWYV, an aphid-vectored polerovirus, has a broad host spectrum encompassing more than 150 species from 23 dicotyledonous families, including Beta vulgaris, Spinacia oleracea, Lactuca sativa, and Brassica oleracea var. Considering the work of Duffus (1964, 1973), Russell (1965), and Beuve et al. (2008), italica holds substantial importance. A further report (Zheng et al., 2018) showcased that the BWYV virus targeted and infected a monocotyledonous plant, Crocus sativus, belonging to the Iridaceae family. In our records, this is the first documented report of BWYV affecting wheat or any other gramineae plant. Subsequent to the study, a risk to cereal crops in the field has been implied by BWYV.
The cultivation of Stevia rebaudiana Bertoni, an important medicinal plant, is widespread across the globe. Stevia leaves are the source of stevioside, a sweetener devoid of calories, used to replace artificial sweeteners. 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). The plants, infected, initially manifested chlorosis and wilting, with subsequent death and retention of their intact foliage. When examining cross-sections of the crown tissue from afflicted stevia plants, a pattern of necrotic tissue and dark brown discoloration was seen in the vascular and cortical regions. Dark brown microsclerotia were a prominent feature observed on the stem bases and necrotic roots of the infected plants. Five plants showing symptoms were sampled to isolate the pathogen, aiming to identify the causative agent. Root and crown tissues (0.5-1cm) underwent a 2-minute treatment using a 1% sodium hypochlorite solution for disinfection, followed by three sterile water rinses, and subsequent plating on potato dextrose agar (PDA). With a 12-hour photoperiod and at a temperature of 28°C, the five isolates displayed a rapid mycelial growth pattern on the PDA. Initially presenting as hyaline, the mycelia exhibited a chromatic shift from gray to black after seven full days. PDA plates, incubated for 3 days, yielded numerous dark, spherical to oblong microsclerotia, with an average width of 75 micrometers and length of 114 micrometers (n=30). The representative isolate Yuma, its mycelia and microsclerotia, underwent genomic DNA extraction using the DNeasy Plant Pro kit (Qiagen, Hilden, Germany) for molecular identification. The respective 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), were utilized for amplifying the internal transcribed spacer (ITS), translation elongation factor-1 (TEF-1), calmodulin (CAL), and -tubulin (-TUB) regions. A BLAST search for sequence similarity found 987% to 100% identity in the sequences examined and Macrophomina phaseolina sequences, including MK757624, KT261797, MK447823, and MK447918. Morphological and molecular examinations unequivocally established the identification of the fungus as M. phaseolina (Holliday and Punithaligam 1970). The submitted sequences are recorded in GenBank under the following accession numbers: OP599770 (ITS), OP690156 (TEF-1), OP612814 (CAL), and OP690157 (-TUB). Nine-week-old stevia plants (a specific variety) were employed for a pathogenicity assay. SW2267, cultivated in 4-inch greenhouse planters. An inoculum was created using a 14-day-old M. phaseolina culture, which was fostered in 250 ml conical flasks of potato dextrose broth, incubated at 28 degrees Celsius. Sterile distilled water, 250 ml in volume, was used to suspend the fungus's mycelial mats; these were subsequently filtered using four layers of cheesecloth and calibrated to 105 microsclerotia per milliliter via a hemocytometer. By applying 50 ml of inoculum per pot via soil drenching, twenty healthy plants were inoculated. Medical Symptom Validity Test (MSVT) The soil of five control plants, not inoculated, was drenched with sterile distilled water. https://www.selleckchem.com/products/kpt-9274.html Greenhouse-maintained plants experienced a 28.3°C temperature and a 12-hour photoperiod. Six weeks into the study, all twenty inoculated plants exhibited necrosis at the base of the petioles, accompanied by leaf chlorosis and wilting, a symptom complex not seen in the five healthy control plants. Identification of the fungus as M. phaseolina stemmed from its reisolation and the matching morphological features with ITS, TEF-1, CAL, and TUB gene sequences. concomitant pathology Despite prior observations of M. phaseolina on stevia plants in North Carolina, USA (Koehler and Shew 2018), this marks the initial discovery of this organism in Arizona, USA. Zveibil et al. (2011) indicate that M. phaseolina, flourishing in high soil temperatures, could significantly affect stevia production in Arizona, USA, in future years.
Tomato plants in Mexico were the initial hosts for the identification of tomato mottled mosaic virus (ToMMV), noted by Li et al. (2013). The positive-sense, single-stranded RNA virus in question is found within the Virgaviridae family, and specifically, the Tobamovirus genus. The viral genome's 6400 nucleotides are responsible for the coding of four proteins: the 126 K protein, the 183 K protein, the movement protein (MP), and the coat protein (CP). This is supported by the research of Tu et al. (2021). For solanaceous crops, ToMMV represents a serious and substantial risk. Tomato plants infected by the virus exhibit a significant reduction in growth, manifested by stunted growth and top necrosis. The leaves demonstrate mottled, shrunken, and necrotic symptoms, which results in a marked decrease in both the quality and yield of the tomato fruit. Li et al. (2017) and Tu et al. (2021) provide supporting evidence. As a perennial climbing herb in the Cucurbitaceae family, the Chinese snake gourd (Trichosanthes kirilowii Maxim) is a source of traditional Chinese medicine, derived from its fruit, seeds, peel, and root. From the Fengyang nursery in Anhui Province, a random selection of twenty-seven symptom-free seedlings, developed from tissue culture plantlets, was made in May 2021. Degenerate tobamovirus primers Tob-Uni1 (5'-ATTTAAGTGGASGGAAAAVCACT-3') and Tob-Uni2 (5'-GTYGTTGATGAGTTCRTGGA-3') were used in the RT-PCR assay on total RNA extracted from each sample, following the procedure of Letschert et al. (2002). Following amplification, six out of twenty-seven samples produced amplicons of the expected size, which were then sequenced. The nucleotide sequence alignment indicated that ToMMV isolates present in the NCBI GenBank database exhibited nucleotide sequence identities varying from 98.7% to 100%. Primers CP-F (5'-ATGTCTTACGCTATTACTT CTCCG-3') and CP-R (5'-TTAGGACGCTGGCGCAGAAG-3') were utilized for the amplification of the ToMMV coat protein (CP) gene. The CP fragment was both obtained and its sequence determined. Analysis of sequence alignments pointed to a distinctive CP sequence in isolate FY, which is further identified through its GenBank accession number. ToMMV isolate LN (MN8535921) demonstrated a perfect 100% genetic match with ON924176. Using purified virus from Nicotiana benthamiana, the author (S.L.) developed the anti-ToMMV polyclonal antibody (PAb) by immunizing a rabbit. This antibody yielded positive outcomes in serological tests (dot-enzyme linked immunosorbent assay, Dot-ELISA) on RNA-positive T. kirilowii leaf samples. A pure culture of ToMMV, derived from an infectious cDNA clone in N. benthamiana (Tu et al., 2021), was used to fulfill Koch's postulates, and healthy T. kirilowii plants were subsequently mechanically inoculated with this prepared inoculum from the infected N. benthamiana, following a previously described method (Sui et al., 2017). At 10 and 20 days post-inoculation, respectively, T. kirilowii seedlings exhibited chlorosis and leaf tip necrosis, a finding corroborated by RT-PCR detection of ToMMV infection in these symptomatic plants, using primers CP-F and CP-R. These results suggest that T. kirilowii naturally harbors ToMMV, a possibility that may impact the productivity of this valuable medicinal species. Despite initial asymptomatic presentation in the nursery seedlings, indoor inoculation resulted in the plants displaying chlorosis and necrosis. Viral accumulation in greenhouse-inoculated plants was dramatically higher (256 times) than in field-collected samples, according to qRT-PCR results. This substantial difference possibly explains the contrasting symptom expression between these two groups. The field has revealed ToMMV in its solanaceous (tomato, pepper, eggplant) and leguminous (pea) crops, a finding corroborated by Li et al. (2014), Ambros et al. (2017), and Zhang et al. (2022). This report, based on our current knowledge, presents the inaugural case of natural ToMMV infection in T. kirilowii, along with its natural infection cycle in Cucurbitaceae plant life.
Safflower cultivation is a source of considerable socioeconomic benefit across the world. The seeds are intended for oil extraction via this production method. In the year 2021, Mexico achieved a global ranking of fifth in agricultural production, a total of roughly 52,553.28 metric tons, as documented by the SIAP. Reports of diseased safflower crops emerged in April 2022 from fields situated in the north-central region of Sinaloa, Mexico. The plants suffered from a combination of chlorosis, vascular bundle necrosis and rot, dwarfed growth, and a bending of the stems towards the ground. Losses to safflower seed production, estimated at 15% compared to the previous year's yield in surveyed fields, were attributed to the disease. For the purpose of isolating the pathogen, twenty-five plants showing symptoms underwent sampling procedures. Roots, precisely excised at the stem base, were divided into 5 mm square portions. For the disinfection procedure, tissue samples were first immersed in 70% alcohol for 10 seconds, followed by immersion in 2% sodium hypochlorite for one minute. The samples were then rinsed in sterilized water and seeded on potato dextrose agar (PDA) plates at 28 degrees Celsius, incubated for seven days in the dark. Detailed morphological examinations were conducted on a collection of twelve monosporic isolates derived from a PDA culture.