Controlling the disease most effectively relies on the use of resistant cultivars. YrTr1, a crucial stripe rust resistance gene, is implemented in wheat breeding projects and is featured in a host differential set for the purpose of determining *P. striiformis f. sp*. Tritici wheat strains race to adapt to different regions within the United States. AvSYrTr1NIL was backcrossed to its recurrent parent, Avocet S (AvS), in order to ascertain the genetic map location of YrTr1. Seedlings from BC7F2, BC7F3, and BC8F1 populations were evaluated for their reactions to YrTr1-avirulent strains in a controlled setting. Subsequently, BC7F2 plants underwent genotyping using simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers. Refrigeration YrTr1's location on the short arm of chromosome 1B was established via the utilization of 4 simple sequence repeat (SSR) markers and 7 single nucleotide polymorphism (SNP) markers. Comparative genetic distances of YrTr1 to the flanking markers IWA2583 and IWA7480 were determined as 18 centimorgans (cM) and 13 cM, respectively. By using DNA amplification of 21 Chinese Spring (CS) nulli-tetrasomic lines and 7 CS 1B deletion lines, together with 3 SSR markers, the chromosome arm location of a gene was verified and placed in chromosomal bin region 1BS18(05). The gene's location was ascertained to be approximately 74 centiMorgans proximal to the Yr10 gene. The multi-race response array, coupled with its chromosomal location, indicated YrTr1 was distinct from other established stripe rust resistance genes on chromosome arm 1BS, leading to its naming as Yr85.
Rice crops worldwide are facing a significant threat from bacterial panicle blight (BPB), a major disease caused by the pathogens Burkholderia gladioli and B. glumae (1). Yield losses of 75% or more are a result of this disease, causing damages in the form of grain spotting, rot, and panicle blight (13). Inbred and hybrid rice varieties have, in recent years, shown symptoms including sheath rot, grain spotting, grain rot, and panicle blight. Symptoms resembling BPB are observed and lead to cultivar-based yield losses. (3) has documented similar symptoms in connection with BPB. From a farmer's field in Mymensingh, Bangladesh, 21 rice panicles of the Haridhan variety, which displayed typical symptoms of BPB, were collected in mid-October 2021, during the rainy season, to determine the disease's origin. The intensity of the outbreak resulted in the panicles becoming a dark brown color and the production of grains with a chaffy texture; almost every rice panicle within that field was substantially infected. Identifying the causal pathogen(s) for BPB, 20 plants with symptomatic rice grain samples each providing 1 gram of grain were surface-sterilized using a brief immersion in 70% ethanol (a few seconds), then treated with 3% sodium hypochlorite solution for one minute. Using sterilized distilled water, the grains were rinsed a total of three times. The surface-sterilized grains were ground using a mortar and pestle, with 5 milliliters of sterile distilled water added while they were being ground. Subsequent to extraction, the 20-liter suspension was applied to the selective S-PG medium (2), either by streaking or spreading it thinly. Colonies of bacteria stained purple on the S-PG medium were selected and purified, representing possible pathogenic organisms. Species-specific primers targeting the gyrB gene were used in a polymerase chain reaction, resulting in a 479-base pair product, as per reference 4, for molecular characterization. Amplification and partial sequencing of 16S rRNA PCR products were carried out, resulting in approximately 1400 base pairs of sequence data (1), and five of the partial 16S rRNA sequences were then submitted to NCBI GenBank (accession numbers OP108276-OP108280). BLAST analysis showed an almost 99% homology of 16S rDNA with Burkholderia gladioli (KU8512481, MZ4254241), and 99% homology of gyrB with B. gladioli (AB220893, CP033430), respectively. On King's B medium, purified bacterial isolates secreted a diffusible light-yellow pigment, indicative of toxoflavin production (3). Following confirmation of the candidate's five bacterial isolates, a 10 mL suspension of 108 CFU/mL was inoculated into the panicles and sheaths of BRRI Dhan28 rice plants under net house conditions, as previously documented (1). Light brown lesions, evident on inoculated leaf sheaths, along with grain spotting, were characteristic of the bacterial isolates obtained from the spotted rice grains. The re-isolation of bacteria from the symptomatic panicles, followed by confirmation of B. gladioli through gyrB and 16s rDNA gene sequence analysis, successfully met Koch's postulates. The combined effect of these results underscores the implication of B. gladioli in causing BPB within the rice grain samples that were sampled. We believe this represents the first instance of BPB stemming from B. gladioli reported in Bangladesh, and further studies are required to design a successful disease management protocol, or else rice output will face substantial setbacks.
An aromatic herb, peppermint (Lamiaceae), plays a multifaceted role in culinary practices, medicinal treatments, and industrial processes. Within the four commercial peppermint (Mentha piperita) fields of San Buenaventura Tecalzingo, San Martin Texmelucan, Puebla, Mexico, foliar rust was observed in June 2022. The specific geographic locations are 19°14′34″N 98°27′25″W; 19°14′16″N 98°27′21″W; 19°14′37″N 98°27′07″W; and 19°15′06″N 98°26′54″W. The collection at each site included two diseased plants. Fifty percent of the plants suffered from the disease, displaying damage to less than seventeen percent of their foliar tissue. Early indicators of the affliction were small chlorotic spots on the adaxial leaf surface, which subsequently developed into a necrotic region with a surrounding wide chlorotic margin. Necrosis was limited to cases exhibiting a dense concentration of reddish-brown pustules positioned on the underside of the leaf, whereas smaller pustules were observed on its upper surface. Reddish-brown pustules, numerous in appearance, were identified on the undersides of the leaves, signifying the signs. In every infected leaf sample, subepidermal uredinia, rupturing through the leaf tissue, were associated with hyaline, cylindrical paraphyses. Individual urediniospores (n=50) were hyaline to light brown, echinulate, and obovoid in shape (165-265 x 115-255 µm, mean ± SD = 22 ± 16 µm and 19 ± 4 µm, and 6 µm wall thickness), supported by a pedicel and having two germinative pores. The morphological descriptions of Puccinia menthae in Kabaktepe et al. (2017) and Solano-Baez et al. (2022) closely corresponded to the observed characteristics. A voucher specimen, destined for the Herbarium of the Department of Plant-Insect Interactions at the Biotic Products Development Center of the National Polytechnic Institute, was deposited under the designated accession number. In the context of the current procedure, IPN 100115 is the key identification. Extraction of genomic DNA from a single sample was followed by amplification of the 28S rDNA gene region via nested PCR. The first PCR reaction utilized the primer sets Rust2inv (Aime, 2006) and LR6 (Vilgalys and Hester, 1990), and the second reaction employed the sets Rust28SF (Aime et al., 2018) and LR5 (Vilgalys and Hester, 1990). The type-specimen sequence of P. menthae (DQ354513), found in Cunila origanoides from the USA, displayed 100% homology (902/1304 base pairs) with the obtained sequence, GenBank accession No. OQ552847, as reported by Aime (2006). A 28S dataset from published studies on Puccinia species was integrated into a Maximum Likelihood phylogenetic analysis. The resultant analysis grouped the isolate IPN 100115 within the P. menthae clade, a grouping supported by a 100% bootstrap value. To evaluate pathogenicity, a suspension of urediniospores (1104 spores/ml) from the IPN 100115 isolate was sprayed on six healthy 30-day-old peppermint plants (Mentha piperita), contrasting with six control plants treated with sterile distilled water. A 48-hour period of 28°C and 95% relative humidity was spent by all plants within a wet chamber, after which the plastic bag was removed. All inoculated plants developed disease symptoms by day 15; the control plants, however, remained unaffected. Two iterations of the pathogenicity assay produced virtually identical outcomes. The morphology of the pathogen isolated from the pustules of the inoculated plants displayed a perfect correspondence with the initially collected form, thereby adhering to Koch's postulates. This is, as far as we can ascertain, the inaugural description of Puccinia menthae causing leaf rust on Mentha piperita within Mexico's agricultural landscape. Using morphological features, this species was previously identified in Brazil, Canada, Poland, and the USA, in the context of Mentha piperita (Farr and Rossman, 2023). Given the disease's effect on peppermint plants, causing leaf loss and subsequently impacting yield, additional knowledge concerning disease control is critical.
Two Monstera deliciosa Liebm. plants were observed to be present in February 2023. Araceae plants at a grocery store in Oconee County, South Carolina, showcased the telltale indicators of leaf rust disease. The leaves exhibited chlorotic leaf spots, along with a substantial presence of brownish uredinia, mainly situated on the upper side of over half of the leaf area. During March 2023, eleven M. deliciosa plants, out of a total of 481, in a greenhouse at a plant nursery within York County, South Carolina, displayed the same disease. To ascertain the rust fungus's pathogenicity, the plant sample collected in February was subjected to morphological characterization and molecular identification. Golden to golden-brown urediniospores, densely clustered and globular in shape, measured between 229 and 279 micrometers in diameter, averaging size. HBsAg hepatitis B surface antigen A 260-meter-diameter cylinder, with a wall thickness ranging from 13 to 26 meters (average), is measured at 11 meters. selleck chemical At 1803 hours, and with the sample count set at fifty, the following observation was made.