Search Results (11)

Wheat stem rust, caused by Puccinia graminis f. sp. tritici, is a major disease that severely affects safe wheat production. The Huanghuai region plays a vital role in China’s wheat production and the wheat stem rust epidemic across China. However, due to China’s effective control measures, wheat stem rust rarely occurs in the region, resulting in little research on this disease, including the determination of resistance genes in cultivars and elite lines. For this purpose, this study utilized two predominant races (21C3CTHQM and 34MKGQM) of P. graminis f. sp. tritici to determine the resistance levels of 64 wheat cultivars in the Huanghuai wheat region. Additionally, molecular markers linked with Sr24, Sr25, Sr26, Sr31, and Sr38 were used to analyze the presence of these genes. The results indicated that among the 62 wheat cultivars and elite lines, 13 cultivars contained Sr31, four cultivars were detected to contain Sr38, and none contained Sr24, Sr25, or Sr26. Field tests in 2023 showed that three (4.8%) cultivars exhibited immunity to both races, while 20 (32.3%) and 23 (37.1%) cultivars showed resistance to moderate resistance, and 39 (62.9%) and 36 (58.1%) cultivars were moderately susceptible to susceptible. In 2024, one (1.6%) and four (6.5%) cultivars demonstrated immunity to both races, 22 (35.5%) and 23 (37.1%) cultivars showed resistance to moderate resistance, and 39 (62.9%) and 35 (56.5%) cultivars were moderately susceptible to susceptible. With over 50% of the cultivars displaying susceptibility, the overall resistance level was relatively low, indicating that stem rust outbreaks could recur if a sufficient inoculum is present. It is crucial to explore new resistance sources, discover novel resistance genes, and breed wheat cultivars with durable resistance and desirable agronomic traits to enhance the overall resistance to stem rust in Chinese wheat-growing regions. Full article

Cassava mosaic disease (CMD) is caused by viruses such as Sri Lankan cassava mosaic virus (SLCMV). It poses a significant threat to the cassava (Manihot esculenta) yield in Southeast Asia. Here, we investigated the expression of WRKY transcription factors (TFs) in SLCMV-infected cassava cultivars KU 50 (tolerant) and R 11 (susceptible) at 21, 32, and 67 days post-inoculation (dpi), representing the early, middle/recovery, and late infection stages, respectively. The 34 identified WRKYs were classified into the following six groups based on the functions of their homologs in the model plant Arabidopsis thaliana (AtWRKYs): plant defense; plant development; hormone signaling (abscisic, salicylic, and jasmonic acid); reactive oxygen species production; basal immune mechanisms; and other related hormones, metabolites, and abiotic stress responses. Regarding the protein interactions of the identified WRKYs, based on the interactions of their homologs (AtWRKYs), WRKYs increased reactive oxygen species production, leading to salicylic acid accumulation and systemic acquired resistance (SAR) against SLCMV. Additionally, some WRKYs were involved in defense-related mitogen-activated protein kinase signaling and abiotic stress responses. Furthermore, crosstalk among WRKYs reflected the robustly restricted viral multiplication in the tolerant cultivar, contributing to CMD recovery. This study highlights the crucial roles of WRKYs in transcriptional reprogramming, innate immunity, and responses to geminivirus infections in cassava, providing valuable insights to enhance disease resistance in cassava and, potentially, other crops. Full article

This research investigates the impacts of pre-processing techniques on the effectiveness of topic modeling algorithms for Arabic texts, focusing on a comparison between BERTopic, Latent Dirichlet Allocation (LDA), and Non-Negative Matrix Factorization (NMF). Using the Single-label Arabic News Article Data set (SANAD), which includes 195,174 Arabic news articles, this study explores pre-processing methods such as cleaning, stemming, normalization, and stop word removal, which are crucial processes given the complex morphology of Arabic. Additionally, the influence of six different embedding models on the topic modeling performance was assessed. The originality of this work lies in addressing the lack of previous studies that optimize BERTopic through adjusting the n-gram range parameter and combining it with different embedding models for effective Arabic topic modeling. Pre-processing techniques were fine-tuned to improve data quality before applying BERTopic, LDA, and NMF, and the performance was assessed using metrics such as topic coherence and diversity. Coherence was measured using Normalized Pointwise Mutual Information (NPMI). The results show that the Tashaphyne stemmer significantly enhanced the performance of LDA and NMF. BERTopic, optimized with pre-processing and bi-grams, outperformed LDA and NMF in both coherence and diversity. The CAMeL-Lab/bert-base-arabic-camelbert-da embedding yielded the best results, emphasizing the importance of pre-processing in Arabic topic modeling. Full article

Wheat stem rust, caused by the fungus Puccinia graminis f. sp. tritici (Pgt), poses a substantial threat to global wheat production. Utilizing stem rust resistance (Sr) genes represents an economically viable, effective, and environmentally friendly approach to disease control. In this study, gene postulation, molecular testing, and pedigree analysis were used to identify the presence of Sr genes in 45 wheat cultivars. In addition, the resistance of these cultivars was evaluated against two predominant Pgt races, 34MRGQM and 21C3CTHTM, at the adult-plant stage during 2021–2022. The results identify seven Sr genes (Sr31, Sr38, Sr30, SrTmp, Sr22, Sr19, and Sr5) within 35 wheat cultivars. Among these, 23 cultivars contained Sr31, whereas Sr5 and SrTmp were present in four cultivars each. Han 5316, Shimai 15, Shiyou 20, and Kenong 1006 exhibited the presence of Sr19, Sr22, Sr30, and Sr38, respectively. Molecular studies confirmed the absence of Sr25 and Sr26 in any of the wheat cultivars. During field evaluation, 37 (82.2%) and 39 (86.7%) wheat cultivars demonstrated resistance to races 34MRGQM and 21C3CTHTM, respectively. Moreover, 33 wheat cultivars (73.3%) exhibited resistance to all the tested races. These study findings will significantly contribute to future research in wheat pre-breeding and abiotic stress tolerance. Full article

The damage to wheat crops by stem rust poses a threat to the food security of the world’s population. The species Thinopyrum ponticum (Podpěra, 1902) (Z.-W. Liu and R.-C. Wang, 1993) is a non-host for the stem rust fungus Puccinia graminis f. sp. tritici Eriks. and Henn. (Pgt). The Sr24, Sr25, and Sr26 genes, transferred from the Th. ponticum to the wheat gene pool, protect cultivars from the disease in different regions of the world. The study of the non-host resistance (NHR) of Th. ponticum and the effects of the introgressed Sr24, Sr25, and Sr26 genes in wheat is important for breeding cultivars with durable resistance to stem rust. The aim of the research is to study the interaction of Pgt with Th. ponticum and common wheat lines with the Sr24, Sr25, and Sr26 genes, in addition to determining the role of ROS in resistance. Wheat lines with Sr24, Sr25, and Sr26 were resistant to the West Siberian Pgt population. Using cytological methods, it was found that the NHR of Th. ponticum and Sr24, Sr25, and Sr26 led to inhibition of the most inoculumdevelopment on the plant surface. This was mainly due to the suppression of the appressoria development and their death at the stage of penetration into the stomata. Upon contact of Pgt appressoria with stomatal guard cells, the generation of the superoxide anion O₂^•− was revealed. This interaction is similar to the stomatal immunity of Arabidopsis thaliana to non-pathogenic bacteria. The results of our studies show that the Sr24, Sr25, and Sr26 genes reproduce the action of some NHR mechanisms in wheat. Full article

The Volga region is one of the main grain-producing regions of Russia. Wheat stem rust caused by Puccinia graminis f. sp. tritici is among the most destructive fungal diseases of wheat. Recently, its harmfulness has increased in the Volga region. In this regard, an analysis of the resistance and diversity of the Sr genes in the Russian wheat cultivars is necessary. In this work, 126 wheat cultivars (including 23 durum wheat cultivars and 103 bread wheat cultivars) approved for use in the Volga region were evaluated for their resistance to two samples of P. graminis f. sp. tritici populations from different Volga region areas at the seedling stage. Specific DNA primers were used to identify resistance genes (Sr2, Sr24, Sr25, Sr26, Sr28, Sr31, Sr32, Sr36, Sr38, Sr39, and Sr57). Highly resistant cultivars (30 from 126) were identified. In bread wheat cultivars, the genes Sr31 (in 19 cultivars), Sr24 (in one cultivar), Sr25 (in 15 spring wheat cultivars), Sr28 (in six cultivars), Sr38 (in two cultivars), and Sr57 (in 15 cultivars) and their combinations—Sr31 + Sr25, Sr31 + Sr38, Sr31 + Sr28, Sr31 + Sr57, Sr31 + Sr28 + Sr57, and Sr31 + Sr24—were identified. The obtained results may be used to develop strategies for breeding rust-resistant cultivars. Full article

Wheat stem rust caused by Puccinia graminis f. sp. tritici is one of the most destructive wheat diseases worldwide. Identifying stem rust races in general, Ug99 lineage particularly, and determining resistance genes are critical goals for disease assessment. Thirty wheat varieties and monogenic lines with major stem rust resistance genes (Sr) were examined here over the course of three succeeding seasons from 2020 to 2022. Fourteen stem rust races have been identified in ten African countries, as well as Central and West Asia and North Africa (CWANA) and ten European countries. The Ug99 group (Clade I) included four races (TTKSK, TTKST, TTKTK, and TTKTT) and was reported in five African countries (Egypt, Kenya, Rwanda, Tanzania, and Uganda) and Iran, but none of the European countries. On the other hand, none of the races in Clade III-B (TTRTF) and Clade IV-B (TKTTF and TTTTF) were found in Egypt. Furthermore, Egyptian races were clustered separately from races identified from other countries, and six races were found only in Egypt, including PKSTC, RKTTH, TKTTC, TTTSK, TCKTC, and TKTTH. Races from Kenya, Tanzania, Uganda, Rwanda, and Iran were all closely associated with one another, according to correlation analysis. However, most races identified from other investigated regions, including Eritrea, Spain, Ethiopia, Morocco, Italy, Poland, Kenya, Tanzania, and Uganda, were adversely linked with Egyptian races. The diagnostic 350 bp long PCR fragment linked with virulence to Sr31, Clement (Sr31), and Brigardier (Sr31) was used to identify the TTKSK (Ug99) race. The identification of the regional associations and genetic diversity of newly emerged races within the Ug99 lineage of P. graminis tritici in Africa, Asia, and Europe is one of the key goals of this study. It will help plant breeders to develop new resistant lines against the virulent races, especially TTKSK (Ug99) and TTTSK. This helps in ensuring global food security in the context of climate change. Full article

Stem rust caused by Puccinia graminis f. sp. tritici Eriks. is a dangerous disease of common wheat worldwide. Development and cultivation of the varieties with genetic resistance is one of the most effective and environmentally important ways for protection of wheat against fungal pathogens. Field phytopathological screening and genome-wide association study (GWAS) were used for assessment of the genetic diversity of a collection of spring wheat genotypes on stem rust resistance loci. The collection consisting of Russian varieties of spring wheat and introgression lines with alien genetic materials was evaluated over three seasons (2016, 2017 and 2018) for resistance to the native population of stem rust specific to the West Siberian region of Russia. The results indicate that most varieties displayed from moderate to high levels of susceptibility to P. graminis; 16% of genotypes had resistance or immune response. In total, 13,006 single-nucleotide polymorphism (SNP) markers obtained from the Infinium 15K array were used to perform genome-wide association analysis. GWAS detected 35 significant marker-trait associations (MTAs) with SNPs located on chromosomes 1A, 2A, 2B, 3B, 5A, 5B, 6A, 7A and 7B. The most significant associations were found on chromosomes 7A and 6A where known resistance genes Sr25 and Sr6Ai = 2 originated from Thinopyrum ssp. are located. Common wheat lines containing introgressed fragments from Triticum timopheevii and Triticum kiharae were found to carry Sr36 gene on 2B chromosome. It has been suggested that the quantitative trait loci (QTL) mapped to the chromosome 5BL may be new loci inherited from the T. timopheevii. It can be inferred that a number of Russian wheat varieties may contain the Sr17 gene, which does not currently provide effective protection against pathogen. This is the first report describing the results of analysis of the genetic factors conferring resistance of Russian spring wheat varieties to stem rust. Full article

The quality of the captured point cloud and the scanning speed of a structured light 3D camera system depend upon their capability of handling the object surface of a large reflectance variation in the trade-off of the required number of patterns to be projected. In this paper, we propose and implement a flexible embedded framework that is capable of triggering the camera single or multiple times for capturing single or multiple projections within a single camera exposure setting. This allows the 3D camera system to synchronize the camera and projector even for miss-matched frame rates such that the system is capable of projecting different types of patterns for different scan speed applications. This makes the system capturing a high quality of 3D point cloud even for the surface of a large reflectance variation while achieving a high scan speed. The proposed framework is implemented on the Field Programmable Gate Array (FPGA), where the camera trigger is adaptively generated in such a way that the position and the number of triggers are automatically determined according to camera exposure settings. In other words, the projection frequency is adaptive to different scanning applications without altering the architecture. In addition, the proposed framework is unique as it does not require any external memory for storage because pattern pixels are generated in real-time, which minimizes the complexity and size of the application-specific integrated circuit (ASIC) design and implementation. Full article

The abundant wind resources in the Penghu area, where the capacity factor of wind turbines can reach 45%, have inspired authorities to build more wind turbines in a diesel-based power system. However, because the wind turbine output is unstable, high wind power penetration in the system may relatively affect the power quality (voltage and frequency) and reliability of the system. Previous studies have suggested that the optimal penetration level for wind power generation under the present dispatching criteria in Penghu is 26.3%. The present study suggests that the criteria for current unit scheduling should be modified; in particular, the spinning reserve (SR) capacity of the diesel engines should be increased without affecting the reliability and power quality of the power system. Such an increase could help avoid the construction of high-cost energy storage systems. Full article