Explore the vast range of titles available.

The TaDIR gene was identified by GWAS and QTL mapping of Fusarium crown rot (FCR) resistance and was functionally verified by VIGS and analysis of tetraploid and hexaploid wheat mutants. (a): Classification of FCR disease index in the surveyed cultivars. (b) Number of accessions with different FCR DI in the association panel. (c) Manhattan and Q‐Q plots for FCR DI in different environments. (d) Distribution of significant SNPs revealed by GWAS on various chromosomes. (e) Haplotype analysis of significant SNPs on 4B identified at multiple environments. (f–g) Comparison of FCR DI of wheat accessions with different alleles in the block on 4B. (h) QTL mapping for FCR DI in the Bainong64/Jingshuang16 (BJ) population. (i) The schematic range of 6 candidate genes including TaDIR identified by haplotype analysis and QTL mapping. (j) Full alignment of amino acid of TaDIR‐B1 alleles between low DI and high DI accessions. (k) Development of the dCAPS marker to distinguish TaDIR‐B1 alleles. Furthermore, TaDIR‐B1 gene was silenced in the FCR‐susceptible cultivar Pingyuan 50 using virus‐induced gene silencing (VIGS) by barley stripe mosaic virus (BSMV). qRT‐PCR analysis showed significant down‐regulation of TaDIR‐B1 in VIGS‐silenced plants (Figure 1l‐2). Compared to the WT and BSMV0 plants, the lignin content in the BSMVTaDIR‐B1 plants was remarkedly increased, and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were also dramatically increased, but the malondialdehyde (MDA) content was significantly decreased in BSMVTaDIR‐B1 plants (Figure 1l‐4). Physiological analysis showed that lignin accumulation was dramatically increased in silenced‐TaDIR‐B1 plants. [...]improvement of FCR resistance caused by loss of function of the TaDIR‐B1 gene may be attributed to accumulation of lignin in wheat plants.

Background Fusarium crown rot (FCR) is a severe and chronic disease in common wheat and is able to cause serious yield loss and health problems to human and livestock. Results Here, 234 Chinese wheat cultivars were evaluated in four greenhouse experiments for FCR resistance and genome-wide association studies (GWAS) were performed using the wheat 660 K genotyping assay. The results indicated that most cultivars evaluated showed FCR disease index (DI) of 40–60, while some cultivars showed stably good FCR resistance (DI < 30). GWAS identified 286 SNPs to be significantly associated with FCR resistance, of which 266, 6 and 8 were distributed on chromosomes 6A, 6B and 6D, respectively. The significant SNPs on 6A were located in a 7.0-Mb region containing 51 annotated genes. On the other hand, QTL mapping using a bi-parental population derived from UC1110 and PI610750 detected three QTLs on chromosomes 6A (explaining 7.77–10.17% of phenotypic variation), 2D (7.15–9.29%) and 2A (5.24–6.92%). The 6A QTL in the UC1110/PI610750 population falls into the same chromosomal region as those detected from GWAS, demonstrating its importance in Chinese materials for FCR resistance. Conclusion This study could provide useful information for utilization of FCR-resistant wheat germplasm and further understanding of molecular and genetics basis of FCR resistance in common wheat.

Key messageTwo QTL mapping approaches were used to identify a total of six QTL associated with Phytophthora root and crown rot resistance in a biparental squash population.Phytophthora root and crown rot, caused by the soilborne oomycete pathogen Phytophthora capsici, leads to severe yield losses in squash (Cucurbita pepo). To identify quantitative trait loci (QTL) involved in resistance to this disease, we crossed a partially resistant squash breeding line with a susceptible zucchini cultivar and evaluated over 13,000 F2 seedlings in a greenhouse screen. Bulked segregant analysis with whole genome resequencing (BSA-Seq) resulted in the identification of five genomic regions—on chromosomes 4, 5, 8, 12, and 16—featuring significant allele frequency differentiation between susceptible and resistant bulks in each of two independent replicates. In addition, we conducted linkage mapping using a population of 176 F3 families derived from individually genotyped F2 individuals. Variation in disease severity among these families was best explained by a four-QTL model, comprising the same loci identified via BSA-Seq on chromosomes 4, 5, and 8 as well as an additional locus on chromosome 19, for a combined total of six QTL identified between both methods. Loci, whether those identified by BSA-Seq or linkage mapping, were of small-to-moderate effect, collectively accounting for 28–35% and individually for 2–10% of the phenotypic variance explained. However, a multiple linear regression model using one marker in each BSA-Seq QTL could predict F2:3 disease severity with only a slight drop in cross-validation accuracy compared to genomic prediction models using genome-wide markers. These results suggest that marker-assisted selection could be a suitable approach for improving Phytophthora crown and root rot resistance in squash.

Fusarium crown rot (FCR) is an important and devastating disease of wheat ( Triticum aestivum ) caused by the fungus Fusarium pseudograminearum and related pathogens. Using two distinct susceptible cultivars, we investigated the isolation frequencies of F. pseudograminearum and quantified its biomass accumulation and the levels of the associated toxins deoxynivalenol (DON) and DON-3-glucoside (D3G) in inoculated field-grown wheat plants. We detected F. pseudograminearum in stem, peduncle, rachis, and husk tissues, but not in grains, whereas DON and D3G accumulated in stem, rachis, husk, and grain tissues. Disease severity was positively correlated with the frequency of pathogen isolation, F. pseudograminearum biomass, and mycotoxin levels. The amount of F. pseudograminearum biomass and mycotoxin contents in asymptomatic tissue of diseased plants were associated with the distance of the tissue from the diseased internode and the disease severity of the plant. Thus, apparently healthy tissue may harbor F. pseudograminearum and contain associated mycotoxins. This research helps clarify the relationship between F. pseudograminearum occurrence, F. pseudograminearum biomass, and mycotoxin accumulation in tissues of susceptible wheat cultivars with or without disease symptoms, providing information that can lead to more effective control measures.

Background Fusarium crown rot (FCR), primarily caused by Fusarium pseudograminearum , has emerged as a globally significant disease severely threatening the stability of wheat production. Breeding FCR-resistant germplasms and clarifying the underlying resistance mechanisms are critical prerequisites for effective disease management. Results In this study, to generate genotypes with enhanced FCR resistance, an EMS-mutagenized population was developed from AK58, and a germplasm X413 with stably moderate resistance to FCR at both the seedling and adult stages was identified. Phenotypic analysis showed that X413 exhibited stronger ability to inhibit the expansion and mycelial growth of F. pseudograminearum . Transcriptome (RNA-seq) comparison with highly susceptible X73 revealed that X413 had fewer differentially expressed genes (DEGs) after pathogen infection, with its specific DEGs significantly enriched in resistance-related pathways such as “lignin metabolic process” and “phenylpropanoid biosynthesis”. In contrast, X73 had more DEGs, and genes related to growth and development including those for DNA replication and post-replication repair were significantly downregulated, consistent with its more obvious plant height reduction after pathogen infection. Weighted gene co-expression network analysis (WGCNA) identified hub genes highly expressed in X413, including ubiquitin-related genes, kinase genes, and three germin-like protein genes (with SOD activity involved in hydrogen peroxide production). Physiological assays confirmed that X413 had significantly higher hydrogen peroxide content and SOD activity than X73. Conclusions Collectively, FCR resistance in X413 may be associated with efficient activation of disease resistance pathways and balanced growth-defense metabolism. This germplasm could serve as a valuable resistance source to support wheat breeding for FCR resistance, and the mechanistic insights obtained may also lay a solid theoretical foundation for the mining and utilization of resistance genes.

Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum). The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

Fusarium crown rot (FCR) is a significant global issue in wheat production. Planting resistant cultivars is the most effective strategy for mitigating FCR damage. However, breeding for FCR resistance is challenged by the lack of a reliable and high-throughput method for rapid and accurate assessment of numerous genotypes. This study evaluated FCR resistance in 50 wheat genotypes using the common soil-based method. None of the genotypes were immune or highly resistant and only 6.0% (three genotypes) showed moderate resistance at the seedling stage. Resistant and susceptible genotypes were then selected for preliminary experiments. A rapid water-culture method for assessing FCR resistance in wheat seedlings was developed. Seedlings were planted in petri dishes and inoculated by spraying conidial suspensions. This new method, which takes 15 days (about 50% of the time required for soil-based methods), requires minimal space and eliminates variability associated with soil or potting mixes. The disease index correlation between water-culture and soil-based methods was significant ( p  < 0.01) with a correlation coefficient of 0.901. The resistance evaluation consistency among 50 genotypes using both methods was 94.0%, indicating high reproducibility and strong agreement with soil-based results. Therefore, this new method should be a valuable tool for initial screening of FCR-resistant germplasms from numerous genotypes in breeding programs.

Wheat crown rot (WCR) caused by Fusarium pseudograminearum threatens wheat productivity, and sustainable control strategies are urgently needed. We constructed a minimal cross-kingdom synthetic community (SynCom) consisting of Trichoderma harzianum T19 and Bacillus rugosus PM16, and evaluated its effects on wheat growth and WCR suppression. Rhizosphere microbiome assembly (full-length 16S rRNA/ITS sequencing) and metabolomic shifts were assessed to elucidate mechanisms. The SynCom significantly suppressed WCR and promoted wheat growth under pathogen pressure, improving biomass, chlorophyll content, and yield-related traits. SynCom inoculation remodeled the rhizosphere microbiome by enriching beneficial taxa (e.g., Mortierella) and reducing pathogen-associated fungi, and it enhanced rhizosphere enzyme activities and nutrient availability. Metabolomics revealed accumulation of growth-promoting and defense-related metabolites, supporting coordinated microbiome-metabolome regulation. A minimal cross-kingdom SynCom can establish a disease-suppressive and growth-promoting rhizosphere through coordinated restructuring of microbial communities and metabolites, highlighting its potential as an eco-friendly strategy for WCR management.

Kazakhstan is the fourteenth largest wheat producer in the world. Despite this fact, there has not been a comprehensive survey of wheat root and crown rot. A quantitative survey was conducted for the purpose of establishing the distribution of fungi associated with root and crown rot on wheat (Triticum spp.). During the 2019 growing season, samples were taken from the affected plants’ roots and stem bases. A total of 1221 fungal isolates were acquired from 65 sites across the central (Karagandy region), eastern (East Kazakhstan region), and southeastern (Almaty region) parts of the country and identified using morphological and molecular tools. The internal transcribed spacer (ITS), translation elongation factor 1-alpha (EF1-α), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) sequences were successfully used to identify the species of fungal isolates. It was found that Bipolaris sorokiniana (44.80%) and Fusarium acuminatum (20.39%) were the most predominant fungal species isolated, which were present in 86.15 and 66.15% of the fields surveyed, respectively, followed by F. equiseti (10.16%), Curvularia spicifera (7.62%), F. culmorum (4.75%), F. oxysporum (4.10%), F. redolens (2.38%), Rhizoctonia solani AG2-1 (1.06%), Nigrospora oryzae (0.98%), C. inaequalis (0.90%), F. pseudograminearum (0.74%), F. flocciferum (0.74%), Macrophomina phaseolina (0.66%), F. cf. incarnatum (0.33%), Fusarium sp. (0.25%), and F. torulosum (0.16%). A total of 74 isolates representing 16 species were tested via inoculation tests on the susceptible Triticum aestivum cv. Seri 82 and the results revealed that F. culmorum and F. pseudograminearum, B. sorokiniana, Fusarium sp., R. solani, F. redolens, C. spicifera, C. inaequalis, and N. oryzae were virulent, whereas others were non-pathogenic. The findings of this investigation demonstrate the presence of a diverse spectrum of pathogenic fungal species relevant to wheat crown and root rot in Kazakhstan. To the best of our knowledge, this is the first report of F. pseudograminearum, Fusarium sp., C. spicifera, and C. inaequalis as pathogens on wheat in Kazakhstan.

Fusarium crown rot (FCR) causes significant grain yield loss in winter cereals around the world. Breeding for resistance and/or tolerance to FCR has been slow with relatively limited success. In this study, multi-species experiments were used to demonstrate an improved method to quantify FCR infection levels at plant maturity using quantitative PCR (qPCR), as well as the genotype yield retention using residual regression deviation. Using qPCR to measure FCR infection allowed a higher degree of resolution between genotypes than traditional visual stem basal browning assessments. The results were consistent across three environments with different levels of disease expression. The improved measure of FCR infection along with genotype yield retention allows for partitioning of both tolerance and partial resistance. Together these methods offer new insights into FCR partial resistance and its relative importance to tolerance in bread wheat and barley. This new approach offers a more robust, unbiased way to select for both FCR traits within breeding programs. Key message: Genetic gain for tolerance and partial resistance against Fusarium crown rot (FCR) in winter cereals has been impeded by laborious and variable visual measures of infection severity. This paper presents results of an improved method to quantify FCR infection that are strongly correlated to yield loss and reveal previously unrecognised partial resistance in barley and wheat varieties.