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Wheat powdery mildew is a destructive disease seriously threatening yield and quality. Comprehensive dissection of new resistance-related loci/genes is necessary to control this disease. LS5082 is a Chinese wheat breeding line with resistance to powdery mildew. Genetic analysis indicated that a single dominant gene, tentatively designated PmLS5082, conferred seedling resistance to different Bgt isolates. Bulked segregant RNA-seq (BSR-seq) was carried out to map the R gene PmLS5082 and profile differentially expressed genes associated with PmLS5082. PmLS5082 was mapped to chromosome arm 2BL and flanked by the markers WGGBH612-5 and YTU19-005 with genetic distances of 0.3 and 0.4 cM, respectively. The physical position was subsequently locked into the interval of 710.3-711.0 Mb. PmLS5082 differs from the catalogued Pm genes on chromosome arm 2BL in its resistant spectrum, physical position and origin, suggesting it is most likely a new Pm gene. Through COG and KEGG analysis, differentially expressed genes associated with PmLS5082 were profiled, and six genes in PmLS5082 interval were confirmed to be associated with PmLS5082 via RT-qPCR, using an additional set of wheat samples and time-course analysis post-inoculation with Bgt. In order to transfer PmLS082 to different genetic backgrounds using marker-assisted selection (MAS), closely linked markers, including Kompetitive Allele-Specific PCR (KASP) markers, were evaluated and nine markers were confirmed to be widely applicable for MAS in different genetic backgrounds.

Additional file 2: Fig. S1. The original and unprocessed amplification patterns of PmCG15-009-linked markers YTU103–101 in genotyping resistant parent ShiCG15–009, susceptible parent Yannong 21, and randomly selected F2:3 families of ShiCG15–009 × Yannong 21. Fig. S2. The original and unprocessed amplification patterns of PmCG15–009-linked markers CIT02g–17 in genotyping resistant parent ShiCG15–009, susceptible parent Yannong 21, and randomly selected F2:3 families of ShiCG15–009 × Yannong 21. Fig. S3. The original and unprocessed amplification patterns of PmCG15–009-linked markers CISSR02g-6 in ShiCG15–009, Yannong 21 and 15 wheat cultivars/lines susceptible to powdery mildew. Fig. S4. The original and unprocessed amplification patterns of PmCG15–009-linked markers CIT02g-17 in ShiCG15–009, Yannong 21 and 15 wheat cultivars/lines susceptible to powdery mildew.

Wheat powdery mildew is a devastating disease that seriously threatens yield worldwide. Utilization of host resistance is considered an effective strategy to minimize powdery mildew damage. Pm21, PmV, and Pm12 confer broad-spectrum resistance to wheat powdery mildew in China, of which Pm21 and PmV are allelic genes derived from the 6VS chromosome of Dasypyrum villosum, and Pm12 is derived from the 6SS chromosome of Aegilops speltoides and most likely orthologous to the former two genes. To accurately and efficiently transfer and pyramid these genes using marker-assisted selection (MAS), distinctive single-nucleotide polymorphisms (SNPs) among the exon sequences of Pm21, PmV, and Pm12 and their homologous sequences in the common wheat genome were identified and then used for developing diagnostic Kompetitive Allele-Specific PCR (KASP) markers. The markers were validated in different genotypes including transgenic vectors, transgenic lines, translocation lines, resistance stocks with documented Pm genes, and in multiple susceptible cultivars without Pm genes. As a result, we initially developed a KASP marker that can simultaneously diagnose Pm21, Pm12, and PmV. Subsequently, we obtained a highly diagnostic KASP marker for each of the three genes that could distinguish among the three genes and also accurately distinguish them from other resistant stocks with documented Pm genes and from multiple susceptible genotypes. Compared with previously reported markers, the highly diagnostic KASP markers developed in this study have the advantages of low cost, easy assay, accuracy, and potentially high throughput for MAS.

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, is a devastating disease that threatens yield and quality. Host resistance is considered the most effective and preferred means to control this disease. Wheat landrace Duanganmang (DGM) showed high resistance or near immunity to Blumeria graminis f. sp. tritici mixture from Henan Province, China. DGM was crossed with highly susceptible Chinese wheat landrace Huixianhong (HXH) and cultivar ‘Shimai 15’ (SM15) to produce genetic populations. The resistance of DGM to Blumeria graminis f. sp. tritici isolate E09 was shown to be controlled by a single dominant Mendelian factor, tentatively designated PmDGM. Marker analysis and 55K single nucleotide polymorphism (SNP) array scanning showed that this gene was positioned in the Pm5 interval (2.4 cM or 1.61 Mb) flanked by Xhenu099 and Xmp1158 in the Chinese Spring reference genome. Homology-based cloning and sequence analysis demonstrated that DGM has the identical NLR gene (Pm5e) and RXL gene reported in Fuzhuang 30 (FZ30), conferring and modifying powdery mildew resistance, respectively. However, based on the different reaction patterns to the Blumeria graminis f. sp. tritici isolate B15 between DGM and FZ30, the authors speculate that DGM may have two tightly linked genes that could not be separated in the current mapping population, one of which is PmDGM and the other being Pm5e. Hence, this study provides a valuable resistance resource for improvement of powdery mildew resistance.

Fungal diseases, drought, pre-harvest sprouting (PHS) and other biotic and abiotic stresses have seriously affected the quality and yield in wheat production. Identifying related genes/loci in released cultivars/lines can provide reference information and theoretical basis for wheat improvement. Yannong series wheat cultivars/lines have distinctive characteristics in wheat cultivars and play an important role in genetic improvement and production of Chinese wheat production system. To dissect their genetic basis of the stress-resistant traits, in this study, 23 representative Yannong series wheat cultivars/lines were tested by 58 molecular markers for 40 genes related to adaptability, disease resistance and stress tolerance to clarify the genetic composition of the key loci. The results showed that most of the tested wheat accessions carried dwarfing genes RhtB1b/RhtD1b/Rht8 and recessive vernalization genes vrn-A1/vrn-B1/vrn-D1/vrn-B3. It was also consistent with the phenotypic traits of tested Yannong series wheat which were dwarf and winter or semi winter wheat. In addition, the overall level of seedling powdery mildew resistance in 23 Yannong wheat cultivars/lines was moderate or inadequate. Eleven accessions carried none of the tested Pm genes and twelve accessions carried Pm2, Pm6, Pm42 and Pm52 singly or in combination. Then, 23 wheat cultivars/lines were also tested by 17 diagnostic markers for 14 Yr genes. The results showed that 16 wheat cultivars/lines were likely to carry one or more of tested Yr genes, whereas Yannong 15, Yannong 17, Yannong 23, Yannong 24, Yannong 377, Yannong 572 and Yannong 999 carried none of the tested Yr genes. Moreover, in our study, nine markers for four genes related to drought tolerance and PHS were used to evaluate the stress tolerance of the 23 wheat cultivars/lines. The results indicated that all 23 wheat cultivars/lines carried drought resistance genes Ta-Dreb1/TaCRT-D, indicating that they had the drought resistance to the extent. Except for Yannong 30, Yannong 377, Yannong 390, Yannong 745 and Yannong 1766, other wheat cultivars/lines carried one to three elite PHS-resistant alleles Vp-1Bc/Vp-1Bf/TaAFP-1Bb.

New powdery mildew resistance gene Pm68 was found in the terminal region of chromosome 2BS of Greek durum wheat TRI 1796. The co-segregated molecular markers could be used for MAS. Durum wheat (Triticum turgidum L. var. durum Desf.) is not only an important cereal crop for pasta making, but also a genetic resource for common wheat improvement. In the present study, a Greek durum wheat TRI 1796 was found to confer high resistance to all 22 tested isolates of Blumeria graminis f. sp. tritici (Bgt). Inheritance study on the F1 plants and the F2 population derived from the cross TRI 1796/PI 584832 revealed that the resistance in TRI 1796 was controlled by a single dominant gene, herein designated Pm68. Using the bulked segregant RNA-Seq (BSR-Seq) analysis combined with molecular analysis, Pm68 was mapped to the terminal part of the short arm of chromosome 2B and flanked by markers Xdw04 and Xdw12/Xdw13 with genetic distances of 0.22 cM each. According to the reference genome of durum wheat cv. Svevo, the corresponding physical region spanned the Pm68 locus was about 1.78-Mb, in which a number of disease resistance-related genes were annotated. This study reports the new powdery mildew resistance gene Pm68 that would be a valuable resource for improvement of both common wheat and durum wheat. The co-segregated markers (Xdw05–Xdw11) developed here would be useful tools for marker-assisted selection (MAS) in breeding.

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most destructive fungal diseases threatening global wheat production. Host resistance is well known to be the most efficient method to control this disease. However, the molecular mechanism of wheat powdery mildew resistance (Pm) is still unclear. To analyze the molecular mechanism of Pm, we used the resistant wheat cultivar Jimai 23 to investigate its potential resistance components and profiled its expression in response to powdery mildew infection using bulked segregant RNA-Seq (BSR-Seq). We showed that the Pm of Jimai 23 was provided by a single dominant gene, tentatively designated PmJM23, and assigned it to the documented Pm2 region of chromosome 5DS. 3,816 consistently different SNPs were called between resistant and susceptible parents and the bulked pools derived from the combinations between the resistant parent Jimai23 and the susceptible parent Tainong18. 58 of the SNPs were assigned to the candidate region of PmJM23. Subsequently, 3,803 differentially expressed genes (DEGs) between parents and bulks were analyzed by GO, COG and KEGG pathway enrichment. The temporal expression patterns of associated genes following Bgt inoculation were further determined by RT-qPCR. Expression of six disease-related genes was investigated during Bgt infection and might serve as valuable genetic resources for the improvement of durable resistance to Bgt.

Powdery mildew infection of wheat (Triticum aestivum L.), caused by Blumeria graminis f. sp. tritici (Bgt), is a destructive disease that threatens yield and quality worldwide. The most effective and preferred means for the control of the disease is to identify broad-spectrum resistance genes for breeding, especially the genes derived from elite cultivars that exhibit desirable agronomic traits. Jimai 23 is a Chinese wheat cultivar with superior agronomic performance, high-quality characteristics, and effective resistance to powdery mildew at all growth stages. Genetic analysis indicated that powdery mildew resistance in Jimai 23 was mediated by a single dominant gene, tentatively designated PmJM23. Using bulked segregant RNA-Seq (BSR-Seq), a series of markers was developed and used to map PmJM23. PmJM23 was then located at the Pm2 locus on the short arm of chromosome 5D (5DS). Resistance spectrum analysis demonstrated that PmJM23 provided a broad resistance spectrum different from that of the documented Pm2 alleles, indicating that PmJM23 is most likely a new allele of Pm2. In view of these combined agronomic, quality, and resistance findings, PmJM23 is expected to be a valuable resistance gene in wheat breeding. To efficiently use PmJM23 in breeding, the closely linked markers of PmJM23 were evaluated and confirmed to be applicable for marker-assisted selection (MAS). Using these markers, a series of resistant breeding lines with high resistance and desirable agronomic performance was selected from the crosses involving PmJM23, resulting in improved powdery mildew resistance of these lines.

This study reports an environmentally friendly process to prepare cellulose nanofibrils (CNFs) from sugarcane bagasse (SCB), by ultrasonication combined with various mechanochemical pretreatments. The pretreatments included continuous steam explosion, dilute alkali-catalyzed (0.4 wt% NaOH) hydrothermal treatment, and bleaching with hydrogen peroxide. The morphology and physiochemical properties of the fibers obtained after each stage of treatment were characterized by various techniques. Suspensions of fibers subjected to different pretreatments were prepared by the same mechanical process. The result proved that continuous steam explosion pretreatment could strip the primary wall and the binding materials related to middle lamella, loosen the structure of fiber cell wall, and promote sequent nanofibrillation of the cellulose fibers. Therefore, the total energy consumption is reduced. The current pretreatments effectively removed non-cellulosic constituents of the raw fibers, using very small amount of chemical reagents. Individual CNFs typically had diameters of 20–40 nm, high aspect ratios, a fine web-like structure, and good thermal stability.

Laboratory-designed continuous steam explosion (CSE) equipment was used to prepare continuous steam-exploded eucalyptus fibers (CSEEFs). The pretreatment intensity was varied by changing treatment time, and effects of CSE on the composition, microstructure, surface composition, thermal properties, and crystallinity of CSEEFs were investigated. Composition analysis showed that CSE had a significant impact on lignin and hemicellulose, but little on cellulose. Scanning electron microscopy indicated that the middle lamella, primary wall, and outer secondary wall were progressively stripped as the CSE time increased. X-ray photoelectron spectroscopy demonstrated that concentrations of extractives and lignin were higher on the surface of eucalyptus wood than CSEEFs’, and the exposed carbohydrate fraction increased with increasing CSE time. Differential scanning calorimetry showed that eucalyptus wood has one glass transition (193.5 °C), whereas two glass transitions at 56.7 and 138.5 °C were observed for CSEEF-5. X-ray diffraction results suggested that crystallinity of samples decreased with increasing CSE time. Thermogravimetric analysis showed the pyrolysis peak temperature of samples first increased and then decreased slightly as CSE time increased. These data will be useful for the optimization and application of CSE technology.

The entrance converging flow method was used to investigate the influences of entrance convergence angle and fiber content on the rheological behavior of Pithecellobium clypearia fiber (PCF)/high-density polyethylene (HDPE) composites. Shear and extensional rheological parameters were also measured. It is found that the extensional action exerted on the materials reaches a maximum at a die angle of 120° at certain plunger rates. Wall slippage occurs easily for PCF/HDPE composites with higher fiber content with a die entry angle of 120°, causing a substantial decrease in the entrance pressure drop of the orifice die. Both shear and extensional non-Newtonian indices of HDPE and PCF/HDPE composites were less than 1, consistent with shear- and tension-thinning rheological behavior. Within the fiber content range used in this study, the shear viscosity increased slightly with fiber content, while the extensional viscosity decreased initially and then increased with increasing fiber content.

A new organic-inorganic hybrid polyoxometalate based on Dawson-like polyoxotungstate anion [SbW18O60]9−, formulated [Co(2,2′-bpy)3]2[Co(2,2′-bpy)2Cl][Co(2,2′-bpy)2]H2[SbW18O60]·4H2O (2,2′-bpy=2,2′-bipyridine) has been synthesized from Sb2O3, Na2WO4, CoCl2, and 2,2′-bipyridine materials by hydrothermal method, and which was characterized by elemental analyses, IR, XPS, EPR, TG, and X-ray single crystal diffraction. Structure analysis shows that the polyoxoanion self-assembled under hydrothermal conditions consists of a Dawson-like polyoxotungstate cluster anion [SbW18O60]9− encapsulating capsulating a pyramidal {SbO3{ group within the {W18{ cluster cage. EPR spectra show that the high-spin octahedral Co∥ and low-spin Co∥ ions coexist in the title compound. Magnetic properties indicate that the compound is antiferromagnetic.