RESUMO
BACKGROUND: Developing novel germplasm by using wheat wild related species is an effective way to rebuild the wheat resource bank. The Psathyrostachys huashanica Keng (P. huashanica, 2n = 2x = 14, NsNs) is regarded as a superior species to improve wheat breeding because of its multi-resistance, early maturation and numerous tiller traits. Introducing genetic components of P. huashanica into the common wheat background is the most important step in achieving the effective use. Therefore, the cytogenetic characterization and influence of the introgressed P. huashanica large segment chromosomes in the wheat background is necessary to be explored. RESULTS: In this study, we characterized a novel derived line, named D88-2a, a progeny of the former characterized wheat-P. huashanica partial amphiploid line H8911 (2n = 7x = 49, AABBDDNs). Cytological identification showed that the chromosomal composition of D88-2a was 2n = 44 = 22II, indicating the addition of exogenous chromosomes. Genomic in situ hybridization demonstrated that the supernumerary chromosomes were a pair of homologues from the P. huashanica and could be stably inherited in the common wheat background. Molecular markers and 15 K SNP array indicated that the additional chromosomes were derived from the sixth homoeologous group (i.e., 6Ns) of P. huashanica. Based on the distribution of the heterozygous single-nucleotide polymorphism sites and fluorescence in situ hybridization karyotype of each chromosome, this pair of additional chromosomes was confirmed as P. huashanica 6Ns large segment chromosomes, which contained the entire short arm and the proximal centromere portion of the long arm. In terms of the agronomic traits, the addition line D88-2a exhibited enhanced stripe rust resistance, improved spike characteristics and increased protein content than its wheat parent line 7182. CONCLUSIONS: The new wheat germplasm D88-2a is a novel cytogenetically stable wheat-P. huashanica 6Ns large segment addition line, and the introgressed large segment alien chromosome has positive impact on plant spikelet number and stripe rust resistance. Thus, this germplasm can be used for genetic improvement of cultivated wheat and the study of functional alien chromosome segment.
Assuntos
Cromossomos de Plantas , Resistência à Doença , Doenças das Plantas , Triticum , Triticum/genética , Triticum/microbiologia , Triticum/crescimento & desenvolvimento , Cromossomos de Plantas/genética , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Melhoramento Vegetal , Poaceae/genética , Poaceae/microbiologia , Poaceae/crescimento & desenvolvimento , Basidiomycota/fisiologiaRESUMO
KEY MESSAGE: Xinong 511, a new wheat-Thinopyrum ponticum variety with excellent fusarium head blight resistance, the QTLs were mapped to the wheat chromosomes 5B and 7A with named QFhb.nwafu-5B and QFhb.nwafu-7A, respectively. Novel Fusarium head blight (FHB) resistance germplasms and genes are valuable for wheat improvement and breeding efforts. Thinopyrum ponticum, a wild relative of common wheat, is a valuable germplasm of disease resistance for wheat improvement and breeding. Xinong 511 (XN511) is a high-quality wheat variety widely cultivated in the Yellow and Huai Rivers Valley of China with stable FHB-resistance. Through analysis of pedigree materials of the wheat cultivar XN511, we found that the genetic material and FHB resistance from Th. ponticum were transmitted to the introgression line, indicating that the FHB resistance in XN511 likely originates from Th. ponticum. To further explore the genetic basis of FHB resistance in XN511, QTL mapping was conducted using the RILs population of XN511 and the susceptible line Aikang 58 (AK58). Survey with makers closely-linked to Fhb1, Fhb2, Fhb4, Fhb5, and Fhb7, indicated that both XN511 and the susceptible lines do not contain these QTL. Using bulked segregant analysis RNA-seq (BSR-Seq) and newly developed allele-specific PCR (AS-PCR) markers, QTLs in XN511 were successfully located on wheat chromosomes 5B and 7A. These findings are significant for further understanding and utilizing FHB resistance genes in wheat improvement.
Assuntos
Mapeamento Cromossômico , Cromossomos de Plantas , Resistência à Doença , Fusarium , Doenças das Plantas , Locos de Características Quantitativas , Triticum , Fusarium/patogenicidade , Fusarium/fisiologia , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Triticum/genética , Triticum/microbiologia , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Melhoramento Vegetal , Fenótipo , Marcadores Genéticos , Poaceae/genética , Poaceae/microbiologia , Ligação GenéticaRESUMO
KEY MESSAGE: A total of 90,000 capture probes derived from wheat and Thinopyrum elongatum were integrated into one chip, which served as an economical genotype for explorating Thinopyrumspecies and their derivatives. Thinopyrum species play a crucial role as a source of new genetic variations for enhancing wheat traits, including resistance to both abiotic and biotic factors. Accurate identification of exogenous chromosome(s) or chromosome segments or genes is essential following the introduction of alien genetic material into wheat, but this task remains challenging. This study aimed to develop a high-resolution wheat-Thinopyrum elongatum array, named GenoBaits®WheatplusEE, to trace alien genetic information by genotyping using a target sequencing system. This GenoBaits®WheatplusEE array included 90,000 capture probes derived from two species and integrated into one chip, with 10,000 and 80,000 originating from wheat and Th. elongatum, respectively. The capture probes were strategically positioned in genes and evenly distributed across the genome, facilitating the development of a roadmap for identifying each alien gene. The array was applied to the high-throughput identification of the alien chromosomes or segments in Thinopyrum and distantly related species and their derivatives. Our results demonstrated that the GenoBaits®WheatplusEE array could be used for direct identification of the breakpoint of alien segments, determine copy number of alien chromosomes, and reveal variations in wheat chromosomes by a single round of target sequencing of the sample. Additionally, we could efficiently and cost-effectively genotype, supporting the exploration of subgenome composition, phylogenetic relationships, and polymorphisms in essential genes (e.g., Fhb7 gene) among Thinopyrum species and their derivatives. We hope that GenoBaits®WheatplusEE will become a widely adopted tool for exporting wild germplasm for wheat improvement in the future.
Assuntos
Poaceae , Triticum , Triticum/genética , Filogenia , Poaceae/genética , Fenótipo , Polimorfismo GenéticoRESUMO
Cytochrome P450 monooxygenases (CYP450s) play a variety of physiological roles, including pesticide resistance, plant allelochemical detoxification, and hormone metabolism catalysis. However, limited information is available on the classification and expression profiles of the CYP450 gene family in aphid species. This is the first study to identify the cytochrome P450 gene family in 19 aphid species at the whole genome level. A total of 1100 CYP450 genes were identified in 19 aphid species. Three hundred CYP450 genes belonged to six cereal crop aphid species, which were further classified into four subfamilies according to the phylogenetic relationship. The conserved motifs, exon-intron structures, and genomic organization of the same subfamilies were similar. Predictions of subcellular localization revealed that the endoplasmic reticulum harbored the majority of CYP450 proteins. In Sitobion avenae and Rhopalosiphum maidis, the increase in the CYP450 gene was primarily caused by segmental duplication events. However, only tandem duplication occurred in the CYP450 gene family of Diuraphis noxia, Rhopalosiphum padi, Schizaphis graminum, and Sitobion miscanthi. Synteny analysis found three continuous colinear CYP450 gene pairs among six cereal crop aphid species. Furthermore, we obtained the expression profiles of four cereal crop aphids, including R. padi, D. noxia, S. graminum, and S. avenae. Differential expression analysis provided growth stage specificity genes, tissue specificity genes, organ specificity genes and some detoxification metabolic genes among these four cereal crop aphids. Meanwhile, their expression patterns were showed. The related functions and pathways of CYP450s were revealed by GO and KEGG enrichment analysis. Above all, we picked the differentially expressed CYP450 genes from all of the differentially expressed genes (DEGs). These differentially expressed CYP450 genes provided some new potential candidates for aphid control and management. This work establishes the foundation for further investigations into the regulatory functions of the CYP450 gene family in aphid species and beyond.
Assuntos
Afídeos , Sistema Enzimático do Citocromo P-450 , Família Multigênica , Filogenia , Afídeos/genética , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Grão Comestível/genética , Grão Comestível/parasitologia , Genoma de Inseto , Perfilação da Expressão Gênica , Sintenia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismoRESUMO
Giardia duodenum (G. duodenalis) can cause giardiasis and infect a variety of hosts. So far, there have been no detailed data regarding the positive rate of G. duodenalis in sheep and goats in China. Here, a systematic literature review was carried out to investigate the epidemiology of G. duodenalis in sheep and goats in China. To perform the meta-analysis, the databases CNKI, VIP, WanFang, PubMed, Web of science and ScienceDirect were employed for screening studies related to the prevalence of G. duodenalis in sheep and goats in China. The total prevalence of G. duodenalis in sheep and goats was estimated to be 7.00% (95% CI: 4.00-10.00). In the age subgroup, the prevalence of G. duodenalis in sheep and goats of >12 months (11.29%; 95% CI: 8.08-14.97) was higher than that in sheep and goats of ≤12 months (7.57%; 95% CI: 3.95-12.24). An analysis based on seasons showed that the prevalence of G. duodenalis in sheep and goats was higher in summer (11.90%; 95% CI: 0.50-35.05) than that in other seasons. The prevalence of G. duodenalis in sheep and goats after 2016 was 8.57% (95% CI: 5.34-11.79), which was higher than others. The highest prevalence of G. duodenalis in sheep and goats was 13.06% (95% CI: 6.26-19.86) recorded in Southwestern China. The prevalence of Giardia infection in sheep (7.28%; 95% CI: 2.30-14.73) was higher than that in goats (5.43%; 95% CI: 2.73-8.98). The NOAA's National Center for Environmental Information (https://gis.ncdc.noaa.gov/maps/ncei/cdo/monthly) was used to extract relevant geoclimatic data (latitude, longitude, elevation, temperature, precipitation, humidity, and climate). By analyzing the data of each subgroup, it was shown that region, genetype, and climate were potential risk factors for giardiasis prevalence in sheep and goats. Based on the analysis of common factors and geographical factors, it is recommended to strengthen effective management measures (e.g. ventilation and disinfection in warm and humid areas) and formulate relevant policies according to local conditions. Breeders should strengthen the detection of G. duodenalis in sheep and goats, customize corresponding control measures according to the diet and living habits of sheep and goats, and strengthen the protection of sheep and lamb calves, so as to reduce the incidence rate and reduce the economic loss of China's animal husbandry.
Assuntos
Giardia lamblia , Giardíase , Animais , Ovinos , Giardíase/epidemiologia , Giardíase/veterinária , Cabras , Prevalência , China/epidemiologia , Fezes , GenótipoRESUMO
Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) is an excellent gene resource for wheat breeding, which is characterized by early maturity, low plant height, and disease resistance. The wheat-P. huashanica derivatives were created by the elite genes of P. huashanica and permeate into common wheat through hybridization. Among them, a long-glume material 20JH1155 was identified, with larger grains and longer spike than its parents. In the present study, the methods of cytological observation, GISH, and sequential FISH analysis showed that 20JH1155 contained 21 pairs of wheat chromosomes and a pair of P. huashanica. There were some differences in 5A and 7B chromosomes between 20JH1155 and parental wheat 7182. Molecular marker, FISH, and sequence cloning indicated 20JH1155 alien chromosomes were 3Ns of P. huashanica. In addition, differentially expressed genes during immature spikelet development of 20JH1155 and 7182 and predicted transcription factors were obtained by transcriptome sequencing. Moreover, a total of 7 makers derived from Ph#3Ns were developed from transcriptome data. Taken together, the wheat-P. huashanica derived line 20JH1155 provides a new horizon on distant hybridization of wheat and accelerates the utilization of genes of P. huashanica.
Assuntos
Melhoramento Vegetal , Triticum , Triticum/genética , Poaceae/genética , Resistência à Doença/genética , Hibridização Genética , Doenças das Plantas/genéticaRESUMO
BACKGROUND: Owing to their excellent resistance to abiotic and biotic stress, Thinopyrum intermedium (2n = 6x = 42, JJJsJsStSt) and Th. ponticum (2n = 10x = 70) are both widely utilized in wheat germplasm innovation programs. Disomic substitution lines (DSLs) carrying one pair of alien chromosomes are valuable bridge materials for transmission of novel genes, fluorescence in situ hybridization (FISH) karyotype construction and specific molecular marker development. RESULTS: Six wheat-Thinopyrum DSLs derived from crosses between Abbondanza nullisomic lines (2n = 40) and two octoploid Trititrigia lines (2n = 8x = 56), were characterized by sequential FISH-genome in situ hybridization (GISH), multicolor GISH (mc-GISH), and an analysis of the wheat 15 K SNP array combined with molecular marker selection. ES-9 (DS2St (2A)) and ES-10 (DS3St (3D)) are wheat-Th. ponticum DSLs, while ES-23 (DS2St (2A)), ES-24 (DS3St (3D)), ES-25(DS2St (2B)), and ES-26 (DS2St (2D)) are wheat-Th. intermedium DSLs. ES-9, ES-23, ES-25 and ES-26 conferred high thousand-kernel weight and stripe rust resistance at adult stages, while ES-10 and ES-24 were highly resistant to stripe rust at all stages. Furthermore, cytological analysis showed that the alien chromosomes belonging to the same homoeologous group (2 or 3) derived from different donors carried the same FISH karyotype and could form a bivalent. Based on specific-locus amplified fragment sequencing (SLAF-seq), two 2St-chromosome-specific markers (PTH-005 and PTH-013) and two 3St-chromosome-specific markers (PTH-113 and PTH-135) were developed. CONCLUSIONS: The six wheat-Thinopyrum DSLs conferring stripe rust resistance can be used as bridging parents for transmission of valuable resistance genes. The utility of PTH-113 and PTH-135 in a BC1F2 population showed that the newly developed markers could be useful tools for efficient identification of St chromosomes in a common wheat background.
Assuntos
Cromossomos de Plantas , Resistência à Doença/genética , Marcadores Genéticos , Poaceae/genética , Poaceae/microbiologia , Puccinia/patogenicidade , Triticum/genética , Triticum/microbiologia , Análise Citogenética , Variação Genética , GenótipoRESUMO
KEY MESSAGE: A novel major QTL for FHB resistance was mapped to a 6.8 Mb region on chromosome 2D in a Chinese wheat cultivar Ji5265, and diagnostic KASP markers were developed for detecting it in a worldwide wheat collection. Fusarium head blight (FHB) is a serious disease in wheat (Triticum aestivum L.) and causes significant reductions in grain yield and quality worldwide. Breeding for FHB resistance is the most effective strategy to minimize the losses caused by FHB; therefore, identification of major quantitative trait loci (QTLs) conferring FHB resistance and development of diagnostic markers for the QTLs are prerequisites for marker-assisted selection (MAS). Ji5265 is a Chinese wheat cultivar resistant to FHB in multiple environments. An F6 population of 179 recombinant inbred lines (RILs) was developed from Ji5265 × Wheaton. The population was genotyped by genotyping-by-sequencing (GBS) and phenotyped for FHB Type II resistance in greenhouses. A major QTL, designated as QFhb-2DL, was mapped in a 6.8 Mb region between the markers GBS10238 and GBS12056 on the long arm of chromosome 2D in Ji5265 and explained ~ 30% of the phenotypic variation for FHB resistance. The effect of QFhb-2DL on FHB resistance was validated using near-isogenic lines (NILs) derived from residual heterozygotes from an F6 RIL of Ji5265 × Wheaton. The two flanking markers were converted into Kompetitive allele-specific PCR (KASP) markers (KASP10238 and KASP12056) and validated to be diagnostic in a collection of 2,065 wheat accessions. These results indicate that QFhb-2DL is a novel major QTL for resistance to FHB spread within a spike (Type II) and the two KASP markers can be used for MAS to improve wheat FHB resistance in wheat breeding programs.
Assuntos
Fusarium , China , Mapeamento Cromossômico , Melhoramento Vegetal , Doenças das Plantas/genética , Locos de Características Quantitativas , Triticum/genéticaRESUMO
Leymus mollis (2n = 4x = 28, NsNsXmXm), a wild relative of common wheat (Triticum aestivum L.), carries numerous loci which could potentially be used in wheat improvement. In this study, line 17DM48 was isolated from the progeny of a wheat and L. mollis hybrid. This line has 42 chromosomes forming 21 bivalents at meiotic metaphase I. Genomic in situ hybridization (GISH) demonstrated the presence of a pair chromosomes from the Ns genome of L. mollis. This pair substituted for wheat chromosome 2D, as shown by fluorescence in situ hybridization (FISH), DNA marker analysis, and hybridization to wheat 55K SNP array. Therefore, 17DM48 is a wheat-L. mollis 2Ns (2D) disomic substitution line. It shows longer spike and a high level of stripe rust resistance. Using specific-locus amplified fragment sequencing (SLAF-seq), 13 DNA markers were developed to identify and trace chromosome 2Ns of L. mollis in wheat background. This line provides a potential bridge germplasm for genetic improvement of wheat stripe rust resistance.
Assuntos
Basidiomycota , Triticum , Basidiomycota/genética , Cromossomos de Plantas/genética , Resistência à Doença/genética , Marcadores Genéticos , Hibridização in Situ Fluorescente , Doenças das Plantas/genética , Poaceae/genética , Triticum/genéticaRESUMO
The grain aphid Sitobion avenae (Fabricius) is one of the most destructive pests of wheat (Triticum aestivum). Deployment of resistant wheat germplasm appears as an excellent solution for this problem. Elite bread wheat cultivars only have limited resistance to this pest. The present study was carried out to investigate the potential of the tetraploid wheat (Triticum turgidum) variety Lanmai, which showed high resistance to S. avenae at both seedling and adult plant stages, as a source of resistance genes. Based on apterous adult aphids' fecundity tests and choice bioassays, Lanmai has been shown to display antixenosis and antibiosis. Suppression subtractive hybridization (SSH) was employed to identify and isolate the putative candidate defense genes in Lanmai against S. avenae infestation. A total of 134 expressed sequence tags (ESTs) were identified and categorized based on their putative functions. RT-qPCR analysis of 30 selected genes confirmed their differential expression over time between the resistant wheat variety Lanmai and susceptible wheat variety Polan305 during S. avenae infestation. There were 11 genes related to the photosynthesis process, and only 3 genes showed higher expression in Lanmai than in Polan305 after S. avenae infestation. Gene expression analysis also revealed that Lanmai played a critical role in salicylic acid and jasmonic acid pathways after S. avenae infestation. This study provided further insights into the role of defense signaling networks in wheat resistance to S. avenae and indicates that the resistant tetraploid wheat variety Lanmai may provide a valuable resource for aphid tolerance improvement in wheat.
Assuntos
Afídeos , Animais , Antibiose , Ácido Salicílico , Tetraploidia , Triticum/genéticaRESUMO
Synthetic hexaploid wheat offers breeders ready access to potentially novel genetic variation in wild ancestral species. In this study, we crossed MY3478 (2n = 4x = 28, AABB) as the maternal parent with the stripe rust-resistant SY41 (2n = 2x = 14, DD) as the paternal parent to construct the new hexaploid wheat line NA0928 through natural allopolyploidization. Agronomic traits and the cytology of the S8-S9 generations of NA0928 were analyzed. Abundant variation in agronomic traits was observed among each strain of NA0928 in the S8 generation. Agronomic traits were superior in strains resistant to stripe rust compared with those of highly susceptible strains. The rank order of the coefficients of variation were tiller number (55.3%) > spike length (15.3%) > number of spikelets (13.9%) > plant height (8.7). Number of tillers and spike length are important traits in wheat breeding to improve yield. Cytological observation and fluorescence in situ hybridization showed that the chromosome number and configuration showed rich variation among NA0928 strains in the S9 generation. Chromosome number ranged from 36 to 44. Variation in chromosome karyotype was detected in the A and B subgenomes. Meiotic chromosome behavior in pollen mother cells and multicolor genomic in situ hybridization revealed that two new synthetic hexaploid wheat strains showed genetic stability; one strain was resistant to stripe rust and developed multiple tillers, and the other strain was susceptible to stripe rust, but both showed improved thousand-kernel weight (TKW) weight and produced multiple tillers. The two strains will be valuable germplasm resources for use in wheat breeding.
RESUMO
BACKGROUND: Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) carries many outstanding agronomic traits, therefore is a valuable resource for wheat genetic improvement. Wheat-P. huashanica translocation lines are important intermediate materials for wheat breeding and studying the functions of alien chromosomes. However, powdery mildew resistance in these translocation lines has not been reported previously. RESULTS: This study developed a novel wheat-P. huashanica translocation line TR77 by selecting a F7 progeny from the cross between heptaploid hybrid H8911 (2n = 7x = 49, AABBDDNs) and durum wheat line Trs-372. Chromosome karyotype of 2n = 42 = 21II was observed in both mitotic and meiotic stages of TR77. Genomic in situ hybridization analysis identified two translocated chromosomes that paired normally at meiosis stage in TR77. Molecular marker analysis showed that part of chromosome 5D was replaced by part of alien chromosome fragment 5Ns. It meant replacement made part 5DL and part 5NsL·5NsS existed in wheat background, and then translocation happened between these chromosomes and wheat 3D chromosome. Fluorescence in situ hybridization demonstrated that TR77 carries dual translocations: T3DS-5NsL·5NsS and T5DL-3DS·3DL. Analysis using a 15 K-wheat-SNP chip confirmed that SNP genotypes on the 5D chromosome of TR77 matched well with these of P. huashanica, but poorly with common wheat line 7182. The translocation was physically located between 202.3 and 213.1 Mb in 5D. TR77 showed longer spikes, more kernels per spike, and much better powdery mildew resistance than its wheat parents: common wheat line 7182 and durum wheat line Trs-372. CONCLUSIONS: TR77 is a novel stable wheat-P. huashanica T3DS-5NsL·5NsS and T5DL-3DS·3DL dual translocation line and showed significant improved spike traits and resistance to powdery mildew compared to its parents, thus, it can be an useful germplasm for breeding disease resistance and studying the genetic mechanism of dual translocations.
Assuntos
Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/microbiologia , Cruzamento , Resistência à Doença/genética , Etiquetas de Sequências Expressas , Hibridização Genética , Hibridização in Situ Fluorescente , Cariótipo , Repetições de Microssatélites , Fenótipo , Poaceae/genética , Poaceae/microbiologia , Translocação GenéticaRESUMO
Fructans play vital roles in abiotic stress tolerance in plants. In this study, we isolated the sucrose:6-fructosyltransferase gene, which is involved in the synthesis of fructans, from Leymus mollis by rapid amplification of cDNA ends. The Lm-6-SFT gene was introduced into Arabidopsis thaliana cv. Columbia by Agrobacterium-mediated transformation. The transgenic plants were evaluated under salt stress conditions. The results showed that the expression of Lm-6-SFT was significantly induced by light, abscisic acid (ABA), salicylic acid (SA), and salt treatment in L. mollis plants. Overexpression of Lm-6-SFT in Arabidopsis promoted seed germination and primary root growth during the early vegetative growth stage under salt stress. We also found that the transgenic plants expressing Lm-6-SFT had increased proline and fructan levels. ß-Glucuronidase staining and promoter analysis indicated that the promoter of Lm-6-SFT was regulated by light, ABA, and salt stress. Quantitative PCR suggested that overexpression of Lm-6-SFT could improve salt tolerance by interacting with the expression of some salt stress tolerance genes. Thus, we demonstrated that the Lm-6-SFT gene is a candidate gene that potentially confers salt stress tolerance to plants. Our study will aid the elucidation of the regulatory mechanism of 6-SFT genes in herb plants.
Assuntos
Arabidopsis/genética , Arabidopsis/metabolismo , Frutanos/metabolismo , Hexosiltransferases/genética , Poaceae/genética , Tolerância ao Sal/genética , Regulação da Expressão Gênica de Plantas , Hexosiltransferases/metabolismo , Fases de Leitura Aberta , Fenótipo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Estresse Fisiológico/genéticaRESUMO
We characterized a wheat-Psathyrostachys huashanica derived line 3-6-4-1 based on genomic in situ hybridization (GISH), molecular marker analysis, and agronomic trait evaluations. The GISH investigations showed that the 3-6-4-1 contained 42 wheat chromosomes and a pair of P. huashanica chromosomes. The homoeologous relationships of the introduced P. huashanica chromosomes were determined using EST-STS multiple loci markers from seven wheat homoeologous groups in the parents and the addition line. Twelve EST-STS markers located on the homoeologous group 2 chromosomes of wheat amplified polymorphic bands in 3-6-4-1, which were unique to P. huashanica. An introduced Ns chromosome pair that belonged to homoeologous group 2 was identified using chromosome-specific markers. Inoculation with isolates of the stripe rust pathotypes, CYR31, CYR32, and SY11-14, and mixed races (CYR31, CYR32, and SY11-14) in the seeding and adult stage, respectively, showed that 3-6-4-1 was generally resistant to stripe rust, which was probably attributable to its P. huashanica parent. We also compared a complete set of wheat-P. huashanica disomic addition lines (1Ns-7Ns, 2n = 44 = 22II) to assess their agronomic traits and morphological characteristics, which showed that 3-6-4-1 had improved spike traits compared with its parents. The P. huashanica 2Ns chromosome-specific molecular markers in 3-6-4-1 could be useful for marker-assisted selection in breeding programs to combat stripe rust. This line can be used as a donor source to introduce novel excellent genes from P. huashanica into wheat to widen its genetic diversity, thereby providing new germplasms for wheat breeding.
Assuntos
Resistência à Doença/genética , Doenças das Plantas/microbiologia , Plântula/genética , Triticum/genética , Sequência de Bases , Basidiomycota/fisiologia , Cromossomos de Plantas/genética , Diploide , Etiquetas de Sequências Expressas , Genes de Plantas , Ligação Genética , Hibridização Genética , Plântula/imunologia , Plântula/microbiologia , Triticum/imunologia , Triticum/microbiologiaRESUMO
Exploiting and utilizing excellent gene(s) from wild species has become an essential strategy for wheat improvement. In the disomic addition line 24-6-3, the 4Ns chromosomes from Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) carried valuable tiller and strip rust resistance gene(s), which was selected from the progeny of common wheat cv. 7182 and P. huashanica via embryo culture. Cytology, genomic in situ hybridization (GISH), and EST-STS analyses were used to detect the 4Ns chromosome in wheat background and its homoeologous relationship. Cytological studies demonstrated that 24-6-3 contained 44 chromosomes and formed 22 bivalents during meiotic metaphase I. GISH using P. huashanica genomic DNA as a probe indicated that a pair of Ns-chromosomes with strong hybridization signals had been introduced into 24-6-3. Ten EST-STS markers, i.e., BE404973, BE442811, BE446061, BE446076, BE497324, BE591356, BF473854, BG274986, BQ161513 and CD373484, which were located on the homoeologous group 4 chromosomes of wheat, amplified bands unique to P. huashanica in 24-6-3. This indicated the presence of an introgressed P. huashanica Ns chromosome pair belonging to homoeologous group 4, which we designated the 4Ns disomic addition line. After it was inoculated using mixed races of stripe rust in the adult stages, 24-6-3 expressed high stripe rust resistance, which was possibly derived from its P. huashanica parent. Moreover, its increased number of tillers was probably controlled by gene(s) located in P. huashanica chromosome 4Ns. These high levels of disease resistance and excellent agronomic traits make the 24-6-3 line a promising germplasm for breeding in wheat.
Assuntos
Cromossomos de Plantas , Doenças das Plantas/microbiologia , Poaceae/genética , Triticum/genética , Triticum/microbiologia , Basidiomycota/patogenicidade , Cruzamento/métodos , Resistência à Doença/genética , Etiquetas de Sequências Expressas , Marcadores Genéticos , Doenças das Plantas/genética , Característica Quantitativa HerdávelRESUMO
We isolated a wheat germplasm line, 22-2, which was derived from common wheat (Triticum aestivum '7182') and Psathyrostachys huashanica 'Keng' (2n = 2x = 14, NsNs). Genomic composition and homoeologous relationships of 22-2 was analyzed using cytology, genomic in situ hybridization (GISH), EST-SSR, and EST-STS to characterize the alien chromatin in the transfer line. The cytological investigations showed that the chromosome number and configuration were 2n = 44 = 22 II. Mitotic and meiotic GISH using P. huashanica genomic DNA as the probe indicated that 22-2 contained a pair of P. huashanica chromosomes. The genomic affinities of the introduced P. huashanica chromosomes were determined by EST-SSR and EST-STS using multiple-loci markers from seven wheat homoeologous groups between the parents and addition line. One EST-SSR and 17 EST-STS markers, which were located on the homoeologous group 3 chromosomes of wheat, amplified polymorphic bands in 22-2 that were unique to P. huashanica. Thus, these markers suggested that the introduced Ns chromosome pair belonged to homoeologous group 3, so we designated 22-2 as a 3Ns disomic addition line. Based on disease reaction to mixed races (CYR31, CYR32, and Shuiyuan14) of stripe rust in the adult stages, 22-2 was found to have high resistance to stripe rust, which was possibly derived from its P. huashanica parent. Consequently, the new disomic addition line 22-2 could be a valuable donor source for wheat improvement depending on the excellent agronomic traits, especially, the introduction of novel disease resistance genes into wheat during breeding programs.
Assuntos
Basidiomycota/crescimento & desenvolvimento , Cromatina/genética , Doenças das Plantas/genética , Poaceae/genética , Triticum/genética , Pareamento Cromossômico , Cromossomos de Plantas , Análise Citogenética , Resistência à Doença , Marcadores Genéticos , Hibridização Genética , Poaceae/crescimento & desenvolvimento , Poaceae/microbiologia , Triticum/crescimento & desenvolvimento , Triticum/microbiologia , Dissomia UniparentalRESUMO
The imbalances of storage capacity and reaction kinetics between carbonaceous cathodes and zinc (Zn) anodes restrict the widespread application of Zn-ion hybrid capacitor (ZIHC). Structure optimization is a promising strategy for carbon materials to achieve sufficient Zn2+ storage sites and satisfied ion-electron kinetics. Herein, porous graphitic carbon nanosheets (PGCN) were simply synthesized using a K3[Fe(C2O4)3]- and urea-assisted foaming strategy with polyvinylpyrrolidone as carbon precursor, followed by activation and graphitization. Sufficient pores with well-matched pore sizes (0.80-1.94 nm) distributed across the carbon nanosheets can effectively shorten mass-transfer distance, promoting accessibility to active sites. A partially graphitic carbon structure with high graphitization degree can accelerate electron transfer. Furthermore, high nitrogen doping (7.2 at.%) provides additional Zn2+ storage sites to increase storage capacity. Consequently, a PGCN-based ZIHC has an exceptional specific capacity of 181 mAh g-1 at 0.5 A g-1, superb energy density of 145 Wh kg-1, and excellent cycling ability without capacity decay over 10,000 cycles. In addition, the flexible solid-state device assembled with PGCN exhibits excellent electrochemical performances even when bent at various angles. This study proposes a straightforward and economical strategy to construct porous graphitic carbon nanosheets with enhanced storage capacity and fast reaction kinetics for the high performance of ZIHC.
RESUMO
The human vagina harbours diverse microorganisms-bacteria, viruses and fungi-with profound implications for women's health. Genome-level analysis of the vaginal microbiome across multiple kingdoms remains limited. Here we utilize metagenomic sequencing data and fungal cultivation to establish the Vaginal Microbial Genome Collection (VMGC), comprising 33,804 microbial genomes spanning 786 prokaryotic species, 11 fungal species and 4,263 viral operational taxonomic units. Notably, over 25% of prokaryotic species and 85% of viral operational taxonomic units remain uncultured. This collection significantly enriches genomic diversity, especially for prevalent vaginal pathogens such as BVAB1 (an uncultured bacterial vaginosis-associated bacterium) and Amygdalobacter spp. (BVAB2 and related species). Leveraging VMGC, we characterize functional traits of prokaryotes, notably Saccharofermentanales (an underexplored yet prevalent order), along with prokaryotic and eukaryotic viruses, offering insights into their niche adaptation and potential roles in the vagina. VMGC serves as a valuable resource for studying vaginal microbiota and its impact on vaginal health.
Assuntos
Bactérias , Microbiota , Vagina , Humanos , Feminino , Vagina/microbiologia , Vagina/virologia , Microbiota/genética , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Metagenômica/métodos , Fungos/genética , Fungos/classificação , Fungos/isolamento & purificação , Filogenia , Genoma Microbiano , Metagenoma , Vírus/genética , Vírus/classificação , Vírus/isolamento & purificação , Vaginose Bacteriana/microbiologiaRESUMO
Frequent exchange of surface water and groundwater occurs in arid/semi-arid areas due to high evaporation and intensive irrigation activities, affecting the migration and transformation of per- and polyfluoroalkyl substances (PFASs) and threatening drinking water safety. This study analyzed legacy PFASs and potential precursors in surface water, groundwater, soil, and aquifer solid samples collected from a typical arid area, the Hetao Irrigation District of Northern China, to explore PFASs distribution and transformation between surface and ground. Total PFASs (ΣPFASs) in surface water was 29-232 ng/L, higher than 2-77 ng/L in groundwater. ΣPFASs in soil were 0.29-0.59 ng/g, higher than 0.09-0.27 in the aquifer solids. Regarding horizontal distribution, the concentration of PFASs in groundwater increased in downtowns and the areas recharged with lake water. In terms of vertical distribution, ΣPFASs decreased with the increase of depth, and more PFASs adsorbed on clay particles in the aquifer. The total oxidable precursor analysis showed that 8:2 FT and 4:2 FT were the dominant precursors of PFASs, resulting in an increment of 0.1-4 ng/L PFASs. Hydrogen and oxygen stable isotope compositions suggest similar sources between surface water and groundwater in the study area, while principal component analysis and Bayesian inference also indicate that surface water is an important source of groundwater PFASs. The annual infiltration PFASs to groundwater from Ulansuhai was estimated by the water balance approach to be 9.39 kg. Results highlight the influence of agricultural irrigation activities and lake infiltration on groundwater PFASs in the arid region.
Assuntos
Fluorocarbonos , Água Subterrânea , Poluentes Químicos da Água , Fluorocarbonos/análise , Teorema de Bayes , Poluentes Químicos da Água/análise , Solo , Lagos , Água/análise , China , Monitoramento Ambiental/métodosRESUMO
In the spot market for air cargo, airlines typically adopt dynamic pricing to tackle demand uncertainty, for which it is difficult to accurately estimate the distribution. This study addresses the problem where a dominant airline dynamically sets prices to sell its capacities within a two-phase sales period with only partial information. That partial information may show as the moments (upper and lower bounds and mean) and the median of the demand distribution. We model the problem of dynamic pricing as a distributional robust stochastic programming, which minimizes the expected regret value under the worst-case distribution in the presence of partial information. We further reformulate the proposed non-convex model to show that the closed-form formulae of the second-stage maximal expected regret are well-structured. We also design an efficient algorithm to characterize robust pricing strategies in a polynomial-sized running time. Using numerical analysis, we present several useful managerial insights for airline managers to strategically collect demand information and make prices for their capacities in different market situations. Moreover, we verify that additional information will not compromise the viability of the pricing strategies being implemented. Therefore, the method we present in this paper is easier for airlines to use.