The addition of Psathyrostachys Huashanica Keng 6Ns large segment chromosomes has positive impact on stripe rust resistance and plant spikelet number of common wheat.

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.

Genome-wide association study and linkage mapping reveal TaqW-6B associated with water-extractable arabinoxylan content in wheat grain.

KEY MESSAGE: A novel QTL, TaqW-6B of water-extractable arabinoxylan content in the wheat grain on chromosome 6BL was identified and fine mapped in a narrow region 3.8 Mb. Water-extractable arabinoxylan (WE-AX), an important component of hemicellulose, is associated with various abundant health benefits. In this study, QTLs for WE-AX content were detected in two populations: (1) a recombinant inbred line (RIL) population with 164 lines derived from a cross between Avocet and Chilero (AC population) genotyped with diversity array technology (DArT), and (2) a natural population of 243 varieties (CH population) genotyped with the Axiom wheat 660 K single-nucleotide polymorphism (SNP) array. A stable QTL Qwe-ax.haust-6B, explaining 8.51-15.59% of the phenotypic variance, was mapped in the physical interval 459.38-572.09 Mb on the long arm of chromosome 6B in the AC population, tightly linked with DArT markers 3,944,740 and 4,991,038 under three experimental conditions. The Qwe-ax.haust-6B was further narrowed down to be delimited in the physical interval 516.47-571.58 Mb on chromosome 6BL, explaining 5.86-16.27% of the phenotypic variance in the CH population. Furthermore, we developed high-throughput kompetitive allele-specific PCR (KASP) markers to reconstruct the genetic linkage map in the AC population, and Qwe-ax.haust-6B was fine mapped into a narrow region named TaqW-6B, which was compressed between KASP-6B-3 and KASP-6B-6 at a physical distance of 3.8 Mb. In the meanwhile, the markers were also validated in a natural population of 160 wheat lines (NP population). Consequently, this study is of great importance to provide the theoretical basis for cloning the key gene and developing functional markers for molecular breeding.

Identification and validation of new quantitative trait loci for spike-related traits in two RIL populations.

Wheat (Triticum aestivum L.) is one of the most important cereal crops for ensuring food security worldwide. Identification of major quantitative trait loci (QTL) for spike-related traits is important for improvement of yield potential in wheat breeding. In this study, by using the wheat 55K single nucleotide polymorphism (SNP) array and diversity array technology (DArT), two recombinant inbred line populations derived from crosses avocet/chilero and avocet/huites were used to map QTL for kernel number per spike (KNS), total spikelet number per spike (TSS), fertile spikelet number per spike (FSS), and spike compactness (SC). Forty-two QTLs were identified on chromosomes 2A (4), 2B (3), 3A (2), 3B (7), 5A (11), 6A (4), 6B, and 7A (10), explaining 3.13-21.80% of the phenotypic variances. Twelve QTLs were detected in multi-environments on chromosomes 2A, 3B (2), 5A (4), 6A (3), 6B, and 7A, while four QTL clusters were detected on chromosomes 3A, 3B, 5A, and 7A. Two stable and new QTL clusters, QKns/Tss/Fss/SC.haust-5A and QKns/Tss/Fss.haust-7A, were detected in the physical intervals of 547.49-590.46 Mb and 511.54-516.15 Mb, accounting for 7.53-14.78% and 7.01-20.66% of the phenotypic variances, respectively. High-confidence annotated genes for QKns/Tss/Fss/SC.haust-5A and QKns/Tss/Fss.haust-7A were more highly expressed in spike development. The results provide new QTL and molecular markers for marker-assisted breeding in wheat. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01401-4.

Molecular cytogenetic characterization of a novel wheat-Psathyrostachys huashanica Keng T3DS-5NsL•5NsS and T5DL-3DS•3DL dual translocation line with powdery mildew resistance.

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.

Addition of Psathyrostachys huashanica HMW glutenin subunit expresses positive contribution to protein polymerization and gluten microstructure of receptor wheat.

Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) is considered as a valuable wild germplasm for wheat improvement on account of its numerous outstanding traits. During this study, 7182-1Ns with higher quality was screened out, a series of experiments were conducted to clarify the reasons of quality improvement. The results indicated 7182-1Ns was carried a novel high-molecular-weight glutenin subunit (HMW-GS) from P. huashanica, designated as P. huashanica' subunit in wheat (HS), which changed the HMW-GS compositions, increased the proportion of glutenins in wheat gluten protein, accelerated the accumulation speed of unextractable polymeric protein (UPP) during grain development stage accelerated, and a denser microstructure of the gluten network was formed in the dough. Therefore, the current research provides important reference on effectively utilize 7182-1Ns as an intermediate germplasm for quality breeding improvement.

Effect of gliadin from Psathrostachys huashanica on dough rheological properties and biscuit quality.

Psathrostachys huashanica (P. huashanica), a wild relative of common wheat, is widely used in wheat variety improvement because of its many beneficial properties. In this study, we carried out preliminary analysis on the grain and flour quality of wheat-P. huashanica addition line 7182-6Ns and its wheat parents 7182, and found that 7182-6Ns had a higher protein content and great dough rheological characteristics and investigated the reasons for the changes. The results indicated that 7182-6Ns contained exogenous gliadin, which changed the gliadin composition and increased the ratio of gliadin in total gluten proteins, rebuilt gluten microstructure and thus optimized dough extensibility. As the addition of 7182-6Ns gliadin gradually increased to wheat flour, the diameter, crispness and spread rate of biscuit increased, the thickness and hardness decreased, and the colour improved. The current research provides a basis for understanding the introduction of exogenic gliadin to improve biscuit wheat varieties.

Molecular Cytogenetic and Agronomic Characterization of the Similarities and Differences Between Wheat-Leymus mollis Trin. and Wheat-Psathyrostachys huashanica Keng 3Ns (3D) Substitution Lines.

Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) and Leymus mollis Trin. (2n = 4x = 28, NsNsXmXm) are valuable resources for wheat breeding improvement as they share the Ns genome, which contains diverse resistance genes. To explore the behaviors and traits of Ns chromosomes from the two species in wheat background, a series of wheat-P. huashanica and wheat-L. mollis substitution lines were developed. In the present study, line DH109 (F7 progeny of wheat-P. huashanica heptaploid line H8911 × durum wheat Trs-372) and line DM131 (F8 progeny of wheat-L. mollis octoploid line M842 × durum wheat Trs-372) were selected. Cytological observation combined with genomic in situ hybridization experiments showed that DH109 and DM131 each had 20 pairs of wheat chromosomes plus a pair of alien chromosomes (Ns chromosome), and the pair of alien chromosomes showed stable inheritance. Multiple molecular markers and wheat 55K SNP array demonstrated that a pair of wheat 3D chromosome in DH109 and in DM131 was substituted by a pair of P. huashanica 3Ns chromosome and a pair of L. mollis 3Ns chromosome, respectively. Fluorescence in situ hybridization (FISH) analysis confirmed that wheat 3D chromosomes were absent from DH109 and DM131, and chromosomal FISH karyotypes of wheat 3D, P. huashanica 3Ns, and L. mollis 3Ns were different. Moreover, the two lines had many differences in agronomic traits. Comparing with their wheat parents, DH109 expressed superior resistance to powdery mildew and fusarium head blight, whereas DM131 had powdery mildew resistance, longer spike, and more tiller number. Therefore, Ns genome from P. huashanica and L. mollis might have some different effects. The two novel wheat-alien substitution lines provide new ideas and resources for disease resistance and high-yield breeding on further utilization of 3Ns chromosomes of P. huashanica or L. mollis.

Fe3S4 Nanoparticles Wrapped in an rGO Matrix for Promising Energy Storage: Outstanding Cyclic and Rate Performance.

Iron sulfides/oxides/fluorides have been profoundly investigated as electrodes for rechargeable batteries recently in view of their high-theory capacities, low cost, and environmentally benign nature. Here, Fe3S4 nanoparticles (NPs) wrapped in reduced graphene oxide (Fe3S4 NPs@rGO) have been obtained using a simple one-pot hydrothermal approach, which is characterized using various techniques. As the anode for Li-ion batteries, Fe3S4 NPs@rGO displays a reversible discharge capacity of 950 mA h/g after 100 cycles at 0.1 A/g, and 720 mA h/g capacity can be achieved after 800 cycles even at 1 A/g. Even at 10 A/g, 462 mA h/g capacity can be maintained. The excellent electrochemical properties for Fe3S4 NPs@rGO can be ascribed to a collaborative effect between Fe3S4 NPs and an rGO matrix, which possess high Li-ion storage ability and excellent conductivity, respectively.