The heading date is an important trait that affects crop adaptability and significantly affects crop yield. The discovery and functional understanding of genes related to heading are crucial for wheat breeding in various environments. Aegilops tauschii, the D-genome donor of wheat, serves as an important model for exploring genetic regulatory mechanisms in common wheat. In this study, extremely early heading mutants were identified after treatment with 0.4% ethyl methanesulfonate (EMS) and compared with the wild type. Genetic analysis revealed that a single recessive gene was responsible for early heading, and gene mapping revealed a mutation in a 10.3-Mb region on the short arm of chromosome 6D. Bulked segregant exon capture sequencing revealed a missense mutation within the highly conserved nucleotide-binding domain of AET6Gv20469900, which encodes a protein phosphatase 2C (PP2C). This gene was in the mapping interval and associated with early heading. Transcriptomic profiling and quantitative validation analyses suggest that PP2C likely modulates vernalization pathways, thereby affecting heading date. This work provides a novel genetic resource for breeding early heading wheat cultivars.

Aegilops variabilis (S^vS^vU^vU^v) is a source of resistance to wheat stripe rust. The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai (KL) can induce homoeologous wheat-alien chromosome pairing and recombination. In this study, we confirmed that the whole 2S^v chromosome introgressed into wheat from Ae. variabilis accession AS116 conferred all-stage stripe rust resistance. The underlying gene(s), named YrAev, was mapped to the long arm 2S^vL using an F₂ population. Two 2S^v-2B recombinants, derived from a cross of the 2S^v (2B) chromosome substitution line and KL, were confirmed to harbor the resistance locus. The physical region containing YrAev, determined from RNA-seq data, was 844.6–852.1 Mb on the chromosome arm 2S^l of the Ae. longissima (S^v genome donor species of Ae. variabilis) accession TL05 assembly v1.0. Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes (annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein, respectively) as promising candidates for YrAev. This study demonstrates the utility of the phKL gene system in alien gene localization and transfer. The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.

Excessive accumulation of cadmium (Cd) impairs crop growth by inducing oxidative damage through the generation of reactive oxygen species (ROS). In this study, a biocompatible ferruginated carbon quantum dots (Fe-CQDs) nanozyme is developed to target ROS, thereby reducing oxidative damage and improving the absorption and transfer of Cd ions in wheat. Notably, Fe-CQDs exhibit multi-enzyme activities mimicking peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD), enabling effective neutralization of active species such as hydroxyl radicals (•OH), hydrogen peroxide (H₂O₂), and superoxide anions (O₂•⁻). Importantly, root application of 10 mg L⁻¹ Fe-CQDs alleviates Cd stress and promotes wheat growth in both hydroponic and soil cultures. Specifically, the levels of O₂•⁻, H₂O₂, and malondialdehyde (MDA) in leaf tissues decrease, whereas the non-enzyme antioxidant, reduced glutathione (GSH), increases. Cell wall thickness in the Fe-CQDs-treated group is reduced by 42.4% compared with the Cd group. Moreover, Fe-CQDs enhance the expression of genes related to antioxidants, stress resistance, Cd detoxification, and nutrient transport. Transcriptomic and metabolomic analyses show that Fe-CQDs stimulate the production of flavonoids and regulate the activity of metal transporter genes (YSL, ABC, ZIP) to maintain ROS homeostasis. These findings highlight the potential of Fe-CQDs nanozyme platforms in mitigating oxidative damage and enhancing crop growth, offering new insights into the application of nanobiotechnology in agriculture.

Wheat stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating disease threaten food security in China and worldwide. Epidemics of wheat stripe rust have been under control through applying resistant cultivars and crop protection approaches. However, due to climate change, innovation of cropping system, improvement of breeding technology, yield level enhancement of wheat cultivars, variation in structure and frequency of virulence genes in Pst populations in the new era, the current status of stripe rust resistance genes in wheat breeding programs need to be evaluated. The results could provide useful information for applying stripe rust resistance genes to develop new wheat cultivars with broad-spectrum and durable rust resistance. After multiple year’s stripe rust resistance survey, genetic analysis, molecular tagging and mining of stripe rust resistance genes in wheat cultivars and advanced breeding lines, the current status of major stripe rust resistance genes utilization was reviewed. We summarized the present situations of major stripe rust resistance gene discovery and germplasm innovation, the most frequently used stripe rust resistance genes, new strategy for pyramiding adult plant partial resistance and all stage resistance, and molecular marker assisted selection for developing wheat cultivars with broad spectrum and durable resistance in China. This review also proposes the major research areas in wheat stripe rust resistance breeding in the new era.

The continued expansion of the world population, increasingly inconsistent climate and shrinking agricultural resources present major challenges to crop breeding. Fortunately, the increasing ability to discover and manipulate genes creates new opportunities to develop more productive and resilient cultivars. Many genes have been described in papers as being beneficial for yield increase. However, few of them have been translated into increased yield on farms. In contrast, commercial breeders are facing gene decidophobia, i.e., puzzled about which gene to choose for breeding among the many identified, a huge chasm between gene discovery and cultivar innovation. The purpose of this paper is to draw attention to the shortfalls in current gene discovery research and to emphasise the need to align with cultivar innovation. The methodology dictates that genetic studies not only focus on gene discovery but also pay good attention to the genetic backgrounds, experimental validation in relevant environments, appropriate crop management, and data reusability. The close of the gaps should accelerate the application of molecular study in breeding and contribute to future global food security.

The Chinese wheat landrace Kaixianluohanmai (KL) expresses the ph-like phenotype. A major QTL, QPh.sicau-3A (syn. phKL), responsible for this effect has been mapped to chromosome arm 3AL. This study presents some characteristics of homoeologous pairing and recombination induced by phKL. In KL haploids, the level of homoeologous pairing was elevated relative to Ph1 Chinese Spring (CS) haploids. There was a clear preference for A–D pairing and less frequent for A–B and B–D, reflecting the higher levels of affinity between genomes A and D in wheat. The characteristics of pairing were affected by temperature and magnesium ion supplementation. The suitability of phKL for chromosome engineering was tested on three pairs of homoeologues: 2S^v-2B, 2S^v-2D, and 2RL-2BL. The recombination rates were 1.68%, 0.17%, and 0%, respectively. The phKL locus in KL induced a moderate level of homoeologous chromosome pairing and recombination when the Ph1 locus of wheat was present, both in wheat haploids and hexaploids. The Ph1-imposed criteria for chromosome pairing and crossing over were relaxed to some degree, permitting homoeologous crossing over but only between closely related chromosomes; there was no crossing over between more differentiated chromosomes. Therefore, the phKL system (QPh.sicau-3A) can be a useful tool in chromosome engineering of wheat to transfer genes from closely related species with the benefit of reduced genomic chaos generated by the ph1b mutation.

The common wheat landrace Chinese Spring (CS) was made famous by the work of Ernie Sears, a great cytogenetist, who developed a number of CS-based aneuploid series that were used to identify individual wheat chromosomes. Based on this, a standard karyotype and nomenclature system was developed for wheat chromosomes that allowed wheat researchers to analyze and manipulate the wheat genome with unprecedented precision and efficiency. Nevertheless, not much is known about the utilization of CS at its hometown, Chengdu in Sichuan province, during early wheat breeding activity. In this review, we follow the speculation that CS is a selection from the Cheng-du-guang-tou (CDGT) landrace. We provide a description of how CDGT became a founder landrace for wheat breeding activities in early times. We show that CDGT-derived varieties were reinforced genetically by crosses to six more exotic parents. These varieties remained the major elite cultivar for several decades. Later, synthetic hexaploid wheats were introduced into the breeding program, firstly using those from CIMMYT and later using materials produced with local tetraploid wheat and goat grass. Finally, we discuss the strategies and future directions to improve wheat yield and resistance through an expanded genetic basis, especially by recapturing lost genetic variations from landraces and related wild species, a process that may set an example for wheat breeders in China and elsewhere.