Drought severely limits global wheat production, and mining drought-adaptive genetic variation is critical for molecular breeding. Here, the elite wheat cultivar Zhou8425B exhibited significantly greater drought tolerance than Chinese Spring (CS), characterized by reduced leaf wilting, enhanced antioxidant capacity, improved osmotic adjustment, and lower oxidative damage under drought stress. Comparative transcriptome analysis across multiple abiotic stresses revealed preferential enrichment of bZIP transcription factors during drought responses. Genome-wide characterization identified 253 TabZIP genes in Zhou8425B, with subgroup A predominantly associated with abscisic acid (ABA)-mediated drought signaling. Integrative differential expression and co-expression network analyses identified TabZIP200 as a central drought-responsive regulator. TabZIP200 was strongly induced by drought and consistently exhibited higher expression in Zhou8425B than in CS. Virus-induced gene silencing significantly compromised drought tolerance, accompanied by increased reactive oxygen species accumulation, reduced antioxidant enzyme activities, and suppressed expression of several drought-responsive genes. Comparative promoter analysis identified a naturally occurring single nucleotide polymorphism within an ABRE cis-element. Promoter truncation, reciprocal site-directed mutagenesis, and dual-luciferase assays demonstrated that this polymorphism is the major cis-regulatory determinant controlling drought-inducible TabZIP200 expression. Furthermore, a functional KASP marker targeting this polymorphism was validated in both a recombinant inbred line population and diverse wheat accessions, showing significant associations with enhanced drought tolerance and favorable yield-related traits. Together, these findings establish TabZIP200 as a key regulator of wheat drought adaptation and demonstrate that natural cis-regulatory variation in its promoter provides a valuable genetic resource for drought-resilient wheat breeding.

Plasmodesmata (PD) play vital roles in plant growth and defense through controlling symplastic transport of important molecules. Here we report that a conserved COBRA-like protein, COBL3, is required for PD-mediated antiviral defense (PMAD) against divergent plant RNA viruses in wheat (Triticum aestivum) and tobacco (Nicotiana benthamiana) via positively regulating callose accumulation. The wheat COBL3 protein, TaCOBL3, interacts with the 17K movement protein (MP) of barley yellow dwarf virus-GAV (BYDV-GAV). TaCOBL3 is associated with the plasma membrane and co-locates with 17K MP at PD. Genetic analysis with overexpression and knockout lines reveals that TaCOBL3 positively regulates wheat defense against BYDV-GAV through modulating callose accumulation at PD. Interestingly, TaCOBL3 interacts with the wheat homolog of PDLP5, a conserved key PD permeability regulator in higher plants. Silencing TaPDLP5 diminishes the elevated BYDV-GAV defense conferred by TaCOBL3 overexpression in wheat. Furthermore, transient expression of TaCOBL3 promotes callose accumulation and lowers PD permeability in tobacco cells, which is, however, largely compromised when tobacco PDLP5 is silenced. Notably, BYDV 17K MP weakens the interaction between TaCOBL3 and TaPDLP5 and inhibits their callose binding activities. Finally, silencing tobacco NbCOBL3 gene decreases callose content and attenuated host defense against two tobraviruses, one potexvirus, and one hordeivirus. Overall, our study reveals a previously unknown role of COBRA-like proteins in PMAD and provides insight into how a plant viral MP sabotages PMAD through perturbing COBL3-PDLP5 interaction to facilitate virus spread through PD. The conserved COBL3 gene may represent a valuable target for engineering broad-spectrum antiviral resistance in crop plants.

Lipoxygenases (LOXs) play vital roles in plant growth and defense. In this study, through genomic and molecular analyses, we discover a major LOX gene (LOX-A4) differentially expressed in Triticum urartu (Tu), the diploid progenitor of A subgenome in polyploid wheat. Compared to Tu accessions carrying wild type gene (LOX-A4W), those bearing mutant allele (LOX-A4m) show better growth but lower stress tolerance. These differences concur with a wider geographical distribution of LOX-A4m accessions than LOX-A4W materials in the Fertile Crescent. Interestingly, only mutant LOX-A4 alleles are detected in 3,516 worldwide tetraploid and hexaploid wheat lines; restoring LOX-A4W expression in common wheat inhibits growth but enhances stress tolerance. Furthermore, genome-wide identity-by-state analysis reveals that polyploid wheat A subgenome is more related to the A genome in 13 LOX-A4m Tu accessions. Thus, our work provides evidence that LOX gene variation shapes plant gene pools and their contributions to polyploid genome formation via regulating growth-defense trade-offs.

Aphids are among the most common insect pests that reduce crop production worldwide. However, the breeding of aphid-resistant crops is currently hindered by the scarcity of resistance genes. This problem is particularly significant in sorghum, for which resistant cultivars are urgently needed to control the aphid Melanaphis sorghi (MES). Here, we report map-based cloning of RMES1A and RMES1B, which encode two atypical resistance proteins that confer strong defense against MES. Analysis of knockout mutants and natural variations demonstrated that RMES1A and RMES1B are both required for sorghum resistance against MES. Both genes are induced by MES feeding, specifically in sclerenchyma cells and vascular bundles. RMES1A/RMES1B interact with the sorghum aphid protein MsEF1 to form a functional complex in sorghum cells, leading to key defense responses such as the H2O2 burst and enhanced callose deposition. Accordingly, silencing of MsEF1 expression by RNA interference disrupted RMES1A/RMES1B-mediated resistance, as evidenced by significantly greater growth and fecundity of MES aphids on a resistant cultivar. Structural modeling predicted that RMES1A/RMES1B possess a potential nucleotide-binding domain and two leucine-rich repeat domains but lack the coiled-coil or Toll/interleukin-1 receptor/resistance domains observed in typical nucleotide-binding leucine-rich repeat immune receptors (NLRs). Moreover, RMES1A/RMES1B and their homologs form a distinct cluster in a phylogenetic tree of plant NLRs and likely represent a new type of plant NLR. Our work thus reveals new resistance genes that can be used to investigate and improve immunity against insect pests in sorghum and other crops.

Plant viruses frequently cause severe economic losses in worldwide crop production. Developing broad-spectrum resistance is the most efficient approach for controlling plant viral diseases. In this work, we found that the 17K protein of barley yellow dwarf viruses (BYDVs), which has multiple functions in viral pathogenesis including acting as a viral suppressor of gene silencing (VSR), interacted with plant methionine synthase (MS), the last enzyme in the methionine cycle. Silencing HvMS gene expression enhanced BYDV symptoms and viral gene expression in barley. In contrast, overexpressing HvMS1 in wheat, another important host of BYDVs, attenuated disease symptoms and decreased viral genome proliferation. Interestingly, the γb VSR of barley stripe mosaic virus (BSMV) also interacted with HvMS protein, and HvMS1 overexpression lines likewise exhibited improved BSMV resistance. Further investigations uncovered that the VSRs of potato virus X (PVX) and tobacco rattle virus (TRV) could interact with the MS protein of Nicotiana benthamiana; lowering NbMS gene expression by genome editing reduced tobacco resistance to PVX and TRV, whereas the reverse was observed in HvMS1 overexpression tobacco lines. Finally, we showed that HvMS1 could counteract the VSR function of 10 distinct RNA and DNA viruses by obstructing their ability to revive GFP expression in 16c tobacco, suggesting that plant MS protein may act broadly in disrupting the anti-gene silencing activities of VSRs. Altogether, our data suggest that plant MS protein positively regulates host defence to diverse viruses through inhibiting their VSRs, thus providing a promising target for engineering broad-spectrum antiviral resistance in crops.

The sorghum aphid (Melanaphis sorghi), a phloem-feeding insect, is a major pest affecting sorghum production. Despite advances in understanding plant resistance mechanisms, the molecular responses of aphids to resistant host plants remain poorly characterized. Here, we aimed to elucidate transcriptional changes in sorghum aphids feeding on the resistant sorghum variety HN16 and to identify key aphid regulatory genes involved in host adaptation. RNA-seq analysis identified 1,388 differentially expressed genes (DEGs) in aphids feeding on HN16. Expression profiling revealed coordinated regulation of genes involved in apoptosis and detoxification. Through weighted gene co-expression network analysis (WGCNA), 10 candidate response genes were identified. Notably, knockdown of the DEG MsCathB1, encoding a cathepsin B-like protease, significantly impaired aphid fitness on resistant plants. Functionally, MsCathB1 also suppressed cryptogein-induced plant cell death and hydrogen peroxide accumulation. These findings suggest that sorghum aphid responses to host resistance are closely linked to apoptosis-related pathways, and that MsCathB1 may function as a virulence effector modulating both aphid performance and plant immunity. This work provides new insights into aphid-host interactions and supports the development of RNAi-based strategies for aphid control.

Unreduced gametes (UGs), also known as 2n gametes, retain the somatic chromosome number and represent a fundamental mechanism for sympatric polyploidization in plants. In common wheat (Triticum aestivum L.) and its triticeae relatives, UGs are not only instrumental in species evolution but may also serve as a powerful tool for modern crop improvement. This review synthesizes progress in understanding the cytological and genetic foundations of UG formation in plants, which primarily arises through meiotic restitution events. The achievements made so far in the exploitation of UGs are detailed, which suggest that appropriate manipulation of UGs has potentials in revolutionizing crop breeding, facilitating de novo synthesis of polyploids, enabling challenging wide hybridizations, and permitting direct introgression of valuable traits from wild relatives into cultivated backgrounds. To fully realize these potentials, there are still many biological and technical hurdles to overcome. We outline the major challenges and propose research directions for further basic and applied studies on UGs, which include elucidating the molecular mechanisms underpinning UG formation, raising the efficiency of UG induction, and integrating UG-based technology with crop genomics and advanced breeding pipelines. Breakthroughs in these areas of research will help to promote a new chapter of crop improvement through enhancing genetic diversities, cultivar innovation, and resilient production of crops in the face of worsening global climate change.

Broad-spectrum resistance (BSR) is highly sought after for the effective management of crop diseases. However, genes suitable for developing BSR remain scarce. In this study, we demonstrate the development of BSR to wheat yellow rust (YR), powdery mildew (PM), and leaf rust (LR) diseases elicited by three biotrophic fungal pathogens using a newly defined module, namely, RFEL1-NPR3. RFEL1 is an active RING-finger E3 ubiquitin ligase identified in diploid and polyploid wheat species, which ubiquitinates and promotes the degradation of wheat NPR3 (TaNPR3), an important negative immune regulator conserved in higher plants, via the 26S proteasome system. Downregulation of TaNPR3 by either overexpressing RFEL1 or knocking out TaNPR3 confers strong resistance against four different YR races as well as the PM and LR diseases without adverse effects on wheat growth and yield traits. Notably, the enhanced disease resistance exhibited by RFEL1-overexpressing and TaNPR3-knockout lines is correlated with increased expression of defense related genes and elevated stability of NPR1, a pivotal positive regulator of plant immune signaling. Our findings underscore the importance of ubiquitination-dependent NPR3 degradation in plant immunity and advocate for the application of the RFEL1-NPR3 module in engineering BSR against biotrophic fungal pathogens in wheat and other crops.

Wheat (Triticum aestivum L.) is the most widely cultivated staple food crop globally. As a primary food source for 35–40% of the world’s population, the stability of its yield is directly linked to global food security. However, extreme weather events triggered by climate change have led to reductions in wheat yield, resulting in an urgent need to enhance the stress tolerance of wheat against drought and high temperatures. In this study, we successfully isolated and cloned a myo-inositol oxygenase gene from wheat. Further research revealed that high temperatures and drought stress significantly increased the expression level of the TaMIOXA gene in wheat leaves. A batch of overexpressing lines was obtained via Agrobacterium-mediated transformation. Compared to the control group, wheat plants with molecularly modified TaMIOXA overexpression exhibited stronger resistance to high temperatures and drought. This significantly increased their survival rates by 10% to 40%. The cumulative amount of hydrogen peroxide decreased from 7.86 × 10−4 to 1.54 × 10−2 mmol/g, and that of malondialdehyde decreased from 8.42 × 10−7 to 2.21 × 10−6 mmol/g. This confirms that overexpression of myo-inositol oxygenase significantly enhances wheat’s tolerance to drought and high temperatures. This study offers valuable genetic resources for wheat stress tolerance.

The WRKY gene family plays a pivotal role in regulating plant growth, development, and stress responses. Zhou8425B, a core wheat parent in Chinese breeding programs known for its superior agronomic traits, remains underexplored in terms of its WRKY functional landscape. In this study, we identified 294 WRKY transcription factors in the Zhou8425B genome and conducted comprehensive bioinformatics analyses covering gene structure, protein properties, phylogenetic relationships, conserved motifs, and cis-regulatory elements. RNA-seq analysis across 12 tissues revealed that 274 WRKY genes are highly expressed and form distinct tissue-specific clusters. Notably, TaWRKY254 (TraesZ8425B6B01G167200) was significantly upregulated under various environmental stresses. RT-qPCR confirmed that TaWRKY254 expression under salt stress was substantially higher in Zhou8425B compared to Chinese Spring. Sequence diversity analysis revealed a 513 bp deletion in the promoter region and a T-to-C nonsynonymous mutation in the exon, resulting in an isoleucine-to-valine substitution in Zhou8425B. Based on this 513 bp difference, we developed a specific molecular marker and genotyped the recombinant inbred lines (RILs) from a Zhou8425B × Chinese Spring. Phenotypic analysis showed that RILs carrying the TaWRKY254Zhou8425B genotype exhibited enhanced salt tolerance, as evidenced by increased catalase, proline, and soluble protein levels, reduced lipid peroxidation, and significantly higher thousand kernel weight compared to those with the TaWRKY254CS genotype. These findings suggest that TaWRKY254 may play an important role in salt stress adaptation and yield-related traits, highlighting its potential as a genetic resource for salt-tolerant wheat breeding.

We identified 479 putative TabHLH genes in Zhou8425B and systematically analyzed their functions. TabHLH319 was revealed as a key salt tolerance gene significantly associated with yield-related traits. The basic helix–loop–helix (bHLH) transcription factors represent one of the largest gene families in plants, playing vital roles in development and stress responses. Here, we bioinformatically identified 479 bHLH genes in the high-quality genome of the wheat core parent Zhou8425B and classified them into 13 subfamilies. We investigated their gene structures and computed their physicochemical properties and phylogenetic relationships. RNA-seq data from 12 tissues revealed diverse and tissue-specific expression patterns, several bHLH genes were identified as responsive to various environmental stresses, among which TabHLH319 was implicated in salt tolerance. Sequence comparison between Zhou8425B and Chinese Spring (CS) revealed a nonsynonymous SNP in the exon of TabHLH319. Moreover, a 57-bp insertion in the promoter region specific to Zhou8425B. A molecular marker targeting the InDel was developed and used to genotype a recombinant inbred line (RIL) population derived from Zhou8425B × CS. Dual-luciferase assays demonstrated that this 57-bp insertion significantly enhanced promoter activity under salt stress, explaining the elevated expression of TabHLH319Zhou8425B observed by RT-qPCR in leaf, root, and stem tissues. Under salt stress, RILs carrying the TabHLH319Zhou8425B exhibited greater salt tolerance, accompanied by higher POD, SOD, and CAT enzyme activities, increased proline content, and lower H₂O₂ and MDA levels. Further analysis showed that TabHLH319Zhou8425B was significantly associated with enhanced yield-related traits, such as thousand kernel weight, kernel length, and kernel width. This study comprehensively characterizes the bHLH genes in Zhou8425B and highlights TabHLH319 as a key gebidopsis bHLH family. Grouping data ne for salt tolerance and wheat molecular breeding.

Durum wheat (Triticum turgidum ssp. durum, 2n = 4x = 28, BBAA) is the second most cultivated lineage of wheat after hexaploid common wheat. Langdon is a prominent durum wheat cultivar, highly valued for its crucial role in the development of synthetic hexaploid wheat and its importance in agricultural research. Here, we present a high-quality chromosome-level genome assembly of Langdon using a combination of HiFi sequencing and high-throughput chromosome conformation capture (Hi-C) techniques. The total genome assembly size was 10.47 Gbp, with a benchmarking universal single-copy orthologs (BUSCO) score of 98.80%, consensus nucleotide quality value (QV) score of 50.31, long terminal repeat assembly index (LAI) value of 19.39, a scaffold N50 reached to 751.30 Mbp and a contig N50 value of 41.18 Mbp. Repetitive elements constituted 88.22% of the assembly, and 68,342 high confidence (HC) genes were annotated. The high-quality chromosome-level Langdon assembly can serve as a valuable reference for durum wheat, aiding gene research and comparative genomics, and leveraging synthetic hexaploid wheat’s genetic resources to advance global wheat improvement.

Wheat (Triticum aestivum L.) is the most widely cultivated staple food crop globally. As a primary food source for 35-40% of the world's population, the stability of its yield is directly linked to global food security. However, extreme weather events triggered by climate change have led to wheat yield reduction, making it an urgent issue to enhance wheat's stress tolerance against drought and high temperatures. In this study, we successfully isolated and cloned an inositol oxidase gene from wheat. Further research revealed that high-temperature and drought stresses significantly increased the expression level of the TaMIOXA gene in wheat leaves. A batch of overexpressing lines was obtained via Agrobacterium-mediated transformation. Compared with the control group, wheat plants with molecularly modified TaMIOXA overexpression exhibited stronger resistance to high temperatures and drought, with their survival rate significantly increased by 10% to 40%. This confirms that overexpression of inositol oxidase significantly enhances wheat's tolerance to drought and high temperatures.

Wheat is one of the most important food crops, both in China and worldwide. Wheat production is facing extreme stresses posed by different diseases, including Fusarium head blight (FHB), which has recently become an increasingly serious concerns. FHB is one of the most significant and destructive diseases affecting wheat crops all over the world. Recent advancements in genomic tools provide a new avenue for the study of virulence factors in relation to the host plants. The current review focuses on recent progress in the study of different strains of Fusarium infection. The presence of genome-wide repeat-induced point (RIP) mutations causes genomic mutations, eventually leading to host plant susceptibility against Fusarium invasion. Furthermore, effector proteins disrupt the host plant resistance mechanism. In this study, we proposed systematic modification of the host genome using modern biological tools to facilitate plant resistance against foreign invasion. We also suggested a number of scientific strategies, such as gene cloning, developing more powerful functional markers, and using haplotype marker-assisted selection, to further improve FHB resistance and associated breeding methods.

BACKGROUND:Environmental stresses, including high salinity and drought, severely diminish wheat yield and quality globally. The xyloglucan endotransglucosylase/hydrolase (XTH) family represents a class of cell wall-modifying enzymes and plays important roles in plants growth, development and stress adaptation. However, systematic analyses of XTH family genes and their functions under salt and drought stresses have not been undertaken in wheat. RESULTS:In this study, we identified a total of 135 XTH genes in wheat, which were clustered into three evolutionary groups. These TaXTHs were unevenly distributed on 21 chromosomes of wheat with a majority of TaXTHs located on homelogous groups 2, 3 and 7. Gene duplication analysis revealed that segmental and tandem duplication were the main reasons for the expansion of XTH family in wheat. Interaction network predictions indicated that TaXTHs could interact with multiple proteins, including three kinases, one methyltransferase and one gibberellin-regulated protein. The promoters of the TaXTH genes harbored various cis-acting elements related to stress and hormone responses. RNA-seq data analyses showed that some TaXTH genes were induced by salt and drought stresses. Furthermore, we verified that TaXTH17 was induced by abiotic stresses and phytohormone treatments, and demonstrated that TaXTH17 was localized in the secretory pathway and cell wall. Functional analyses conducted in heterologous expression systems and in wheat established that TaXTH17 plays a negative role in plant resistance to salt and drought. CONCLUSIONS:We identified 135 XTH genes in wheat and conducted comprehensive analyses of their phylogenetic relationships, gene structures, conserved motifs, gene duplication events, chromosome locations, interaction networks, cis-acting elements and gene expression patterns. Furthermore, we provided solid evidence supporting the notion that TaXTH17 plays a negative role in plant resistance to salt and drought stresses. Collectively, our results provide valuable insights into understanding wheat XTHs, particularly their involvement in plant stress responses, and establish a foundation for further functional and mechanistic studies of TaXTHs.

Molecular characterization of resistance genes is crucial for efficiently understanding and fortifying plant immunity against insect herbivores. Here we report that RMES1A and RMES1B proteins confer resistance to the sorghum aphid Melanaphis sorghi when activated by an insect effector MsEF1. Map-based cloning plus genetic analysis of knockout mutants confirm that RMES1A and RMES1B are both required for aphid resistance. Upon aphid attack, RMES1A and RMES1B expression is elevated in the sclerenchyma cells and vascular bundles of leaves; the two proteins interact with MsEF1 in the exocysts, thus upregulating key defense processes such as reactive oxygen species burst. Structural modeling predicts that RMES1A and RMES1B each carry an ATP binding site and two leucine-rich-repeat domains but lack coiled-coil or Toll/Interleukin-1 receptor/resistance domain, thus likely representing a new type of resistance controlling proteins in plants. Our work reveals new genes and mechanisms for further deciphering and improving plant immunity to insect pests. ### Competing Interest Statement The authors have declared no competing interest.

Barley yellow dwarf viruses (BYDVs) cause widespread damage to global cereal crops. Here we report a novel strategy for elevating resistance to BYDV infection. The 17K protein, a potent virulence factor conserved in BYDVs, interacted with barley IMP-α1 and -α2 proteins that are nuclear transport receptors. Consistently, a nuclear localization signal was predicted in 17K, which was found essential for 17K to be transported into the nucleus and to interact with IMP-α1 and -α2. Reducing HvIMP-α1 and -α2 expression by gene silencing attenuated BYDV-elicited dwarfism, accompanied by a lowered nuclear accumulation of 17K. Among the eight common wheat CRISPR mutants with two to four TaIMP-α1 and -α2 genes mutated, the triple mutant α1aaBBDD /α2AAbbdd and the tetra-mutant α1aabbdd /α2AAbbDD displayed strong BYDV resistance without negative effects on plant growth under field conditions. The BYDV resistance exhibited by α1aaBBDD /α2AAbbdd and α1aabbdd /α2AAbbDD was correlated with decreased nuclear accumulation of 17K and lowered viral proliferation in infected plants. Our work uncovers the function of host IMP-α proteins in BYDV pathogenesis and generates the germplasm valuable for breeding BYDV-resistant wheat. Appropriate reduction of IMP-α gene expression may be broadly useful for enhancing antiviral resistance in agricultural crops and other economically important organisms.

The United Nations has estimated that the world population will surpass 8 billion on Nov. 15, 2022, and will continue to rise to 11.2 billion by 2100. Considering that agricultural resources are limited, it will be a huge challenge to produce sufficient food to feed such a rapidly rising global population. Furthermore, the ongoing climate changes are adding more pressures on worldwide crop productions. To cope with these problems, it is both imperative and urgent to develop the crop cultivars with higher yield potential, improved nutritional quality, and better resilience to environmental stresses.

High-quality genome information is essential for efficiently deciphering and improving crop traits. Here we report a highly contiguous hexaploid genome assembly for the key wheat breeding parent Zhou8425B, an elite 1BL/1RS translocation line with durable adult plant resistance (APR) against rust diseases. By using HiFi and Hi-C sequencing reads, a 14.75 Gb genome assembly, with contig N50 and scaffold N50 values reaching 70.94 and 735.11 Mb, respectively, was developed. Comparison with 16 previously sequenced common wheat cultivars revealed unique chromosomal structural features in Zhou8425B. Notably, the 1RS translocation in Zhou8425B was apparently longer and carried more genes encoding AP2/ERF-ERF and B3 transcription factors relative to its counterpart in several genome sequenced 1BL/1RS varieties and rye lines. Aided by Zhou8425B genome assembly, a new APR locus (i.e., YrZH3B ) against yellow rust (YR) disease was finely mapped to a 1 - 2 Mb interval on chromosome 3BS. Analysis with 212 Zhou8425B derivative varieties showed that pyramiding of YrZH3B with two other APR loci ( YrZH22 and YrZH84 ) significantly decreased YR severity and enhanced grain yield, with triple combination ( YrZH3B/YrZH22/YrZH84 ) having the highest effects. Our data demonstrate the high value of Zhou8425B assembly in studying wheat genome and agronomically important genes.### Competing Interest StatementThe authors have declared no competing interest.

Scaling current cereal production to meet the globally increasing food demand will be a challenge under climate change. Pre-vious studies have shown that crop diversification, such as intercropping, can increase crop yield, stability, resource-use effi- ciency and resistance to both biotic and abiotic stresses in agroecosystems. However, more evidence is needed to explain the influence of inter-annual climate variations on crop yield in the context of genetic diversity. Here, we conducted a field experi-ment over four years in the North China Plain to test the effect of genetic diversity on yield under varied climate conditions. We compared the performance of eight winter wheat cultivars in monocropping with that of mixed cropping of two (mixture -2), four (mixture-4), and eight (mixture-8) cultivars. Our results showed that the yields of all cultivar mixtures were higher than those of their component cultivars in monocropping from 2017 to 2020. In particular, the grain yields of mixture-4 and mix-ture-8 were significantly increased by 7.37% and 5.94% in the drier years (2017 and 2019), compared with that of the highest yield of local cultivar (LY502). From 2017 to 2020, yield components in wheat mixed cropping had synergetic effects that could offset the tradeoffs among them and obtained an optimized combination at population level. Moreover, the yield stability of all mixtures was higher than the weighted means of monocultures averaged across the four years. The cultivation of mixtures of wheat cultivars effectively alleviated the negative effect of high temperature stress on 1000-grain weight, and improved grain water use efficiency in the drier years. Our findings showed that enhancing wheat genetic diversity at population level can effectively promote grain yield under drought and high temperature, which can be considered as an ecological approach to cope with global climate change towards food security. (c) 2023 The Authors. Published by Elsevier GmbH on behalf of Gesellschaft fur okologie. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)