Advances in Understanding Cadmium Stress and Breeding of Cadmium-Tolerant Crops

Cadmium(Cd) pollution has emerged as a critical global environmental concern, due to its significant toxicity, environmental persistence, and the pervasiveness of contamination. Significantly, the bioaccumulation of Cd in agricultural crops constitutes a primary vector for its entry into the human diet. This issue warrants urgent attention from both the scientific community and policymakers to develop and implement effective mitigation strategies. This review delves into the physiological impacts of Cd stress on plants, including the suppression of photosynthetic activity, amplification of oxidative stress, and disruptions in mineral nutrient homeostasis. Additionally, the resistance mechanisms deployed by plants in response to Cd stress have been explored, and the prospective contributions of molecular breeding strategies in augmenting crop tolerance to Cd and minimizing its bioaccumulation have been assessed. By integrating and analyzing these findings, we seek to inform future research trajectories and proffer strategic approaches to enhance agricultural sustainability, safeguard human health, and protect environmental integrity.

Advancing Crop Breeding via Targeted Genome Modification

Modern crop breeding is entering a new era of genome design,led by genome editing technologies as mainstream tools for targeted genome modification.In a review published in Nature Reviews Genetics on April 24,Dr.GAO Caixia from the Institute of Genetics and Developmental Biology(IGDB)of the Chinese Academy of Sciences described the progress of technical innovation in editing tools,the development of superior delivery methods,and their advanced applications in crop breeding.

Structural variations in oil crops:Types,and roles on domestication and breeding

Structural variations(SVs),a newly discovered genetic variation,have gained increasing recognition for their importance,yet much about them remains unknown.With the completion of whole-genome sequencing projects in oil crops,more SVs have been identified,revealing their types,genomic distribution,and characteristics.These findings have demonstrated the crucial roles of SVs in regulating gene expression,driving trait innovation,facilitating domestication,making this an opportune time for a systematic review.We summarized the progress of SV-related studies in oil crops,focusing on the types of SVs and their mechanisms of occurrence,the strategies and methods for SV detection,and the SVs identified in oil crops such as rapeseed,soybean,peanut,and sesame.The various types of SVs,such as presence-absence variations(PAVs),copy number variations(CNVs),and homeologous exchanges(HEs),have been shown.Along with their genomic characterization,their roles in crop domestication and breeding,and regulatory impact on gene expression and agronomic traits have also been demonstrated.This review will provide an overview of the SV research process in oil crops,enabling researchers to quickly understand key information and apply this knowledge in future studies and crop breeding.

Investigation on Breeding Direction of Grain Crops——Taking Henan Province as an example

[Objective] This paper aimed to investigate the breeding direction of grain crops in Henan Province. [Method] Superior varieties are the basis of grain yield-increase, and a proper breeding direction is essential for breeding of superior varieties. According to the actual situation and production requirements in Henan Province, by using statistical data of grain production, this paper analyzed the current situation and influencing factors of grain production in Henan Province, and summarized the breeding direction of current grain production. [Result] The increase of grain output in Henan Province mainly relies on the increase of grain yield per unit area and is achieved based on the increase of wheat and corn yield. There are several main factors affecting grain production in Henan Province, including the frequent meteorological disasters, low resistance to natural disasters, excessive chemical fertilizer inputs, decreased material conversion efficiency, aggravated pollution of the agricultural surface source, imbalanced quality and the distribution of cultivated land, emphasizing yield traits but neglecting related traits during crop breeding pro- cess, unitary dominant varieties resulting from narrow germplasm resources, and reduced grain-planting population with the migration of rural labor force. On this basis, the grain breeding direction is proposed with high yield, high efficiency, adaptability, stress resistance, specificity and safety, to enhance the grain crop breeding level, breed superior varieties, and realize the intensive use of cultivated land, intensive saving of materials, intensive substitution of labor force, intensive protection of environment and intensive efficiency of technologies by adjusting the breeding direction, thus promoting the sustained and stable development of grain production. [Conclusion] This paper provides basis for the breeding of superior varieties of grain crops and improvement of grain output in Henan Province.

High-throughput phenotyping: Breaking through the bottleneck in future crop breeding

With the rapid development of genetic analysis techniques and crop population size,phenotyping has become the bottleneck restricting crop breeding.Breaking through this bottleneck will require phenomics,defined as the accurate,high-throughput acquisition and analysis of multi-dimensional phenotypes during crop growth at organism-wide levels,ranging from cells to organs,individual plants,plots,and fields.Here we offer an overview of crop phenomics research from technological and platform viewpoints at various scales,including microscopic,ground-based,and aerial phenotyping and phenotypic data analysis.We describe recent applications of high-throughput phenotyping platforms for abiotic/biotic stress and yield assessment.Finally,we discuss current challenges and offer perspectives on future phenomics research.

Breeding better cultivars,faster:applications of new technologies for the rapid deployment of superior horticultural tree crops

Woody perennial plants,including trees that produce fruits and nuts of horticultural value,typically have long breeding cycles,and development and introduction of improved cultivars by plant breeders may require many breeding cycles and dozens of years.However,recent advances in biotechnologies and genomics have the potential to accelerate cultivar development greatly in all crops.This mini-review summarizes approaches to reduce the number and the duration of breeding cycles for horticultural tree crops,and outlines the challenges that remain to implement these into efficient breeding pipelines.

Genome-editing technologies and their potential application in horticultural crop breeding

Plant breeding,one of the oldest agricultural activities,parallels human civilization.Many crops have been domesticated to satisfy human's food and aesthetical needs,including numerous specialty horticultural crops such as fruits,vegetables,ornamental flowers,shrubs,and trees.Crop varieties originated through selection during early human civilization.Other technologies,such as various forms of hybridization,mutation,and transgenics,have also been invented and applied to crop breeding over the past centuries.The progress made in these breeding technologies,especially the modern biotechnology-based breeding technologies,has had a great impact on crop breeding as well as on our lives.Here,we first review the developmental process and applications of these technologies in horticultural crop breeding.Then,we mainly describe the principles of the latest genome-editing technologies and discuss their potential applications in the genetic improvement of horticultural crops.The advantages and challenges of genome-editing technologies in horticultural crop breeding are also discussed.

DNA-informed breeding of rosaceous crops: promises, progress and prospects

Crops of the Rosaceae family provide valuable contributions to rural economies and human health and enjoyment.Sustained solutions to production challenges and market demands can be met with genetically improved new cultivars.Traditional rosaceous crop breeding is expensive and time-consuming and would benefit from improvements in efficiency and accuracy.Use of DNA information is becoming conventional in rosaceous crop breeding,contributing to many decisions and operations,but only after past decades of solved challenges and generation of sufficient resources.Successes in deployment of DNA-based knowledge and tools have arisen when the‘chasm’between genomics discoveries and practical application is bridged systematically.Key steps are establishing breeder desire for use of DNA information,adapting tools to local breeding utility,identifying efficient application schemes,accessing effective services in DNA-based diagnostics and gaining experience in integrating DNA information into breeding operations and decisions.DNA-informed germplasm characterization for revealing identity and relatedness has benefitted many programs and provides a compelling entry point to reaping benefits of genomics research.DNA-informed germplasm evaluation for predicting trait performance has enabled effective reallocation of breeding resources when applied in pioneering programs.DNA-based diagnostics is now expanding from specific loci to genome-wide considerations.Realizing the full potential of this expansion will require improved accuracy of predictions,multi-trait DNA profiling capabilities,streamlined breeding information management systems,strategies that overcome plant-based features that limit breeding progress and widespread training of current and future breeding personnel and allied scientists.

Turbocharging introgression breeding of perennial fruit crops:a case study on apple

The allelic diversity of primitive germplasm of fruit crops provides a useful resource for introgressing novel genes to meet consumer preferences and environmental challenges.Pre-breeding facilitates the identification of novel genetic variation in the primitive germplasm and expedite its utilisation in cultivar breeding programmes.Several generations of pre-breeding could be required to minimise linkage drag from the donor parent and to maximise the genomic content of the recipient parent.In this study we investigated the potential of genomic selection(GS)as a tool for rapid background selection of parents for the successive generation.A diverse set of 274 accessions was genotyped using random-tag genotyping-by-sequencing,and phenotyped for eight fruit quality traits.The relationship between‘own phenotypes’of 274 accessions and their general combining ability(GCA)was also examined.Trait heritability influenced the strength of correspondence between own phenotype and the GCA.The average(across eight traits)accuracy of predicting own phenotype was 0.70,and the correlations between genomic-predicted own phenotype and GCA were similar to the observed correlations.Our results suggest that genome-assisted parental selection(GAPS)is a credible alternative to phenotypic parental selection,so could help reduce the generation interval to allow faster accumulation of favourable alleles from donor and recipient parents.

Genomics-assisted breeding——A revolutionary strategy for crop improvement

Food shortages arise more frequently owing to unpredictable crop yield losses caused by biotic and abiotic stresses. With advances in molecular biology and marker technology, a new era of molecular breeding has emerged that has greatly accelerated the pace of plant breeding. High-throughput genotyping technology and phenotyping platforms have enabled large-scale marker-trait association analysis, such as genome-wide association studies, to precisely dissect the genetic architecture of plant traits. Large-scale mapping of agronomically important quantitative trait loci, gene cloning and characterization, mining of elite alleles/haplotypes, exploitation of natural variations, and genomic selection have paved the way towards genomics-assisted breeding（GAB）. With the availability of more and more informative genomic datasets, GAB would become a promising technique to expedite the breeding cycle for crop improvement.

QTL-allele matrix detected from RTM-GWAS is a powerful tool for studies in genetics, evolution, and breeding by design of crops

The plant germplasm resources harboring abundant genetic variations are necessary wealth in developing new cultivars adapted to various geographic and seasonal conditions.Unraveling the complex genetic architecture underlying phenotypic diversity in germplasm population is essential in studies on genetics,evolution and breeding plans for crop species.Mapping quantitative trait loci(QTLs)using molecular markers provide a basic tool for understanding the inheritance of quantitative traits,while the genomewide association study(GWAS)is a potential approach to detecting the whole-genome QTLs and their corresponding alleles in a germplasm population.The previous GWAS detects QTLs by taking high-density single-nucleotide polymorphism(SNP)markers to identify genotypephenotype associations,and has been extensively used for genetic dissection of quantitative traits in plants(Huang and Han 2014).

RosBREED:bridging the chasm between discovery and application to enable DNA-informed breeding in rosaceous crops

The Rosaceae crop family(including almond,apple,apricot,blackberry,peach,pear,plum,raspberry,rose,strawberry,sweet cherry,and sour cherry)provides vital contributions to human well-being and is economically significant across the U.S.In 2003,industry stakeholder initiatives prioritized the utilization of genomics,genetics,and breeding to develop new cultivars exhibiting both disease resistance and superior horticultural quality.However,rosaceous crop breeders lacked certain knowledge and tools to fully implement DNA-informed breeding—a“chasm”existed between existing genomics and genetic information and the application of this knowledge in breeding.The RosBREED project(“Ros”signifying a Rosaceae genomics,genetics,and breeding community initiative,and“BREED”,indicating the core focus on breeding programs),addressed this challenge through a comprehensive and coordinated 10-year effort funded by the USDA-NIFA Specialty Crop Research Initiative.RosBREED was designed to enable the routine application of modern genomics and genetics technologies in U.S.rosaceous crop breeding programs,thereby enhancing their efficiency and effectiveness in delivering cultivars with producer-required disease resistances and market-essential horticultural quality.This review presents a synopsis of the approach,deliverables,and impacts of RosBREED,highlighting synergistic global collaborations and future needs.Enabling technologies and tools developed are described,including genome-wide scanning platforms and DNA diagnostic tests.Examples of DNA-informed breeding use by project participants are presented for all breeding stages,including pre-breeding for disease resistance,parental and seedling selection,and elite selection advancement.The chasm is now bridged,accelerating rosaceous crop genetic improvement.

Harness the power of genomic selection and the potential of germplasm in crop breeding for global food security in the era with rapid climate change

Crop genetic improvements catalysed population growth,which in turn has increased the pressure for food security.We need to produce 70%more food to meet the demands of 9.5 billion people by 2050.Climate changes have posed challenges for global food supply,while the narrow genetic base of elite crop cultivars has further limited our capacity to increase genetic gain through conventional breeding.The effective utilization of genetic resources in germplasm collections for crop improvement is crucial to increasing genetic gain to address challenges in the global food supply.Genomic selection(GS)uses genome-wide markers and phenotype information from observed populations to establish associations,followed by genome-wide markers to predict phenotypic values in test populations.Characterizing an extensive germplasm collection can serve a dual purpose in GS,as a reference population for predicting model,and mining desirable genetic variants for incorporation into elite cultivars.New technologies,such as high-throughput genotyping and phenotyping,machine learning,and gene editing,have great potential to contribute to genomeassisted breeding.Breeding programmes integrating germplasm characterization,GS and emerging technologies offer promise for accelerating the development of cultivars with improved yield and enhanced resistance and tolerance to biotic and abiotic stresses.Finally,scientifically informed regulations on new breeding technologies,and increased sharing of genetic resources,genomic data,and bioinformatics expertise between developed and developing economies will be the key to meeting the challenges of the rapidly changing climate and increased demand for food.

基于AquaCrop和WinSRFR组合的夏玉米沟灌方案优化

确定作物合理的灌溉制度和灌水技术要素组合是科学管理农业水资源的基础,可有效缓解水资源短缺矛盾和保障区域粮食安全。基于此,该研究利用在陕西省杨陵区(2022年)和武功县(2017年)进行的夏玉米田间试验,分别对AquaCrop模型和WinSRFR软件进行校准和验证,确定了研究区夏玉米典型水文年(丰水年、平水年和干旱年)的灌溉制度;通过反演沟灌土壤入渗参数和田面糙率,结合确定的灌溉制度,优化了沟灌灌水技术要素组合(入沟流量和灌水时间),并量化评价了优化灌溉制度和灌水技术要素组合对夏玉米的增产能力。结果表明,AquaCrop模型能准确模拟研究区夏玉米生长过程,其中产量模拟值与实测值的相对误差绝对值均值分别为1.85%(校准)和7.47%(验证);研究区夏玉米丰水年(灌浆期)和平水年(拔节期)需灌水1次,干旱年(拔节期和灌浆期)需灌水2次,单次灌水量均为55 mm;反演所得研究区沟灌土壤入渗参数k和α取值范围分别为是55.416~98.437 mm/h^(α)和0.351~0.858,田面糙率n均值为0.056;合理的入沟流量和停水时间取值范围分别为2.2~3.3 L/s和35~16 min,可获得高灌水质量(综合灌水质量指标C_(i)≥85%);以2022年夏玉米优化的灌溉制度和灌水技术要素优化组合为基础,模拟所得夏玉米产量为7.819 t/hm^(2),与无灌溉(5.972 t/hm^(2))、现状条件(7.424 t/hm^(2))和仅对灌溉制度优化(7.659 t/hm^(2))情景相比较,分别提高了30.9%、5.3%和2.1%,且所需灌水量较现状条件可减少59 mm。研究结果可为研究区域夏玉米灌溉制度制定和沟灌方案设计提供理论基础和技术支撑。

Crop genome editing: A way to breeding by design

Increasing population and consumption in our planet is placing unprecedented challenges on agriculture for meeting food security and sustainability needs[1].Meanwhile,the adaptation of modern agricultural techniques[2]is central to minimize extensive losses due to abiotic stresses[3]under global climate change.

Genomic dissection of widely planted soybean cultivars leads to a new breeding strategy of crops in the post-genomic era

Soybeans specially the widely planted cultivars have been dramatically improved in agronomic performance and is well adapted to local planting environments after long-time domestication and breeding.Uncovering the unique genomic features of popular cultivars will help to understand how soybean genomes have been modified through breeding.We re-sequenced 134 soybean cultivars that were released and most widely planted over the last century in China.Phylogenetic analyses established that these cultivars comprise two geographically distinct sub-populations:Northeast China (NE) versus the HuangHuai-Hai River Valley and South China (HS).A total of 309 selective regions were identified as being impacted by geographical origins.The HS sub-population exhibited higher genetic diversity and linkage disequilibrium decayed more rapidly compared to the NE sub-population.To study the association between phenotypic differences and geographical origins,we recorded the vegetative period under different growing conditions for two years,and found that clustering based on the phenotypic data was closely correlated with cultivar geographical origin.By iteratively calculating accumulated genetic diversity,we established a platform panel of cultivars and have proposed a novel breeding strategy named "Potalaization"for selecting and utilizing the platform cultivars that represent the most genetically diversity and the highest available agronomic performance as the "plateau"for accumulating elite loci and traits,breeding novel widely adapted cultivars,and upgrading breeding technology.In addition to providing new genomic information for the soybean research community,the "Potalaization"strategy that we devised will also be practical for integrating the conventional and molecular breeding programs of crops in the post-genomic era.

Stress-Tolerant Cassava: The Role of Integrative Ecophysiology-Breeding Research in Crop Improvement

This review highlights an integrative multidisciplinary eco-physiological, breeding and agronomical research on the tropical starchy root crop cassava conducted at CIAT. Laboratory and field studies have elucidated several physio-logical/biochemical mechanisms and plant traits underlying the high productivity in favorable conditions and tolerance to stressful environments, such as prolonged water stress and marginal low-fertility soils. Cassava is endowed with inherent high photosynthetic capacity expressed in near optimal environments that correlates with biological produc- tivity across environments and wide range of germplasm.Field-measured photosynthetic rates were also associated with root yield, particularly under prolonged drought. Extensive rooting systems and stomatal sensitivity to both atmospheric humidity and soil water shortages underlie tolerance to drought. The C4 phosphoenolpyruvate carboxylase (PEPC) was associated with photosynthesis and yield making it a selectable trait, along with leaf duration, particularly for stressful environments. Germplasm from the core collection was screened for tolerance to soils low in P and K, resulting in the identification of several accessions with good levels of tolerance. Cassava has a comparative advantage against major tropical food and energy crops in terms of biological productivity. Results also point to the importance of field research versus greenhouse or growth-chamber studies. In globally warming climate,the crop is predicted to play more role in tropical and subtropical agro-ecosystems. More research is needed under tropical field conditions to understand the interactive responses to elevated carbon dioxide, temperature, soil fertility, and plant water relations.

Construction and Exploration of Ideological and Political Education in Crop Breeding Course

In order to start a new situation for the development of higher education in China,and to achieve the goal of educating people through the whole process and all-round education in colleges and universities,this paper takes Crop Breeding Course as an example,from the characteristics of the curriculum,the history of crop breeding and the ideological and political elements of professional courses,explored the curriculum construction in the aspects of excavation,and summarized the effects of the ideological and political construction of Crop Breeding Course.

Germplasm and molecular breeding in horticultural crops

Horticulture is an important part of agricultural planting and production, which is of great significance for enriching human nutrition and beautifying and transforming the human living environment. At present, the area of horticultural crops in China is about 40 million ha, accounting for about onefourth of the national crop planting area, while the production of primary agricultural products is 1 billion tons, and the output value accounts for more than half of the total output value of the planting industry.

Straw return increases crop production by improving soil organic carbon sequestration and soil aggregation in a long-term wheat-cotton cropping system

Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cotton(Gossypium hirsutum L.)cropping system remains uncertain.The objective of this study was to quantify the long-term(10 years)impact of carbon(C)input on SOC sequestration,soil aggregation and crop yields in a wheat-cotton cropping system in the Yangtze River Valley,China.Five treatments were arranged with a single-factor randomized design as follows:no straw return(Control),return of wheat straw only(Wt),return of cotton straw only(Ct),return of 50%wheat and 50%cotton straw(Wh-Ch)and return of 100%wheat and 100%cotton straw(Wt-Ct).In comparison to the Control,the SOC content increased by 8.4 to 20.2%under straw return.A significant linear positive correlation between SOC sequestration and C input(1.42-7.19 Mg ha^(−1)yr^(−1))(P<0.05)was detected.The percentages of aggregates of sizes>2 and 1-2 mm at the 0-20 cm soil depth were also significantly elevated under straw return,with the greatest increase of the aggregate stability in the Wt-Ct treatment(28.1%).The average wheat yields increased by 12.4-36.0%and cotton yields increased by 29.4-73.7%,and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.The average sustainable yield index(SYI)reached a maximum value of 0.69 when the C input was 7.08 Mg ha^(−1)yr^(−1),which was close to the maximum value(SYI of 0.69,C input of 7.19 Mg ha^(−1)yr^(-1))in the Wt-Ct treatment.Overall,the return of both wheat and cotton straw was the best strategy for improving SOC sequestration,soil aggregation,yields and their sustainability in the wheat-cotton rotation system.