Octoploid Strawberry Research Articles

Integration of ATAC-Seq and RNA-Seq Reveals the Role of FaTIP1 in Red Light-Induced Fruit Ripening in Strawberry.

Light is an important environmental factor affecting the ripening and quality of strawberry fruit. Previous studies have shown that red light treatment can promote strawberry ripening. Gene expression is closely associated with chromatin openness, and changes in chromatin accessibility are crucial for the binding of transcription factors to downstream regulatory sequences. However, the changes in chromatin accessibility in response to different light treatments in octoploid strawberry plants are still unclear. In this study, the landscape of chromatin accessibility of octoploid strawberry under red (R) and yellow-green (YG) light conditions was analyzed by the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq). Through bioinformatics and Venn diagram analyses, a total of 1456 and 1854 group-specific genes (GSGs) were screened in the R and YG groups, respectively. By using RNA sequencing (RNA-seq), 440 differentially expressed genes (DEGs) were identified. Among these genes, 194 were upregulated under red light treatment. Through joint analysis of ATAC-seq and RNA-seq data, three red group-specific genes with increased expression were identified, namely, FaTIP1, FaQKY and FaLBD1. Through gene expression and transient transformation analyses of strawberry fruit, we further demonstrated that FaTIP1 can respond to red light induction and promote the ripening process of strawberry fruit. Our results provide a reference for the study of chromatin accessibility in octoploid strawberry and reveal new factors involved in the fruit's response to red light and the regulation of the ripening process of strawberry fruit.

Optimization of Shoot Regeneration and Agrobacterium-mediated Transformation in Strawberry (Fragaria ×ananassa)

Efficient methods of plant transformation and tissue culture are essential for the genetic engineering and advanced molecular breeding of plants, but neither is well established in cultivated octoploid strawberry (Fragaria ×ananassa). In the present study, a method for shoot regeneration was established and optimized for two genetically different strawberry cultivars, Sweet Sensation® Florida 127 (FL127) and Florida Brilliance (FB). Runner segments at the tip, node, and petiole obtained from greenhouse-grown plants were used as explants for comparisons of shoot regeneration rate. ‘FL127’ showed the highest frequency of shoot regeneration in the optimized condition, whereas ‘FB’ showed the best response to a lower concentration of N6-benzyladenine (BA) (0.01 mg/L) in the same media type. The average conversion frequencies of somatic embryos into shoot regenerations from the runner tips (RTs) were 42.8% in ‘FL127’ and 56.9% in ‘FB’, respectively. Using these optimized tissue culture conditions, Agrobacterium-mediated CRISPR/Cas9 gene editing was conducted to examine the efficiency of transformation and target gene editing for the phytoene desaturase, FaPDS, in the cultivar, FL127. A total of 234 explants inoculated with Agrobacterium harboring Cas9-FaPDS resulted in an 80.3% callus induction efficiency, with 13.3% of regenerated plants exhibiting partial or complete albino phenotypes. Amplicon sequencing of edited progeny showed mutations (substitutions, insertions, and deletions) at the guide RNA (gRNA) target sites or flanking regions of all FaPDS homoeologous copies. Our results provide effective tissue culture and transformation methods for strawberry functional genomics research and gene editing guided cultivar improvement.

Agrobacterium-Mediated Transient Expression Methods to Validate Gene Functions in Strawberry (F. × ananassa).

Understanding gene function is important for crop improvement and breeding efforts, especially in a genetically complex polyploid plant species such as the octoploid strawberry. Agrobacterium-mediated transient assays are a widely used tool for investigating gene functions and offer a reliable alternative to stable transformation. However, variability in tissue-specific responses and inconsistent applicability of Agrobacterium-mediated transient assay across diverse plant species can be challenging. In this study, we provide a method utilizing Agrobacterium-mediated transient expression to examine the function of genes in octoploid strawberry. Our approach encompasses leaf, root, and fruit tissues, providing a comprehensive strategy for validating gene functions in strawberries. Through meticulous optimization and validation in planta, this method offers valuable insights into gene function in strawberry functional genomics and genetics research. By addressing tissue-specific variability, our methodology serves as a valuable technical resource that could facilitate advancements in identifying gene functions in octoploid strawberry.

Transcriptome analysis of fruit development and identification of key transcription factors related to anthocyanin pathway in cultivated octoploid strawberry

Transcriptome analysis of fruit development and identification of key transcription factors related to anthocyanin pathway in cultivated octoploid strawberry

Characterization of Superoxide Dismutase (SOD) Gene Family and Their Responses to Salinity Stress and Fruit Development in Octoploid Strawberry

Superoxide dismutases (SODs), as the first line of defense against reactive oxygen species (ROS), play an essential role in protecting plants from adverse elicitors during plant growth and development. However, little is known about the SOD gene family and their response to salinity stress and fruit development in cultivated strawberries (Fragaria × ananassa). In this study, 32 SOD genes consisting of 16 Cu/ZnSODs, 11 FeSODs, and 5 MnSOD were identified, which presented three well-resolved clades in the phylogenetic tree. Each clade had similar motifs, and exon–intron structures, which in turn supported the evolutionary classification. Cis-acting element analysis suggested that FaSOD genes might be involved in the plant response to abiotic and biotic stresses, hormones, and light. The analysis of previously published transcriptome data revealed that FaSOD genes are expressed variably under salt stress. Among these SODs, FaMSD5 was expressed at relatively high levels in strawberry root and leaf, and its transcript abundance significantly increased after salt treatment. Some transcription factors related to photomorphogenesis, hormone signaling pathways, and hyperosmotic salinity response were predicted to bind to the FaMSD5 promoter. These outcomes implied that FaMSD5 might play an important role in protection against salt stress. In addition, the comprehensive transcriptome analysis of FaSOD genes in strawberry fruit showed that almost all FaCSDs and FaMSDs were more highly expressed than FaFSDs at different developmental stages, and the expression patterns of FaCSD1, FaCSD2, FaCSD7, FaCSD8, and FaCSD10 suggested that they were likely to be involved in fruit development and ripening. This study provides a basis for further exploration of the function of the FaSOD gene family in strawberry and provides candidate FaSOD genes for enhancing salinity tolerance and regulating fruit development and ripening.

A Dominance Hypothesis Argument for Historical Genetic Gains and the Fixation of Heterosis in Octoploid Strawberry.

Heterosis was the catalyst for the domestication of cultivated strawberry (Fragaria × ananassa), an interspecific hybrid species that originated in the 1700s. The hybrid origin was discovered because the phenotypes of spontaneous hybrids transgressed those of their parent species. The transgressions included fruit yield increases and other genetic gains in the twentieth century that sparked the global expansion of strawberry production. The importance of heterosis to the agricultural success of the hybrid species, however, has remained a mystery. Here we show that heterosis has disappeared (become fixed) among improved hybrids within a population (the California population) that has been under long-term selection for increased fruit yield, weight, and firmness. We found that the highest yielding hybrids are among the most highly inbred (59-79%), which seems counterintuitive for a highly heterozygous, outbreeder carrying heavy genetic loads. Although faint remnants of heterosis were discovered, the between-parent allele frequency differences and dispersed favorable dominant alleles necessary for heterosis have decreased nearly genome-wide within the California population. Conversely, heterosis was prevalent and significant among wide hybrids, especially for fruit count, a significant driver of genetic gains for fruit yield. We attributed the disappearance (fixation) of heterosis within the California population to increased homozygosity of favorable dominant alleles and inbreeding associated with selection, random genetic drift, and selective sweeps. Despite historical inbreeding, the highest yielding hybrids reported to-date are estimated to be heterozygous for 20,370-44,280 of 97,000-108,000 genes in the octoploid genome, the equivalent of an entire diploid genome or more.

Genome-wide gene network uncover temporal and spatial changes of genes in auxin homeostasis during fruit development in strawberry (F. × ananassa)

BackgroundThe plant hormone auxin plays a crucial role in regulating important functions in strawberry fruit development. Although a few studies have described the complex auxin biosynthetic and signaling pathway in wild diploid strawberry (Fragaria vesca), the molecular mechanisms underlying auxin biosynthesis and crosstalk in octoploid strawberry fruit development are not fully characterized. To address this knowledge gap, comprehensive transcriptomic analyses were conducted at different stages of fruit development and compared between the achene and receptacle to identify developmentally regulated auxin biosynthetic genes and transcription factors during the fruit ripening process. Similar to wild diploid strawberry, octoploid strawberry accumulates high levels of auxin in achene compared to receptacle.ResultsGenes involved in auxin biosynthesis and conjugation, such as Tryptophan Aminotransferase of Arabidopsis (TAAs), YUCCA (YUCs), and Gretchen Hagen 3 (GH3s), were found to be primarily expressed in the achene, with low expression in the receptacle. Interestingly, several genes involved in auxin transport and signaling like Pin-Formed (PINs), Auxin/Indole-3-Acetic Acid Proteins (Aux/IAAs), Transport Inhibitor Response 1 / Auxin-Signaling F-Box (TIR/AFBs) and Auxin Response Factor (ARFs) were more abundantly expressed in the receptacle. Moreover, by examining DEGs and their transcriptional profiles across all six developmental stages, we identified key auxin-related genes co-clustered with transcription factors from the NAM-ATAF1,2-CUC2/ WRKYGQK motif (NAC/WYKY), Heat Shock Transcription Factor and Heat Shock Proteins (HSF/HSP), APETALA2/Ethylene Responsive Factor (AP2/ERF) and MYB transcription factor groups.ConclusionsThese results elucidate the complex regulatory network of auxin biosynthesis and its intricate crosstalk within the achene and receptacle, enriching our understanding of fruit development in octoploid strawberries.

FveDREB1B improves cold tolerance of woodland strawberry by positively regulating FveSCL23 and FveCHS.

Cold stress has seriously inhibited the growth and development of strawberry during production. CBF/DREB1 is a key central transcription factor regulating plant cold tolerance, but its regulatory mechanisms are varied in different plants. Especially in strawberry, the molecular mechanism of CBF/DREB1 regulating cold tolerance is still unclear. In this study, we found that FveDREB1B was most significantly induced by cold stress in CBF/DREB1 family of diploid woodland strawberry. FveDREB1B was localized to the nucleus, and DREB1B sequences were highly conserved in diploid and octoploid strawberry, and even similar in Rosaceae. And FveDREB1B overexpressed strawberry plants showed delayed flowering and increased cold tolerance, while FveDREB1B silenced plants showed early flowering and decreased cold tolerance. Under cold stress, FveDREB1B activated FveSCL23 expression by directly binding to its promoter. Meanwhile, FveDREB1B and FveSCL23 interacted with FveDELLA, respectively. In addition, we also found that FveDREB1B promoted anthocyanin accumulation in strawberry leaves by directly activating FveCHS expression after cold treatment and recovery to 25°C. DREB1B genes were also detected to be highly expressed in cold-tolerant strawberry resources 'Fragaria mandschurica' and 'Fragaria nipponica'. In conclusion, our study reveals the molecular mechanism of FveDREB1B-FveSCL23-FveDELLA module and FveDREB1B-FveCHS module to enhance the cold tolerance of woodland strawberry. It provides a new idea for improving the cold tolerance of cultivated strawberry and evaluating the cold tolerance of strawberry germplasm resources.

Genome-Wide Analysis of Polygalacturonase Gene Family Reveals Its Role in Strawberry Softening.

Fruit softening is a prominent attribute governing both longevity on shelves and commercial worth. Polygalacturonase (PG) plays a major role in strawberry fruit softening. However, the PG gene family in strawberry has not been comprehensively analyzed. In this study, 75 FaPG genes were identified in the octoploid strawberry genome, which were classified into three groups according to phylogenetic analysis. Subcellular localization prediction indicated that FaPGs are mostly localized to the plasma membrane, cytoplasm, and chloroplasts. Moreover, the expression of FaPGs during strawberry development and ripening of 'Benihoppe' and its softer mutant was estimated. The results showed that among all 75 FaPGs, most genes exhibited low expression across developmental stages, while two group c members (FxaC_21g15770 and FxaC_20g05360) and one group b member, FxaC_19g05040, displayed relatively higher and gradual increases in their expression trends during strawberry ripening and softening. FxaC_21g15770 was selected for subsequent silencing to validate its role in strawberry softening due to the fact that it exhibited the highest and most changed expression level across different developmental stages in 'Benihoppe' and its mutant. Silencing FxaC_21g15770 could significantly improve strawberry fruit firmness without affecting fruit color, soluble solids, cellulose, and hemicellulose. Conversely, silencing FxaC_21g15770 could significantly suppress the expression of other genes related to pectin degradation such as FaPG-like, FaPL, FaPME, FaCX, FaCel, FaGlu, FaXET, and FaEG. These findings provide basic information on the FaPG gene family for further functional research and indicate that FxaC_21g15770 plays a vital role in strawberry fruit softening.

Multi-model GWAS reveals key loci for horticultural traits in reconstructed garden strawberry.

The cultivated garden strawberry (Fragaria × ananassa) has a rich history, originating from the hybridization of two wild octoploid strawberry species in the 18th century. Two-step reconstruction of Fragaria × ananassa through controlled crossings between pre-improved selections of its parental species is a promising approach for enriching the breeding germplasm of strawberry for wider adaptability. We created a population of reconstructed strawberry by hybridizing elite selections of F. virginiana and F. chiloensis. A replicated field experiment was conducted to evaluate the population's performance for eleven horticulturally important traits, over multiple years. Population structure analyses based on Fana-50 k SNP array data confirmed pedigree-based grouping of the progenies into four distinct groups. As complex traits are often influenced by environmental variables, and population structure can lead to spurious associations, we tested multiple genome-wide association study (GWAS) models. GWAS uncovered 39 quantitative trait loci (QTL) regions for eight traits distributed across twenty chromosomes, including 11 consistent and 28 putative QTLs. Candidate genes for traits including winter survival, flowering time, runnering vigor, and hermaphrodism were identified within the QTL regions. To our knowledge, this study marks the first comprehensive investigation of adaptive and horticultural traits in a large, multi-familial reconstructed strawberry population using SNP markers.

Updates on Strawberry DNA Testing and Marker-Assisted Breeding at the University of Florida

ABSTRACT Developing new strawberry varieties with high level of disease resistance and superior fruit quality is critical for strawberry production. Despite the complexity of the octoploid strawberry genome, recent advances in genomics and DNA sequencing technologies have allowed us to identify causal sequence variants associated with specific phenotypes. These have enabled the development of new and improved DNA markers for integration in marker-assisted breeding (MAB) efforts. The use of MAB has significantly improved the efficiency of stacking loci responsible for disease resistance and fruit quality characteristics. The “Strawberry DNA Testing Handbook” is currently accessible in the Genome Database for Rosaceae and has been an essential resource for the national and international strawberry research community. Based on the information provided in the handbook, the UF strawberry breeding program implemented seedling selection from 2021 to 2023, retaining 25.3%, 19.2%, and 37.9% of seedlings for further evaluation in each respective year. In this report, we provide updates on DNA markers associated with disease resistance and fruit quality traits. Additionally, we demonstrate the practical implementation of these markers in high-throughput marker-assisted selection and their potential to enhance strawberry breeding.

Genetic loci associated with tissue-specific resistance to powdery mildew in octoploid strawberry (Fragaria × ananassa).

Powdery mildew is one of the most problematic diseases in strawberry production. To date, few commercial strawberry cultivars are deemed to have complete resistance and as such, an extensive spray programme must be implemented to control the pathogen. Here, a large-scale field experiment was used to determine the powdery mildew resistance status of leaf and fruit tissues across a diverse panel of strawberry genotypes. This phenotypic data was used to identify Quantitative Trait Nucleotides (QTN) associated with tissue-specific powdery mildew resistance. In total, six stable QTN were found to be associated with foliar resistance, with one QTN on chromosome 7D associated with a 61% increase in resistance. In contrast to the foliage results, there were no QTN associated with fruit disease resistance and there was a high level of resistance observed on strawberry fruit, with no genetic correlation observed between fruit and foliar symptoms, indicating a tissue-specific response. Beyond the identification of genetic loci, we also demonstrate that genomic selection can lead to rapid gains in foliar resistance across genotypes, with the potential to capture >50% of the genetic foliage resistance present in the population. To date, breeding of robust powdery mildew resistance in strawberry has been impeded by the quantitative nature of natural resistance and a lack of knowledge relating to the genetic control of the trait. These results address this shortfall, through providing the community with a wealth of information that could be utilized for genomic informed breeding, implementation of which could deliver a natural resistance strategy for combatting powdery mildew.

Light-dependent chloroplast relocation in wild strawberry (Fragaria vesca)

ABSTRACT Chloroplast photorelocation is a vital organellar response that optimizes photosynthesis in plants amid fluctuating environmental conditions. Chloroplasts exhibit an accumulation response, in which they move toward weak light to enhance photoreception, and an avoidance response, in which they move away from strong light to avoid photodamage. Although chloroplast photorelocation has been extensively studied in model plants such as Arabidopsis thaliana, little is known about this process in the economically important crop strawberry. Here, we investigated chloroplast photorelocation in leaf mesophyll cells of wild strawberry (Fragaria vesca), a diploid relative of commercially cultivated octoploid strawberry (F. × ananassa). Microscopy observation revealed that the periclinal area of leaf mesophyll cells in F. vesca is considerably smaller than that of A. thaliana. Given this small cell size, we investigated chloroplast photorelocation in F. vesca by measuring light transmittance in leaves. Weak blue light induced the accumulation response, whereas strong blue light induced the avoidance response. Unexpectedly, strong red light also induced the accumulation response in F. vesca. These findings shed light on chloroplast photorelocation as an intracellular response, laying the foundation for enhancing photosynthesis and productivity in Fragaria.

Dynamics of accessible chromatin regions and subgenome dominance in octoploid strawberry

Subgenome dominance has been reported in diverse allopolyploid species, where genes from one subgenome are preferentially retained and are more highly expressed than those from other subgenome(s). However, the molecular mechanisms responsible for subgenome dominance remain poorly understood. Here, we develop genome-wide map of accessible chromatin regions (ACRs) in cultivated strawberry (2n = 8x = 56, with A, B, C, D subgenomes). Each ACR is identified as an MNase hypersensitive site (MHS). We discover that the dominant subgenome A contains a greater number of total MHSs and MHS per gene than the submissive B/C/D subgenomes. Subgenome A suffers fewer losses of MHS-related DNA sequences and fewer MHS fragmentations caused by insertions of transposable elements. We also discover that genes and MHSs related to stress response have been preferentially retained in subgenome A. We conclude that preservation of genes and their cognate ACRs, especially those related to stress responses, play a major role in the establishment of subgenome dominance in octoploid strawberry.

Optimization of an efficient hydroponic cultivation method for high yield of strawberry plants

The widely grown octoploid strawberry (2n = 8x = 56) (Fragaria × Ananassa Duch.), cherished for its delectable flavour, rich nutritional content, and pleasing aroma has consistently held a significant position in global fruit market. Despite of rising demand, strawberry plants are not grown universally, likely due to variations in weather conditions across regions, available of infectious soil pathogen and insufficient knowledge of soilless hydroponic cultivation. The current research aims to establish an efficient nutrient medium that enhances the growth and yield of strawberry (Fragaria × Ananassa Duch.) Cv. Winter Dawn, using soilless hydroponic and semi-hydroponic cultivation methods. The fruit fresh weight and total fruit yield of formulation 2 treated plants (EC 2.41 mScm−1) in hydroponic condition exhibited a 1.73-fold and 2.18-fold higher respectively as compared to soil control plants. Among the five different growing medium treatments in semi-hydroponic condition, the fresh weight and total strawberry fruit yield was found to be maximum in treatment 3 and observed 2.04-fold and 3.03-fold increase respectively as compared to plants grown in soil control condition. The high yield may be due to higher uptake of macronutrients (NPK) by the plants supplemented with F2 formulation and T3 substrate medium the plants. As a result, the strawberry fruits of these plants accumulated higher amount of anthocyanin, which ultimately enhanced the fruit quality. The studies concluded that formulation 2 in hydroponic and treatment 3 in semi-hydroponic were most effective in terms of growth, nutrient uptake, physiology, fruit yield and anthocyanin content. The result of this study gives an alternative to the farmers for cultivation of strawberry plants in soilless hydroponic and semi-hydroponic conditions.

Genomic analyses provide insights into sex differentiation of tetraploid strawberry (Fragaria moupinensis).

The strawberry genus, Fragaria, exhibits a wide range of sexual systems and natural ploidy variation. Nearly, all polyploid strawberry species exhibit separate sexes (dioecy). Research has identified the sex-determining sequences as roughly conserved but with repeatedly changed genomic locations across octoploid strawberries. However, it remains unclear whether tetraploid wild strawberries evolved dioecy independently or shared a common origin with octoploid strawberries. In this study, we investigated the sex determinants of F. moupinensis, a dioecious plant with heterogametic females (ZW). Utilizing a combination of haplotype-resolved genome sequencing of the female F. moupinensis, k-mer-based and coverage-based genome-wide association studies (GWAS), and transcriptomic analysis, we discovered a non-recombining, approximately 33.6 kb W-specific region on chromosome 2a. Within this region, only one candidate sex-determining gene (FmoAFT) was identified. Furthermore, an extensive resequencing of the entire Fragaria genus indicated that the W-specific region displays conservative female specificity across all tetraploid species. This observation suggests that dioecy evolved independently in tetraploid and octoploid strawberries. Moreover, employing virus-induced gene silencing (VIGS), we knocked down the expression of the FmoAFT homologue transcript in cultivated strawberries, revealing its potential role in promoting female functions during early carpel development. We also applied DNA affinity purification sequencing (DAP-seq) and yeast one-hybrid assays to identify potential direct targets of FmoAFT. These insights shed new light on the genetic basis and evolutionary history of sex determination in strawberries, thereby facilitating the formulation of strategies to manipulate sex determination in breeding programs.

Advances in genomics and genome editing for improving strawberry (Fragaria ×ananassa).

The cultivated strawberry, Fragaria ×ananassa, is a recently domesticated fruit species of economic interest worldwide. As such, there is significant interest in continuous varietal improvement. Genomics-assisted improvement, including the use of DNA markers and genomic selection have facilitated significant improvements of numerous key traits during strawberry breeding. CRISPR/Cas-mediated genome editing allows targeted mutations and precision nucleotide substitutions in the target genome, revolutionizing functional genomics and crop improvement. Genome editing is beginning to gain traction in the more challenging polyploid crops, including allo-octoploid strawberry. The release of high-quality reference genomes and comprehensive subgenome-specific genotyping and gene expression profiling data in octoploid strawberry will lead to a surge in trait discovery and modification by using CRISPR/Cas. Genome editing has already been successfully applied for modification of several strawberry genes, including anthocyanin content, fruit firmness and tolerance to post-harvest disease. However, reports on many other important breeding characteristics associated with fruit quality and production are still lacking, indicating a need for streamlined genome editing approaches and tools in Fragaria ×ananassa. In this review, we present an overview of the latest advancements in knowledge and breeding efforts involving CRISPR/Cas genome editing for the enhancement of strawberry varieties. Furthermore, we explore potential applications of this technology for improving other Rosaceous plant species.

Selection and validation of reference genes for qRT-PCR in cultivated octoploid strawberry

Selection and validation of reference genes for qRT-PCR in cultivated octoploid strawberry

Genome-wide analysis of the bHLH family and identification ofbHLHgenes involved in fruit development and ripening of cultivated octoploid strawberry

AbstractObjectivesThe basic helix–loop–helix (bHLH) transcription factors (TFs) regulate fruit growth in many plants. However, there is no available study on the bHLH gene family in the haplotype-resolved genome of cultivated strawberry (Fragaria × ananassa).Materials and MethodsThe 131 FabHLH genes identified in the strawberry cultivar ‘Yanli’ haplotype-resolved genome were classified into 24 subfamilies according to their phylogenetic relationships. Gene structure, conserved motifs, and chromosomal locations were investigated using bioinformatics.ResultsIn total, 15 FabHLH genes potentially involved in fruit development were screened based on transcriptome analysis of different stages of fruit development. We also identified the cis-regulatory elements of these 15 FabHLH genes, predicted upstream transcription factors, and identified protein–protein interactions.ConclusionsThe findings of this study improve our understanding of the regulation mediated by bHLH TFs during strawberry fruit growth and maturation.

Phased gap-free genome assembly of octoploid cultivated strawberry illustrates the genetic and epigenetic divergence among subgenomes.

The genetic and epigenetic mechanisms underlying the coexistence and coordination of the four diverged subgenomes (ABCD) in octoploid strawberries (Fragaria × ananassa) remains poorly understood. In this study, we have assembled a haplotype-phased gap-free octoploid genome for the strawberry, which allowed us to uncover the sequence, structure, and epigenetic divergences among the subgenomes. The diploid progenitors of the octoploid strawberry, apart from subgenome A (Fragaria vesca), have been a subject of public controversy. Phylogenomic analyses revealed a close relationship between diploid species Fragaria iinumae and subgenomes B, C, and D. Subgenome A, closely related to F. vesca, retains the highest number of genes, exhibits the lowest content of transposable elements (TEs), experiences the strongest purifying selection, shows the lowest DNA methylation levels, and displays the highest expression level compared to the other three subgenomes. Transcriptome and DNA methylome analyses revealed that subgenome A-biased genes were enriched in fruit development biological processes. In contrast, although subgenomes B, C, and D contain equivalent amounts of repetitive sequences, they exhibit diverged methylation levels, particularly for TEs located near genes. Taken together, our findings provide valuable insights into the evolutionary patterns of subgenome structure, divergence and epigenetic dynamics in octoploid strawberries, which could be utilized in strawberry genetics and breeding research.