Prickles on blackberry and raspberry canes make pruning, harvesting, and handling more difficult and can increase labor costs for growers. The trait has been challenging to improve in these clonal crops because it is recessive and linked to undesirable agronomic traits. In blackberry and red raspberry, breeding programs have used recessive mutants at the S locus to generate prickleless cultivars for the last century. In this study, we identified independent loss-of-function mutations in a WUSCHEL-LIKE HOMEOBOX transcription factor, WOX1 , as the genetic basis of the prickleless S locus in both blackberry and red raspberry. We mapped the S locus using integrated genome-wide association, bulked segregant analysis, and identity-by-descent analyses informed by breeding pedigrees. Additionally, we generated a genome sequence from Luther Burbank’s prickleless blackberry variety Burbank Thornless that contained an additional allele of WOX1 . To verify the gene’s role, we used gene editing to knock out WOX1 in an elite prickled commercial blackberry line. All edited plants were prickleless and lacked glandular trichomes, confirming that WOX1 controls a joint developmental pathway. Other plant traits were unchanged, indicating WOX1 is a specific and safe target for improvement. Gene editing can enable breeders to remove prickles directly from elite varieties, reducing the need for extensive breeding cycles and delivering safer, easier-to-harvest cultivars to growers.

Prickle-free blackberry (Rubus subgenus Rubus) canes are strongly preferred by growers due to food and worker safety concerns and damage to fruit from mechanical injury by prickles. This project was conducted to identify the genetic region responsible for prickle-free canes derived from the recessive "Merton Thornless" source in autotetraploid blackberry using a genome-wide association study, develop diagnostic Kompetitive Allele-Specific PCR markers for prickle-free canes, and determine the effects of allele dosage at the prickle-free locus on prickle density in 2 biparental populations. The prickle locus was located on chromosome Ra04 from 30.48 to 36.04 Mb in an extensive LD block, with the peak single-nucleotide polymorphism located at 33.64 Mb. Five potential candidate genes with functional annotations related to epidermal, trichome, or prickle development were identified within the prickle-free locus. One missense mutation in the third exon of the HOX3 homolog Ra_g19498, which resulted in a serine to leucine substitution at position 91 in the amino acid sequence, was discovered using whole-genome sequence data of 17 tetraploid blackberry genotypes. Three diagnostic Kompetitive Allele-Specific PCR markers were developed targeting the missense mutation in Ra_g19498 and the 2 single-nucleotide polymorphisms most strongly associated with the prickle-free trait in the genome-wide association study. These 3 markers each correctly predicted the phenotype of between 96 and 97% and of 626 diverse fresh-market blackberry genotypes from multiple breeding programs, respectively. Allele dosage at the prickle-free locus had a significant impact on prickle density, with duplex prickly genotypes having significantly higher prickle density than simplex genotypes in both biparental populations studied.

Although the significance of some plant WRKYs in response to cold stress have been identified, the molecular mechanisms of most WRKYs remain unclear in grapevine. In this study, we demonstrate that cold-induced expression of VaBAM3 in Vitis amurensis executes a beneficial role in enhancing resistance by the regulating starch decomposition. VaWRKY65 was identified as an upstream transcriptional activator of VaBAM3 through yeast one-hybrid library screening and validated to directly interact with the W-box region inside the VaBAM3 promoter. Transgenic Arabidopsis thaliana plants and grapevine roots overexpression VaWRKY65 exhibited improved cold tolerance along with higher BAM activity and soluble sugar levels, whereas opposite changes were observed in VaWRKY65 knockdown lines created by virus-induced gene silencing (VIGS) in grapevine plants and in the knockout wrky65 mutants generated by CRISPR/Cas9 technology in grapevine roots. The transcriptome data show that overexpression of VaWRKY65 led to significant alteration of a diverse set of stress-related genes at the transcriptional level. One of the genes, Peroxidase 36 (VaPOD36), was further verified as a direct target of VaWRKY65. Consistently, VaWRKY65-overexpressing plants had higher VaPOD36 transcript levels and POD activity but a reduced ROS level, while silencing VaWRKY65 results in contrary changes. Collectively, these results reveal that VaWRKY65 enhanced cold tolerance through modulating soluble sugars produced from starch breakdown and ROS scavenging.

Cissus quadrangularis is a tetraploid species belonging to the Vitaceae family and is known for the Crassulacean acid metabolism (CAM) pathway in the succulent stem, while the leaves perform C3 photosynthesis. Here, we report a high-quality genome of C. quadrangularis comprising a total size of 679.2 Mb which was phased into two subgenomes. Genome annotation identified 51 857 protein-coding genes, while approximately 47.75% of the genome was composed of repetitive sequences. Gene expression ratios of two subgenomes demonstrated that the sub-A genome as the dominant subgenome played a vital role during the drought tolerance. Genome divergence analysis suggests that the tetraploidization event occurred around 8.9 million years ago. Transcriptome data revealed that pathways related to cutin, suberine, and wax metabolism were enriched in the stem during drought treatment, suggesting that these genes contributed to the drought adaption. Additionally, a subset of CAM-related genes displayed diurnal expression patterns in the succulent stems but not in leaves, indicating that stem-biased expression of existing genes contributed to the CAM evolution. Our findings provide insights into the mechanisms of drought adaptation and photosynthesis transition in plants.

Cold stress is an adverse environmental factor that limits the growth and productivity of horticulture crops such as grapes (Vitis vinifera). In this study, we identified a grapevine cold-induced basic helix-loop-helix (bHLH) transcription factor (VvbHLH036). Overexpression and CRISPR/Cas9-mediated knockout (KO) of VvbHLH036 enhanced and decreased cold tolerance in grapevine roots, respectively. Transcriptome analysis of VvbHLH036-overexpressed roots identified threonine synthase (VvThrC1) as a potential downstream target of VvbHLH036. We confirmed that VvbHLH036 could bind the VvThrC1 promoter and activate its expression. Both the transcripts of VvThrC1 and the content of threonine were significantly induced in the leaves and roots of grapevine under cold treatment compared to controls. Conversely, these dynamics were significantly suppressed in the roots of CRISPR/Cas9-induced KO of VvbHLH036. These observations support the regulation of threonine accumulation by VvbHLH036 through VvThrC1 during cold stress in grapevine. Furthermore, overexpression and CRISPR/Cas9-mediated KO of VvThrC1 also confirmed its role in regulating threonine content and cold tolerance in transgenic roots at low temperature. Exogenous threonine treatment increased cold tolerance and reduced the accumulation of superoxide anions and hydrogen peroxide in grapevine leaves. Together, these findings point to the pivotal role of VvbHLH036 and VvThrC1 in the cold stress response in grapes by regulating threonine biosynthesis. A basic helix-loop-helix transcription factor, VvbHLH036, improves the cold tolerance of grapevine through VvThrC-activated threonine biosynthesis.

IntroductionBlackberry (Rubus subgenus Rubus) is a soft-fruited specialty crop that often suffers economic losses due to degradation in the shipping process. During transportation, fresh-market blackberries commonly leak, decay, deform, or become discolored through a disorder known as red drupelet reversion (RDR). Over the past 50 years, breeding programs have achieved better fruit firmness and postharvest quality through traditional selection methods, but the underlying genetic variation is poorly understood.MethodsWe conducted a genome-wide association of fruit firmness and RDR measured in 300 tetraploid fresh-market blackberry genotypes from 2019-2021 with 65,995 SNPs concentrated in genic regions of the R. argutus reference genome.ResultsFruit firmness and RDR had entry-mean broad sense heritabilities of 68% and 34%, respectively. Three variants on homologs of polygalacturonase (PG), pectin methylesterase (PME), and glucan endo-1,3-β-glucosidase explained 27% of variance in fruit firmness and were located on chromosomes Ra06, Ra01, and Ra02, respectively. Another PG homolog variant on chromosome Ra02 explained 8% of variance in RDR, but it was in strong linkage disequilibrium with 212 other RDR-associated SNPs across a 23 Mb region. A large cluster of six PME and PME inhibitor homologs was located near the fruit firmness quantitative trait locus (QTL) identified on Ra01. RDR and fruit firmness shared a significant negative correlation (r = -0.28) and overlapping QTL regions on Ra02 in this study.DiscussionOur work demonstrates the complex nature of postharvest quality traits in blackberry, which are likely controlled by many small-effect QTLs. This study is the first large-scale effort to map the genetic control of quantitative traits in blackberry and provides a strong framework for future GWAS. Phenotypic and genotypic datasets may be used to train genomic selection models that target the improvement of postharvest quality.

Blackberries (Rubus spp.) are the fourth most economically important berry crop worldwide. Genome assemblies and annotations have been developed for Rubus species in subgenus Idaeobatus, including black raspberry (R. occidentalis), red raspberry (R. idaeus), and R. chingii, but very few genomic resources exist for blackberries and their relatives in subgenus Rubus. Here we present a chromosome-length assembly and annotation of the diploid blackberry germplasm accession "Hillquist" (R. argutus). "Hillquist" is the only known source of primocane-fruiting (annual-fruiting) in tetraploid fresh-market blackberry breeding programs and is represented in the pedigree of many important cultivars worldwide. The "Hillquist" assembly, generated using Pacific Biosciences long reads scaffolded with high-throughput chromosome conformation capture sequencing, consisted of 298 Mb, of which 270 Mb (90%) was placed on 7 chromosome-length scaffolds with an average length of 38.6 Mb. Approximately 52.8% of the genome was composed of repetitive elements. The genome sequence was highly collinear with a novel maternal haplotype-resolved linkage map of the tetraploid blackberry selection A-2551TN and genome assemblies of R. chingii and red raspberry. A total of 38,503 protein-coding genes were predicted, of which 72% were functionally annotated. Eighteen flowering gene homologs within a previously mapped locus aligning to an 11.2 Mb region on chromosome Ra02 were identified as potential candidate genes for primocane-fruiting. The utility of the "Hillquist" genome has been demonstrated here by the development of the first genotyping-by-sequencing-based linkage map of tetraploid blackberry and the identification of possible candidate genes for primocane-fruiting. This chromosome-length assembly will facilitate future studies in Rubus biology, genetics, and genomics and strengthen applied breeding programs.

The success of plant breeding depends on diversity in plant genetic resources and their responses to changing environments. Accordingly, 20 strawberry genotypes with diverse genetic background were evaluated for their performance under different environments based on the estimation of their genetic variability and heritability. The results showed that environmental factors have great influences on changing the size of the measured traits. Also, a high heritability and genetic variation detected for yield and its components showed a strong potential for improvement among the strawberry genotypes and being considered as raw materials in breeding programs. Biplot and heatmap, in line with the clustering, showed to be key methods for finding the structural association among genotypes and traits. Cluster analysis showed that the genotypes originating from the same geographic area were not necessarily placed in the same clusters which could be due to the environmental variability and the different responses of the genotypes coming from altered genetic materials. The overall results regarding multivariate analyses showed that genotypes Kurdistan, Queen Elisa and No.14 could be considered as a cluster with high similarity for being crossed by other genotypes in the clusters such as groups of Pajaro and Chandler, or the group of Selva and Gaviota.

Reliable and high-throughput genotyping platforms are of immense importance for identifying and dissecting genomic regions controlling important phenotypes, supporting selection processes in breeding programs, and managing wild populations and germplasm collections. Amongst available genotyping tools, single nucleotide polymorphism arrays have been shown to be comparatively easy to use and generate highly accurate genotypic data. Single-species arrays are the most commonly used type so far; however, some multi-species arrays have been developed for closely related species that share single nucleotide polymorphism markers, exploiting inter-species cross-amplification. In this study, the suitability of a multiplexed plant-animal single nucleotide polymorphism array, including both closely and distantly related species, was explored. The performance of the single nucleotide polymorphism array across species for diverse applications, ranging from intra-species diversity assessments to parentage analysis, was assessed. Moreover, the value of genotyping pooled DNA of distantly related species on the single nucleotide polymorphism array as a technique to further reduce costs was evaluated. Single nucleotide polymorphism performance was generally high, and species-specific single nucleotide polymorphisms proved suitable for diverse applications. The multi-species single nucleotide polymorphism array approach reported here could be transferred to other species to achieve cost savings resulting from the increased throughput when several projects use the same array, and the pooling technique adds another highly promising advancement to additionally decrease genotyping costs by half.

Breeding strategies for improving blueberry (Vaccinium corymbosum and V. virgatum) cultivars often include introgressing regionally adapted species into the cultivated gene pools through interspecific hybridization. However, these approaches are complicated by variation in ploidy, triploid blocks and infertility, production of unreduced gametes, and aneuploidy. The objective of this study was to use flow cytometry, k-mer distribution analysis, and known pedigree information to evaluate genome sizes (2C nuclear and 1Cx monoploid), and ploidy of diverse accessions from Vaccinium sections and species. A total of 369 accessions, including a diversity panel (DP) of 251 inter- and intra-specific hybrid Vaccinium accessions, as well as 118 non-hybrid Vaccinium species across multiple sections, were sampled from the North Carolina State University blueberry breeding program and the National Clonal Germplasm Repository. The nuclear DNA content was analyzed via flow cytometry. The mean (range) DNA content of diploid, tetraploid, and hexaploid reference species were 1.20 pg (0.99 pg in V. crassifolium 'Well's Delight' to 1.41 pg in V. caesariense NC79–24), 2.37 pg (2.11 pg in V. corymbosum 'Concord' to 3.01 pg in V. corymbosum DE599), and 3.64 pg (3.24 in V. constablaei NC83–21–2 to 3.80 in V. virgatum 'Premier' and NC4790), respectively. Of the 369 unique accessions analyzed for ploidy, 259 were tetraploid, 46 were diploid, one was triploid, 51 were pentaploid or aneuploid with 2C values between tetraploid and hexaploid values, and 12 were hexaploid. Tetraploid hybrid pedigrees, which involved hexaploid crosses within three prior generations, had a 2C value range between 2.22 pg and 2.59 pg. Interspecific pentaploid and aneuploid progeny 2C DNA content ranged from 2.61 pg to 3.15 pg. We speculate some of these progeny to be near tetraploids with extra chromosomes from hexaploid progenitors. Further karyotyping of these individuals is necessary to ascertain aneuploidy anomalies. This research provides an expanded knowledge base of genome sizes, ploidy, and reproductive pathways for diverse species and hybrids to enhance future breeding, improvement, and the genomic study of blueberry.

Two hemibiotrophic pathogens, Colletotrichum acutatum (Ca) and C . gloeosporioides (Cg), cause anthracnose fruit rot and anthracnose crown rot in strawberry ( Fragaria × ananassa Duchesne), respectively. Both Ca and Cg can initially infect through a brief biotrophic phase, which is associated with the production of intracellular primary hyphae that can infect host cells without causing cell death and establishing hemibiotrophic infection (HBI) or quiescent (latent infections) in leaf tissues. The Ca and Cg HBI in nurseries and subsequent distribution of asymptomatic infected transplants to fruit production fields is the major source of anthracnose epidemics in North Carolina. In the absence of complete resistance, strawberry varieties with good fruit quality showing rate-reducing resistance have frequently been used as a source of resistance to Ca and Cg. However, the molecular mechanisms underlying the rate-reducing resistance or susceptibility to Ca and Cg are still unknown. We performed comparative transcriptome analyses to examine how rate-reducing resistant genotype NCS 10-147 and susceptible genotype ‘Chandler’ respond to Ca and Cg and identify molecular events between 0 and 48 h after the pathogen-inoculated and mock-inoculated leaf tissues. Although plant response to both Ca and Cg at the same timepoint was not similar, more genes in the resistant interaction were upregulated at 24 hpi with Ca compared with those at 48 hpi. In contrast, a few genes were upregulated in the resistant interaction at 48 hpi with Cg. Resistance response to both Ca and Cg was associated with upregulation of MLP-like protein 44, LRR receptor-like serine/threonine-protein kinase, and auxin signaling pathway, whereas susceptibility was linked to modulation of the phenylpropanoid pathway. Gene regulatory network inference analysis revealed candidate transcription factors (TFs) such as GATA5 and MYB-10, and their downstream targets were upregulated in resistant interactions. Our results provide valuable insights into transcriptional changes during resistant and susceptible interactions, which can further facilitate assessing candidate genes necessary for resistance to two hemibiotrophic Colletotrichum spp. in strawberry.

Cissus is the largest genus in Vitaceae and is mainly distributed in the tropics and subtropics. Crassulacean acid metabolism (CAM), a photosynthetic adaptation to the occurrence of succulent leaves or stems, indicates that convergent evolution occurred in response to drought stress during species radiation. Here we provide the chromosomal level assembly of Cissus rotundifolia (an endemic species in Eastern Africa) and a genome-wide comparison with grape to understand genome divergence within an ancient eudicot family. Extensive transcriptome data were produced to illustrate the genetics underpinning C. rotundifolia's ecological adaption to seasonal aridity. The modern karyotype and smaller genome of C. rotundifolia (n=12, 350.69 Mb/1C), which lack further whole-genome duplication, were mainly derived from gross chromosomal rearrangements such as fusions and segmental duplications, and were sculpted by a very recent burst of retrotransposon activity. Bias in local gene amplification contributed to its remarkable functional divergence from grape, and the specific proliferated genes associated with abiotic and biotic responses (e.g. HSP-20, NBS-LRR) enabled C. rotundifolia to survive in a hostile environment. Reorganization of existing enzymes of CAM characterized as diurnal expression patterns of relevant genes further confer the ability to thrive in dry savannas.

The feeding habits of adult Brachycera are understudied and may provide important context for understanding invasive pest biology, as with the polyphagous small fruit pest Drosophila suzukii. We developed molecular methods to study adult D. suzukii gut content in order to understand its feeding habits. We designed and verified two primer pairs specific for either blueberries or blackberries and used a qPCR melt curve analysis to determine whether we can detect the presence or absence of berry feeding by adult flies. In a laboratory assay, the blueberry fly meal DNA can be detected for longer periods than the blackberry meal DNA. Generally, female gut contents are less variable than male gut contents. We also tested recently emerged flies that were not fed as adults but developed as larvae in either blueberries or blackberries. Some adult flies from each fruit had detectable fruit DNA in their gut, which could be due to pupal meconium feeding after emergence. Next, we aimed to test the primers in the field to develop techniques to track fruit feeding by D. suzukii in its natural field environment. First, to identify the most appropriate collection method, we determined how long we could detect fruit DNA, using previously developed primers within D. suzukii gut preserved in four types of trap fluid in the laboratory. The likelihood of detecting blackberry DNA differed by day, trap fluid, and between sexes. For the blueberry primer, the possibility of detecting blueberry DNA differed by trap fluid only. Based on those results, we used RV antifreeze with a Scentry SWD lure in field trials at two research station locations, one containing blackberries and one with blueberries. We established transects away from each fruit planting and collected up to 120 total flies at each point along transects. There were no significant differences in the number of flies containing berry DNA among collection points along the transect in both locations. These results suggest that adult flies move between crop and non-crop habitats and may not be highly dependent on fruit food resources.

Background Tripidium ravennae is a cold-hardy, diploid species in the sugarcane complex ( Poaceae subtribe Saccharinae ) with considerable potential as a genetic resource for developing improved bioenergy and ornamental grasses. An improved understanding of the genetic regulation of reproductive processes (e.g., floral induction, inflorescence development, and seed development) will enable future applications of precision breeding and gene editing of floral and seed development. In particular, the ability to silence reproductive processes would allow for developing seedless forms of valuable but potentially invasive plants. The objective of this research was to characterize the gene expression environment of reproductive development in T. ravennae. Results During the early phases of inflorescence development, multiple key canonical floral integrators and pathways were identified. Annotations of type II subfamily of MADS-box transcription factors, in particular, were over-represented in the GO enrichment analyses and tests for differential expression (FDR p -value < 0.05). The differential expression of floral integrators observed in the early phases of inflorescence development diminished prior to inflorescence determinacy regulation. Differential expression analysis did not identify many unique genes at mid-inflorescence development stages, though typical biological processes involved in plant growth and development expressed abundantly. The increase in inflorescence determinacy regulatory elements and putative homeotic floral development unigenes at mid-inflorescence development coincided with the expression of multiple meiosis annotations and multicellular organism developmental processes. Analysis of seed development identified multiple unigenes involved in oxidative-reductive processes. Conclusion Reproduction in grasses is a dynamic system involving the sequential coordination of complex gene regulatory networks and developmental processes. This research identified differentially expressed transcripts associated with floral induction, inflorescence development, and seed development in T. ravennae . These results provide insights into the molecular regulation of reproductive development and provide a foundation for future investigations and analyses, including genome annotation, functional genomics characterization, gene family evolutionary studies, comparative genomics, and precision breeding.

The success of plant breeding depends on diversity in plant genetic resources and their responses to changing environments. In this regard, twenty strawberry genotypes with altered genetic background were evaluated for their performance under different environments based on the estimation of their genetic variability and heritability. Furthermore, genetic distances and associations were assessed by using data mining techniques. The combined ANOVA results showed that environmental factors have great influences on changing the values’ size of the measured-traits. Also, high heritability and genetic variation were detected for yield and its components showed a high potential for improvement among the strawberry genotypes and being considered as raw materials in breeding programs. The biplot and heatmap, in line with clustering, showed to be key methods for finding about the structural association among genotypes, the measured-traits, and their cross relationships and their influences on one another simultaneously. Cluster analysis showed that the genotypes of the same geographic origin did not necessarily group in the same clusters which could be due to the environmental variability and the different responses of the genotypes coming from altered genetic materials. The overall results regarding multivariate analyses showed that genotypes Kurdistan, Queen Elisa, and No.14 could be considered as a cluster with high similarity for being crossed by other genotype in the clusters such as groups of Pajaro and Chandler, or the group of Silva and Gaviota.

Background In northern Iran and other cold regions, winter freezing injury and resultant yield instability are major limitations to strawberry production. However, there is scarcity of information on the physiological and biochemical responses of strawberry cultivars to freezing stress. This study aimed to investigate the physiological and biochemical responses of strawberry cultivars (Tennessee Beauty, Blakemore, Kurdistan, Queen Elisa, Chandler, Krasnyy Bereg, and Yalova) to different freezing temperature treatments (− 5, − 10, − 15, − 20, and − 25 °C) under controlled conditions. Results All measured physiological and biochemical features were significantly affected by the interaction effect between low temperatures and cultivars. Tennessee Beauty showed the highest RWC at − 25 °C. The highest Fv/Fm was observed in Queen Elisa. Krasnyy Bereg had the least freezing injury (FI) in crown and leaf, while Yalova and Chandler showed the highest crown and leaf FI, respectively. At − 20 to − 25 °C, the highest carbohydrates contents of crown and leaf were noted in Blakemore and Krasnyy Bereg cultivars, respectively. The Yalova showed the highest protein content in both crown and leaf tissues at − 25 °C. The Tennessee Beauty and Blackmore cultivars showed the highest proline in crowns and leaves at − 15 °C, respectively. The highest ThioBarbituric Acid Reactive Substances (TBARS) contents in the crown and leaf were observed in Kurdistan and Queen Elisa, respectively. Queen Elisa and Krasnyy Bereg cultivars showed SOD and POD peaks in the crown at − 15 °C, respectively. Conclusion Freezing stress was characterized by decreased Fv/Fm and RWC, and increased FI, TBARS, total carbohydrates, total proteins, proline content, and antioxidant enzyme activity. The extent of changes in above mentioned traits was cultivar dependent. FI and TBARS were the best traits among destructive parameters for evaluating freezing tolerance. Moreover, maximum quantum yield of PSII (Fv/Fm index), as non-destructive parameters, showed a significant efficiency in rapid assessment for screening of freezing tolerant strawberry cultivars. The cultivars Krasnyy Bereg, Queen Elisa, and Kurdistan were the most tolerant cultivars to freezing stress. These cultivars can be used as parents in breeding programs to develop new freezing tolerant cultivars.

The application of molecular breeding in blackberry is a complex problem due to polyploidy, multisomic inheritance, and heterozygosity. However, recent advances in computational tools for mapping and quantitative trait loci analyses in polyploids and development of genomic resources for Rubus crops have removed many of these barriers. The objective of this project was to develop high-quality draft genomes for two diploid blackberry accessions and a polyploid resequencing panel. The diploid accessions chosen for reference genome development, `Burbank Thornless' (R. ulmifolius inermis, PI 554060) and `Hillquist' (R. argutus, PI 553951), represented important sources of thornlessness and primocane fruiting in fresh-market blackberry breeding programs. The genome sizes were estimated to be 405 Mb in `Burbank Thornless' and 376 Mb in `Hillquist' using nuclear flow cytometry. Single-molecule realtime (SMRT) sequencing technology generated similar to 80X genome coverage for each genome. The reads were assembled using Falcon-unzip and Purge Haplotigs into a 341 Mb genome with contig N50 of 1.19 Mb for `Burbank Thornless' and a 297 Mb genome with contig N50 of 650 kb for `Hillquist'. Chromosome-level assemblies for both accessions are being developed using 10X genomic and Hi-C scaffolding tools. Genome annotation will be performed using diverse tissue samples collected from `Hillquist' and ` Burbank Thornless'. Breeders can use these resources in combination with new computational tools and genotyping strategies for polyploid crops to develop effective molecular breeding strategies for blackberry.