Integrating whole-genome resequencing and machine learning to refine QTL analysis for fruit quality traits in peach.

Increasing marker density results in better map coverage and efficiency of genetic analysis. Here, we resequenced a large ( = 235) F1 progeny from two distant peach cultivars, 'Zhongyou Pan #9' and 'September Free', and constructed two parental maps (1:1 segregations) and one combined map (1:2:1 segregations) with 134 277 SNPs. Markers with the same genotype for all individuals studied were grouped in bins and a unique genotype for each bin was inferred to avoid mapping problems derived from erroneous data.

Panvariome and pangenome of 1,020 global peach accessions shed light on evolution patterns, hidden natural variations, and efficient gene discovery.

Natural variations are the foundation of crop improvement. However, genomic variability remains largely understudied. Here, we present the full-spectrum integrated panvariome and pangenome of 1,020 peach accessions, including 10.

QTL mapping of almond kernel quality traits in the F progeny of 'Marcona' × 'Marinada'.

Almond breeding is increasingly focusing on kernel quality. However, unlike other agronomic traits, the genetic basis of physical and chemical kernel quality traits has been poorly investigated. To address this gap, we conducted a QTL mapping of these traits to enhance our understanding of their genetic control.

A phased genome of the highly heterozygous 'Texas' almond uncovers patterns of allele-specific expression linked to heterozygous structural variants.

The vast majority of traditional almond varieties are self-incompatible, and the level of variability of the species is very high, resulting in a high-heterozygosity genome. Therefore, information on the different haplotypes is particularly relevant to understand the genetic basis of trait variability in this species. However, although reference genomes for several almond varieties exist, none of them is phased and has genome information at the haplotype level.

Exploring large-scale gene coexpression networks in peach ( L.): a new tool for predicting gene function.

Peach is a model for genetics and genomics, however, identifying and validating genes associated to peach breeding traits is a complex task. A gene coexpression network (GCN) capable of capturing stable gene-gene relationships would help researchers overcome the intrinsic limitations of peach genetics and genomics approaches and outline future research opportunities. In this study, we created four GCNs from 604 Illumina RNA-Seq libraries.

PERSEUS: an interactive and intuitive web-based tool for pedigree visualization.

Summary: Pedigree-based analyses' prime role is to unravel relationships between individuals in breeding programs and germplasms. This is critical information for decoding the genetics underlying main inherited traits of relevance, and unlocking the genotypic variability of a species to carry out genomic selections and predictions. Despite the great interest, current lineage visualizations become quite limiting in terms of public display, exploration, and tracing of traits up to ancestral donors.

Inheritance of Fruit Red-Flesh Patterns in Peach.

Fruit color is an important trait in peach from the point of view of consumer preference, nutritional content, and diversification of fruit typologies. Several genes and phenotypes have been described for peach flesh and skin color, and although peach color knowledge has increased in the last few years, some fruit color patterns observed in peach breeding programs have not been carefully described. In this work, we first describe some peach mesocarp color patterns that have not yet been described in a collection of commercial peach cultivars, and we also study the genetic inheritance of the red dots present in the flesh (RDF) and red color around the stone (CAS) in several intra- and interspecific segregating populations for both traits.

Development and Evaluation of an Axiom 60K SNP Array for Almond ().

A high-density single nucleotide polymorphism (SNP) array is essential to enable faster progress in plant breeding for new cultivar development. In this regard, we have developed an Axiom 60K almond SNP array by resequencing 81 almond accessions. For the validation of the array, a set of 210 accessions were genotyped and 82.

Chromosome-level genome assemblies of four wild peach species provide insights into genome evolution and genetic basis of stress resistance.

Background: Peach (Prunus persica) is an economically important stone fruit crop in Rosaceae and widely cultivated in temperate and subtropical regions, emerging as an excellent material to study the interaction between plant and environment. During its genus, there are four wild species of peach, all living in harsh environments. For example, one of the wild species, P.

Construction of a collection of introgression lines of "Texas" almond DNA fragments in the "Earlygold" peach genetic background.

Peach [ L. Batsch] is one of the major temperate fruit tree species, the commercial materials of which have a low level of genetic variability. Almond [ (Mill) DA Webb], a close relative of peach cultivated for its kernels, has a much higher level of diversity.

Peach allergen Pru p 1 content is generally low in fruit but with large variation in different varieties.

Background: Pru p 1 is a major allergen in peach and nectarine, and the different content in varieties may affect the degree of allergic reactions. This study aimed to quantify Pru p 1 levels in representative peach varieties and select hypoallergenic Pru p 1 varieties.

Methods: To obtain monoclonal and polyclonal antibodies, mice and rabbits, respectively, were immunized with recombinant Pru p 1.

Genomic analyses provide insights into peach local adaptation and responses to climate change.

The environment has constantly shaped plant genomes, but the genetic bases underlying how plants adapt to environmental influences remain largely unknown. We constructed a high-density genomic variation map of 263 geographically representative peach landraces and wild relatives. A combination of whole-genome selection scans and genome-wide environmental association studies (GWEAS) was performed to reveal the genomic bases of peach adaptation to diverse climates.

Pedigree analysis of 220 almond genotypes reveals two world mainstream breeding lines based on only three different cultivars.

Loss of genetic variability is an increasing challenge in tree breeding programs due to the repeated use of a reduced number of founder genotypes. However, in almond, little is known about the genetic variability in current breeding stocks, although several cases of inbreeding depression have been reported. To gain insights into the genetic structure in modern breeding programs worldwide, marker-verified pedigree data of 220 almond cultivars and breeding selections were analyzed.

Fine mapping and identification of candidate genes for the peach powdery mildew resistance gene Vr3.

Powdery mildew is one of the major diseases of peach (Prunus persica), caused by the ascomycete Podosphaera pannosa. Currently, it is controlled through calendar-based fungicide treatments starting at petal fall, but an alternative is to develop resistant peach varieties. Previous studies mapped a resistance gene (Vr3) in interspecific populations between almond ('Texas') and peach ('Earlygold').

Resynthesis: Marker-Based Partial Reconstruction of Elite Genotypes in Clonally-Reproducing Plant Species.

We propose a method for marker-based selection of cultivars of clonally-reproducing plant species which keeps the basic genetic architecture of a top-performing cultivar (usually a partly heterozygous genotype), with the addition of some agronomically relevant differences (such as production time, product appearance or quality), providing added value to the product or cultivation process. The method is based on selecting a) two complementary nearly-inbred lines from successive selfing generations (ideally only F and F) of large size, that may generate individuals with most of their genome identical to the original cultivar but being homozygous for either of the two component haplotypes in the rest, and b) individuals with such characteristics already occurring in the F. Option a) allows for introgressing genes from other individuals in one or both of these nearly-inbred lines.

The Multisite Collection: A True Cultural Heritage and International Scientific Tool for Fruit Trees.

Plants have evolved a range of adaptive mechanisms that adjust their development and physiology to variable external conditions, particularly in perennial species subjected to long-term interplay with the environment. Exploiting the allelic diversity within available germplasm and leveraging the knowledge of the mechanisms regulating genotype interaction with the environment are crucial to address climatic challenges and assist the breeding of novel cultivars with improved resilience. The development of multisite collections is of utmost importance for the conservation and utilization of genetic materials and will greatly facilitate the dissection of genotype-by-environment interaction.

Expression QTL (eQTLs) Analyses Reveal Candidate Genes Associated With Fruit Flesh Softening Rate in Peach [ (L.) Batsch].

Significant differences in softening rate have been reported between melting flesh in peach and nectarine varieties. This trait seems to be controlled by several genes. We aimed to identify candidate genes involved in fruit softening rate by integrating quantitative trait loci (QTL) and expression QTL (eQTL) analyses, comparing siblings with contrasting softening rates.

Transposons played a major role in the diversification between the closely related almond and peach genomes: results from the almond genome sequence.

We sequenced the genome of the highly heterozygous almond Prunus dulcis cv. Texas combining short- and long-read sequencing. We obtained a genome assembly totaling 227.

genetics and applications after de novo genome sequencing: achievements and prospects.

Prior to the availability of whole-genome sequences, our understanding of the structural and functional aspects of tree genomes was limited mostly to molecular genetic mapping of important traits and development of EST resources. With public release of the peach genome and others that followed, significant advances in our knowledge of genomes and the genetic underpinnings of important traits ensued. In this review, we highlight key achievements in genetics and breeding driven by the availability of these whole-genome sequences.

Exploring sources of resistance to brown rot in an interspecific almond × peach population.

Background: Monilinia spp. are responsible for brown rot, one of the most significant stone fruit diseases. Planting resistant cultivars seems a promising alternative, although most commercial cultivars are susceptible to brown rot.

High-density multi-population consensus genetic linkage map for peach.

Highly saturated genetic linkage maps are extremely helpful to breeders and are an essential prerequisite for many biological applications such as the identification of marker-trait associations, mapping quantitative trait loci (QTL), candidate gene identification, development of molecular markers for marker-assisted selection (MAS) and comparative genetic studies. Several high-density genetic maps, constructed using the 9K SNP peach array, are available for peach. However, each of these maps is based on a single mapping population and has limited use for QTL discovery and comparative studies.

Identification of a new allele of the Dw gene causing brachytic dwarfing in peach.

Objective: Peach brachytic dwarfism determined by Dwarf gene (Dw) is an undesired trait segregating in some peach breeding programs. Recently, a single nucleotide polymorphism (SNP) mutation in the gibberellin insensitive dwarf 1 (GID1) peach gene causing brachytic dwarfism was described. In this research we wanted to validate this marker in an F population of the 'Nectavantop' peach cultivar (Nv) to include it as a marker assisted selection tool for peach breeding programs.