Biology subjects

Duval, H.

Publications and source records attributed to Duval, H..

4 recordsLinked to original sources

bioRxiv2026

From Phenomics to Genomics: Macro-GWAS of Almond Morphology and Quality

In plant breeding and genetics, recent advances in high-throughput phenotyping are beginning to meet the growing demand for large-scale, high-quality phenotypic data that emerged after the development of next-generation sequencing technologies. Recent developments in phenomics have been incorporated into almond breeding programs, facilitating the large-scale acquisition of quantitative phenotypes and the dissection of the genetic architecture underlying morphological and quality-related traits. The implementation of a high-throughput phenotyping platform integrating RGB and hyperspectral imaging with genotyping using the 60K almond SNP array enabled the large-scale characterization of almond populations and the identification of 567 robust marker-trait associations across 66 traits. These analyses revealed two major genomic hotspots on chromosomes 2 and 5 associated with morphological and quality-related traits. These regions harbored biologically relevant candidate genes, including genes associated with OVATE family proteins, brassinosteroid signaling, protein ubiquitination, and acyl-CoA metabolism, as well as other regulators of organ growth, cell proliferation, hormone signaling, and seed development. Furthermore, a novel candidate gene encoding a COMT-like O-methyltransferase involved in lignin biosynthesis was identified and proposed to contribute to shell hardness, a major genetically controlled trait in almond. Together, these findings demonstrate the potential of integrating high-throughput phenomics and genomics to dissect complex traits, identify candidate genes, and accelerate genomics-informed breeding in almond.

plant biology↗

bioRxiv2024

Identification and Expression of the peach TNL RMia genes for the Resistance to the Root-knot Nematode Meloidogyne incognita

Root-Knot Nematodes (RKN) are major pests for world agriculture. As RKN are polyphagous endoparasites, present in various climates and able to multiply rapidly, the quest to discover new natural resistances in plants is essential. In Prunus species, several major resistance genes to RKN that belong to the NLR family, have been detected in recent years. In Peach, the RMia gene, which confers resistance to the RKN Meloidogyne incognita, M. arenaria, and M. ethiopica, was localized on the chromosome 2. In this study, we used short-and long-read sequencing technologies to identify the RMia gene in two independent RKN-resistant peach varieties. We characterized three candidate genes and studied their expression profile upon RKN infection. Our study identified and characterized these candidates that are most likely involved in the RKN resistance. Ultimately, we developed new molecular markers associated to this resistance that can be used in breeding programs.

plant biology↗

bioRxiv2020

PEDIGREE ANALYSIS OF 222 ALMOND GENOTYPES REVEALS TWO WORLD MAINSTREAM BREEDING LINES BASED ON ONLY THREE DIFFERENT CULTIVARS

Loss of genetic variability is a steadily increasing challenge in tree breeding programs due to the repeated use of a reduced number of founder genotypes. High-quality pedigree data of 222 almond [Prunus dulcis (Miller) D.A. Webb, syn. P. amygdalus (L) Batsch] cultivars and breeding selections were used to study global genetic variability in modern breeding programs from Argentina, Australia, France, Greece, Israel, Italy, Russia, Spain and the USA. Inbreeding coefficients, pairwise relatedness and genetic contribution were calculated for these genotypes. The results reveal two mainstream breeding lines based on three cultivars from two different geographical regions: Tuono- Cristomorto (local landraces from Puglia, Italy) and Nonpareil (chance seedling selected in California, USA, from French original stock). Direct descendants from Tuono or Cristomorto number 75 (sharing 30 descendants), while Nonpareil has 72 direct descendants. The mean inbreeding coefficient of the analyzed genotypes was 0.036, with 13 genotypes presenting a high inbreeding coefficient, over 0.250. Breeding programs from the USA, France and Spain showed inbreeding coefficients of 0.067, 0.050 and 0.034, respectively. According to their genetic contribution, modern cultivars from Israel, France, the USA, Spain and Australia, trace back to six, five, four, four and two main founding genotypes respectively. Among the group of 65 genotypes carrying the Sf allele for self-compatibility, the mean relatedness coefficient was 0.133, with Tuono as the main founding genotype (23.75% of total genetic contribution). Increasing as well as preserving current genetic variability is required in almond breeding programs worldwide to assure genetic gain and continuing breeding progress. Breeding objectives, apart from high and efficient productivity, should include disease resistance and adaptation to climate change. Ultimately, any new commercial almond cultivar has to be economically viable and breeders play a critical role in achieving this goal.

genetics↗

bioRxiv2019

Transposons played a major role in the diversification between the closely related almond (Prunus dulcis) and peach (P. persica) genomes: Results from the almond genome sequence

Combining both short and long-read sequencing, we have estimated the almond Prunus dulcis cv. Texas genome size in 235 Mbp and assembled 227.6 Mb of its sequence. The highly heterozygous compact genome of Texas comprises eight chromosomes, to which we have anchored over 91% of the assembly. We annotated 27,042 protein-coding genes and 6,800 non-coding transcripts. High levels of genetic variability were characterized after resequencing a collection of ten almond accessions. Phylogenomic comparison with the genomes of 16 other close and distant species allowed estimating that almond and peach diverged around 5.88 Mya. Comparison between peach and almond genomes confirmed the high synteny between these close relatives, but also revealed high numbers of presence-absence variants, many attributable to the movement of transposable elements (TEs). The number and distribution of TEs between peach and almond was similar, but the history of TE movement was distinct, with peach having a larger proportion of recent transpositions and almond preserving a higher level of polymorphism in the older TEs. When focusing on specific genes involved in key characters such as the bitter vs. sweet kernel taste and the formation of a fleshy mesocarp, we found that for one gene associated with the biosynthesis of amygdalin that confers the bitter kernel taste, several TEs were inserted in its vicinity only in sweet almond cultivars but not in bitter cultivars and Prunus bitter kernel relatives, including P. webbii, P. mume, and other species like peach and cherry. TE insertions likely to produce affects in the expression of six more genes involved in the formation of the fleshy mesocarp were also identified. Altogether, our results suggest a key role of TEs in the recent history and diversification of almond with respect to peach.

genomics↗