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van Dooijeweert, W.

Publications and source records attributed to van Dooijeweert, W..

2 recordsLinked to original sources

Three novel genomes broaden the wild side of the Capsicum pangenome

This study presents three genome assemblies within the Capsicum genus, enabling comprehensive comparative analyses for the Annuum and Baccatum complexes within the genus. We produced highly continuous assemblies of the nuclear genomes and complete chloroplast assemblies. Subsequent genome annotation identified 34,580 genes in non-pungent C. annuum cv. ECW, and 32,704 and 33,994 genes in pungent C. chacoense and C. galapagoense, respectively. These assemblies, including the first complete genomes for C. chacoense and C. galapagoense, provide additional genomic resolution within the Capsicum genus. The novel genomes were analyzed within a pangenomic framework, integrating 16 Capsicum genomes across the Annuum, Baccatum, and Pubescens complexes. Homology grouping was used to identify core, accessory and unique genes and showed a wide spectrum of genetic diversity, particularly in homology groups exclusive to C. chacoense and C. galapagoense. Out of 79,267 homology groups identified, 13% were core groups, present in all accessions, corresponding to approximately 30% of core genes per genome. Comparative analyses revealed distinct species and genus specific genomic characteristics. Additionally, we used the graph pangenome to illustrate locus-level exploration by examining the Pun1 locus associated with capsaicinoid biosynthesis, identifying multiple Pun1-like genes including their genomic position and homology information. The integration of these new resources into a dynamic Capsicum pangenome framework provides a versatile platform for extracting genetic information relevant to both fundamental research and breeding applications.

genomics↗

Pollen sequencing reveals barriers and aberrant patterns of recombination in interspecific tomato hybrids

Tomato is the most consumed vegetable in the world. Increasing its natural resistance and resilience is key for ensuring food security within a changing climate. Plant breeders improve those traits by generating crosses of cultivated tomatoes with their wild relatives. Specific allele introgression relying on meiotic recombination, is hampered by structural divergence between parental genomes. However, previous studies of interspecific tomato hybridization focused in single cross or lacked resolution due to prohibitive sequencing costs of large segregating populations. Here, we used pooled-pollen sequencing to reveal unprecedented details of recombination patterns in five interspecific tomato hybrids. We detected hybrid-specific recombination coldspots that underscore the influence of structural divergence in shaping recombination landscape. Crossover regions and coldspots show strong association with specific TE superfamilies exhibiting differentially accessible chromatin between somatic and meiotic cells. We also found gene complexes associated with metabolic processes, stress resistance and domestication syndrome traits, revealing undesired consequences of recombination suppression to phenotypes. Finally, we demonstrate that by using resequencing data of wild and domesticated tomato populations, we can screen for alternative parental genomes to overcome recombination barriers. Overall, our results will allow breeders better informed decisions on generating disease-resistant and climate-resilient tomato.

genomics↗