Genomic signals of divergence and hybridization between a wild grape (Vitis adenoclada) and domesticated grape ('Shine Muscat')

Abstract

Interspecific hybridization in Vitis holds immense potential for combining valuable adaptive traits and breeding superior cultivar development. To evaluate the feasibility of hybrid breeding using the resilient wild species Vitis adenoclada and the commercially successful cultivar V. vinifera 'Shine Muscat', their signatures of hybridization, genetic divergence, and divergent selection were investigated. Analyses of 28 resequencing genomes revealed pronounced genetic differentiation between these two lineages and corroborated the hybridization event within a derived progeny. Notably, 'Shine Muscat' exhibited stronger genome-wide selection signals, reflecting its intensive breeding history. While divergent selection signatures associated with disease resistance were evident in both species, V. adenoclada displayed enrichment in pathways linked to abiotic stress resistance. Furthermore, while 'Shine Muscat' displayed potentially mitigated deleterious mutations compared to V. adenoclada, their hybrid offspring exhibited an accumulation of heterozygous deleterious alleles, emphasizing the crucial need for monitoring such mutations in future breeding endeavors. Collectively, the findings unveil the significant genetic divergence and contrasting adaptations between V. adenoclada and 'Shine Muscat', highlighting their immense potential for breeding next-generation cultivars with enhanced resilience and superior quality.

Keywords

• vitis adenoclada
• 'shine muscat'
• hybridization
• genetic divergence
• genetic load