Influence of the interactions of qualitative and quantitative genetic factors on fruit yield and quality in tomato (Solanum lycopersicum)

• Ano de defesa: 2024
• Autor(a) principal: Barbosa, Guilherme Mateus Dias
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Tomate - Melhoramento genético; Marcadores genéticos; Heterozigosidade; Alelos; Epitase; Fisiologia Vegetal
• Link de acesso: https://locus.ufv.br/handle/123456789/34379; https://doi.org/10.47328/ufvbbt.2025.155

The study of gene relationships at the level of a single locus (allelic relationships) as well as at the level of multiple loci (epistasis), is crucial for crop genetic improvement. In the case of single loci, understanding overdominance can enable the selection of heterozygotes that maximize hybrid vigor. For multiple loci, understanding epistasis allows for the combination of desirable traits. In this research, certain tools become important, such as the evaluation of yield in field trials to verify whether the observed effect is verified in real crop environments, where factors like climate, soil, and agricultural practices influence plant performance and the identification of differentially expressed genes (DEGs) to pinpoint which candidate genes are potentially involved in traits of interest. In this context, the present study aimed to evaluate a set of tomato (Solanum lycopersicum L.) F1 hybrids involving the epinastic (epi) mutation to estimate potential heterotic effects associated with the presence of this mutation in different tomato genetic backgrounds. Mutations in pleiotropic genes potentially involved in the synthesis of plant hormones, such as epi, can result in broad changes in gene expression patterns and alter numerous metabolic pathways that may affect tomato growth and production. Here, transcriptomic analysis via RNA- seq was employed as a tool to identify a set of differentially expressed genes (DEGs) potentially modulated by the epi mutation in contrasting genetic backgrounds. A chromosome landing strategy on the candidate epi gene(s) was carried out involving a combination of genomic mapping and information derived from the transcriptome of two contrasting near-isogenic lines (NILs). The results suggest that a heterozygous mutation can alter both the level of allelic interaction and several epistatic interactions, particularly in relation to hormonal pathways, which culminates in phenotypes that may be of interest from a breeding perspective. Keywords: Heterosis ; overdominance ethylene; mutation ; Solanaceae; transcriptome.