Characterization and enhancement of genetic resources for the improvement of nutritional and organoleptic quality in solanaceae vegetable crops

• Autores: Elena Rosa Martínez
• Directores de la Tesis: María de la O Plazas Avila (dir. tes.), Salvador Soler Aleixandre (dir. tes.), Jaime Prohens Tomás (dir. tes.)
• Lectura: En la Universitat Politècnica de València ( España ) en 2022
• Idioma: español
• Tribunal Calificador de la Tesis: Santiago García Martínez (presid.), José María Bellés Albert (secret.), Amilcar Manuel Marreiros Duarte (voc.)
• Programa de doctorado: Programa de Doctorado en Biotecnología por la Universitat Politècnica de València
• Materias:
  • Ciencias de la vida
    • Biología vegetal (botánica)
      • Genética vegetal
  • Ciencias agrarias
    • Horticultura
• Enlaces
  • Tesis en acceso abierto en: RiuNet
• Resumen

  • In the present doctoral thesis, we have focused on studying the variability and providing new useful resources for the improvement of the nutritional and organoleptic quality of tomato, eggplant and pepper fruits, adapting crops to lower nitrogen (N) inputs. To achieve this purpose, we carried out a comprehensive characterization of fruit composition, together with important agronomic traits, of a set of genetic resources scarcely explored up to date. In the first chapter of this thesis, a comprehensive characterization of 36 compounds and fruit compositional parameters, including sugars, organic acids, antioxidants and minerals, was carried out on a set of 10 accessions per cultivar of tomato, pepper and eggplant, grown under the same organic farming practices. The results showed a considerably different composition profile among the three species, mainly in the antioxidant profile. In addition, a great variability was found within each species, which is of interest for the selection of varieties with better nutritional and organoleptic profiles. In the second chapter of this thesis, the characterization of a set of eggplant introgression lines (ILs) with Solanum incanum L. as the donor parent was addressed. The use of ILs in eggplant breeding requires ensuring that fruit glycoalkaloid levels are below safety limits. In a two-environment trial, we evaluated 25 fruit compositional traits, including proximal composition, sugars, acids, phenolic compounds, glycoalkaloids, and minerals in a set of 16 eggplant ILs with S. incanum, along with the recurrent and donor parents, and the hybrid. The results showed that the fruits produced by the ILs were safe for consumption, with a composition similar to that of the recurrent parent. We also evaluated a set of 10 of these ILs, along with the recurrent parent S. melongena, under two doses of N fertilization supplied with the irrigation system (8.25 mM NH4NO3 added to the irrigation water, and no external N supply to the irrigation water). Although there was a significant limitation in plant growth, N and C distribution, fruit load and dry matter in response to minimized N inputs, the ILs achieved, on average, similar final yields under both N treatments, as well as produced fruits with similar morphology, weight and phenolic content. These results enhance ILs as useful breeding materials for the adaptation of eggplant to low N inputs. Thanks to the availability of genotyping of eggplant ILs, the investigations carried out using this population enabled the identification of several QTLs associated with morpho-agronomic and fruit composition traits, providing new relevant information to expand the genetic knowledge of eggplant. The last chapter presents the first evaluation of fruit quality and yield parameters of a collection of 44 varieties of the resilient tomato 'de penjar' under two levels of N fertilization (162 kg N ha-1 and 49 kg N ha-1). A large variation was observed. Reduced N inputs had a significant effect on hue, whose mean increased slightly, and on sweetness-related compounds and parameters, whose mean decreased by 11-16%, while yield and most quality traits were unaffected. These are promising results that promote the conservation of the 'de penjar' tomato and its use in breeding programs. Ultimately, we believe that this work will provide new phenomic and genomic resources useful for future breeding programs of vegetables of the Solanaceae family.