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Projecte llegit

Títol: Variability in shelf-life and colour in an F2 population of tomato segregating for the alcobaça allele

Estudiant que ha llegit aquest projecte:

Tutor/a o Cotutor/a: CASALS MISSIO, JOAN

Departament: DEAB

Títol: Variability in shelf-life and colour in an F2 population of tomato segregating for the alcobaça allele

Data inici oferta: 17-01-2024      Data finalització oferta: 17-09-2024

Estudis d'assignació del projecte:
    GR ENG CIEN AGRONOM

Lloc de realització:
EEABB

Paraules clau:
Tomàquet, Solanum lycopersicum, mutant de maduració, alcobaça, F2, co-segregació

Descripció del contingut i pla d'activitats:
Els mutants de maduració són àmpliament emprats en programes de millora de tomàquet per incrementar la vida útil del fruit. Entre les mutacions descrites, l'al·lel alcobaça es troba present en les varietats tradicionals de tomàquet. Aquest al·lel és poc emprat en la millora genètica moderna, alhora que els efectes pleiotròpics sobre paràmetres de qualitat estan poc descrits. En aquest treball es pretén estudiar la co-segregació de la mutació alcobaça amb diferents caràcters agronòmics, de qualitat i postcollita en una població F2. Per realitzar l'experiment, l'alumne haurà de gestionar un assaig de camp i fenotipar per diferents caràcters fenotípics la població F2, l'híbrid i els parentals. Un cop realitzat l'assaig de camp l'alumne haurà de realitzar anàlisis estadístiques per tal de determinar les possibles correlacions fenotípiques entre llarga vida postcollita i paràmetres de qualitat.

Overview (resum en anglès): Tomato is a short shelf-life climacteric fruit. The alcobaça (alc) mutation delays fruit ripening but has negative pleiotropic effects in fruit colour (red colour) and firmness, while also provoking the loss of tomato-like climacteric behaviour. Previous studies of this mutant described the effect of alc on fruit colour using qualitative descriptors (yellow, orange, and pale red), but a quantitative approach to understand the impact of alc on colour is still lacking. The main objective of this thesis was studying the relation of shelf-life and fruit colour intensity in alc mutant homozygous and heterozygous genotypes, using a quantitative approach. For this purpose, an F2 segregating population for the alc mutation was developed from an alc mutant parent (LC215, Penjar tomato landrace) and a non-mutant parent (LC854, processing tomato). Yield-related traits, colour, and shelf life (measured up to 5 months postharvest) were studied in a per plant basis in an experimental field developed in Agropolis-UPC (Viladecans, Spain). LC854 showed a red colour and short shelf-life, while LC215 showed a pale red colour and a long shelf-life. The hybrid showed a lower red colour intensity, but increased shelf-life compared with LC854; however, F1 shelf-life was much lower than the alc mutant parent, signalling the recessive behaviour of the alc allele. In the F2 population, a broad diversity was found for all the traits, including shelf life and fruit colour intensity; some individuals showed fruits with a long shelf-life, similar than LC215, while other individuals showed a red colouration similar than LC854. However, long shelf-life F2-individuals had also a low red colour intensity, and high yellow colour intensity, signalling the pleiotropic negative effect of the alc allele on the fruit colour. Furthermore, a positive relation between shelf-life and yellow colour intensity was found, as well as negative correlation between red colour intensity and shelf-life. Five genotypes with high shelf life, intermediate colour intensity, and good agronomic performance have been selected to develop a breeding program.

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