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Projecte llegit

Títol: Resposta de les espècies silvestres de tomàquet a la sequera: acceleració de la floració

Estudiant que ha llegit aquest projecte:

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

Departament: DEAB

Títol: Resposta de les espècies silvestres de tomàquet a la sequera: acceleració de la floració

Data inici oferta: 23-07-2024      Data finalització oferta: 23-03-2025

Estudis d'assignació del projecte:
    GR ENG SIS BIOLÒG 23

Lloc de realització:
EEABB

Paraules clau:
Tomàquet; espècie silvestre emparentada; Solanum pimpinellifolium; Solanum lycopersicum var. cerasiforme; sequera; precocitat

Descripció del contingut i pla d'activitats:
Tot i que el fenomen de l'acceleració de l'etapa reproductiva ha estat àmpliament descrita com un mecanisme de resposta de les plantes a l'estrès hídric, existeixen poques evidències experimentals de la seva intensitat en el tomàquet cultivat i les espècies silvestres emprarentades. Emprant una població recombinant MAGIC, desenvolupada a partir de 4 línies parentals pertanyents a Solanum pimpinellifolium i 4 a S. lyc. var cerasiforme, s'estudiarà la resposta dels diferents genotips a l'estrès hídric, específicament sobre caràcters fenològics (preocitat a floració) i d'arquitectura de la inflorescència.

Overview (resum en anglès): This work addresses the impact of water stress on genotypes of wild species related to
cultivated tomato (Solanum pimpinellifolium, Solanum lycopersicum var. cerasiforme), with an
analysis of the escape mechanism, understood as the alteration of the flowering cycle of
individuals under water stress conditions. The main objective is to evaluate the diversity in
adaptive responses to drought, such as the alteration of earliness (days elapsed from sowing to
anthesis of each inflorescence) and flowering speed (days elapsed between two consecutive
inflorescences). The experiment was carried out using an interspecific mapping population of
the Multiparent Advanced Generation Inter-Cross (MAGIC) type, consisting of 127 genotypes,
as well as the parental lines, which were subjected to two irrigation treatments: normal
irrigation (RN) and deficit irrigation (RD). The methodology included the evaluation of
flowering-related traits (earliness and speed) in six consecutive inflorescences, in addition to
reproductive parameters such as the number of flowers, fruits and the percentage of setting.
Water stress was applied in two periods of plant development. The results show that water
stress significantly reduces the earliness and speed of flowering in most genotypes. The
genotype*irrigation interaction was significant in all the parameters evaluated, indicating a
high genetic diversity in the response to water stress in the studied population, with some
lines showing an acceleration of flowering under RD conditions, indicating a possible escape
mechanism. A significant decrease in the parameters number of flowers, fruits and percentage
of setting was also observed under RD conditions, although certain genotypes maintained a
satisfactory agronomic behavior. To continue the study, two groups of 5 lines have been
selected that show antagonistic responses to water stress in terms of alteration of
reproductive cycles. This work shows that the escape mechanism is present in some wild lines,
a response that has not been described so far in the tomato gene pool. This adaptation could
be a character of interest for the genetic improvement of the cultivated species for adaptation
to the phenomenon of climate change.

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