Suchergebnisse

Melon is as an alternative model to understand fruit ripening due to the coexistence of climacteric and non-climacteric varieties within the same species, allowing the study of the processes that regulate this complex trait with genetic approaches. We phenotyped a population of recombinant inbred lines (RILs), obtained by crossing a climacteric (Védrantais, cantalupensis type) and a non-climcteric variety (Piel de Sapo T111, inodorus type), for traits related to climacteric maturation and ethylene production. Individuals in the RIL population exhibited various combinations of phenotypes that differed in the amount of ethylene produced, the early onset of ethylene production, and other phenotypes associated with ripening. We characterized a major QTL on chromosome 8, ETHQV8.1, which is sufficient to activate climacteric ripening, and other minor QTLs that may modulate the climacteric response. The ETHQV8.1 allele was validated by using two reciprocal introgression line populations generated by crossing Védrantais and Piel de Sapo and analyzing the ETHQV8.1 region in each of the genetic backgrounds. A Genome-wide association study (GWAS) using 211 accessions of the ssp. melo further identified two regions on chromosome 8 associated with the production of aromas, one of these regions overlapping with the 154.1 kb interval containing ETHQV8.1. The ETHQV8.1 region contains several candidate genes that may be related to fruit ripening. This work sheds light into the regulation mechanisms of a complex trait such as fruit ripening. ; This work was supported by the Spanish Ministry of Economy and Competitiveness grants AGL2015–64625-C2–1-R and RTI2018-097665-B-C2, Severo Ochoa Programme for Centres of Excellence in R&D 2016–2010 (SEV-2015-0533) and the CERCA Programme/Generalitat de Catalunya to J.G.-M., L.P. and M.S.-D. were supported by a FPI grant from the Spanish Ministry of Economy and Competitiveness. V.R. was supported by the European Union's Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement No 6655919. Y.X. was supported by the China Agriculture Research System (CARS-25). ; Peer reviewed