PT - JOURNAL ARTICLE AU - José Correa AU - Maribel Mamani AU - Claudia Muñoz-Espinoza AU - Mauricio González-Agüero AU - Bruno G. Defilippi AU - Reinaldo Campos-Vargas AU - Manuel Pinto AU - Patricio Hinrichsen TI - New Stable QTLs for Berry Firmness in Table Grapes AID - 10.5344/ajev.2015.15049 DP - 2016 Mar 01 TA - American Journal of Enology and Viticulture PG - ajev.2015.15049 4099 - http://www.ajevonline.org/content/early/2016/02/25/ajev.2015.15049.short 4100 - http://www.ajevonline.org/content/early/2016/02/25/ajev.2015.15049.full AB - Berry firmness is one of the most important quality traits in table grape production, and consequently a key aspect for table grape breeding programs. In order to identify the genes determining the berry firmness in grape, a progeny of ‘Ruby Seedless’ × ‘Sultanina’ (n = 137) was evaluated during three consecutive seasons. Results showed that even though the heritability was about 90%, there was an important effect of season on this trait. Quantitative Trait Loci (QTL) analysis and genetic mapping showed that the determinants for this trait are distributed in linkage groups (LG) 8 and 18. This is the first time that a stable QTL for berry firmness across seasons has been identified on LG8. This QTL is mainly given by a male allelic and additive effect. Together these two QTLs explained around 27.6% of the phenotypic variance, with confidence intervals of up 10 cM. Among the tens of genes found in these two QTLs, we highlighted a cation/calcium exchanger, a xylosyltransferase, a probable cellulose synthase and a putative invertase. This study shows that the berry firmness has a clear genetic basis. These results could also be used for the development of markers to assist table grape breeding.