ISHS Acta Horticulturae 592: V International Peach Symposium
QTLS AND GENES CONTROLLING PEACH FRUIT QUALITY |
| Authors: | C. Etienne, E. Dirlewanger, P. Cosson, L. Svanella-Dumas, R. Monet, A. Moing, C. Rothan, C. Bodénès, C. Plomion, J. Kervella |
| Keywords: | candidate genes, fruit quality, genetic map, organic acids, Prunus persica, quantitative trait loci, soluble sugars |
| Abstract:
The sugar/acid ratio contributes greatly to fleshy fruit quality. We undertook a QTL-candidate gene approach for this character in peach fruit. QTLs involved in peach sugar and acidity variations at maturity were detected using data from 3 years on an F2 progeny issued from a hybrid between ‘Jalousia’ (flat non-acid peach) and ‘Fantasia’ (round acid nectarine). We assumed that, among the genes involved in sugar and organic acid metabolic pathways, some may be responsible for the variability observed in peach fruit quality. Eighteen peach cDNAs encoding key proteins for cell expansion, sugar loading, or sugar and organic acid metabolism and vacuolar storage were isolated. They could not be mapped using the intra-specific progeny. However, they were located within the European Prunus reference map (Joobeur et al. 1998) derived from an interspecific almond x peach cross, which allowed to search for co-locations of cDNAs and QTLs by comparing the intraspecific map and the reference map. Using SSCP, we located 12 cDNAs to 4 linkage groups of the peach genome, and detected a cDNA/QTL co-location. It involved a cDNA encoding a tonoplast pyrophosphatase (PRUpe-Vp2) energizing the vacuolar storage of sugars and organic acids, and QTLs controlling peach soluble solid content and sucrose content at maturity. We further showed differences between ‘Jalousia’ and ‘Fantasia’ in the accumulation of mRNAs related to PRUpe-Vp2 during the fruit development. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
