AFLP-based bulk segregant analysis for tagging the slow-ripening trait in peach [Prunus persica (L.) Batsch]

Flesh texture is an important quality trait in peach, affecting both fruit firmness and the ripening process. An interesting variation, "slow ripening" (SR), described in some progeny from 'Fantasia' nectarine, interferes with the completion of ripening. In these plants, fruit development appears to cease before the end of the cell expansion phase. The SR process was studied at the genetic level using amplified fragment length polymorphisms (AFLPs) combined with bulked segregant analysis (BSA). A marker linked to the SR trait was found at 5.6 cM in a segregating 'BO 95021' selfed progeny related to the cultivars 'Fantasia' and 'Fairlane'. The original F, parent tree was not available at the time of this trial which prevented traditional gene mapping and required the use of BSA. The F, plant was derived by crossing 'Fantasia', a normal melting-flesh (M) nectarine, and 'BO 7803302', an SR selection generated by open-pollination of 'Fairlane', another M-flesh nectarine, putatively heterozygous for the SR trait. The generally high level of inbreeding in peach could explain the low level of genetic variability observed in our AFLP patterns.