2020 Volume 19 Issue 1 Pages 61-67
Flesh texture of peach (Prunus persica (L.) Batsch) is one of the most important traits regarding post-harvest preservation and consumer preference. Melting flesh peaches show a typical climacteric type of ripening characterized by a burst of ethylene production and rapid loss of firmness in the late maturing stage. In contrast, stony hard peaches produce little ethylene and maintain flesh firmness on the tree and after harvest. Here, we demonstrated that ‘Tosui’ peach, which is selected from open-pollinated seedlings of ‘Kawanakajimahakuto’, bears stony hard characteristics. ‘Tosui’ peach shows a long shelf life and crisp flesh; however, its ethylene production and softening characteristics remain unclear. We investigated the change of ethylene production and flesh firmness of ‘Tosui’ peach treated with or without exogenous propylene, an ethylene analogue. In non-treated control fruit, little ethylene production was detected and marked flesh firmness was maintained irrespective of the harvest season and production area. Although the flesh firmness was significantly reduced by propylene treatment, little ethylene production was detected during fruit softening. Analysis of the PpYUC11 gene, a strong candidate for the stony hard phenotype in peaches, revealed that the genotype of the transposon insertion of the 5′-flanking region and simple sequence repeat (SSR) of the first intron of ‘Tosui’ is the same as that of other stony hard peaches. These results collectively suggest that ‘Tosui’ is a stony hard peach whose ethylene production and resulting loss of firmness are suppressed.