Validation of PCNA breeding strategy at the Institute of Fruit Tree and Tea Science, NARO, Japan
The persimmon breeding program of the Institute of Fruit Tree and Tea Science, NARO (NIFTS), Japan, has worked to release new pollination-constant non-astringent (PCNA) cultivars since 1938. However, as the Japanese PCNA (J-PCNA) genotype is recessive and genetic resources are limited, inbreeding depression had become a serious problem by the 1980s owing to repeated crossing within the narrow gene pool. Therefore, a strategy for generating PCNA offspring through pseudo-backcrossing (non-PCNA × J-PCNA) × J-PCNA and through crosses using Chinese PCNA (C-PCNA) cultivars, whose non-astringency trait is dominant, has been conducted since the 1990s. Here, we validated these breeding strategies by comparing fruit traits of PCNA offspring derived from crosses within the J-PCNA group genotype, from crosses using the non-PCNA group genotype, and from crosses using the C-PCNA group genotype. The non-PCNA and C-PCNA group fruits were significantly heavier than the J-PCNA group fruits. Degrees of fruit cracking at both the apex and the calyx end were significantly lower in the C-PCNA group than in the other groups. In contrast, the soluble solids content was significantly higher in the J-PCNA group than in the other groups. These results suggest that using non-PCNA and C-PCNA cultivars as cross parents is useful for generating PCNA offspring with large fruits and less fruit cracking, both of which are important objectives in the breeding program at NIFTS.
Saito, T., Onoue, N., Matsuzaki, R., Shimizu, T., Azuma, A. and Sato, A. (2022). Validation of PCNA breeding strategy at the Institute of Fruit Tree and Tea Science, NARO, Japan. Acta Hortic. 1338, 299-304
astringency, cross-breeding, fruit quality, Diospyros kaki