Association of Pollination Constant Non-astringent (PCNA) Trait with Fruit Weight, Fruit Shape, and Two Types of Fruit Cracking in Offspring Derived from Japanese- and Chinese-PCNA in Persimmon (Diospyros kaki Thunb.)

Abstract

Oriental persimmon (Diospyros kaki Thunb.) is classified into four types: pollination constant and non-astringent (PCNA), pollination variant and non-astringent (PVNA), pollination variant and astringent (PVA), and pollination constant and astringent (PCA). Furthermore, PCNA is subdivided into two types: Japanese (JPCNA) and Chinese (CPCNA). The mechanisms underlying the removal of astringency differ between the two types. Moreover, the JPCNA trait is recessive, and so only recessive homozygotes exhibit the PCNA trait, whereas the CPCNA trait is controlled by the dominant gene at a different locus from JPCNA. In this study, we compared fruit weight, fruit shape, and two types of cracking habits in PCNA and non-PCNA offspring segregated from pseudo-backcrosses ([non-PCNA × JPCNA] × JPCNA) and crosses between CPCNA and non-PCNA. Analysis of variance revealed significantly lower family means of fruit weight in PCNA than non-PCNA individuals in both types of cross. No significant interactions between astringency type and cross were identified, which indicates that PCNA traits similarly influenced the decrease in fruit weight in both types of crosses. The fruit weight of PCNA offspring was 14 and 13% lower than that of non-PCNA offspring in the JPCNA pseudo-backcross and CPCNA cross, respectively. The fruit shape in PCNA was flatter than that in non-PCNA in the CPCNA cross. The family means of cracking at the fruit apex in PCNA offspring were significantly larger than those in non-PCNA offspring in the JPCNA pseudo-backcross. However, cracking at the calyx end did not significantly differ among astringency types in both types of cross.