Molecular size profiles of tannins in persimmon fruits of Japanese and Chinese pollination-constant non-astringent (PCN A)-type cultivars and their offspring revealed by size-exclusion chromatography

Abstract

The size distribution patterns of tannin molecules in the fruits of 'Luo Tian Tian Shi' (a Chinese PCNA) and several Japanese PCNA and non-PCNA (PVNA, PVA, PCA) cultivars were examined by size-exclusion chromatography by using a TSK gel Toyopearl HW-55F column with a mobile phase of acetone-8 M urea (6:4; adjusted to pH 2.0). The progeny from the cross between 'Luo Tian Tian Shi' and 'Taishu' (a Japanese PCNA), or between 'Fuyu' (a Japanese PCNA) and 275-13 (a selection from the cross between 'Aizumishirazu' (a Japanese non-PCNA) and 'Taishu'), were also examined for the size distribution pattern of tannin molecules. The tannin molecules of the fruits from Japanese PCNA cultivars were relatively small, whereas those from Japanese non-PCNA cultivars were large. Moreover, all PCNA individuals segregated from the cross between 'Fuyu' and 275-13, had small tannin molecules in the fruits, and all non-PCNA-type individuals segregated from the same cross had large tannin molecules. However, the size distribution in the fruits of 'Luo Tian Tian Shi', a Chinese PCNA cultivar, was the same as that in non-PCNA cultivars that have large tannin molecules. Although both PCNA-type and non-PCNA-type were segregated in the F 1 progeny from the cross between 'Luo Tian Tian Shi' and 'Taishu', the fruits of all offspring in this progeny had large tannin molecules irrespective of whatever it was PCNA or non-PCNA. These results clearly indicate that the Chinese PCNA, 'Luo Tian Tian Shi', is distinguishable among PCNA cultivars of Japanese origin and supported the previous hypothesis that the origin of PCNA- type in China differs from that in Japan.