セイヨウナシ果実の発育中および追熟中におけるポリフェノール含量の品種間差異と台木の影響

Abstract

Changes in polyphenol content during fruit growth and ripening of pear cultivars on different rootstocks were investigated to clarify the possible cause of astringency in 'Le lectier' pears, as compared to the non-astringent 'Marguerite Marillat' and la France'.1. Polyphenol content on fresh weight basis was highest in the fruitlets at the end of May and then decreased until harvest in all cultivars tested in 1993. However, polyphenol content at harvest in 'Le Lectier' pears, which sometimes produce some astringent fruit, was two to four times higher than those of non-astringent 'Marguerite Marillat' and 'La France'.2. Polyphenol content on a fruit basis in 'Marguerite Marillat' and 'La France' showed little change throughout the fruit growth period, while it increased until harvest in 'Le Lectier'.3. Fruit produced on Old Home/Quince A interstock/rootstock had higher polyphenol content during fruit growth than those on Pyrus betulaefolia in both 1993 and 1994.4. Effect of rootstock on ethylene evolution during ripening period after harvest was not consistent in 'La France' and 'Le Lectier' pears.5. During fruit ripening after harvest, polyphenol content remained at an amount similar to that found at harvest in all cultivars.6. In 1994, fruit from potted trees on Pyrus betulaefolia had higher polyphenol content than those from field-grown trees on the same rootstock in 'La France' and 'Le Lecrier' pears, resulting in a higher degree of astringency in pot-grown 'Le Lectier' pears.