Studies on the fruit development of Japanese pears (I)

On the flesh cell-division, cell-enlargement and the relation between flesh cell-size and fruit size in some varieties

Abstract

In 1953 the authors reported the phase of flesh cell-division and cell-enlargement of the “Nijisseiki” pear. In this report we added the experiments observed on the “Yakumo” pear (early variety) and the “Okusankichi” pear (late variety) and the comparative examination with the“Nijisseiki” pear. In the case of “Yakumo” a flesh cell division took place for 25_??_30 days after florescence, i.e., until the middle of May. At that time a fruit was 16_??_18mm in diameter. The “Yakumo” showed the same tendency as the “Nijisseiki”. In the “Okusankichi” a cell division took place for about 45 days after florescence, i, e., until the beginning of June. A fruit was 28_??_30mm in diameter. In comparison with the “Yakumo” and the “Nijisseiki”, the duration of a flesh cell division of the “Okusankichi” was longer. Further, a cell of the “Okusankichi” was big at the closing period of a cell division and a flesh cell was also big at the harvesting season. As to the same variety a big fruit had more numerous and bigger cell than a little one. In the “Okusankichi” the fleshiness of a fruit near the harvesting season was observed to be influenced by the increase of a cell space as well as the growth of a cell. From the result of this examination, the authors thought that the conditions which effect the determination of cell number, must reasonably be treated.