STUDIES ON REGULARITIES OF GROWTH AND DEVELOPMENT OF CHINQUAPIN (CASTANEA HENRYI) FRUITS

Abstract

The fruit growth and development of different cultivars of chinquapin were systematically studied. The results indicated that chinquapin fruits could be divided into two parts as bur and nut. The burs of most cultivars bore only one nut while some few bore one to three nuts. The shapes, sizes and weights of nuts varied from cultivars to cultivars. Most cultivars of chinquapin shed flowers between late May and early June and then formed young fruits that would gradually grow and develop. The whole development process could be divided into two stages. In the early stage before early August, the bur rapidly grew while the increase of nuts' weights declined. The anatomy of fruits in different early stages showed that only milky white hairs were seen in 8 to 10 loculi and only an ovule under development was seen on the top of fruits while the others turned brown; during the late stage after middle of August, the increase in the volumes of prickly burs slowed down while the weight of single fruit increased rapidly before finally matured. The anatomies showed that ovules quickly developed into seeds with disappearing white hairs. As fruits matured, fleshy cotyledons would occupy the whole fruit space. During this stage, once ovules developed abnormally, the phenomena of 'empty seeded ness' would happen. The single fruit weight of different varieties varied little in the early stages but significantly different during the late stage. Most cultivars had closer harvest periods except few ones. The transverse and vertical development of chinquapin fruits were positively related with the changes of single fruit weights. The growth and development of chinquapin fruits featured an S-shape curve representing Quick-Slow-Quick trend.