Accumulation and occurrence characteristics of amyloid in Ginkgo biloba L. endosperm

In this study, three Ginkgo biloba L. cultivars, namely, ‘ixingguo’, ‘Maling’ and ‘Longyan’, were used to investigate the accumulation and occurrence of amyloid in the endosperm using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Results showed that endosperm morphology differed among the three ginkgo cultivars, being fusiform, oval, and ovoid in ‘Qixingguo’, ‘Maling’ and ‘Longyan’, respectively. The endosperms from the three cultivars were green in the early developing stage and yellow in the later developing stage. Rapid endosperm growth occurred from 65 d to 125 d after pollination. The accumulation of starch grains in the endosperm cells showed a spatial accumulation pattern, with gradual enrichment by the aleurone layer-ecto-endosperm-inner endosperm from the edge of the cell wall to the cell interior. Amyloid developed from the grana lamella of chloroplast-like plastids. These amyloid proliferated by budding, contraction, or budding and contraction. The matured amyloid was single-starch and round, oval, or irregular in shape. In summary, the starch grains accumulated from the outside to the inside in the ginkgo endosperm. The amyloid originated from chloroplast-like plastids and proliferated by budding, contraction, or budding and contraction at the same time.