Structural Features of White-Belly and White-Core Rice Endosperm Under Scanning Electron Microscopic Observation

White-belly and white-core are the considered two types of rice grain chalkiness, which negatively affect grain quality. This study was arranged to identify whether there is any difference in the morphological observation between white-belly and white-core of the rice grains by using a scanning electron microscope. Three rice cultivars (Akitakomachi, IR28, and NERICA 4) were compared in three replications. Grain dimension, appearance, and morphological observation were carried out at the maturity stage. The results showed that NERICA 4 and IR28 were the longest while Akitakomachi was the thickest grain producer cultivars. The scanning electron microscopic observation revealed obvious variations of starch accumulation in the endosperms of white-belly and white-core rice grains; including size, shape, and arrangement of amyloplasts across all cultivars but the differences were not considerable among the cultivars. In the white-core grain endosperm, irregular starch granules with round shape were poorly arranged. Besides, numerous air gaps, holes, and dent-portions among as well as on the surface of starch granules were appeared compared to white-belly. These results will be helpful to develop our comprehensive understanding related to the complicated mechanism of white-core and white-belly chalkiness from the visibility of starch accumulation in the endosperm of rice grain.