Abstract
In order to investigate the development of white-core structure in rice kernel, some observations and measurements were conducted on the cross sections of rice kernels. Results and discussion are summarized as follows: About 5 to 6 days after flowering, a radial arrangement of starch tissue which mainly consisted of thin cells became clear to be seen. And the thin cells especially along the dorso-ventral diameter remained thin and sometimes opaque through the entire ripening period. The radial tissue was well-arranged in the common kernels, whereas polygonal large-cells enclosing a bundle of thin-cells were observed in the white-core kernels. The progress of translucentization of starch tissue of white-core varieties was somewhat sluggish in early stages of ripening. Generally the growth of kernel was rather rapid on its abdominal side in early ripening stage except for several days after pollination and on its dorsal side in the later stages. The ventral side of the kernel of white core variety showed the better growth, especially at the sarly stage of the kernel development, compared with that of common variety. It is considered that vigorous developent of ventral side causes more but thinner cells in that side and thinner cells in the opposite side, resulting in the formation of inavcive tissues of thin cells along the dorso-ventral diameter, and censequently the occurrence of white core in those tissues.
