Abstract
In this report, the test for Japanese upland rice varieties was dealt with, and then the size of endosperm and number of cell layers in the whole Japanese rice varieties were discussed, comparing with the paddy rice varieties reported previously. In case of the longitudinal diameter of the endosperm, upland varieties were longer by 7 % on an average than paddy ones, and the number of cell layers was also 10% over the paddy varieties. There was a positive correlation between the length and number of cell layers. This relationship was very similar to that found in the paddy varieties. As to the dorsal radius, upland varieties were almost similar to paddy ones both in the length and number of cell layers. However, number of starch cell layers in case of upland varieties was slightly less than that in the case of paddy varieties in view of the difference in the number of aleuron cell layers. As to the ventral radius, upland varieties were longer by 10 % than paddy ones, but there was no difference in the number of cell layers between upland and paddy varieties. The ratio of dorsal to ventral radius of upland varieties ranged from 0.9 to 1.6 against to 1.1 to 1.9 in case of paddy varieties. In case of a few varieties of upland rice, the ventral radius was longer than the dorsal radius. Since such case has never been found in the case of paddy rice, it was regarded as one of the characteristics of upland rice. As to the lateral radius, upland varieties were slightly superior to the paddy ones both in the length and number of cell layers. Both long and short grain varieties did not show any peculiarity ad to the dorsal, ventral and lateral radii compared with common (middle-size grain) varieties. There was no difference in the morphological characteristics between glutinous and non-glutinous varieties of upland rice. On the whole of Japanese rice varieties, varietal differences in the cellular structure of endosperm existed in the longitudinal diameter, but little or no difference in the cross section. Therefore, volume of the endosperm and whole number of the endosperm cells has a close correlation with the length (or number of cell layers) of the longitudinal diameter.
