On the Grain Quality of Paddy Rice Cultivated on Upland Field.

Abstract

The grain quality of paddy rice cultivated on upland fields was studied in comparison with that of paddy rice cultivated on paddy field or upland rise cultivated on upland field. The results obtained were as follows; 1) The histological differences in kernel between paddy and upland rice were found in the location of central point on the cross section of kernel and in number of aleulon layers on abdominal region of kernel. The central point was located close upon the middle of dorso-ventral diameter in upland rice (dorsal radius/ventral radius=0.9-1.2), and it was deflected toward the abdominal side in paddy rice (dorsal radius/ventral radius=1.3-1.7). Aleulon cells on the abdominal region of kernel were arranged usually in single layer in paddy rice, but frequently in two layers in upland rice. Then the location of central point and number of aleulon layers on abdominal region of kernel did not vary with paddy-or upland-field condition so large extent as the difference between paddy and upland rice. 2) Percentages of abdominal-white grains, milk-white grains and partially-chalky grains, and the specific gravity and thickness of bran layer in perfect kernels were investigated to compare the grain quality. Paddy rice varieties were less in percentages of milk-white grains and partially-chalky grains, higher in spesific gravity and thinner in bran layer than upland rice varieties. Consequently the grain quality of paddy rice was recognized to be superior to that of upland rice. On the comparison between paddy rice varieties grown under upland-field condition and the same varieties grown under paddy-field condition, some varieties were more or less superior in upland-field condition and the others were superior in paddy-field condition. Former varieties were regarded to be more adaptable to upland-field condition than latter varieties.