抄録
Changes and differences in the content in mineral elements of the hull were compared during the process of ripening in fertile and sterile grains located in the same position on the panicle. The results are as follows: 1. After heading, there was a clear difference in the pattern of increase of the dry weight between hull and kernel, and the increase in dry weight of hull proceeded faster than that of kernel. 2. The dry weight of hull at heading was 2.7 mg. But after heading there was a large difference in the increase in the dry weight of hull between fertile and sterile grains. As a result the dry weight of fertile grain was 3.9 mg and that of sterile grain was 3.0 mg, 40 days after heading. 3. Mineral elements in hull were grouped as follows according to the changes in their contents in the hull during ripening. Group 1……As ripening proceeded, mineral elements accumulated into the hull, but they flowed out of the hull with the development of kernel. However, in sterile grain, they hardly flowed out.-N, P and Mg. Group 2……They accumulated slowly into the hull after heading, and quickly from the middle stage to the late stage of ripening. However in sterile grain, they leached out.-K. Group 3……During ripening, they accumulated into the hull without flowing out. However, the content of SiO2 was always much higher in fertile than in sterile grain, while that of Ca and Mn showed a reverse pattern.-SiO2, Ca and Mg. From these results, it was demonstrated that the changes in the mineral elements of the hull are closely related to thc development of the kernel. Especially, K and SiO2 whose contents were much higher in fertile than in sterile grain, and which are known to promote translocation of carbohydrates are thought to play an important role in the ripening of grain.
