Studies on Large Vascular Bundles in Paddy Rice Plant and Panicle Formation : II. Relationships between the number of lage vascular bundles in the blades of high-ranking leaves and the number of paddies per the primary branch of the panicle

Abstract

1. Viewed from the fact that several primary branches tended to gather closely with one another by making a circle on the rachis, it is possible to classify them under some primary branch groups. The ten paddy rice varieties grown in the paddy field at the Fukui Prefectural Agricultural Experiment Station could be classified under 4 to 7 primary branch troups. 2. The number of the elongated internodes showed a tendency to increase according to the increase in the total number of leaves on the main culm. The ten rice varieties mentioned above could be classified under the groups bearing 4 to 7 elongated internodes. There was a tendency that the number of the primary branch groups coincided with the number of the elongated internodes more than 0.5 cm in length. 3. The average number of paddies per piece of the primary branch showed sometimes a tendency to become less than the average number of the differentiated flowers in case of the first and second primary branch group from the bottom of a panicle. This might be ascribed to the fact that some of the differentiated flowers have degenerated. In cases of the spikelet groups ranking higher than the fourth primary branch group, it showed that the average number of the differentiated flowers was nearly close upon the average number of paddies per piece of the primary branch.