Studies on Large Vascular Bundles in Paddy Rice Plant and Panicle Formation : I. Relationships between the number of lage vascular bundles in the culm and the plant types

1. In case of early-maturing rice variety Honen-wase, the correlation coefficients between the number of large vascular bundles in the first (highest) internode and the number of the primary branches of the panicle, the number of paddies per panicle, the weight of a panicle were γ=0.903, γ=0.877 and γ=0.850, respectively. And a fairly intimate interrelationship (γ=0.948) was noticed between the number of the primary branches and the number of paddies per panicle. 2. As the difference between the number of large vascular bundles in the first elongated internode and that in the second elongated internode showed the same tendency with the difference in the number of panicles per hill, it was regarded that the ratios of the number of large vascular bundles in the first elongated internodes to that in the second elongated intermode displayed the plant types' own characteristics; that is, the ratios of panicle-number type varieties, biased panicle-number type varieties, medium panicle-number type varieties, biased panicle-weight type varieties, and panicle-weight type varieties, stood at 1:3, 1:2.75, 1:2.5, 1:2.25, and 1:2, respectively.