Physiological and Ecological Studies of Rice Plant in Well-drained and Ill-drained Field. : (8) Distribution of silicified tissues of rice culm and silicate content in each internode as affected by diffierent cultural conditions.

Abstract

Silicified tissues of rice culm were ascertained by following technique; the spodgrammes of internode, culm-node and leaf sheath-node were made, and then they were dissolved by heated dilute hydrogen chloride. As silicified tissue is insoluble, the silicified tissue in epidermis of internode, epidermis at the bottom of internode, inner parts of culm-node, node-plate and node-plate abutting on the culm could be observed under microscope as shown in Fig. 1-8. The culm differs from leaf blade in that the culm contains silicate in various tissues, while leaf blade contains was found silicate only in epidermis. Silicate content in internode was found closely related with growth stages and cultural conditions as summarized below: 1) Seasonal changes of silicate content in each internode indicate that percentages of silicate content at harvesting time are in higher level than that at heading time. 2) Relation with cultural conditions; a) As compared with ill-drained field, rice culm in well-drained field contained more silicate, especially in upper internodes (N1∼N3). b) In plot with heavy application of nitrogen, amount of silicate content in upper internodes was less. c) Silicate content in lower internode was high in plot with silicate calcium application.