Abstract
The culm tissues of paddy rice plants, cultivated in various conditions in this area, were analyzed with histological methods. After the observations on the various histological changes in those culm tissues, it was recognized that all the lodging rice plants had longer lower-internodes and thinner cortical fiber tissues than the standing ones, and the cell walls of cortical fibres of the former were thinner than the later ones, because of the feeble thickening in the middle layer of the secondary wall. It seemed, in addition, that the lower-internodes of lodging ones had greater cell length in peridermis and metaxylar vessels, but, on the contrary, shorter in cortical fibres being elongated by "sliding growth", than the standing ones. The culm tissues of paddy rice variety, cultivated in upland condition with sprinkler irrigation, represented the "xeromorphism".
