Studies on Vessel Elements of Crown Roots in Rice Grown on Border and in the Inner Part of Paddy Fields

Abstract

As reported previously, there was a clear difference in the size, form and type of pitting of lateral wall of vessel elements between the shoots of rice plants grown on the border and in the interior of a field. In this experiment, a similar difference in the type of pitting of lateral wall of metaxylem vessel elements between the crown roots of the plants grown on the border and those grown in the interior of a field was observed. The difference was most remarkable in the basal zone of the crown roots which initiated in the upper "shoot units". As compared with those of the crown roots in the interior, the lateral wall of vessel elements in the crown roots of border plants showed a tendency of increasing of the alternate pitting and decreasing diameter of pits. It may be concluded from the result that the degree of effectiveness of the factors, which may control the water balance of plants grown on the border and in the interior of a field, is likely to be different.