Bleeding Rate of Field-Grown Maize with Reference to Root System Development

Japanese Journal of Crop Science

Jun ABE¹  Junko YAMAGISHI¹  Miwa OKAMOTO¹  Shigenori MORITA¹ 

关键词: Bleeding rate;    Diurnal change;    溢泌液;    Maize;    根系;    Nodal root;    出液速度;    Root;    節根;    Root system;    トウモロコシ;    Xylem sap;    日変化;    Zea mays L.;   

DOI  :  10.1626/jcs.69.80

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

Bleeding rate could be an effective index for the physiological activity of a whole root system in field-grown crops, because it is based on active water absorption caused by root pressure. We examined the bleeding rate of field-grown maize with reference to root system development. The bleeding rate decreased rapidly just after detopping, which suggested negative effects of shoot removal on bleeding in maize. The bleeding rate of different plants at every hour showed that it has a diurnal change pattern with the maximum value occurring at around 8 a.m. Then we examined the bleeding rate early in the morning with reference to shoot growth. It increased with shoot growth and root development to reach the maximum value at around tasselling and decreased thereafter. The number and diameter of nodal roots emerging acropetally along the stem were increasing until tasselling. Therefore significant positive correlations were evident between the bleeding rate and the root morphological traits, such as total number, diameter, and cross area of nodal roots of a whole root system until tasseling, although these relationships were not clear afterwards. Physiological activity per unit root mass was estimated on the assumption that bleeding rate is a product of root morphology and its physiological activity. The physiological activity per unit root mass increased in the former half of the growing period, then decreased, possibly because of the relative relationship between the formation of new roots and the senescense of existing roots.

【 授权许可】

Unknown