Abstract
We previously recommended the improved soil profile method to grasp root system morphology of field-grown crops. Root system morphology of rice plants can be characterized by total root length and its distribution in soil both of which are determined by the combinations of number, length and direction of roots, respectively. It is already known that direction and length of roots could be influenced with root diameter. These important traits, number, length and diameter of roots, might be determined by number and size of phytomers composing shoot. These results suggest the possible interrelationship between plant and root types. A root system model which has uniformly elongating roots was proposed as the standard to compare with. The model had been evolved into a more sophisticated root system model based on simple and reasonable conditions to analyze root system morphology in detail.
