The Role of Root System of Rice Plant in Relation to the Physiological and Morphological Characteristics of Aerial Parts : II. Interrelationships of aerial parts and root characteristics in mutated strains of rice plants

Abstract

In a previous paper it was shown that the characters and activities of roots were closely related to the charecteristics of aerial parts with varieties of different plant type. The present paper is concerned with using mutatel strains derived from Norin 8 the relationships of root characteristics to the number of panicles and the angle of leaf inclination. The results obtained were as follows. (1) The inclination of the flag leaf is closely related with the root activity. The higher the root activity, the larger the inclination of the flog leaf. (2) In general, the panicle-number-type varieties produced more upper nodal roots than the lower ones. The upper nodal roots, as a result, occupied the major portion of the total root weight but the roots were slender. The activity of the lower nodal roots was not so high as that of the upper ones. This might be, the reason why the panicle-number-type varieties showed faster senescence of the leaves. (3) On the other hand, the panicle-weight-type verieties produced thicker and more active lower nodal roots Which might be responsible for the later leaf senescence as compared with the panicle-number-type varieties.