The Role of Root System of Rice Plant in Relation to the Phlysiological and Morphological Characteristics of Aerial Parts : I. Interrelationships of aerial parts and root characteristics in varieties of different plant types

Abstract

The interrelationships of aerial parts and root characteristics in varieties of different plant types in rice plant were studied with respect to yleld components, leaf senescence, and the angle of leaf inclination. The results obtained were as follows : (1) Among 16 early duration varieties of different types, there was highly significant correlation between the number of panicles and the weight of upper nodal roots. While, there was a close correlation between the weight of lower nodal roots and the weight of panicle, which was negatively correlated with the number of panicles. (2) During the ripening stage, a close correlation was found between the activity of upper nodal roots and the degree of drooping of leaves in early duratioll varieties. However, similar data collected from late duratioll varieties did not show a clear correlation between the two characteristics. (3) A close correlation was found between root activity and chlorophyll content of leaves, leaf senescence in early duration varieties at their ripening stage. The same result was obtained with late duration varieties. (4) Among late duration varieties, close correlation was found between root activity at the ripening stage and grain yield.