The salt tolerance of crops has received considerable attention in recent years and so it was deemed advisable in understanding nature of saline injury to investigate on rice varieties viewed from root development under saline conditions. The plants of which roots were sheared closely on the crown part were set on salinized medium irrigated with saline solution containing 0.3% NaCl and were harvested after the lapse of 4 weeks and immediatly the roots newly developed were weighed.
Degree of saline injury, root development, growth in plant height and chloride contents were closely connected with one another and in regard to the individualized relation, which excepted the interferance of other elements, it was found that the chloride contents in a given leaf were highest correlated with saline injury and that the root development was distinguished as a second player. Though the correlation between growth in plant height and saline injury was higher, with exception or fixation of variation ovserved in root development there was no connection between the two and also the inverse relation between chloride contents and plant growth was calculated from observed data. Accordingly, as compared with other elements, it was suggested that the excessive chloride accumulation appeared to be significant factor for the development of saline injury. The correlations between chloride contents required for the same degree of symptom on a leaf and the other elememts were not significant, but the detalis of this factor connected with saline injury still remain obscure, while it is considered that the chloride contents for same injurious degree are more important factors for the light of saline injury mechanism.