On the Functional Differentiation of Tap Roots and Adventitious Roots in Tobacco Plant.

[摘要] 1) Solution of red ink which had been absorbed by the cut surface of the tap root, stained most of the lower leaves, passing through the inner layer of the stem xylem. On the other hand, solution applied to adventitious roots passed through the outer layer of xylem and stained most of the upper leaves. 2) Similar results were obtained by supplying various parts of the root system with solution of ammonium sulphate or biurette. When these chemicals were supplied to the tap root, much nitrogenous substance was accumulated in the lower leaves, and the other way round, if applied to the adventitious roots. 3) The results of the experiments reveal that tap roots and adventitious roots play a different roles as suppliers of nutrients, namely, tap roots nourish mainly the lower leaves and adventitious roots feed the upper leaves.

[学科分类] 农业科学（综合）