66 



MINERAL SALTS ABSORPTION IN PLANTS 



25- 



Reldive thickness 



days 



Fig. 22. Effects of disk thickness [a] and internal salt concentration [b] on 

 salt absorption by storage tissue slices 



a. Effect of disk thickness on absorption of rubidium and bromide by potato 

 disks in 72 hr at 23 °C. Redrawn from Steward and Harrison (1939); 



b. Absorption of potassium by red beet root tissue from 0-02 M potassium 

 chloride solutions at 25 °C after preliminary washing in distilled water for a 

 few hours (A— A).; 4 days (□— □) and 8 days (O— O) (from Sutcliffe, 



1952). 



(Sutcliffe, 1952). Tissues with high salt content tend to be more 

 turgid than those low in salts and internal concentration may thus 

 exert part of its effect indirectly through an influence on cell 

 turgidity (cf. p. 63). 



3. Internal Sugar Concentration 



The ability of low-salt excised roots to absorb salts rapidly is 



i 



