Water and solute flow through mung bean roots under applied pressure

The technique of applying hydrostatic pressure on the root medium to study water and solute flows through excised plant roots and to study various characteristics of roots in relation to flow has been used by many workers but flows in excised roots have not been compared with those in intact transpiring plants. In the present study this comparison has been made using mung bean roots. Results show that excised roots under pressure lack the ion selectivity which is observed in intact plant roots and conduct salt many times higher than salt flows through intact plant roots. The role of stem resistance in the rates of water and salt flow through roots has been discussed. The suitability of this technique for solute flow studies through mung bean roots is questioned.