Question

Give 2 technique to measure the % of loss conductivity and xylem tension in plant and also discuss there a limitation and in-plant what causes the reduction in conductivity at more negative tension

Answer 1

Even though there are various techniques to measure the % loss of conductivity and xylem tension in plant, simple techniques are vacuum chamber method and centrifuge method

Limitations of these methods are, Vacuum chamber method is useful for measurements of only low conductivity material (like leaves, petioles,small branches and small roots) and Centrifuge method overestimates vulnerability of water stress induced low conductivity.

At more negative tension, dissolved air within water expands and fill either the vessels or tracheids known as cavitation and due to air bubble formed during cavitation results in blocking of vessel or tracheid of xylem is known as embolism. which ultimately results in reduction in conductivity