2.4. Electrolyte leakage
Leaf disks of 2.5 cm in diameter were excised from the lowest
leaves for EL determination according to the modified methods
of Mao et al. (2007). After being rinsed 3 times for
2–3 min with de-ionized water, 5 pieces were put into 20 ml
of de-ionized water in test tubes and shaken every 5 min for
30 min. Conductivity was measured using a conductivity
meter. Total conductivity was obtained after keeping the test
tubes boiling for 15 min and electrolyte leakage was expressed
as percentage of total conductivity.