Plant material and treatments

The experiment was conducted during November in the Department of Botany, Government College University of Faisalabad 38000, Pakistan under the natural climatic conditions (average temperatures of day and night were 25 °C and 13 °C, respectively). Relative humidity (RH) ranged from 50% to 85%, and length of the day from 11–12 h. Tubers of two potato cultivars SH-5 and FD.73-110 were collected from Ayyub Agricultural Research Institute (AARI) Faisalabad, Pakistan. Five potato tubers were sown in plastic pots (25 centimeter height and 20 centimeters internal diameter) containing 10 kg silt loam soil with a pH ranging between 5.5 to over 7.5 and with electrical conductivity (EC) of 1.60 dSm⁻¹. After sprouting of potato seedlings, pots were irrigated with canal water. The seedlings were irrigated with canal water served as control. After those 15 days old seedlings were exposed to two separate moisture regimes (65% field capacity as drought stress and 100% field capacity as control). At soil dry weight basis soil moisture was calculated. After 2 days’ interval to recompense the water deficiency by evapotranspiration the pots were weighed. Thus, the soil moisture of pots was kept at 65% and 100% field capacity regarding to the treatments. After 2 weeks of applying drought stress at 65% field capacity except control all seedlings were treated with rooting media of thiourea application (0.5 & 0.75 mM) as 25 ml solution from each concentration at vegetative stage. The potato samples were dried in oven at 75 °C for 2 weeks. Potato roots and leaves sampling was done after 15 and 30 days of application of the treatment. Data was recorded for growth, physiological and biochemical attributes at vegetative stage. The experiment was laid out in a completely randomized design with three replications. This study did not include any information regarding human sciences.