Physiological and Agromorphological Responses of Tossa Jute (Corchorus olitorius L.) to Drought Stress
The effect of water deficit on physiological and agro-morphological parameters related to water deficit tolerance was studied in Tossa Jute (Corchorus olitorius L.), from Tunisian oasis. The experiments were carried at the Arid and Oases Cropping Laboratory, Institute of Arid Lands (IRA), Tunisia. Seeds were allowed to germinate in pots filled with sand and peat at a 2:1 ratio, respectively. After 1 month, the plants were subjected to 3 water treatments: control irrigation (R1: 100% of field capacity, FC), moderate water deficit (R2: 70% FC), and severe water deficit (R3: 40% FC). At 4 weeks of stress, the plants were harvested and subjected to some agrophysiological and biochemical analyses related to tolerance. The effect of different treatments on all studied traits was significantly important. Whole growth and leaves traits and reproductive traits were more significantly affected by 40% FC than the 70% FC and control. In addition, the water limitation for 40% (R1) and 70% (R2) of field capacities caused severe reduction of dry weight of aerial part by 50.6 and 79.4 % respectively and relative water content (RWC) of 20.99 and 53.35% respectively compared to controls plants. The net photosynthetic, the transpiration rates and the contents of chlorophyll significantly decreased in plants subjected to water deficit. Plants submitted to 40% FC accumulated higher concentrations of proline (2.07 mg/g DW) and soluble sugars (12.68 μg/g FW) than the controls ones. Tossa jute seedlings make different strategies to tolerate the water deficit by increasing the osmo-regulators contents, developing roots and reducing leaves size.