Growth and antioxidant responses during early growth of winter and spring chickpea (Cicer arietinum) under water deficit as affected by osmopriming

Seed osmopriming has positive influences on germination and growth in many plant species, particularly under tough environmental conditions such as drought. In this study, seeds of five Moroccan chickpea (Cicer arietinum) varieties were osmoprimed with polyethylene glycol (PEG 6000) solutions (-0.5 MPa (P1) and -0.7 MPa (P2)), for 24 hours at 20°C and germinated for eight days at osmotic potential of 0, -0.2 and -0.4 MPa PEG 6000. Several germination and growth parameters were assessed, as well as antioxidant activities and malonyldialdehyde (MDA) content in germinated seedlings. Drought decreased germination and growth in all of the studied genotypes with significant variation between them. Osmoprimed seeds presented higher germination and growth than unprimed ones. 'Zahour' and 'Rizki' seeds from P1 presented the highest percentage of normal seedlings (PNS) of 91.6 and 88.3%, respectively, under severe stress (-0.4 MPa) and the highest peroxidase activity and the lowest MDA content. 'Rizki' seedlings from P2 presented the highest vigour index (SVI) of 2496 mm, while 'Farihane' and 'Mazouzia' did not show good germination performances and had inefficient antioxidant activities under stress. Strong correlations were detected between the priming effect, antioxidant activities, germination parameters and malonyldialdehyde content.