Under NaCl stress, the morphology and photosystem of the sweet orange (Citrus sinensis) scion cv. Pusa Sharad were altered by rootstock.

Abstract

Research on the rootstock that gives the citrus scion cultivar [Citrus sinensis (L.) Osbeck] resistance to saline
stress is scarce. At the ICAR-Indian Agricultural Research Institute's nursery unit in New Delhi, the effects of
sodium chloride on sweet orange cv. Pusa Sharad (PS) grafted on eleven distinct rootstocks—Jatti khatti (JK),
X–639 (X9), CRH–12 (C12), NRCC–1 (N1), NRCC–2 (N2), NRCC–3 (N3), NRCC–4 (N4), and Cleopatra
mandarin (CM). Scion/rootstock pairs were treated with irrigation water containing 30 and 60 mM sodium
chloride (NaCl) as opposed to the control (no NaCl) until the start of salt damage symptoms, or 42 days. In
comparison to PS scions grafted onto JK, C12, N2, N4, N5, and TC rootstocks under 60 mM NaCl stress, the PS
scion grafted onto CM, X9, C47, N1, and N3 rootstocks showed the least reduction in scion height, leaf area
ratio, root to shoot ratio, total chlorophyll content, total carotenoid content, transpiration rate, photosynthesis
rate, internal CO2 concentration, and stomatal conductance under salinity stress. The results demonstrated that
by boosting pigment content and fortifying the photosystem, a particular rootstock may improve salt-tolerance
capability. PS scions grafted onto CM, C47, X9, N1, and N3 showed higher NaCl tolerance than those grafted
onto JK, C12, N2, N4, N5, and TC; as a result, they are advised for regions with salt levels up to 60 mM.