Effects of Salt Stress on Growth and Inorganic Ion Distribution in Narcissus tazetta L. var. chinensis Roem. Seedlings

Abstract

Narcissus tazetta L. var. chinensis Roem. seedlings were subjected to substrate salinity and salt spray during greenhouse cultivation. The results demonstrated that N. tazetta L. seedlings treated with substrate salinity and salt spray exhibited slower growth rates than the control group. The sedimentation of Na+ and Cl− was primarily observed in the leaf apex, which was consistent with the location of lesions induced by salt stress. Under the two methods of salt stress, the mass fraction of ash in the leaf was significantly higher than that in the control group (P < 0.05). The sedimentation of Na+ and Cl− was mostly distributed in young leaves in the salt spray treatment, whereas the sedimentation was mostly distributed in old leaves under substrate salinity. There was a significant positive correlation between contents of Na+ and Cl− under the two methods of salt stress (P < 0.01). Not only the mass concentrations of Ca2+, Mg2+, Na+, K+, and Cl− in the seedlings exhibited variation, but also the distribution of mineral elements in the seedlings changed after both salt stress treatments. Moreover, the ratio of K+/Na+ under salt spray was greater than that under substrate salinity at the 300 mm NaCl treatment level. These results show that ion toxicity in N. tazetta L. seedlings was more serious under substrate salinity than under salt spray.