Intraspecific variation of Haloxylon salicornicum (Amaranthaceae) seed germination under salinity and simulated drought

Abstract

Haloxylon salicornicum (Moq.) Bunge ex Boiss. is a suitable species for desert and coastal restoration for its forage production and dune stabilization. Inter-population variation of seed parameters has previously received little attention. Variation in seed germination response to drought and salinity stress was evaluated for three Kuwaiti populations for use in restoration projects. Germination parameters varied significantly among populations. Seeds from Kabd were larger and germinated at a higher percentage than the other two populations, Mutla and Liya, under conditions of saline (62.8%, 40.0%, and 50.7% respectively) and moisture (58.2%, 32.6%, and 45.6%) stress. Increasing salinity and drought simulation progressively inhibited seed germination across all populations. Drought simulation by PEG 6000 inhibited germination from −0.3 MPa, while salinity affected the germination proportion from 400 mM NaCl for all the studied populations. All populations exhibited a high recovery from NaCl and PEG stress, indicating the species is broadly adapted to survival through drought and saline conditions. Our findings indicate that revegetation success with this species will be influenced by the population characteristics of the maternal seed source.