Effects of Salinity and Drought Stresses on Seed Germination and Seedling Growth of Desert Wheatgrass Agropyron desertorum

Document Type: Research and Full Length Article

Authors

1 Range Management, Department of Reclamation of Arid and Mountainous Regions, University of Tehran

2 College of Natural Resources, Agriculture Science and Natural Resources University of Sari

3 Combat Desertification, Faculty of Natural Resources and Earth Science, University of Kashan

Abstract

Considering forage grass species, germination is one of the important stages
concerning the growing stage that is often influenced by environmental stresses,
particularly salinity and drought stresses. Thus, this study aims to assess the effects of
salinity and drought stresses on germination characteristics and seedling growth of desert
wheatgrass, Agropyron desertorum (Fisch. ex Link) Schult. in laboratory conditions. Two
separate experiments were conducted using completely randomized design with four
replicates. Six salinity treatments (control, 50, 100, 150, 200 and 300 mM NaCl) and six
drought treatments (control, -0.2, -0.4, -0.6, -0.8 and -1 MPa polyethylene glycol) were
utilized in four replicates. Germination percentage and rate were calculated while
computing the germinated seeds every day. Growth parameters (rootlet, shoot and seedling
length), allometric index and seed vigor have been accordingly given. For each
experiment, one-way ANOVA was used to determine significant effects of treatments and
mean comparison was done by the means of Duncan method using SPSS software. Results
showed that salinity and drought stresses had the significant effects on germination and
growth indices of Agropyron desertorum so that germination rate and percentage, root
length, shoot length, seedling length and seed vigor indices were decreased by increasing
the concentrations of salinity and drought treatments. Also, seed germination and growth
were observed only until -0.4 MPa drought level so that germination at φs = -0.6 MP was
completely stopped.

Keywords