تأثیر تنش‌های خشکی و شوری بر جوانه‌زنی بذر گیاه قدومه (Alyssum homalocarpum)

Due to the limited Alyssum habitats (Alyssum homalocarpum) in rangeland ecosystems, it is necessary to study various aspects of plant growth under different environmental conditions such as abiotic stresses. The aim of this study was to evaluate the effect of salinity and drought on Alyssum seed germination characteristics in laboratory conditions. The experiment was conducted based on completely randomized design with four replications in the fall of 2014 in the culturing and Proliferation laboratory of Zabol University. To create different levels of drought and salinity, polyethylene glycol 6000 and NaCl were used respectively .Drought treatments were included four levels (zero, -0/25, -0/41, -0/99 MPa) and five levels of salinity (zero, 50, 100, 150, 200 mM). Variance analysis results showed that drought and salinity stress significantly affected Alyssum seed germination characteristics (p<0.05) Mean comparison showed that by increasing salinity and drought, germination percentage ,germination speed ,shoot length and root length and root and shoot dry weight decreased (p<0.05). The Alyssum seeds endured drought potential up to -0/25 MPa and the highest germination percentage was observed in this level however increasing drought causing reduced germination percentage. According to the higher seed germination rates in different levels of draught stress rather than salinity, it could be assumed that the sodium chloride solution has decreased germination more than the polyethylene glycol indicated the higher sensitivity of this species to salinity.