Determination of Germination Parameters of Safflower (Carthamus tinctorius L.) Cultivars Under Salt Stress

Abstract

The present study was carried out to characterize germination capacity of 10 safflower cultivars under saline conditions. Five salt (NaCl) levels (0, 60, 120, 180, 240 mM) were used to test safflower seeds. Germination of seeds was counted every day for 14 days and germination percentage, Timson’s germination index, mean germination time, mean germination rate and germination stress index were calculated. Cultivar and salinity treatments were important for all parameters; however mean germination time and mean germination rate interactions were not important. Germination percentage, Timson’s germination and germination stress indices decreased significantly with increased salt concentrations. However, mean germination time increased with higher salt concentrations. The most significant reductions in germination percentage were observed at 180 and 240 mM salt concentrations. Correlation coefficients were all important for germination indices. Based on germination indices, Leed and FO2 were more sensitive to salt stress at germination stage and Royal was more resistant than the other cultivars tested. Germination percentage, Timson’s germination index and germination stress index were better to assess germination capacity of safflower cultivars under salt stress conditions. Mean germination time and rate were not suitable to assess differences in germination parameters of the cultivars under stress conditions.