Changes in stomatal properties of safflower cultivars under salinity

The stomatal characteristics in the leaves play a key role to adapt to several abiotic stresses such as drought, heat, and salinity. This study aimed to examine the abaxial and adaxial stomatal properties of 9 safflower cultivars (Dinçer 5-18-1, Remzibey-05, Balcı, Yekta, Linas, Olas, Olein, Safir, and Zirkon) under salt stress (100 mM NaCl). The density, width, length, size, and index of stomata were measured. The results showed that significant differences for all stomatal features of the safflower cultivars were determined. The stomata density changed with safflower cultivars between 143 and 57 number mm-2 and stomata size was observed as 510-698 µm2. The number of abaxial stomata was higher than adaxial part of leaves and the stomatal density on abaxial part of six safflower cultivars (Remzibey-05, Balcı, Yekta, Olas, Olein, and Safir) was decreased by salinity. In addition, abnormal stomata were observed in salt-affected cultivars of Dinçer 5-18-1, Remzibey-05, Yekta, Olein, and Zirkon. The stomata density mainly depended on genetic factors, suggesting that it should be used for separating safflower cultivars, but they declined considerably by salinity. It was concluded that stomatal properties should be considered to clarify the salt tolerance of safflower genotypes.