Effects of priming with different concentrations of potassium nitrate salt on seed germination and vigor indices of Capparis cartilaginea

Kavar (Capparis cartilaginea) is a medicinal shrub with scattered extensive branches, or up vertical, that grow in the southern and southeastern provinces of Iran. In addition to its role of stabilization and reduction of soil erosion, this species is used as traditional medicine. A factorial experiment in a completely randomized design was used to study the effects of potassium nitrate with concentrations of 0, 50, 100 and 200 mM and duration of 24, 48 and 72 soaking hours with four replications to break the seed dormancy and improve the germination components of the species. The results showed that the seed germination parameters of Kavar were affected significantly by the priming treatments. The germination rate, vigor index, shoot fresh weight and shoot dry weight of the species were increased 78.2%, 147%, 78.9% and 90% respectively compared with the control by using 200 mM potassium nitrate salt and 24 hours soaking treatment. The germination percentage of the species was increased by 72.5% compared with control in 200 mM with 24 and 72 hours soaking treatments. 200 mM concentration and 72 hours soaking treatment increased maximum rootlets fresh weight, rootlets dry weight and rootlets length by 438%, 400% and 112% respectively compared with control. Overall, the contamination levels of 200 mM and time soaking of 72 and 24 hours are suggested as the most appropriate treatments in order to improve the germination characteristics of Capparis cartilaginea.