Efficacy of KNO3 and priming duration for improving germination, seedling growth, and antioxidant enzymes of Keluss (Kelussia odoratissma Mozaff)

Abstract

Germination is a vital factor affecting plant survival and seedling establishment direct planting in fields. Medicinal plant (Kelussia odoratissma Mozaff) with the name Keluss is an aromatic plant species with high industrial value in essential oil from the Apiaceae family. Due to seed dormancy and unprincipled harvesting of natural resources, this valuable native species of Iran has become extinct. There is little information about how and treatment to break the dormancy of the valuable medicinal plant Keluss. In this research, pre-germination priming with the osmotic solution was used to improve the germination percentage of Keluss. Seeds in a Petri dish with concentrations (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6%) of KNO3 solution at a constant temperature of 2 °C for 12, 24, 48, and 72 h were placed in the growth chamber. Germination percentage was different based on the duration of priming and the concentration of priming. Based on the germination percentage 14 days after absorption, the most promising priming conditions were treatment with 0.4 and 0.3% KNO3 for 72 h at a constant temperature of 2 °C and 0.2 to 0.4% KNO3 for 48 h. Both concentrations of 0.3% and 0.4% in 24, 48 and 72 h showed a reasonable germination percentage of more than 85%. Improvement in growth and increase in antioxidant activity was observed in concentrations of 0.2 to 0.4 and 48 and 72 h. Priming with concentrations of 0.2 to 0.4% of KNO3 for 48 and 72 h is a recommended method for better domestication and conservation that can practically increase germination and antioxidant enzymes at 2C in the Keluss. In conclusion, the seed priming with KNO3 due to improve germination performance of Keluss can enhance germination percentage and seedling growth characteristics.