Effect of Sodium Azide Mutagen on Lavender Plant Salinity Tolerance

Abstract

This study aimed to induce mutation in Lavandula angustifolia plants to enhance salinity tolerance using sodium azide as a chemical mutagen. Lavender seeds were treated with various concentrations of sodium azide (0.0%, 0.5%, 1.0%, 2.0%, and 3.0%). The mutagenized seedlings were subsequently subjected to different salinity levels (0.0, 500, 1000, 2000, and 3000 ppm NaCl). Results indicated that a 0.5 and 1.0% sodium azide concentration provided optimal mutagenesis, enhancing salinity tolerance at 500 and 1000 ppm NaCl.

Treated plants showed improved germination rates (77.1 and 75.5%), increased growth parameters, and enhanced biochemical evaluation, including higher chlorophyll content and proline accumulation. Proline content decreased to 5.6 mg/g fresh weight at 500 ppm but increased to 8.6 and 9.5 mg/g at higher NaCl concentrations. The highest carbohydrate levels were recorded at 500 and 1000 ppm NaCl. Sodium ion concentration in plants increased to 13.1 and 15.4 g/kg at 2000 and 3000 ppm NaCl, respectively. Potassium content was higher in plants treated with 500 and 1000 ppm NaCl. Iron ion content significantly increased with higher NaCl concentrations, peaking at 3000 ppm, while a decrease was observed at 500 ppm. Zinc ion content was highest at 3000 ppm NaCl (5.7 mg/kg) and decreased to 4.5 mg/kg at 500 ppm. Moderate salinity levels (500 and 1000 ppm) led to significant improvements in pigment concentrations and ion balance, maintaining higher potassium and lower sodium levels. Genetic variability induced by sodium azide was confirmed via ISSR-PCR analysis, revealing unique polymorphic banding patterns in treated plants.