Changes in biochemical parameters and essential oil of dill (Anethum graveolens L.) under salinity stress in two planting dates

Abstract

In order to investigate the effect of saline irrigation water and planting date on yield, biochemical parameters and essential oil of dill, a field study was conducted using a split-plot experiment on the basis of randomized complete block design with three replications in Isfahan, Iran. Planting dates were 13 March and 11 June and salinity treatments were 0 (control), 3, 6 and 9 dS m-1 NaCl. The measured parameters were: seed and biological yield, seed and shoot essential oil yield, seed and shoot essential oil percentage, essential oil compositions, total protein, proline, reducing sugar, malondialdehyde and concentration of K+ and Na+. According to results, there was a significant difference between the two planting dates in terms of biological yield and the essential oil yield of shoot. The essential oil percentage of seed was significantly higher than that of the shoot. Essential oil percentage had no significant differences in different salinity levels, however, essential oil yield and essential oil composition was changed in different salinity levels. Carvone was the main component in all treatments and the control treatment had the highest values of it with 54.96 % in seed and 63.56 % in shoot. The highest rate of protein content was recorded at non-stress conditions which decreased with increasing stress levels by 91.67 %. Increasing salinity levels increased shoot proline, root proline, reducing sugar and malondialdehyde by 181.25, 150, 75 and 160 %, respectively compared to the control treatment. In general, planting in summer had more biomass and essential oil yield.