تأثیر محلول‌پاشی گیاه مادری با اسید سالیسیلیک و اسپرمین تحت تنش خشکی بر شاخص‌های جوانه‌زنی بذر سرخارگل (Echinacea purpurea)

DOR: 98.1000/2383-1251.1397.5.1.9.1.1578.32 Extended abstract Introduction: Echinacea purpurea, a member of Asteraceae family, is a herbal medicine which is effective for promoting human immune system. Enviromental stresses including water defecit, which limit maternal plant growth, can also affect their seed quality and germination. Various compounds such as salicylic acid and spermin are known to be useful in the alleviation of harmful effects of drought on plants and their seed production. Materials and Methods: In order to investigate the seed vigor of Purple Coneflower after foliar  application of salicylic acid (SA) and spermine (SPM) on maternal plant (no spray,75 mg/l SA, 150 mg/L SA, 75 mg/L SPM, 75 mg/l SA+75 mg/L SPM and 150 mg/L SA+75 mg/L SPM) under three irrigation regimes (irrigation after 20, 40 and 60% depletion of soil available water), a split plot experiment was conducted based on a completely randomized block design with three replications during 2016- 2017 growing seasons at research field of Institute of Forests and Rangelands, Iran. Results: Water stress decreased the percentage and rate of germination, shoot and seedling length, shoot dry weight, germination energy and seed germination vigour. The results showed that foliar application had a significant effect on shoot, root and seedling length, shoot, root and seedling dry weight, germination rate, allometric factor, and germination vigour. The interaction effect of drought stress and foliar application indicated that non-stress and 150 SA+70 SPM mg/L had the highest radicle length (28.8 mm), radicle dry weight (1.81mg), seedling dry weight (6.20 mg) and Allometric factor (0.412). Conclusions: Based on the results of the current experiment, the foliar application of salicylic acid and spermine improved the seed germination of coneflower plants under both normal and water stress conditions and the highest values of these parameters were obtained under combained application of high concentrations of salicylic acid (150 mg/L) and spermine (75 mg/L).     Highlights: 1- Investigating the foliar application of salicylic acid and spermine in maternal Echinacea purpurea plant under drought stress in germination of seed. 2- The foliar application of salicylic acid and spermine on maternal plants of Echinacea improved germination quality under water stress.