Improvement of germination characteristics of Capper (Capparis spinosa) with biological, chemical, and mechanical priming

Capper (Capparis spinosa) is a resistant plant with remarkable sustainability to adverse environmental conditions. It has special importance from the side of soil conservation and it’s a suitable species for bio-restoration in arid and semi-arid regions. Weak germination and seed dormancy in capper is an obstacle to inclusive use in restoration projects. In the current study, with the aim of investigating the effects of chemical, mechanical, and biological priming on germination and primary growth in plants, an exam was designed. The experiment performed in two conditions: 1) In a petri dish, 2) Seedling tray both under completely randomized design. Chemical priming included Salicylic Acid and Giberlic Acid in three levels of 1000, 2000, and 3000 ppm. The 24 kHz wavelength of the ultrasonic device was applied as mechanical priming for 5 minutes. Bio-priming Included Azotobacter chroococcum, Flavobacterium F-40, Azospirillum lipoferum, Bacillus megaterium, and Pseudomonas fluorescens. Results showed a significant level (p <0.01) on seed germination percentage, root and shoot length, seedling growth, root and shoot fresh weight, and root and shoot dry weight in petri dish test. In seedling tray test, root length, shoot length, root length to shoot length ratio, seedling growth, root dry weight, fresh and dry weight of shoot and leaf and leaf number at 1%, and root fresh weight at 5 percent were significant. In the Petri dish test, ultrasonic treatment increased shoot length compared to control treatment. Bacillus megaterium and GA3 (Gibberellic Acid 3000ppm) in Petri dish test and GA1 and GA2 in seedling tray test had a more positive effect on germination characteristics than other treatments. Bacillus megaterium had a 25 percent positive effect on germination percentage in comparision with control treatment. Using bio-priming, several waves of ultrasonic treatment, and different Gibberellic Acid concentrations could be a proper solution to solve the problem and develop C. spinosa implantation.