How Pretreatment Affect the Dormancy, Germination and Seedling Growth of Caper (Capparis Spinosa L.) Populations   Alireza Talebi۱, Ali Soleymani۲*, Majid Shams۳ ۱. Graduate of Agrotechnology, Department of Agronomy and Plant Breeding, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran. ۲. Professor, Plant Improvement and Seed Production Research Center, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran ۳. Assistant Professor, Department of Agronomy and Plant Breeding, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.   *Corresponding author: a_soleymani@khuisf.ac.ir Received: ۱۰ March ۲۰۱۹                                             Accepted: ۲۰ June ۲۰۱۹   Abstract In order to investigate the effects of pretreatments on dormancy and seedling germination of two caper populations, a laboratory experiment was conducted (۲۰۱۹-۲۰۲۰) in Islamic Azad University (Isfahan Branch). The study was performed as a split factorial experiment in a completely randomized design. Main plot consisted of different leaching levels (soaking in distilled water for ۰, ۶, ۱۲, ۱۸ and ۲۴ hours) and subplots included factorial of two seed populationes (Najafabad, Izeh) and nine levels of  hormone or chemical treatments (gibberellic acid (۱۰۰ mg/l), benzyl adenine ۶ (۱۰-۵ M), kinetin (۱۰-۵ M), gibberellic acid+ benzyl adenine, Gibberellic acid+ kinetin, benzyl adenine+ kinetin, gibberellic acid+ benzyl adenine+ kinetin, potassium nitrate ۰.۴%, distilled water as control). According to the results, ۱۸ hours leaching of Najafabad population plus gibberellic acid +kinetin and ۲۴ hours leaching of Najafabad population with benzyl adenine showed the highest germination uniformity.  The highest germination percentage was observed in ۲۴ hour leaching of Izeh population plus gibberellic acid+ benzyl adenine+ kinetin and also ۲۴-hour leaching of Izeh population plus gibberellic acid+ benzyl adenine. ۱۲ hours leaching of Izeh population plus gibberellic acid+ benzyl adenine+ kinetin showed the highest germination time and seed vigor index. The highest germination rate was belonging to Najafabad population without leaching plus kinetin and also ۶ hours plus kinetin. On the whole, ۱۸ and ۲۴ hours of leaching plus gibberellic acid and kinetin alone or in combination seem to be suitable to break the seed dormancy. Keywords: Leaching, Benzyl adenine, Gibberellin, Kinetin, Seed vigor index  

Keywords: Leaching, Benzyl Adenine, Gibberellin, Kinetin, seed vigor index