SEED STRUCTURE, POLYMORPHISM, GERMINATION an‎d ONTOGENESIS OF SALSOLA KALI SUBSP. TRAGUS (CHENOPODIACEAE) UNDER GREENHOUSE CONDITION

Protection of desert soil vegetation is one of the key requirements for environmental protection programs. Survival of desert plants is related to dispersal characters and germination mechanisms that ensure germination and successful establishment of seedlings in suitable time and place. Salsola kali subsp. tragus is annual halophyte found in some dry land and rangeland of Tarom-Abbar (Province of Zanjan). In this area it names as Chogan and in ancient times, was used as laundry soap. In this research, seed structure, polymorphism, germination and growing of S. kali subsp.tragus were studied under greenhouse conditions. Three types of seeds were observed: a, dark; b, light yellow and c, yellow color. All seeds had a spiral-shaped embryo. Spiral-shaped embryo gives quick ability for fast germination in good condition. Some of the yellow seeds had a transparent shield which causes gradual penetration of water into the seed. These features cause the seeds that germinate later than the others. Comparison of germination between scarified and not scarified seeds showed that non scarified seeds had more than 2 mounts dormancy. The stages of germination process and morphological characters of plant in different growing life cycle are presented. The special characters of this plant, such as the fast opening of compressed spiral shape embryo, which we report in this research, is a creative natural mechanism for rapid germination and immediately establishes on unreliable conditions. Study of halophytes life cycle, discovery of germination mechanisms and biological structures involved in stress conditions will be very important and necessary for improving of desertification programs, soil improvement, soil erosion control and forage production. Keywords