بررسي روش هاي شكست خواب بذر در گونه. Astragalus fridae Rech

Methods of seed dormancy breakage in endangered species of Astragalus fridae Rech

Astragalus are among the most abundant floral species in the world which involve more than 3300 types and they are considerable from medicinal feeding and economical points of view. The goal of this study is to evalate the germination and the seed dormancy breakage of Astragalus fridae. This was carried out in a form of a completely randomized design with eight treatments and three replications. The seeds were treated using different methods of scarification and stratification. The results indicated that the most percentage of germination was observed in the scarification treatments (with or without chilling, about 97%). Also, vigor index and germination speed were higher in those treatments. Mechanical scarification with sandpaper was the most appropriate treatment to make the seed coat permeable to water with no adverse effect on embryo. The lowest germination occurred in control stratification, hot water and freeze-thaw treatments. Considering low germination percentage in ten days of stratification (without scarification), hardness of seed coat could be suggested as a major reason for dormancy in Astragalus fridae.