Seed treatments to break seed dormancy and Standardization of viability test procedure in Abrus precatorious

Abstract

Abrus precatorius is an indigenous medicinal plant belongs to Fabaceae family and grow as wild vine in tropical and subtropical climate conditions. Seeds of this species posses seed dormancy and restricts germination to overcome unfavorable environmental conditions. This dormancy need to be removed to enhance germination under favourable condition of plant growth. Hence, different dormancy breaking treatments were imposed on freshly harvested seeds to improve germination. Treatments includes physical and physiological methods like soaking in water (24 h), conc. H2SO4 (2 min), KNO3 (2%) (24 h), GA3 100 ppm (24 h), Kinetin 100 ppm (24 h) and mechanically damaging the seed coat. The experimental results revealed that A. precatorius posses seed dormancy, mainly due to leathery testa leading to impermeability for water and oxygen so called hard seeds. Among treatments, damaging the seed coat (Nicking) enhanced germination from 32 to 84%, followed by seeds soaked in gibberlic acid (100 pm) for 24 h (78 %). In nature, dormancy was gradually reduced and found no dormancy behavior after seven months of harvest. For quick viability test, seed coat must be mechanically damaged before preconditioning of seeds for better results. Also, seeds soaked in Tz solution of 1.0 (%) for 6 h or 0.1% for 12 h helps for clear distinguishing of viable and non viable seeds in abrus.