Effect of Gibberellic Acid (GA3) and Kinetin on Seed Germination of Sesbania sesban L. and Sesbania rostrata L. (Fabaceae)

Abstract

We investigated the effects of gibberellic acid (GA3) and kinetin on seed germination of S. sesban L. and S. rostrata L. The matured seeds used for this study were obtained from International Institute for Tropical Agriculture (IITA) Ibadan, Nigeria. The seeds were harvested in 2014 and stored dry in a glass container and kept (15°C) in the refrigerator. The viability of the seeds were determined by floating the intact seeds in water and water uptake (imbibition) was carried out. Four replicates of 20 seeds per replicate were germinated and the seeds observed daily and final count was recorded after 14 days of incubation at 30°C. Intact seeds were soaked in gibberellic acid (GA3) and kinetin for 24h and germination percentage taken. The results from the water absorption demonstrated that the seeds of S. rostrata is more permeable compared to S. sesnban as indicated by higher water absorption of seeds of S. rostrata (70%) to S. sesban (25.4%) after 24hrs of incubation. The anatomy of the seed coats indicated the presence of water and gas impermeable tissues namely cuticle, macrosclereids, osteosclereids and disintegrated parenchyma layer. Generally, 0.1 mM kinetin and GA3 enhanced significant germinations compared to the control with 0% germination for the 14 days period of germination. The percentage germination of seeds of S. sesban and S. rotrata subjected to different treatments and germinated in 0.1 mM GA3 and water showed a progressive decrease in germination. From our study, 0.1 mM GA3 and Kinetin significantly enhanced seed germination of S. sesban and S. rostrata.