Inhibition of Seed Germination By Propyl Gallate, A Free Radical Scavenger and Recovery of Germination By Hydrogen Peroxide and Ethylene in Vigna Radiata

In the present investigation, effect of propyl gallate, a free radical scavenger, was studied on germination of Vigna radiata seeds to verify the role of active oxygen species in the regulation of seed germination. Propyl gallate inhibited germination and such inhibition was not due to osmotic effect as verified by the treatment with sucrose solution of similar concentrations. Treatments were also effective in a similar way on water uptake and growth kinetics of isolated embryonic axes. Increasing duration of pretreatment with propyl gallate also retarded seed germination as well as water uptake and growth of axes proportionately. Conversely, incubation in water followed by treatment with propyl gallate caused inhibition of germination immediately after the transfer. Same pattern was noted in case of water uptake and growth kinetics of isolated axes. When the seeds were simultaneously treated with propyl gallate and hydrogen peroxide, germination was restored to a great extent. Such recovery, though to a far lesser extent, was also found with ethylene (in the form of ethrel) given simultaneously with propyl gallate. No added effect was found when seeds were treated with both ethylene and hydrogen peroxide together in presence of propyl gallate. However, recovery effect by these combined treatments was not reflected in case of water uptake and growth kinetics of isolated axes.