Submitted to: Research Day Abstracts: Regional Universities Research Day
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2002
Publication Date: 11/25/2002
Citation: PEAL, L., WILLIAMS, R.D. THE EFFECTS OF COUMARIN ON RADISH SEED GERMINATION AND RADICLE ELONGATION. RESEARCH DAY ABSTRACTS: REGIONAL UNIVERSITIES RESEARCH DAY. 2002. Abstract p. 74.
Interpretive Summary: Abstract Only.
Technical Abstract: Coumarin is a compound that inhibits seed germination and seedling growth. This inhibitory effect may confer a competitive advantage for the plants that secrete coumarin into the environment. This study was conducted to evaluate the effect of hydration-dehydration of radish seed in the presence of coumarin on subsequent germination and seedling growth. Radish seed were placed in petri dishes or in seed pouches containing water (control) or coumarin solutions of 10^-5 to 10^-3 M. At all concentrations coumarin had a negative effect on radish seed germination and radicle growth. The greatest inhibitory effect was observed with 10^-3 M. Concentrations of 10^-5 and 10^-4 M initially inhibited germination and radicle elongation, but after 72 hours values approached those observed in the control. After 24 hours germination percentages were: control, 92%; 10^-5 M coumarin, 85%; 10^-4 M coumarin, 50% and 10^-3 M coumarin, 1%. After 48 hours the germination percentages were: control, 98%; 10^-5 M coumarin 96%; 10^-4 M coumarin, 96%; and 10^-3 M coumarin, 24%. Radicle length recorded at 48 hours was 18 mm, 14 mm and 4 mm for the control, 01^-5 M and 10^-3 M coumarin, respectively; while at 72 hours radicle length was 46 mm, 49 mm and 12 mm, respectively. Seed hydrated in coumarin solutions for up to 5 hours and then transferred to water or to coumarin solutions showed similar results as those reported above. The process of hydration and dehydration of seed in the soil in the presence of allelochemicals may provide further insight as to the soil-seed dynamics in allelopathic interactions among plants.