Interaction of Parthenin with Gibberellic Acid on Growth Responses in Achyranthes Aspera and Barley

The seeds of Achyranthes aspera and Hordeum vulgare when treated with parthenin (1,6β- dihydroxy-4- oxo-10αH- ambrosa-2,11(13)- dien- 12- oic acid -γlactone) showed significant inhibition in their germination and growth of radicle/root and coleoptile. Lower concentrations of gibberellic acid (GA₃) (2β, 4α ∝ 7-trihydroxy-1-methyl-8-methylene-4bβ-gibb-3-ene-1α, 10β-dicarboxylic acid 1,4 β lactone) significantly increased the plumule/coleoptile length whereas, higher concentrations reduced their length as well as germination. The GA₃ induced seed germination and seedling growth was (suppressed by treatment with parthenin applied in combination with GA3 or alone applied subsequent to GA3 treatment. GA3 applied after parthenin treatment reduced the inhibitory effect induced by parthenin bet could not completely reverse the effects.