Studies on Dormancy and Germination in Rice Seed
VI. The chromatographic identification of a germination inhibitor in rice seed
1979 Volume 23 Issue 1 Pages 1-5
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1979 Volume 23 Issue 1 Pages 1-5
An endogenous germination inhibitor causing rice seed dormancy was analyzed by chromatography, using the strongly dormant seed of rice variety Ketaktara.
The acidic ethyl acetate soluble fraction of the extract was fractionated by a charcoal adsorption chromatography with aqueous acetone solution using stepwise-elution method, and each fraction was bioassayed with rice seedling elongation. The 50 - 70% acetone fraction which showed the most prominent growth inhibiting activity was purified further by the silicic acid partitione chromatography with ethyl acetate in n-hexane solution, and the resulted 11 fractions were bioassayed. The result obtained indicated that the 30% ethyl acetate fraction contained the inhibitor most abundantly. Then the sample of this fraction was methylated by diazomethane and analyzed by gas chromatography with 2 kinds of glass column packed with different silicons at 210°C, and this substance had the same retention time as authentic abscisic acid (ABA) . The detected ABA was consisted almost entirely of cis-ABA with small quantity of trans-ABA. The quantity of cis-ABA was estimated to be over 280μg in the seed of 1 kg in fresh weight.
Gibberellin like substance was detected in the 60% ethyl acetate in n-hexane solution on a silicic acid partition chromatography, and the identification of gibberellin is now in progress.
