A Simple Method to Determine Amino Acid Leakage and Germination Capabilities from Single Radish (Raphanus sativus L.) and Chinese Cabbage (Brassica rapa ssp. pe/dnensis) Seeds

摘要

The viability of radish (Raphanus sativus L.) and Chinese cabbage (Brassica rapa ssp. pekinensis ) seeds were evaluated using a seed leachate treated ninhydrin reagent that develops color from amino acid leakage. Three different cultivars of artificially aged radish and Chinese cabbage seeds were used for this purpose. The radish and Chinese cabbage seeds were individually soaked in distilled water and treated with the ninhydrin reagent. A clearly distinct purple color was observed for the treated seed leachate, with intensities that varied depending on the seed quality. Depending on the intensity, the color could be classified into four separate fractions: colorless, weak, medium or strong. Color absorbance values were classified into 9 fractions for radish seeds and 11 fractions for Chinese cabbage seeds. Subsequently, a germination test was performed with the seeds in any given fraction (classified by color intensity and absorbance) and correlations between germination and color intensity or absorbance were evaluated. In a test of three cultivars of artificially aged radish and Chinese cabbage seeds, the relationship between percent germinated and color intensity appeared to have a very high negative correlation in linear regression, with r~2 =0.97 for radish seeds and r~2 = 0.95 for Chinese cabbage seeds. Similarly, the relationship between the percent germinated and the absorbance had a high negative correlation, with r~2 = 0.90 for radish seeds and r~2 = 0.94 for Chinese cabbage seeds. Inconclusion, the simple detection of amino acid leakage with ninhydrin reagent was successful at assessing individual seed quality, as high correlations between germination and color intensity/absorbance were revealed.