Physiological Investigations on the Banana Plant I. Biochemical Constituents Detected in the Banana Plant

The interest and economic importance of a better understanding of the physiology and biochemistry of the banana plant is emphasized. Methods are described which are to be applied to the detection and determination of the nitrogenous constituents of alcohol-soluble extracts, and for the detection and analysis of keto acids and non-volatile organic acids. The classes of nitrogen compounds to which attention is given are the amino-acids and their amides, certain volatile amines, ureido and guanido compounds, and certain indole compounds. In view of the large amount present in fruit of the variety Gros Michel from Honduras, free histidine was isolated and critically identified. The use of various reagents and tests for these various classes of substances on paper chromatograms is described. The range of substances which have been detected by these means in the banana leaf, leaf-sheath, fruit (pulp and peel), and stem exudate are indicated by their location on paper chromatograms. Evidence is presented which indicates qualitatively the degree of prominence of the different substances in the tissues or extracts which have been examined. When substances were recognized but not yet identified, they are designated by suitable codes, the conditions of their occurrence are noted, and their distinguishing characteristics are given. This descriptive evidence on the biochemistry of the banana plant provides the background for the more quantitative work which is to follow.