AIM To evaluate the antioxidant potential and indole alkaloid variations in different parts of two varieties (rosea and alba) of Catharanthus roseus. METHODS The antioxidant potentials were examined in terms of non-enzymatic antioxidant molecules and activities of antioxidant enzymes. The non-enzymatic antioxidant molecules studied were ascorbic acid, α-tocopherol and reduced glutathione. The estimated antioxidant enzymes were superoxide dismutase, ascorbate peroxidase, catalase, peroxidase and polyphenol oxidase. The analyses were carried out in the field-collected samples. The antioxidant and alkaloid profiles were estimated from roots, stems, leaves, flowers and pods. RESULTS The roots and stems had higher antioxidant content when compared with other parts of the plant. The lowest content was found in flowers and pods. The rosea variety was good performer in terms of antioxidant and alkaloid contents. The activities of antioxidant enzymes were higher in leaves when compared with other parts. But indole alkaloid content was found to be higher in the roots of rosea variety. CONCLUSION The pink-flowered rosea variety of Catharanthus roseus is more suitable for cultivation in terms of antioxidant and alkaloid contents.

The ability of triadimefon (TDM), a triazolic fungicide, to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam (Dioscorea rotundata Poir.) tubers during storage under (30+/-2) degrees C in the dark, was studied. TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10, 25 and 40 d after storage (DAS). Starch, sugars, protein, amino acid contents as well as protease and alpha-amylase activities were estimated on 15, 30 and 45 DAS from two physiological regions viz., apical and basal regions of the tubers. In normal conditions (control) sprouting occurred on 70 to 80 DAS. The starch content decreased, while protein, amino acid, sugar contents and protease and alpha-amylase activities were increased due to TDM treatment and led to early sprouting.
Dioscorea ; drug effects ; growth & development ; metabolism ; Food Preservation ; Plant Tubers ; drug effects ; growth & development ; metabolism ; Temperature ; Time Factors ; Triazoles