摘要
Callus cultures of Annona muricata and Annona purpurea were induced in Murashige and Skoog(MS)medium supplemented with different concentrations of 1-naphthylacetic acid(NAA),6-benzyladenine(BA)and 2,4-dichlorophenoxyacetic acid(2,4-D)utilized hypocotyls with explant.The highest percentage of callus formation was the treatment supplemented with 3 mg L-1 NAA for A.muricata(100%)while for A.purpurea in lower percentage(75%).BA stimulated the formation of shoots in all the evaluated concentrations,being the concentration of 2 mg L-1 the one that induced the greater formation of shoots for A.muricata(23 shoots/explant)and A.purpurea(28 shoots/explant).The content of total phenols,flavonoids and antioxidant activity was measured in the callus obtained from both species.The results showed that a higher content of total phenols was quantified in callus of A.purpurea(27.8 mg g-1 dw)compared to A.muricata(23.2 mg g-1 dw).The highest content of total flavonoids was observed in the callus of A.purpurea(8.0μg g-1 dw).Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydracil radical assay.The concentration required for 50%inhibition(IC50)of the 2,2-diphenyl-1-picrylhydracil radicals were 4.22μg mL-1 in methanolic extracts of callus of A.muricata,while in extracts of callus of A.purpurea was 2.86μg mL-1,in both cases was greater than that found for leaves.Callus culture of the species studied in this work represents an alternative for the production of natural antioxidants.
