Increase of callus and embryoid production from hypocotyl protoplasts of sunflower (Helianthus annuus L.) by culture in microdrops

Abstract

Hypocotyls of seedling plants of the sunflower inbred line HNK-81 were used as a source of protoplasts. Optimal conditions of isolation and culture of protoplasts were established. Using the method of individual culture in microdrops, a 77 % final plating efficiency was achieved. Cytokinins, especially zeatin, showed a significant influence on the formation of globular embryo-like structures, but these failed to develop into mature embryos. Calli obtained in liquid media containing auxins and cytokinins grew on agar solidified media without growth regulators.