MORPHOGENESIS OF POLLEN CALLUS CULTURES OF HYOSCYAMUS NIGER

Abstract

Morphogenesis of calluses of single pollen grain origin shed from anthers of Hyoscyamus niger cultured in a liquid medium containing 2,4‐dichlorophenoxyacetic acid (2,4‐D) was followed upon their transfer to a solid medium with or without 2,4‐D. In a solid medium lacking 2,4‐D, small calluses consisting of one to five nodular groups of cells at the time of inoculation differentiated root and shoot systems and formed miniature seedlings. In the same medium large calluses with several nodules initially formed a crop of bipolar somatic embryoids with well‐defined root and shoot axes which subsequently differentiated into seedlings. Irrespective of their size at the time of transfer, calluses grown in a solid medium containing 2,4‐D continued to proliferate without showing signs of organogenesis or embryogenesis.