Embryoid and plantlet formation from leaf segments of Dactylis glomerata L

Abstract

The purpose of this investigation was to demonstrate callus induction and plantlet formation from cultured leaf segments of 12-15 week-old Dactylis glomerata L. (orchardgrass) plants. Flat half-leaf sections, approximately 2-3 mm square, from the three innermost (youngest) leaves were isolated and individually plated serially beginning at the leaf base on a solid SH medium containing 30 μM of 3,6-dichloro-oanisic acid (dicamba). Callus formed on leaf sections from all 50 plants used in the study. After transfer to SH medium with 1 μM dicamba, plantlets formed from leaf sections of 9 of the 50 plants. In most cases plantlets formed from embryogenic callus but in a few cases embryoids formed directly on the leaf surface without an intervening callus state. These developed into plantlets when transferred to low auxin medium. The response for both callus and plantlet formation decreased with increasing distance both spatially and temporally from the shoot apex. Histological examination of embryogenic callus revealed the presence of non-zygotic embryos in various stages of development. The results provide further support for compentency (if not totipotency) of Gramineae leaf cells.