Direct as well as indirect somatic embryogenesis from immature (unemerged)inflorescence of a minor millet Paspalum scrobiculatum L.

Somatic embryos differentiated directly on the rachis of immature infloresc ences of Paspalum scrobiculatum L. cv. PSC 1 on culture to MS or N-6 medium supplemented with different concentrations (4.5-22.5 muM) of 2,4-dichlorop henoxyacetic acid (2,4-D). Direct embryogenesis on the rachis of infloresce nce explants forms the first instance in graminaceous plants. Highest frequ ency of direct embryogenesis (34% and 30% cultures, respectively) was possi ble on N-6 medium supplemented with 4.5 muM of 2,4-D and MS medium fortifie d with 9.0 muM of 2,4-D. Other tissues of the explant, floral-primordia, on ly after an initial phase of callusing differentiated into somatic embryos; indirect embryogenesis. Somatic embryogenesis, direct as well as indirect, was resolved by scanning electron microscopy. The somatic embryos germinat ed and developed into plantlets on regeneration medium. Interestingly, one week incubation of somatic embryos on activated charcoal (0.5%) fortified b asal medium, supported high potential for 'germination' on transfer to char coal-free basal medium. This beneficial effect of activated charcoal on reg eneration of somatic embryos into plantlets is the first record in the Gram ineae.