Variation and long term regenerative capacity of two important tropical forage legumes: Cavalcade (<i>Centrosema pascuorum</i> cv. Cavalcade) and Stylo 184 (<i>Stylosanthes guianensis</i> CIAT184) <i>in vitro</i>

Abstract

Shoots of Cavalcade (Centrosema pascuorum cv. Cavalcade) and Stylo 184 (Stylosanthes guianensis CIAT 184) from in vitro germinated seeds were cultured on Murashige and Skoog (MS) medium supplemented with 0 to 7 mg L^-1 N 6-benzyladenine (BA) in combination with 0 to 0.5 mg L^-1 napthalene acetic acid (NAA) for shoot induction and MS supplemented with 0 to 0.5 mg L^-1 indolebutyric acid (IBA) for root induction. For Cavalcade, the medium containing 1 mg L^-1 BA produced the best shoot multiplication with an excess of six shoots produced from a single shoot (over four weeks) with a mean height 2.0 ± 0.01 cm. Adventitious shoot regeneration was obtained directly from stem axes. For Stylo 184, the maximum shoot regeneration (29.5 ± 1.0 cm shoots/explant) and height (1.5 ± 0.1 cm) was achieved using 7 mg L^-1 BA and 0.01 mg L^-1 NAA. Direct and indirect shoot regeneration was obtained on the medium containing 1 mg L^-1 BA and 0.01 mg L^-1 NAA. The regeneration of shoots from callus of Stylo 184 varied between different genotypes and was high (2.6 to 5.8 shoots/explant) even after maintenance in culture of over three years. Both Cavalcade and Stylo 184 shoots were rooted on media supplemented with IBA (0 to 0.5 mg L^-1) and readily transferred to soil (Stylo 184).

Key words: Callus, forage legume, micropropagation, organogenesis, root induction.