REGENERATION OF A METAL TOLERANT GRASS ECHINOCHLOA-COLONA VIA SOMATICEMBRYOGENESIS FROM SUSPENSION-CULTURE

An efficient protocol was developed for in vitro plant regeneration vi a somatic embryogenesis from cell suspension cultures of metal toleran t grass Echinochloa colona (L.) Link. Callus was obtained by culturing leaf base on MS medium supplemented with 0.5 mg dm(-3) of 6-benzylami nopurine (BAP) and 2.0 mg dm(-1) of 1-naphthaleneacetic acid (NAA). Ce ll suspensions were initiated and established in MS liquid medium cont aining 0.5 mg dm(-3) BAP, 1.0 mg dm(-3) NAA and 2.0 mg dm(-3) 2,4-dich lorophenoxyacetic acid (2,4-D). A reduction in the concentration of 2, 4-D to 0.5 mg dm(-3) induced formation of somatic embryos, The embryos developed and grew into normal plants in the presence of half strengt h MS medium without growth regulators. The regenerated plants were har dened in the greenhouse and subsequently grown in the open. This syste m may be also used for isolation and culture of protoplasts as a first step in somatic hybridization.