Macroptilium atropurpureum is a model legume with a broad symbiont range fo
r nodulation. We have achieved the first in vitro plant regeneration of thi
s species using cv. Siratro. Hypocotyl explants excised from dark-grown see
dlings generated slimy, friable calli after three weeks' culture on B5 medi
um containing 1-2 mg/l kinetin and 0.05 mg/l alpha-naphthaleneacetic acid.
This was followed by the generation of green organogenic callus with shoot
buds by subculturing the explants to hormone-free B5 medium 20 days after t
he start of culture. The green organogenic calli with shoot buds were maint
ained as organogenic callus by subculturing on the same medium, and shoots
were elongated on hormone-free B5 medium. Elongated shoots were rooted on h
alf-strength B5 medium. Most regenerated plants were morphologically normal
, diploid and fertile, although tetraploid plants appeared at a low frequen
cy (8%). (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.