In vitro shoot growth, direct organogenesis and somatic embryogenesis promoted by silver nitrate in Coffea dewevrei.

Direct differentiation of shoot buds in Coffea
dewevrei was evident from the seedling shoots with collar
region and also from collar region end of hypocotyl segments
in presence of 40 μM AgNO3, 8.88 μM of BA and
2.85 μM of IAA. Apart from this, shoot end of hypocotyl
explants mainly supported yellow friable callus or somatic
embryos. Subsequent transfer to the same medium induced
secondary somatic embryogenesis. The collar region of the
hypocotyl explants not only showed direct organogenesis by
producing 1–3 shoots per explant and also able to produce
globular somatic embryos and embryogenic yellow friable
callus. Similarly direct somatic embryogenesis along with
yellow friable embryogenic callus formation on 1/2 strength
MS medium comprising 1.47 μM IAA, 2.22 μM BA and
40 μM AgNO3 was noticed from cut portion of in vitro leaf
and stalk of regenerated plants. The microshoots rooted well
upon subculturing onto the same medium in 6 weeks and
showed 60 % survival in green house and resumed growth
upon hardening.