Silver nitrate induced rooting and flowering<i style=""> in vitro</i> on rare rhoeophytic woody medicinal plant, <i style="">Rotula aquatica</i> Lour.

418-421Silver nitrate induced enhanced rooting and flowering in vitro was achieved on Rotula aquatica L., a rare rhoeophytic woody aromatic medicinal plant. Solid and liquid nature of the medium, and growth regulators significantly influenced in vitro rooting and flowering. Half-strength MS liquid medium fortified with 2.69 M -naphthaleneacetic acid (NAA) was effective among different auxins, which induced a mean of 7.3 roots per shoot. Plantlets acclimatized after auxin alone induced rooting exhibited 80% survival in field conditions. Nevertheless, the established plantlets exhibited 50% loss within 3 months. Addition of 11.7 M silver nitrate to half-strength MS liquid medium containing 2.69 M NAA increased the number of roots to 16.8 per shoot. Plantlets established after rooting in silver nitrate supplemented medium facilitated 95% survival, and the established plantlets did not exhibit loss even after 3 months. Dipping of the basal end of shoots developed in vitro in NAA (2.69 M) and silver nitrate (11.7 M) solution (made in water) for 25 days induced a mean of 12.4 roots per shoot. These plantlets transferred to small pots facilitated 90% survival. Half-strength MS liquid medium containing 2.69 M NAA and 11.7 M silver nitrate induced flowering earlier. The flowers were morphologically and structurally similar to that on plants growing in field conditions

Rapid axillary bud proliferation and <i style="">ex vitro</i> rooting of herbal spice, <i style="">Mentha piperita</i> L.

108-112Efficient protocol for rapid multiplication of the herbal spice Mentha piperita L. through axillary bud multiplication and ex vitro rooting was established using Murashige and Skoog (MS) medium. Media prepared with tap water and commercial sugar, and those prepared with double distilled water and tissue culture grade sucrose did not show significant difference in the in vitro induction of shoots/node, and roots/shoot. MS medium fortified with 4.44 M N6-benzyladenine (BA) and 2.32 M kinetin (Kn) was the best for proliferation of shoots; induced a mean of 4.1 shoots/node explant. The shoots attained a height of more than 4.5 cm bearing more than 5 nodes within 40 days. Excision and culture of in vitro derived node segments on medium with 3.33 M BA and 2.32 M Kn facilitated enhanced axillary bud proliferation. Shoots developed were rooted best on half-strength MS medium with 0.49 M indole-3-butyric acid (IBA); induced a mean of 10.3 roots. In vitro rooted shoots exhibited 100% survival in field conditions. Dipping of the basal end of shoots harvested from multiplication medium in 0.49 M IBA solution for 10 days induced a mean of 8 roots and its transfer to small pots facilitated survival of 95% rooted shoots. Ex vitro rooting by direct transfer of the shoots from multiplication medium to small pots showed 72% survival. Commercial sugar and tap water and ex vitro rooting make the protocol economic