Micropropagation, Micromorphological Studies, and In Vitro Flowering in Rungia pectinata L.

A tissue culture protocol was developed for an important medicinal plant Rungia pectinata L. in the present study. Nodal shoots were used as explants and surface-sterilized with 0.1% HgCl2 solution. Murashige and Skoog (MS) medium was used to establish the cultures of R. pectinata. The bud break was reported on MS medium supplemented with 1.0 mg L(-1) 6-benzylaminopurine (BAP). About 98% response was observed with this media combination and maximum 3.2 shoots per explant with 4.3 cm length were recorded. The shoots were further multiplied using MS medium augmented with 0.5 mg L(-1) each of BAP and kinetin (Kin) + 0.1 mg L(-1) indole-3 acetic acid (IAA). Maximum 13.2 shoots per explant with 5.2 cm length were observed. All the shoots were rooted (4.9 roots per shoot with 3.5 cm length) on half strength MS medium fortified with 2.0 mg L(-1) indole-3 butyric acid (IBA). In vitro flowering was induced from the shoots on half strength MS medium supplemented with same concentrations and combinations of growth regulators used for shoot multiplication under 12/12 hr light/dark photoperiod. The plantlets were hardened in the greenhouse for two months and finally transferred to the field. The foliar micromorphological studies revealed the developmental changes in stomata, vein density, and trichomes during the culture of shoots under in vitro conditions.

An Improved Micropropagation Protocol by Ex Vitro Rooting of Passiflora edulis Sims. f. flavicarpa Deg. through Nodal Segment Culture.

A procedure for rapid clonal propagation of Passiflora edulis Sims. f. flavicarpa Deg. (Passifloraceae) has been developed in this study. Nodal explants were sterilized with 0.1% HgCl2 and inoculated on Murashige and Skoog (MS) basal medium. The addition of 2.0 mgL(-1) 6-benzylaminopurine (BAP) to MS medium caused an extensive proliferation of multiple shoots (8.21 ± 1.13) primordial from the nodal meristems. Subculturing of these multiple shoots on the MS medium augmented with 1.0 mgL(-1) of each BAP and Kinetin (Kin) was successful for the multiplication of the shoots in vitro with maximum numbers of shoots (25.73 ± 0.06) within four weeks of incubation. Shoots were rooted best (7.13 ± 0.56 roots/shoots) on half strength MS medium supplemented with 2.0 mgL(-1) indole-3 butyric acid (IBA). All in vitro regenerated shoots were rooted by ex vitro method, and this has achieved 6-7 roots per shoot by pulsing of cut ends of the shoots using 200 as well as 300 mgL(-1) IBA. The plantlets were hardened in the greenhouse for 4-5 weeks. The hardened plantlets were shifted to manure containing nursery polybags after five weeks and then transferred to a sand bed for another four weeks for acclimatization before field planting with 88% survival rate.

In vitro regeneration of shoots and ex vitro rooting of an important medicinal plant Passiflora foetida L. through nodal segment cultures.

Methods were developed in the present investigation for cloning and large scale plant production of Passiflora foetida L. germplasm selected from the East-Coast region of South India. Nodal shoot segments were used as explants. The explants were dressed and surface sterilized with 0.1% (w/v) HgCl2. Multiple shoots were induced (6.13 ± 0.22 shoots per explant) by proliferation of nodal shoot meristems on Murashige and Skoog (MS) semi-solid medium + 2.0 mg l-1 6-benzylaminopurine (BAP). The shoots of P. foetida were further multiplied (16.45 ± 0.44 shoots per explant) on MS medium + 0.5 mg l-1 each of BAP and Kinetin (Kin). The in vitro generated shoots were rooted on half-strength MS medium containing 2.5 mg l-1 indole-3 butyric acid (IBA). By this method 67% shoots were rooted. About 97% shoots were rooted ex vitro (8.33 ± 0.29 roots per shoot) when the cut ends of the shoots were treated with 300 mg l-1 IBA for 5 min. The in vitro rooted plants were hardened and acclimatized in the greenhouse and successfully (100%) transplanted to the field.