Micropropagation of Three Bamboo Species from Nodal Explants of Mature Culms

A micropropagation technique is developed for the multiplication of Dendrocalamus strictus （D. strictus）, Dendrocalamus asper （19. asper） and Bambusa bambos （B. bambos） through shoot proliferation. Nodal explants obtained from field gown clumps were used to initiate cultures. Shoots were induced on Murashige and Skoog＇s （MS） medium supplemented with 5 mg L^-1 6-benzylamino purine （BAP）. Rapid shoot multiplication was obtained on MS medium containing 3 mg Lt BAP in D. asper, B. bambos and 2 mg L^-1 BAP in D. strictus. In vitro multiplied shoots showed best root induction on half strength MS supplemented with 1 mg L^-1 indole-3 butyric acid （IBA） and 0.5 mg L^-1 1-naphthalene acetic acid （NAA） in D. asper. Pre-rooting conditioning followed by culturing on half strength MS supplemented with 1 mg L^-1 IBA and 2 mg L^-1 IBA showed maximum root induction in D. strictus and B. bambos, respectively. Further root proliferation was obtained on hormone free medium. The micropropagated plantlets were acclimatized and successfully transferred on soil in green house.

Efficient in vitro Propagation of an Endangered Species Kolkwitzia amabilis Graebn

This study developed an efficient in vitro cultivation and propagation sys- tem for an endangered species Kolkwitzia amabilis using nodal segments as ex- plants. Multiple shoots were induced through axillary bud formation. The highest fre- quency of multiple shoot induction was achieved when the nodal segment explants were incubated in Murashige and Skoog （MS） medium supplemented with 4.44 pM 6-benzyladenine （6-BA） in combination with 0.54 μM a-naphthaleneacetic acid （NAA）, followed by treatment with 4.44 μM 6-BA in combination with 0.27 μM NAA. Shoot multiplication could be induced in MS medium supplemented with stand-alone 6-BA or 6-BA in combination with indole-3-acetic acid （1.71 μM） or NAA （0.27 or 0.54 μM）, with 6-BA and either compound, exhibiting a stronger effect on shoot multiplication. The optimum combination of plant growth regulators for shoot multiplication was 4.44 μM 6-BA with 0.27 μM NAA. The maximum rooting percentage was obtained in a half-strength MS medium supplemented with indole-3-butyric acid alone and in com- bination with NAA and 2,4-dichlorophenoxyacetic acid, but the best combination of plant growth regulators for rooting was 1.48 μM indole-3-butyric acid with 1.08 μM NAA and 0.05 μM 2,4-dichlorophenoxyacetic acid. The rooted shoots were trans- ferred to a greenhouse with a success rate of 100%.

Plantlet regeneration of adult Pinus massoniana Lamb. trees using explants collected in March and thidiazuron in culture medium

A protocol for micropropagation using nodal explants from mature Pinus massoniana trees has been developed. Time of explant collection is crucial for the initial success of aseptic culture. Explants collected in early March gave the highest percentage of explant survival (64.5%) and shoot-forming percentage (52.3%). Thidiazuron (TDZ) concentration significantly influenced shoot formation; 4 mu M TDZ was optimum, with 4.8 shoots produced per explant with a mean length of 7.1 cm after 120 days of culture. Regenerated shoots rooted for 60 days in basic medium with 1 mu M NAA were ready for growth in pots. This is the first report on plantlet regeneration in vitro from mature trees of P. massoniana that provides a reliable method for propagating selected elites.

Artificial Seed Production of Tylophora indica for Interim Storing and Swapping of Germplasm

Our research work demonstrates the single bead alginate-encapsulation, interim storing and conversion of Tylophora indica(Burm. Fil.) Merrill.Most effective encapsulation of in vitro nodal segments [(4 ± 1) mm long], ensuing in sphere-shaped artificial seeds of similar morphology, was achieved through 75 mmol·L^(-1)calcium chloride(CaCl_2 · 2H_2O) plus 3%(w/v) Na-alginate with 93.3% conversion frequency. The earliest conversion(within 7 days of incubation) of artificial seeds occurred in half-strength liquid Murashige and Skoog medium. Among the three different temperature regimes [(5 ± 1) °C,(15 ± 1) °C, and(25 ± 1) °C], storage of artificial seeds at(15 ± 1) °C executed the highest frequency of conversion(90%) after 15 days of storage. Lengthier storage significantly reduced the conversion frequency of artificial seeds irrespective of storage temperature. Nevertheless, the conversion frequency after 30 days of storage at(15 ± 1) °C was recorded at 70% without further decline even following45 days of storage, which evidently suggests that lower temperature(15 ± 1) °C is apt for storage and subsequent conversion of T. indica artificial seeds. The present protocol could be expedient for short-term storing and swapping of T. indica germplasms between national and international laboratories.