In Vitroseed Germination And Micropropagation Of Dendrobiumlindleyisteud. An Indigenous Orchid Of Bangladesh

The seeds of Dendrobium lindleyi were germinated on 0.8% (w/v) agar solidified Murashige and Skoog (MS) as well as Phytamax (PM) basal media. The germination rate was found to be better on PM medium. The germinated seedlings underwent rapid elongation on Plant Growth Regulators (PGRs) supplemented media and the highest growth was recorded on MS with 3% (w/v) sucrose + 2.0 mg/1 6-Benzyl Amino Purine (BAP) + 0.1mg/1 Indole-3-Butyric Acid (IBA). The seed derived seedlings developed strong and stout roots on half strength MS medium with 1.5% sucrose. For micropropagation the pseudobulb segments were used as explant and the lower part of pseudobulb segment produced highest number of multiple shoot buds (9-10/segment) on agar solidified MS medium supplemented with 3% (w/v) sucrose + 2.5 mg/1BAP + 0.1% (w/v) Activated Charcoal. The highest rate of elongation and rooting was found from multiple shoot bud derived seedlings as well as same seed derived seedlings. Seed and multiple shoot bud derived rooted seedlings were finally transferred to outside natural environment by successive phases of acclimatization. Asiat. Soc. Bangladesh, Sci. 41(2): 163-171, December 2015

In vitro Embryo Morphogenesis and Micropropagation of Dendrobium aggregatum Roxb.

In vitro embryo morphogenesis and micropropagation of Dendrobium aggregatum Roxb. were described. The gradual developmental stages of embryos to seedlings were traced out. Within two weeks of culture the cells of undifferented embryos underwent repeated aniclinal and periclinal division producing a compact, green parenchymatous cell mass called spherule that emerged out by rupturing the testa. The spherules subsequently differentiated into greenish protocorms were considered as typical seed germination. Germination occurred on both (MS and Phytamax (PM) medium but MS medium proved to be more efficient. The primary protocorms underwent profuse proliferation through production of secondary (2º) protocorms when transferred to different plant growth regulators (PGRs) supplemented MS; the medium fortified with 2.0 mg/l BAP and 1.0 mg/l NAA proved to be most effective for induction of 2º protocorms and seedling development. Multiple shoot buds (MSBs) were induced in pseudobulb segments of the in vitro grown seedlings when cultured on different PGRs supplemented media; and the maximum number of MSBs were obtained MS + 2.0 mg/l BAP + 0.5 mg/l picloram. The MSBs underwent elongation and then they rooted when they were transferred to half strength of MS + 0.5 mg/l IAA. The well rooted plantlets were finally transferred to outside natural environment with 80% survival. D. O. I. http://dx.doi.org/10.3329/ptcb.v23i2.17525 Plant Tissue Cult. & Biotech. 23(2): 241-249, 2013 (December)

In vitro micropropagation of Rauvolfia serpentina (L.) Benth through induction of direct and indirect organogenesis

Leaf and nodal segments of two months old field grown seedlings of Rauvolfia serpentina (L.) Benth were aseptically cultured on agar solidified MS medium supplemented with various combinations and concentrations of auxins (NAA, IAA, 2,4-D and picloram) and cytokinins (BAP and Kn). The nodal segments produced highest number of multiple shoot buds (5.85/explant) on MS medium supplemented with 2.0 mgl-1 BAP + 0.2 mgl-1 NAA or 2.0 mgl-1 BAP + 0.1 mgl-1 IAA. Whereas nodal segment produced callus tissue of different nature on MS medium supplemented with 1.5 mgl-1 BAP + 0.5 mgl-1 IAA+ 1.5 mgl-1 2,4-D; 3.0 mgl-1 BAP + 1.0 mgl-1 NAA + 1.5 mgl-1 Kn and 0.1 mgl-1 Pic + 1.0 mgl-1 Kn. The callus tissue of light green and nodular nature on further subculture in a wide range of plant growth regulators (PGRs) supplemented media, differentiated into multiple shoot buds that underwent rapid elongation on 2.0 mg/l BAP and 0.2 mg/l NAA supplemented media. The elongated shoot buds on further subculture in rooting media produced strong and stout roots. Half strength MS with 1.5% (w/v) sucrose was most effective for enhancing rooting. Finally those plantlets were acclimatized in field. Thus a protocol was established for rapid micropropagation of this medicinal plant through induction of direct and indirect organogenesis from nodal explant. DOI: http://dx.doi.org/10.3329/cujbs.v3i1.13401 The Chittagong Univ. J. B. Sci.,Vol. 3(1&2):01-09, 2008

Plant Regeneration from Excised Cotyledons of Mature Strawberry Achenes

A protocol was developed for excising and culturing cotyledon explants from mature achenes of strawberry (Fragaria × ananassa Duch.). Cotyledon explants formed callus with multiple shoot buds on agar-solidified Murashige and Skoog media containing several combinations of hormones (1 μm 2,4-D; 10 μm 2,4-D; 1 μm BA + 1 μm 2,4-D; 1 μm BA + 10 μm 2,4-D; 5 μm BA; 5 μm BA + 1 μm 2,4-D; 5 μm BA + 10 μ m 2,4-D; 5 μ m BA + 5 μm NAA; 5 μ m BA + 15 μ m NAA). After three subcultures, only tissues maintained on the medium containing 5 μm BA + 5 μm NAA continued to form shoots. Tissues transferred to other media eventually died (1 μm 2,4-D; 1 μ m BA + 10 μ m 2,4-D; 5 μ m BA; 5 μ m BA + 1 μ m 2,4-D), became unorganized (1 μm BA + 1 μm 2,4-D; 5 μm BA + 10 μm 2,4-D; 5 μm BA + 15 μm NAA), or formed roots (10 μm 2,4-D). Whole plantlets were produced by transferring callus with buds to medium lacking hormones. The rapid regeneration of clonal plantlets from cotyledon explants may be useful for reducing variability in future developmental studies. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); (2,4-dichlorophenoxy) acetic acid (2,4-D); and 1-naphthaleneacetic acid (NAA).

Effect of Bavistin and Adenine Sulphate on In vitro Shoot Multiplication of Picrorhiza scrophulariiflora

An alternative protocol for in vitro propagation of Picrorhiza scrophulariiflora is described using bavistin and adenine sulphate. The explants differentiated into multiple shoot buds on MS supplemented with various concentrations of bavistin and adenine sulphate ranging from 0 - 400 mg/l either alone or in combination. Maximum number of multiple shoots were obtained on MS containing the combination of bavistin (100 mg/l) and adenine sulphate (100 mg/l). In this combination as high as 28 shoots per explant was achieved and also vetrification of the cultures were not recorded. This study also demonstrates that the bavistin has stronger cytokinin-like activity than adenine sulphate. For instance, it was observed that bavistin alone in the concentration of 300 mg/l produced as high as 24 shoots per explant, however, adenine sulphate (100 mg/l) could produce a maximum of 18 shoots per explant. Moreover, higher or lower concentration did not improve the shoot multiplication. The microshoots were separated from the multiple shoots and transferred to MS containing various concentrations of auxins. Among them, NAA (1 mg/l) produced as high as 6 roots per explant. The regenerated plantlets were hardened in plastic cups (6 x 8 cm) containing 9 : 1 virgin soil and soil at Kyongnosla nursery and acclimated for four weeks. A 90% survival rate of the plants was recorded after 60 days. D.O.I. 10.3329/ptcb.v19i2.5441 Plant Tissue Cult. & Biotech. 19(2): 237-245, 2009 (December)

In vitro Micropropagation of Plumbago indica L. Through Induction of Direct and Indirect Organogenesis

Leaf and nodal segments of two months old field grown seedlings of Plumbago indica L. were cultured on agar solidified MS supplemented with different concentrations and combinations of NAA, IAA, 2,4-D and picloram, and BAP and Kn. The nodal segments produced either multiple shoot buds (MSBs) or callus of different nature depending on the combinations of plant growth regulators (PGRs). The callus of light green and nodular shape, on further subculture on wide range of PGRs supplemented media, differentiated into MSBs. These MSBs underwent rapid elongation on different PGRs supplemented media. The elongated shoot buds were rooted on transferring in rooting medium and were acclimated in field with 90% survivability. The leaf segments, however, produced only white and friable calluses failed to undergo any differentiation in some of the media combinations. Key words: Callus induction, Organogenesis, Plumbago indica D.O.I. 10.3329/ptcb.v19i2.5434 Plant Tissue Cult. & Biotech. 19(2): 169-175, 2009 (December)

In vitro Regeneration of Aristolochia tagala Champ. A Rare Medicinal Plant of Chittagong Hill Tracts

An efficient regeneration protocol through in vitro direct organogenesis was developed for a valuable medicinal plant Aristolochia tagala Champ. using nodal segments as explants. Multiple shoot buds were induced directly from nodal explants cultured on MS (Murashige and Skoog 1962) basal medium supplemented with 2.0 mg/l BAP (N6- benzylaminopurine) and 0.5 mg/l NAA (a-naphthalenacetic acid). The average number of shoots induced per culture was found to be six. Excised shoot roots were cultured on half-strength MS medium containing 0.5 mg/l IBA. The rooted plantlets were transferred to natural environment after proper acclimatization. Â Key words: Aristolochia tagala, rare medicinal plant, direct organogenesis. doi: 10.3329/jbs.v15i0.2204 J. bio-sci. 15: 63-67, 2007 Â Â Â Â