A MICROPROPAGATION TECHNIQUE OF HEMIDESMUS INDICUS (ASCLEPIADACEAE),A VALUABLE MEDICINAL PLANT

An efficient protocol was established for in vitro clonal propagation of Hemidesmus indicus (Anantamul) belongs to the family Asclepiadaceae, a widely used medicinal plant through callus culture in using nodal segment. Yellowish nodular callus was observed from nodal segments on MS basal medium supplemented with 0.5 mg/L BAP + 0.2 mg/L NAA within four weeks of culture. Large number of shoots (11.4±0.2) and roots (8.2±0.4) were obtained when the callus was sub cultured on MS medium with 0.2 mg/L BAP. The regenerated plantlets were acclimatized by transferring them to soil. The survival rate of plantlets was found to be 90%. Regenerated plants were morphologically comparable having normal leaf shape and growth.

Regeneration of Paeonia mlokosewitschii Lom. and P. tenuifolia L. in vitro from different explants

The pattern of regeneration from tissues of <em>Paeonia mlokosewitschii</em> and <em>P. tenuifolia</em> cultured in vitro in the same chemical conditions depended on the initial explant. Direct shoot regeneration was obtained from the bases of petioles and petals, and leaf veins. Vegetative initial buds and regenerated in vitro shoots produced on their bases slowly growing nodular callus which was very productive in repetitive shoot regeneration. The tops of stems, flower bases, sepals, petals and ovary walls produced small callus which regenerated white and red spherical structures within 1.5 years. After that time also from those cultures arised nodular, shoot regenerating callus developed.

Callus induction and plant regeneration of paederia foetida L., a widely used medicinal vine in Bangladesh

An efficient protocol was established for in vitro plant regeneration of Paederia foetada L. (Family. Rubiaceae), a widely used medicinal vine of Bangladesh through callus culture in using nodal segment. Yellowish green nodular callus was observed from nodal segments on MS basal medium supplemented with 1.5 mg/L BAP + 0.5 mg/L NAA within three weeks. Large number of shoots (14.4±1.29) were obtained when the callus was sub cultured on MS medium with 0.5 mg/L BAP. In vitro raised shoots rooted on half strength MS medium with 0.5 mg/L IBA. The survival rate of plantlets was found to be 85%. Regenerated plants were morphologically uniform having normal leaf shape and growth. Bangladesh J. Sci. Ind. Res. 47(4), 373-378, 2012 DOI: http://dx.doi.org/10.3329/bjsir.v47i4.14066

Callus Induction and Plant Regeneration from Immature Embryos of Zelkova sinica Schneid.

Zelkova sinica Schneid. is a popular landscape plant in China because of its wide adaptation, strong disease resistance, large crown, and beautiful fall color. Immature embryos from Z. sinica seeds were cultured on woody plant medium (WPM) supplemented with 4.5 μM 6-Benzylaminopurine (BA) and 5.4 μM α-naphthaleneacetic acid (NAA) to induce callus, and 60% of immature embryos formed callus. The cream-white, friable, nodular callus with proembryogenic structures was then cultured on WPM containing 5.4 μM NAA in combination with 9.0 or 11.2 μM BA to regenerate shoots; approximately five shoots per explant were induced on 70% callus. Shoots were rooted on WPM containing 0.5 μM indole-3-butyric acid (IBA), on which 62.3% shoots developed roots with an average of 4.2 roots per shoot at 4 weeks. The regenerated plantlets were acclimatized and transplanted into the field. This protocol could be used for mass production for field plantation, genetic improvement, and germplasm exchange of Z. sinica.

Somatic Embryogenesis in Centella asiatica, a Valuable Medicinal Plant

Centella asiatica L. (Apiaceae family), also called `Indian Pennywort,' is a prostrate, faintly aromatic, and stoloniferous perennial herb with long petiolated leaves. In the Ayurvedic medicine, it is reputed as a nervine tonic along with antibacterial, antifeedant, antileprotic and wound healing properties. Centella contains glycosides, indocentelloside, brahmoside, and asiaticoside. Its leaves are rich in carotenoids and vitamins B and C. In vitro culture techniques which offer a viable tool for mass propagation of plants have recently become increasingly popular for conservation of rare, endangered and threatened medicinal plants germplasm. Centella tissue culture has been reported to experience high incidences of microbial contamination which drastically reduces survival of explants. Thus, the main purpose of this study was to develop an efficient micropropagation technique for Centella asiatica to reduce explant contamination and rapidly disseminate superior clones for research and production. Here we present induction and further development of somatic embryos, using Centella stolons as explants. Somatic embryos were induced in response to 2,4-D shock on MS medium. Initially, somatic embryos appeared as highly nodular callus and eventually developed into somatic embryos that exhibited globular, heart shaped and cotyledonary stages. After auxin shock, cultures were regularly transferred to MS basal medium where somatic embryos completed various developmental stages and then germinated to give rise to new plantlets. In this presentation, we will demonstrate complete protocols for the successful sterilization of Centella explants prepared from plants that had abundance of fungal and bacterial contamination.

SOMATIC EMBRYOGENESIS FROM LEAF OF WITLOOF CHICORY (Cichorium intybus L.)

A method for regeneration of somatic embryogenesis from witloof chicory is described. Explants were taken from leaf veins of stored witloof chicory. Internal bacterial infection was found in 100% of the leaf bases but decreased gradually toward the leaf tips. Bacterial free explants were taken from the distal third and cultured on Murashige and Skoog medium (MS) containing 1.3 uM 2,4-D, 1.3 uM kinetin, and 100 mg/L casein hydrolysate. A pale yellowish, nodular callus formed after 4 weeks and were maintained in the same medium for 8-12 months with one change to a fresh medium every 4 weeks. Callus were suspended in the same medium without agar for 4-6 weeks with one change to a fresh medium every 2 weeks. Embryo-like structure appeared upon transfer to MS liquid medium containing 1.8 uM benzyladenine. Embryo germination was accomplished in 1/4 strength of MS medium with 01 without 1 g/L activated charcoal.

Ontogeny of shoot regenerants on excised immature peach embryos

Excised immature peach embryos when cultured on an auxin-containing medium produced both a friable callus and a nodular callus. Upon further subculturing on an auxin-reduced medium only the nodular callus differentiated into highly regenerative nodular callus. This callus comprised dense meristematic cells which arose near or at the surface of the nodular tissue. Cells containing starch granules often surrounded these meristemoid areas. Shoots could be induced to form on shoot-inducing medium from the meristemoid areas. Vascular connections developed between the parental material and the shoot. The friable callus never appeared to differentiate into a nodular callus on either friable callus or nodular callus medium, nor were plantlets derived from this tissue on shoot-inducing medium. No stages of somatic embryogenesis were ever apparent. The evidence supports the view that the regenerative shoots were derived from indirect organogenesis on nodular callus derived from the embryonic tissue.Key words: Organogenesis, Prunus persica (L.) Batsch, shoot formation