Gangadhar S. Mulgund

Efficient Regeneration of Vanda Coerulea, an Endangered Orchid Using Thidiazuron

Efficient shoot regeneration of Vanda coerulea was achieved using thin shoot tip sections and thidiazuron. Protocorm-like bodies or proliferating shoot buds was observed when thin shoot tip sections were cultured on Vacin and Wents (VW) (1949) basal medium supplemented with 11.35 µM thidiazuron. The highest percentage of protocorm-like bodies (95%) survived and ultimately produced healthy shoots with 2 – 3 leaves when subjected to a 4 week thidiazuron treatment. A culture period longer than 8 weeks with thidiazuron resulted in the formation of fasciated or distorted shoots. Shoots produced roots when cultured on half strength VW basal medium supplemented with 11.42 µM IAA. The well rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1) and a 98% survival rate was achieved.

Plant regeneration via somatic embryogenesis in Pinus kesiya (Rolye ex. Gord.) influenced by triacontanol

Embryogenic cultures were initiated and established for the first time in 3 different genotypes of Pinus kesiya using mature zygotic embryos and triacontanol. Mature zygotic embryos produced white-mucilaginous embryogenic callus when cultured on half strength MSG (Becwar et al. 1990) basal medium supplemented with 90 mM maltose, 2.0 g l−1 Gellan gum, 9.0 M 2, 4-D and 10 g l−1triacontanol. On subculture of such embryogenic callus on the maintenance medium (II) containing 2.0 M 2,4-D and 2.0 g l−1 triacontanol induced cleavage polyembryogenesis with proembryos. The percentage of somatic embryogenesis was not similar in all the three genotypes. The highest percentage of somatic embryogenesis (88.5 %) was recorded in PK04 genotype. Somatic embryos were successfully germinated on half strength MSG basal medium without growth regulators. Somatic seedlings showed fast growth and a survival rate of 95%. This work for the first time reveals that triacontanol can be used as an effective growth regulator for inducing somatic embryogenesis in conifers.

EFFECT OF TRIACONTANOL ON THE MICROPROPAGATION OF COSTUS SPECIOSUS (KOEN.) SM. USING RHIZOME THIN SECTIONS

SummaryThe highest percentage of shoot regeneration of Costus speciosus was achieved using thin rhizome sections and triacontanol (TRIA). Factors affecting the rate of shoot multiplication and rooting with TRIA have been investigated. Initiation of shoot buds was observed when rhizome thin sections were cultured on B5 basal medium supplemented with 5μgl−1 TRIA. Shoots with two to three leaves produced roots when cultured on B5 basad medium supplemented with 2 μgl−1 TRIA. The well-rooted shoots were hardened and transferred to soil where they showed normal growth and a 100% survival rate was achieved. Results of this study showed that TRIA can be used as an effective growth regulator in the micropropagation and conservation of C. speciosus.

Thidiazuron induced shoot regeneration of Costus speciosus (Koen.) Sm using thin rhizome sections

The best shoot regeneration was achieved in Costus speciosus by using thin rhizome sections. Efficient initiation of shoot buds was observed when thin rhizome sections were cultured on modified Gamborg-B5 basal medium (1968) supplemented with 18.16μM thidiazuron. Shoots with two to three leaves were successfully rooted on modified half strength Gamborg-B5 basal medium containing 5.37μM NAA. The rooted plantlets were transferred to soil and acclimatised showing normal growth. Survival rate was 100 percent.

Evaluation of wound healing property of Caesalpinia mimosoides Lam.

ETHNOPHARMACOLOGICAL RELEVANCE Caesalpinia mimosoides Lam. is one of the important traditional folk medicinal plants in the treatment of skin diseases and wounds used by healers of Uttara Kannada district of Karnataka state (India). However scientific validation of documented traditional knowledge related to medicinal plants is an important path in current scenario to fulfill the increasing demand of herbal medicine. AIM OF THE STUDY The study was carried out to evaluate the claimed uses of Caesalpinia mimosoides using antimicrobial, wound healing and antioxidant activities followed by detection of possible active bio-constituents. MATERIALS AND METHODS Extracts prepared by hot percolation method were subjected to preliminary phytochemical analysis followed by antimicrobial activity using MIC assay. In vivo wound healing activity was evaluated by circular excision and linear incision wound models. The extract with significant antimicrobial and wound healing activity was investigated for antioxidant capacity using DPPH, nitric oxide, antilipid peroxidation and total antioxidant activity methods. Total phenolic and flavonoid contents were also determined by Folin-Ciocalteu, Swain and Hillis methods. Possible bio-active constituents were identified by GC-MS technique. RP-UFLC-DAD analysis was carried out to quantify ethyl gallate and gallic acid in the plant extract. RESULTS Preliminary phytochemical analysis showed positive results for ethanol and aqueous extracts for all the chemical constituents. The ethanol extract proved potent antimicrobial activity against both bacterial and fungal skin pathogens compared to other extracts. The efficacy of topical application of potent ethanol extract and traditionally used aqueous extracts was evidenced by the complete re-epithelization of the epidermal layer with increased percentage of wound contraction in a shorter period. However, aqueous extract failed to perform a consistent effect in the histopathological assessment. Ethanol extract showed effective scavenging activity against DPPH and nitric oxide free radicals with an expressive amount of phenolic and moderate concentration of flavonoid contents. Ethyl gallate and gallic acid were found to be the probable bio-active compounds evidenced by GCMS and RP-UFLC-DAD analysis. CONCLUSION The study revealed the significant antimicrobial, wound healing and antioxidant activities of tender parts of C. mimosoides and proved the traditional folklore knowledge.