Papers by Ravindhran Ramalingam
Notulae Scientia Biologicae, Aug 1, 2013
Orthosiphon aristatus is a valuable medicinal plant and different parts of the plant are pharmace... more Orthosiphon aristatus is a valuable medicinal plant and different parts of the plant are pharmaceutically used for the treatment of various diseases. The present study was designed to develop an efficient protocol for micropropagation of O. aristatus from nodal explants and to study the influence of additives on the enhancement of the number of shoots per explant. Among the different types of additives used, 10% coconut water and 30 mg/L glutamine added to Murashige and Skoog's (MS) medium supplemented with 1.0 mg/L 6-benzyl amino purine (BAP) and 0.5 mg/L kinetin (KIN) was found to be most effective. Maximum number of shoots (44.07 ± 0.38) with 100% shooting response and shoot length of 7.47 ± 0.10 cm was recorded. In vitro rooting of the microshoots was achieved on halfstrength MS medium containing 0.5 mg/L indole-3-butyric acid (IBA), producing an average of 30.27 ± 0.36 roots and 6.02 ± 0.20 cm root length. The rooted shoots were acclimatized with 100% survival rate on coco pith: soil (3:1) planting substrate and was successfully transferred to field conditions. The hardened plants exhibited homogeneity and no morphological variations were observed among the regenerants and the mother plants. Thus, the procedure described is a quick and reliable method which could be applied for efficient large-scale propagation, genetic transformation assays and secondary metabolite production.
Asian Journal of Biological Sciences, 2019
ABSTRACT The present study was focused to screen the antimicrobial activity of hexane, ethyl acet... more ABSTRACT The present study was focused to screen the antimicrobial activity of hexane, ethyl acetate and methanol extracts from the roots of Ecbolium viride (Forssk.) Alston. The extracts were treated against nineteen bacterial and twelve fungal species using disc diffusion method followed by determination of minimum inhibitory concentration (MIC) by broth dilution method. The results of the study revealed that ethyl acetate extract possesses higher degree of antimicrobial activity than other extracts. The highest antibacterial activity (MIC-0.039 mg/ml) was exhibited against Staphylococcus aureus (ATCC 25923), while the highest antifungal activity (MIC-0.25 mg/ml) was exhibited against Malassezia pachydermatis. Thus the ethyl acetate extract showing significant antibacterial and moderate antifungal activity could be used in the treatment of infectious diseases.
Acta Physiologiae Plantarum
Biosciences Biotechnology Research Asia
South African Journal of Botany, 2015
Talinum triangulare is a medicinal herb known to have originated from tropical Africa and is now ... more Talinum triangulare is a medicinal herb known to have originated from tropical Africa and is now widely cultivated in the humid tropical countries. The characterization of plant germplasm using molecular descriptors aids in describing the genotypic traits of the plant T. triangulare. Ten different accessions of T. triangulare were collected from nine districts of Tamil Nadu. High quality genomic DNA was isolated from the different samples, checked for purity and quantified. The DNA samples were subjected to PCR amplification using RAPD markers and by DNA barcoding technique. RAPD fingerprints were generated for the 10 different accessions of T. triangulare for the first time. Ten random decamer primers resulted in 73.08% of polymorphism by producing a total of 78 fragments, of which, 57 bands were determined as polymorphic loci. Phylogenetic relationship and intra-specific variation among the samples were established by constructing a dendrogram based on Jaccard's coefficient. DNA barcoding studies included the amplification of chloroplast large subunit of ribulosebisphosphate carboxylase (rbcL), trnH-psbA intergenic spacer (trnH-psbA), maturase K (matK) and nuclear internal transcribed spacer (ITS). The amplicons were gel eluted, sequenced and checked for homology by using the BLAST tool. However, no variation was detected among the samples after sequencing, proving that the accessions were identical at the genetic level.
American Journal of Plant Sciences, 2014
The present study was designed to develop an efficient protocol for micro propagation of S. rebau... more The present study was designed to develop an efficient protocol for micro propagation of S. rebaudiana from nodal explants and study the influence of additives on enhancement of shoot proliferation. A two-step protocol has been standardized in which, first step comprising growth hormones concentration is optimized and it was found that MS medium supplemented with 2.0 mg/l BAP + 0.5 mg/l Kin + 0.1 mg/l NAA turned out to be the best treatment for shoot induction. In the second step, the best treatment for shoot induction was fortified with different growth additives for further shoot proliferation. Among the different types of additives used, casein hydrolysate at 0.05% (w/v) was found to be most effective, resulted with maximum of 15.0 shoots. 90% regeneration frequency and shoot length of 6.0 cm were recorded per explant. Thus, the procedure described is a quick and reliable method which could be applied for efficient large scale propagation, genetic transformation assays and secondary metabolite production of Stevia.
Plant Growth Regulation, 2013
ABSTRACT Talinum triangulare is an important medicinal herb used traditionally in the treatment o... more ABSTRACT Talinum triangulare is an important medicinal herb used traditionally in the treatment of various diseases. The present study was intended to develop a rapid and efficient protocol for indirect organogenesis from leaf discs and transverse thin cell layer (tTCL) of internodal explants of T. triangulare. Best callusing response (100 %) was observed with tTCL explants on Murashige and Skoog (MS) medium supplemented with 4.44 μM 6-benzyl amino purine and 5.37 μM α-naphthalene acetic acid (NAA). High frequency shoot regeneration (96.67 %) was obtained from tTCL derived calli on MS medium supplemented with a combination of 0.45 μM thidiazuron and 0.27 μM NAA, by producing 9.20 ± 0.35 shoots with a shoot length of 2.74 ± 0.03 cm. In vitro rooting of the microshoots was recorded on half-strength MS medium containing 2.46 μM indole-3-butyric acid by eliciting 15.20 ± 0.27 roots with a length of 4.25 ± 0.11 cm. The rooted shoots were acclimatized on garden soil, sand and coco pith (1:1:3 v/v) planting substrate. The plantlets were successfully established under field conditions with 100 % survival rate. The hardened plants exhibited homogeneity and no observable morphological variations were detected among the regenerants and the mother plants of T. triangulare.
Food Chemistry, 2013
Talinum triangulare (Jacq.) Willd is an erect, succulent, perennial herb belonging to the family ... more Talinum triangulare (Jacq.) Willd is an erect, succulent, perennial herb belonging to the family Portulacaceae. Under extreme environmental conditions, the plant produces betalain pigments which get accumulated in the stem region. Hence, in the present study, the betaxanthin and betacyanin patterns from different samples of T. triangulare have been investigated by applying high-performance liquid chromatography photo-diode array detection (HPLC-PDA) coupled with positive ion electro-spray mass spectrometry. Two betacyanins and two betaxanthins were identified in aqueous methanolic extract of flower, stem and leaf. Betanin, isobetanin, immonium conjugates of betalamic acid with dopamine and tyrosine were elucidated. The total betalain content was estimated by photometric analysis. In vitro antioxidant activity for the betalain extract determined by various methods revealed potent scavenging ability. The current work may possibly be considered beneficial in utilisation of the plant T. triangulare as a natural colourant in food and beverage industries.
Acta Physiologiae Plantarum, 2012
ABSTRACT Talinum triangulare is a medicinally important herb and various parts of the plant are u... more ABSTRACT Talinum triangulare is a medicinally important herb and various parts of the plant are used pharmaceutically for the treatment of different diseases. In our study, a rapid and efficient protocol for micropropagation has been developed from shoot tip and nodal explants of T. triangulare. High shooting frequency (93.33 %) was achieved with shoot tip explants when cultured on Murashige and Skoog’s (MS) medium supplemented with 1.0 mg/L 6-benzyl amino purine (BAP) producing an average of 12.50 ± 0.23 shoots and 5.07 ± 0.02 cm shoot length per explant. A combination of 0.5 mg/L BAP and 0.5 mg/L kinetin was found to be more effective by producing 15.67 ± 0.25 shoots and 6.22 ± 0.02 cm shoot length per explant. The microshoots were excised and cultured on half-strength MS and full-strength MS medium containing different concentrations of indole-3-acetic acid and indole-3-butyric acid (IBA) for root induction. More number of roots (45.10 ± 0.96) with an average length of 5.46 ± 0.08 cm was obtained on half-strength MS medium supplemented with 0.5 mg/L IBA. The rooted shoots were successfully transplanted from different planting substrates to the field with a 100 % survival rate. Random amplified polymorphic DNA analysis was carried out using four random decamer primers. The amplification products were monomorphic in the micropropagated plants and were similar to the mother plant. Absence of polymorphism revealed that no variation was induced, thus maintaining the genetic integrity of the micropropagated plants of T. triangulare.
Encyclopedia of Food Security and Sustainability, 2019
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Papers by Ravindhran Ramalingam