Pramod Tandon - Academia.edu (original) (raw)

Papers by Pramod Tandon

Journal of Agricultural Science and Technology, Dec 1, 2013

Dendrobium chrysanthum (Orchidaceae) is highly valued in the ornamental industry and has importan... more Dendrobium chrysanthum (Orchidaceae) is highly valued in the ornamental industry and has important medicinal properties used in the preparation of herbal medicines in different parts of the world. However, this orchid species is getting depleted from its natural habitats due to unsystematic collections. Therefore, in the present study, an efficient mass propagation protocol through direct shoot bud formation from axenic nodal segments of D. chrysanthum has been developed. The synergistic action between thidiazuron (TDZ) and 6-benzyl amino purine (BAP) was applied to enhance proliferation and elongation of shoots from the nodal segments. The explants were inoculated in MS medium fortified with different plant growth regulators viz., 2, 4-dichlorophenoxy acetic acid (2, 4-D), BAP, and TDZ, separately and in combinations. The maximum frequency of explants forming buds (100%), highest number of shoots/explant (14.33±0.14), the bud forming capacity (BFC) index of 14.33, and the maximum length of shoots (1.97±0.04) were obtained in MS medium supplemented with 5 µM each of TDZ and BAP. Hundred percent rooting of regenerated shoots with an average number of 11.26 roots/shoot and having average root length of around 2.45 cm was obtained in MS medium fortified with 10 µM α α α α-naphthaleneacetic acid (NAA). Sixty days after transfer to the greenhouse following in vitro acclimatization for 30 days, 79% survival was recorded. The protocol developed will not only help to alleviate the pressure on the natural population under stress, but will also help in meeting its demands in pharmaceutical and ornamental industries, and also form the basis for conservation.

Nepenthes khasiana Hook f., is the only representative member of the genus Nepenthes found in Ind... more Nepenthes khasiana Hook f., is the only representative member of the genus Nepenthes found in India. The species has great ethnomedicinal importance in addition to its ornamental value. It is used for treatment of several diseases by the local people of Meghalaya. The plant is also characterized by synthesis of bioactive compound called naphthoquinones which is a potent antifungal agent. However, it has become threatened in its natural habitat due to several anthropogenic activities. N. khasiana has been included in the Appendix-I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). The potential for long term survival of this species in the wild is uncertain, but will surely depend upon the continuing efforts of the local communities to preserve its habitats. The present review highlights the significance of the species and also elucidates the recent findings on the species on various aspects.

Tropical Plant Biology, Jul 18, 2016

Carnivorous plants are among the curiosities of nature being different from the normal plants in ... more Carnivorous plants are among the curiosities of nature being different from the normal plants in their mode of nutrition. These plants have fascinated several researchers for centuries. They are also characterized by synthesis of bioactive compounds which are used as a mechanism for self defense. These compounds possess a broad spectrum of biological activities such as antiparasitic, antibacterial, insecticidal, fungicidal, anti-inflammatory, antipyretic, antiproliferative activities. Although, several antimicrobial drugs have been introduced during the recent decades, the problems of microbial infections resistant to synthetic pesticides still exist which necessitate the introduction of novel antimicrobial agents with additional modes of actions than the currently available therapeutic agents. Naphthoquinones are one of the most studied bioactive compounds which have been reported to inhibit the growth of proliferative cells and microbes. Efforts have been made to induce the biosynthesis of naphthoquinone in different species of carnivorous plants. It has been demonstrated that the accumulation of naphthoquinones in carnivorous plants was increased by injecting chitin into the plant tissues. Also, their biosynthesis could be enhanced by the incorporation of elicitors in in vitro cultures of plants. In the present review, we discuss the applications of naphthoquinones and its biosynthesis in carnivorous plants.

F1000Research, Aug 14, 2017

Botanical carnivory is spread across four major angiosperm Background: lineages and five orders: ... more Botanical carnivory is spread across four major angiosperm Background: lineages and five orders: Poales, Caryophyllales, Oxalidales, Ericales and Lamiales. The carnivorous plant family Droseraceae is well known for its wide range of representatives in the temperate zone. Taxonomically, it is regarded as one of the most problematic and unresolved carnivorous plant families. In the present study, the phylogenetic position and biogeographic analysis of the genus is revisited by taking two species from the Drosera genus (and) found in Meghalaya (Northeast Drosera D. burmanii D. Peltata India). The purposes of this study were to investigate the monophyly, Methods: reconstruct phylogenetic relationships and ancestral area of the genus , and to infer its origin and dispersal using molecular markers from Drosera the whole ITS (18S, 28S, ITS1, ITS2) region and ribulose bisphosphate carboxylase (rbcL) sequences. The present study recovered most of the findings by previous Results: studies. The basal position of Droseraceae within the non-carnivorous Caryophyllales indicated in the tree topologies and fossil findings strongly support a date of origin for Droseraceae during the Paleocene (55-65 mya). Within the family Droseraceae, the sister relationship between Aldrovanda and is supported by our ITS and rbcL dataset. This information can Dionaea be used for further comparative and experimental studies. species are best suited as model systems for Conclusions: Drosera addressing a wide array of questions concerning evolutionary dynamics and ecological processes governing botanical carnivory.

Scientia Horticulturae, Dec 1, 2013

An in vitro plantlet regeneration system has been developed from cotyledon segments of Capsicum c... more An in vitro plantlet regeneration system has been developed from cotyledon segments of Capsicum chinense Jacq. cv. Naga King Chili, a very pungent chili species of India. Rosette-like structures (RLS) were induced on the explants which on transfer to medium containing indole-3-acetic acid (IAA) resulted in multiple shoots in course of time. Agar-based Murashige and Skoog (MS) medium fortified with 18.16 M thidiazuron (TDZ) was found to be the most suitable medium for RLS induction and shoot formation. Maximum number of multiple shoots (9.5 ± 0.39) and roots (8.6 ± 0.50), and root length (2.4 ± 0.02 cm) were obtained from rosette-like structures in medium containing 5.70 M IAA. Combined effect of putrescine (Put) (5.6 M) and TDZ (4.54 M) mediated direct multiple shoot (5.8 ± 0.44) induction. The in vitro rooted plantlets were transferred to glass house for hardening and acclimatization, wherein 90% survival was recorded. The hardened plantlets, thus developed were established in soil and bore normal fruits after 4 months of transfer. The capsaicin content in matured fruits of in vitro propagated plants was found to be 0.05236 g/g d wt (837,760 Scoville Heat Units, SHU), where as in vivo raised plantlets yielded 0.0545 g/g d wt (872,000 SHU) respectively.

Gene, Sep 1, 2011

A total of 53 primers belonging to three SPAR methods, viz. RAPD, ISSR and DAMD, collectively pro... more A total of 53 primers belonging to three SPAR methods, viz. RAPD, ISSR and DAMD, collectively produced 456 polymorphic amplicons with 96.6% polymorphism at inter-specific level in five species of Cymbidium, viz. C. aloifolium, C. mastersii, C. elegans, C. eburneum and C. tigrinum, whereas at intra-specific level, the observed polymorphism ranged from 51.2% to 77.1% among them. Three SPARs collectively revealed 25 unique species-specific amplicons; most of them were amplified with RAPD and DAMD primers besides few bands which were either missed (absent) or lost (heterozygosity). UPGMA clustering evidently distinguished the representatives of C. aloifolium and C. tigrinum, with distinct genetic distance, which may be due to their entirely different habitats as well as discrete morphological characteristics. Upon analysis of the data generated, all the three SPAR methods, either independently and/or in combination, revealed wide range of genetic variation between and within five species of Cymbidium. Comparison of matrix of individual SPAR method revealed that analysis of natural genetic variation using combination of SPAR methods, rather than an isolated approach, is highly effective. The critical analyses of the amplicon data are indicative of DAMD as the most powerful SPAR method by showing highest resolving power (Rp) followed by ISSR and RAPD. Alternatively, the total polymorphic information content was highest in case of RAPD followed by other two SPAR methods. Thus, the present investigation for the first time provides a valuable baseline data for genetic variation at inter- and intra-specific levels in horticultural Cymbidiums and also addresses conservation concerns.

Proc Indian Nam Sci Acad 74 No.4 pp. 167-171 (2008) 167 ft Research Paper Optimization of Nutrien... more Proc Indian Nam Sci Acad 74 No.4 pp. 167-171 (2008) 167 ft Research Paper Optimization of Nutrient Requirements for Asymbiotic Seed Germination of Dendrobium longicornu Lindi, and D. formosura Roxb. STADWELSON DOHL1NG. SUMAN KUMARIA* and PRAMOD ...

Indian Journal of Traditional Knowledge, 2009

The Northeast India region is rich in biodiversity due to high rainfall and plenty of sunlight co... more The Northeast India region is rich in biodiversity due to high rainfall and plenty of sunlight coupled with unique biogeographical positioning. It is known as the 'Cradle of Flowering Plants' because of remarkably rich and diverse flora. The valuable plant genetic resources of the region are being lost at an alarming rate due to varied human activities including shifting cultivation which have in turn led to the depletion of forest cover. Therefore, there is an urgent need for conservation, sustainable utilization and management of plant genetic resources of the region so as to meet the growing requirements of food, fodder, fibre, health, water and other needs.

The present paper describes the germination of mature embryo (~seed), seedling development, and i... more The present paper describes the germination of mature embryo (~seed), seedling development, and in vitro shoot induction and plant regeneration from pseudonode explants of an endangered ornamental orchid, Thunia marshalliana Rcbh. f. The observations on efficacy of nutrient medium composition on in vitro embryo germination and early seedling development demonstrated that nitrogen in any form induced germination and the presence of both organic and inorganic nitrogen into the medium enhanced both germination and seedling development. The modified MS medium having 10% coconut water was found to be the best for germination. Addition of cytokinin did not favour protocorm formation and seedling development. However, multiple shoots were induced directly from the pseudonode explants cultured on MS medium containing different concentrations of 6-benzyl amino purine (BAP) and kinetin (Kn). Amongst the two cytokinins (BAP & Kn) tested, BAP was more effective for direct shoot induction from t...

South African Journal of Botany, 2022

International Journal of Current Microbiology and Applied Sciences, 2019

Physiology and Molecular Biology of Plants, 2017

Malaxis wallichii (Lindl.) Deb, a small, perennial, monopodial, terrestrial orchid, is endemic to... more Malaxis wallichii (Lindl.) Deb, a small, perennial, monopodial, terrestrial orchid, is endemic to tropical Himalayas at an altitude of 1200-2000 m asl. The pseudobulbs are important ingredients of century old drug 'Ashtavarga' and a polyherbal energetic tonic 'Chyavanprash'. An efficient genetically stable in vitro propagation protocol using transverse thin cell layer culture system was established for M. wallichii. In the present report, metatopolin alone proved to be three times more beneficial compared to other routinely used cytokinins in inducing highest number of shoot buds, plant height and growth of regenerated shoots. The highest regeneration frequency (89%) along with maximum number of adventitious shoots per explant (22.5 ± 0.6) was observed in MS medium supplemented with 1.0 mg/l meta-topolin and 0.5 mg/l anaphthalene acetic acid. Highest rooting frequency with highest number of roots (8.66 ± 0.3) was achieved in halfstrength MS medium fortified with 1.0 mg/l indole acetic acid. Clonal stability of in vitro-derived plantlets was evaluated and compared to donor plant using intron splice junction (ISJ) markers and flow cytometry. ISJ markers revealed 4.76% clonal variability indicating high degree of genetic stability amongst the in vitro-derived regenerants. The nuclear DNA content of M. wallichii (2n) was found to be 2C = 2.760 ± 0.02 pg and therefore, 1349.64 Mbp (1C). Flow cytometry analysis of actively growing young and mature leaves from donor as well as in vitro-derived plantlets revealed presence of three peaks corresponding to 2C, 4C and 8C, while 2C was the most abundant. In the present investigation, there was no significant difference in the 2C DNA content between the mother and in vitroderived plants; however, the frequency of endopolyploid cells varied in young and adult plants. An increased H 2 O 2 content as well as lipid peroxidation activities were observed during early stages of acclimatization which declined afterwards. The enhanced activities of antioxidant enzymes like superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase in acclimatized plantlets as compared to in vitro-grown ones revealed their active involvement in growth and development against oxidative stress under external adverse environment.

Genome Announcements, 2016

The orchid species Dendrobium nobile belonging to the family Orchidaceae and genus Dendrobium (a ... more The orchid species Dendrobium nobile belonging to the family Orchidaceae and genus Dendrobium (a vast genus that encompasses nearly 1,200 species) has an herbal medicinal history of about 2000 years in east and south Asian countries. Here, we report the complete chloroplast genome sequence of D. nobile from northeastern India for the first time.

South African Journal of Botany, 2016

Low rates of shoot multiplication, clonal instability, poor rooting frequency and high cost of pr... more Low rates of shoot multiplication, clonal instability, poor rooting frequency and high cost of production are major impediments challenging the micropropagation of orchids and other ornamental plants. These problems can be solved with the proper usage of plant growth regulators (PGRs) in the medium. The highest shoot proliferation rate of 21 shoots/explant was recorded in Murashige and Skoog (MS) medium containing 1 mg/l meta-topolin and 0.8 mg/l Putrescine. To date, this is the best frequency of shoot induction for Dendrobium nobile and one of the highest among other orchids. Higher rooting frequency was also recorded with the highest rooting of 10.1 roots/shoot achieved in plants grown in half strength MS media supplemented with 2 mg/l of indole butyric acid and 0.5 mg/l of phloroglucinol. The plantlets were successfully acclimatized in the greenhouse with a survival rate of 82.3% exhibiting normal developmental patterns. The regenerated plantlets were assessed for genetic stability using the molecular markers namely SCoT and IRAP revealing high degree of genetic stability within the micropropagated plants of D. nobile. Being a highly medicinal orchid, the antioxidant potentials of the mother and the micropropagated plants were assessed using DPPH, FRAP and metal chelating assays which revealed a significantly higher antioxidant activity in the micropropagated plants. Rapid multiplication rate, higher genetic stability and significantly higher antioxidant power reported in the present study on D. nobile ensure the use of this micropropagation protocol for ex-situ conservation and commercial exploitation which could also be extended to other important orchid species.

Plant Cell, Tissue and Organ Culture (PCTOC), 2015

Nardostachys jatamansi (D. Don) DC., a small, perennial, rhizomatous herb of immense medicinal im... more Nardostachys jatamansi (D. Don) DC., a small, perennial, rhizomatous herb of immense medicinal importance since ancient times, is restricted to specialized habitats of alpine Himalayas ranging from 3000 to 5200 m asl. The species has been recently listed as critically endangered under IUCN Red list of threatened species due to over exploitation of its rhizomes for medicinal uses, habitat degradation, trade and other biotic and anthropogenic interferences. An efficient protocol using both indirect and direct shoot organogenesis has been optimized for N. jatamansi. Best callusing was achieved from the cut ends of leaf and petiole explants within 15 days of culture in MS medium supplemented with 1.5 mg/l α-naphthalene acetic acid and 1.0 mg/l meta-Topolin. Culturing the explants at low temperature (13 ± 1 °C) resulted in better callus growth, shoot regeneration, hyperhydricity control and improvement in photosynthetic pigment content in regenerated shoots. Also, direct organogenesis from shoot tip and petiole explants was achieved in MS medium containing 1.0 mg/l meta-Topolin. Optimum rooting was achieved in the same medium supplemented with 1.0 mg/l indole acetic acid wherein averages of 4.52 roots/shoot were induced. Genetic stability of in vitro-derived plantlets was assessed and compared to mother plant using molecular markers and flow cytometry. Intron Splice Junction (ISJ) and Start Codon Targeted polymorphism (SCoT) marker based profiling revealed uniform banding profile in case of direct shoot organogenesis (DSO)-derived plants while callus mediated organogenesis (CMO)-derived plants showed slight variations as compared to mother plant. The genome size of N. jatamansi was found to be 2C = 1.40 ± 0.01 pg and therefore 684.6 Mbp (1C). Although organogenic calli showed mixoploidy but no major phenotypic and genetic rearrangements were detected by flow cytometry in callus-derived plants. Significantly higher antioxidant activity was observed in callus-derived plants as compared to mother and DSO-derived plants. Plant parts, regeneration pathways and various solvent systems greatly affected the yields of total phenolics, flavonoids, alkaloids, tannins contents present in the in vitro raised plantlets.

Cryo letters

The present investigation was aimed at developing a protocol for long-term preservation of germpl... more The present investigation was aimed at developing a protocol for long-term preservation of germplasm of Pinus kesiya Royle ex. Gord. through vitrification. Some of the critical components affecting explant tolerance to cryopreservation, such as effects of preculture, vitrification solutions, exposure time to vitrification solutions, volume of vitrification solution and its toxicity, washing of vitrified tissues after thawing, were analysed. The results showed that shoot regrowth of P. kesiya shoot-tips was considerably affected when exposed to cryoprotectants for longer periods of time (longer than 10 min). Among different vitrification solutions studied, maximum survival (76 percent) of shoot-tips was achieved with mVSL (using 0.6 ml of the solution) in MS basal medium containing 4.0 mg l-1 N6-benzyladenine (BA).

South African Journal of Botany, 2017

The present scenario of urbanization and commercialization has adversely affected orchid's popula... more The present scenario of urbanization and commercialization has adversely affected orchid's population; as a consequence they are diminishing from the nature very rapidly. Paphiopedilum insigne (lady's slipper orchid) is one such orchid of horticultural importance. Apart from being listed as endangered in IUCN red data list; it finds a place in Appendix I of CITES in the global platform. In the present study, capsules b180 days after pollination (DAP) were found to be immature and 180 DAP was found optimal for seed germination. Capsules N 240 DAP were found to have mature seeds that were treated prior to germination and TTC tested for viability. Seeds derived from 180 DAP capsules showed the highest germination of 88.5% in modified Burgeff medium (BG1) with initiation in 26 days. Incorporation of plant growth regulators like 5 μM kinetin (KN) + 10 μM indole-3acetic acid (IAA) in 1/2 MS medium influenced the stage-wise development of the seedlings in a short duration. Mature seeds stored at −196°C for 360 days followed by pre-treatment with 3% NaOCl showed viability of 70.5% and recorded germination of 79.2%. Sixty-nine percent of the plantlets were successfully hardened and acclimatized in the green house.

South African Journal of Botany, 2017

Orchids have been used traditionally in various herbal preparations of which Dendrobium thyrsiflo... more Orchids have been used traditionally in various herbal preparations of which Dendrobium thyrsiflorum deserves special mention. However, in spite of being such an important medicinal plant taxa, information on the genetic diversity of the orchids is limited. In order to establish an association with antioxidant activity of D. thyrsiflorum, five geographically distinct populations of D. thyrsiflorum were analyzed. Total phenolics, flavonoids and alkaloid contents along with antioxidant activity measured by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays revealed a significant level of variability across populations. Higher phytochemical activity was recorded in the representatives from Sikkim as compared to those from Mizoram. The genetic information obtained from fifty genotypes sampled from five natural populations using nine AFLP markers exhibited a total of 1207 scorable peaks of which 1188 peaks were polymorphic with high genetic diversity [percentage polymorphic bands (PPB)-98.50%; Shannon's index (I)-0.42 and Nei's Gene Diversity index (h) = 0.28]. Analysis of Molecular Variance (AMOVA) revealed that variation amongst the populations was significantly higher than within the populations. Both UPGMA and STRUCTURE analyses were employed to estimate the genetic relationships of D. thyrsiflorum germplasm. Interestingly, both methods revealed similar grouping patterns. Further, statistical analysis of molecular data revealed that four out of these nine AFLP markers tested were found to be correlated with the antioxidant activity measured by DPPH assay. With no available genetic information like linkage maps and Quantative trait loci (QTL) available, the present research finding can be utilized for conservation strategy formulation of this important medicinal orchid with high antioxidant activity.

Indian Journal of Experimental Biology, 1993

Journal of Agricultural Science and Technology, Dec 1, 2013

Dendrobium chrysanthum (Orchidaceae) is highly valued in the ornamental industry and has importan... more Dendrobium chrysanthum (Orchidaceae) is highly valued in the ornamental industry and has important medicinal properties used in the preparation of herbal medicines in different parts of the world. However, this orchid species is getting depleted from its natural habitats due to unsystematic collections. Therefore, in the present study, an efficient mass propagation protocol through direct shoot bud formation from axenic nodal segments of D. chrysanthum has been developed. The synergistic action between thidiazuron (TDZ) and 6-benzyl amino purine (BAP) was applied to enhance proliferation and elongation of shoots from the nodal segments. The explants were inoculated in MS medium fortified with different plant growth regulators viz., 2, 4-dichlorophenoxy acetic acid (2, 4-D), BAP, and TDZ, separately and in combinations. The maximum frequency of explants forming buds (100%), highest number of shoots/explant (14.33±0.14), the bud forming capacity (BFC) index of 14.33, and the maximum length of shoots (1.97±0.04) were obtained in MS medium supplemented with 5 µM each of TDZ and BAP. Hundred percent rooting of regenerated shoots with an average number of 11.26 roots/shoot and having average root length of around 2.45 cm was obtained in MS medium fortified with 10 µM α α α α-naphthaleneacetic acid (NAA). Sixty days after transfer to the greenhouse following in vitro acclimatization for 30 days, 79% survival was recorded. The protocol developed will not only help to alleviate the pressure on the natural population under stress, but will also help in meeting its demands in pharmaceutical and ornamental industries, and also form the basis for conservation.

Nepenthes khasiana Hook f., is the only representative member of the genus Nepenthes found in Ind... more Nepenthes khasiana Hook f., is the only representative member of the genus Nepenthes found in India. The species has great ethnomedicinal importance in addition to its ornamental value. It is used for treatment of several diseases by the local people of Meghalaya. The plant is also characterized by synthesis of bioactive compound called naphthoquinones which is a potent antifungal agent. However, it has become threatened in its natural habitat due to several anthropogenic activities. N. khasiana has been included in the Appendix-I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). The potential for long term survival of this species in the wild is uncertain, but will surely depend upon the continuing efforts of the local communities to preserve its habitats. The present review highlights the significance of the species and also elucidates the recent findings on the species on various aspects.

Tropical Plant Biology, Jul 18, 2016

Carnivorous plants are among the curiosities of nature being different from the normal plants in ... more Carnivorous plants are among the curiosities of nature being different from the normal plants in their mode of nutrition. These plants have fascinated several researchers for centuries. They are also characterized by synthesis of bioactive compounds which are used as a mechanism for self defense. These compounds possess a broad spectrum of biological activities such as antiparasitic, antibacterial, insecticidal, fungicidal, anti-inflammatory, antipyretic, antiproliferative activities. Although, several antimicrobial drugs have been introduced during the recent decades, the problems of microbial infections resistant to synthetic pesticides still exist which necessitate the introduction of novel antimicrobial agents with additional modes of actions than the currently available therapeutic agents. Naphthoquinones are one of the most studied bioactive compounds which have been reported to inhibit the growth of proliferative cells and microbes. Efforts have been made to induce the biosynthesis of naphthoquinone in different species of carnivorous plants. It has been demonstrated that the accumulation of naphthoquinones in carnivorous plants was increased by injecting chitin into the plant tissues. Also, their biosynthesis could be enhanced by the incorporation of elicitors in in vitro cultures of plants. In the present review, we discuss the applications of naphthoquinones and its biosynthesis in carnivorous plants.

F1000Research, Aug 14, 2017

Botanical carnivory is spread across four major angiosperm Background: lineages and five orders: ... more Botanical carnivory is spread across four major angiosperm Background: lineages and five orders: Poales, Caryophyllales, Oxalidales, Ericales and Lamiales. The carnivorous plant family Droseraceae is well known for its wide range of representatives in the temperate zone. Taxonomically, it is regarded as one of the most problematic and unresolved carnivorous plant families. In the present study, the phylogenetic position and biogeographic analysis of the genus is revisited by taking two species from the Drosera genus (and) found in Meghalaya (Northeast Drosera D. burmanii D. Peltata India). The purposes of this study were to investigate the monophyly, Methods: reconstruct phylogenetic relationships and ancestral area of the genus , and to infer its origin and dispersal using molecular markers from Drosera the whole ITS (18S, 28S, ITS1, ITS2) region and ribulose bisphosphate carboxylase (rbcL) sequences. The present study recovered most of the findings by previous Results: studies. The basal position of Droseraceae within the non-carnivorous Caryophyllales indicated in the tree topologies and fossil findings strongly support a date of origin for Droseraceae during the Paleocene (55-65 mya). Within the family Droseraceae, the sister relationship between Aldrovanda and is supported by our ITS and rbcL dataset. This information can Dionaea be used for further comparative and experimental studies. species are best suited as model systems for Conclusions: Drosera addressing a wide array of questions concerning evolutionary dynamics and ecological processes governing botanical carnivory.

Scientia Horticulturae, Dec 1, 2013

An in vitro plantlet regeneration system has been developed from cotyledon segments of Capsicum c... more An in vitro plantlet regeneration system has been developed from cotyledon segments of Capsicum chinense Jacq. cv. Naga King Chili, a very pungent chili species of India. Rosette-like structures (RLS) were induced on the explants which on transfer to medium containing indole-3-acetic acid (IAA) resulted in multiple shoots in course of time. Agar-based Murashige and Skoog (MS) medium fortified with 18.16 M thidiazuron (TDZ) was found to be the most suitable medium for RLS induction and shoot formation. Maximum number of multiple shoots (9.5 ± 0.39) and roots (8.6 ± 0.50), and root length (2.4 ± 0.02 cm) were obtained from rosette-like structures in medium containing 5.70 M IAA. Combined effect of putrescine (Put) (5.6 M) and TDZ (4.54 M) mediated direct multiple shoot (5.8 ± 0.44) induction. The in vitro rooted plantlets were transferred to glass house for hardening and acclimatization, wherein 90% survival was recorded. The hardened plantlets, thus developed were established in soil and bore normal fruits after 4 months of transfer. The capsaicin content in matured fruits of in vitro propagated plants was found to be 0.05236 g/g d wt (837,760 Scoville Heat Units, SHU), where as in vivo raised plantlets yielded 0.0545 g/g d wt (872,000 SHU) respectively.

Gene, Sep 1, 2011

A total of 53 primers belonging to three SPAR methods, viz. RAPD, ISSR and DAMD, collectively pro... more A total of 53 primers belonging to three SPAR methods, viz. RAPD, ISSR and DAMD, collectively produced 456 polymorphic amplicons with 96.6% polymorphism at inter-specific level in five species of Cymbidium, viz. C. aloifolium, C. mastersii, C. elegans, C. eburneum and C. tigrinum, whereas at intra-specific level, the observed polymorphism ranged from 51.2% to 77.1% among them. Three SPARs collectively revealed 25 unique species-specific amplicons; most of them were amplified with RAPD and DAMD primers besides few bands which were either missed (absent) or lost (heterozygosity). UPGMA clustering evidently distinguished the representatives of C. aloifolium and C. tigrinum, with distinct genetic distance, which may be due to their entirely different habitats as well as discrete morphological characteristics. Upon analysis of the data generated, all the three SPAR methods, either independently and/or in combination, revealed wide range of genetic variation between and within five species of Cymbidium. Comparison of matrix of individual SPAR method revealed that analysis of natural genetic variation using combination of SPAR methods, rather than an isolated approach, is highly effective. The critical analyses of the amplicon data are indicative of DAMD as the most powerful SPAR method by showing highest resolving power (Rp) followed by ISSR and RAPD. Alternatively, the total polymorphic information content was highest in case of RAPD followed by other two SPAR methods. Thus, the present investigation for the first time provides a valuable baseline data for genetic variation at inter- and intra-specific levels in horticultural Cymbidiums and also addresses conservation concerns.

Proc Indian Nam Sci Acad 74 No.4 pp. 167-171 (2008) 167 ft Research Paper Optimization of Nutrien... more Proc Indian Nam Sci Acad 74 No.4 pp. 167-171 (2008) 167 ft Research Paper Optimization of Nutrient Requirements for Asymbiotic Seed Germination of Dendrobium longicornu Lindi, and D. formosura Roxb. STADWELSON DOHL1NG. SUMAN KUMARIA* and PRAMOD ...

Indian Journal of Traditional Knowledge, 2009

The Northeast India region is rich in biodiversity due to high rainfall and plenty of sunlight co... more The Northeast India region is rich in biodiversity due to high rainfall and plenty of sunlight coupled with unique biogeographical positioning. It is known as the 'Cradle of Flowering Plants' because of remarkably rich and diverse flora. The valuable plant genetic resources of the region are being lost at an alarming rate due to varied human activities including shifting cultivation which have in turn led to the depletion of forest cover. Therefore, there is an urgent need for conservation, sustainable utilization and management of plant genetic resources of the region so as to meet the growing requirements of food, fodder, fibre, health, water and other needs.

The present paper describes the germination of mature embryo (~seed), seedling development, and i... more The present paper describes the germination of mature embryo (~seed), seedling development, and in vitro shoot induction and plant regeneration from pseudonode explants of an endangered ornamental orchid, Thunia marshalliana Rcbh. f. The observations on efficacy of nutrient medium composition on in vitro embryo germination and early seedling development demonstrated that nitrogen in any form induced germination and the presence of both organic and inorganic nitrogen into the medium enhanced both germination and seedling development. The modified MS medium having 10% coconut water was found to be the best for germination. Addition of cytokinin did not favour protocorm formation and seedling development. However, multiple shoots were induced directly from the pseudonode explants cultured on MS medium containing different concentrations of 6-benzyl amino purine (BAP) and kinetin (Kn). Amongst the two cytokinins (BAP & Kn) tested, BAP was more effective for direct shoot induction from t...

South African Journal of Botany, 2022

International Journal of Current Microbiology and Applied Sciences, 2019

Physiology and Molecular Biology of Plants, 2017

Malaxis wallichii (Lindl.) Deb, a small, perennial, monopodial, terrestrial orchid, is endemic to... more Malaxis wallichii (Lindl.) Deb, a small, perennial, monopodial, terrestrial orchid, is endemic to tropical Himalayas at an altitude of 1200-2000 m asl. The pseudobulbs are important ingredients of century old drug 'Ashtavarga' and a polyherbal energetic tonic 'Chyavanprash'. An efficient genetically stable in vitro propagation protocol using transverse thin cell layer culture system was established for M. wallichii. In the present report, metatopolin alone proved to be three times more beneficial compared to other routinely used cytokinins in inducing highest number of shoot buds, plant height and growth of regenerated shoots. The highest regeneration frequency (89%) along with maximum number of adventitious shoots per explant (22.5 ± 0.6) was observed in MS medium supplemented with 1.0 mg/l meta-topolin and 0.5 mg/l anaphthalene acetic acid. Highest rooting frequency with highest number of roots (8.66 ± 0.3) was achieved in halfstrength MS medium fortified with 1.0 mg/l indole acetic acid. Clonal stability of in vitro-derived plantlets was evaluated and compared to donor plant using intron splice junction (ISJ) markers and flow cytometry. ISJ markers revealed 4.76% clonal variability indicating high degree of genetic stability amongst the in vitro-derived regenerants. The nuclear DNA content of M. wallichii (2n) was found to be 2C = 2.760 ± 0.02 pg and therefore, 1349.64 Mbp (1C). Flow cytometry analysis of actively growing young and mature leaves from donor as well as in vitro-derived plantlets revealed presence of three peaks corresponding to 2C, 4C and 8C, while 2C was the most abundant. In the present investigation, there was no significant difference in the 2C DNA content between the mother and in vitroderived plants; however, the frequency of endopolyploid cells varied in young and adult plants. An increased H 2 O 2 content as well as lipid peroxidation activities were observed during early stages of acclimatization which declined afterwards. The enhanced activities of antioxidant enzymes like superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase in acclimatized plantlets as compared to in vitro-grown ones revealed their active involvement in growth and development against oxidative stress under external adverse environment.

Genome Announcements, 2016

The orchid species Dendrobium nobile belonging to the family Orchidaceae and genus Dendrobium (a ... more The orchid species Dendrobium nobile belonging to the family Orchidaceae and genus Dendrobium (a vast genus that encompasses nearly 1,200 species) has an herbal medicinal history of about 2000 years in east and south Asian countries. Here, we report the complete chloroplast genome sequence of D. nobile from northeastern India for the first time.

South African Journal of Botany, 2016

Low rates of shoot multiplication, clonal instability, poor rooting frequency and high cost of pr... more Low rates of shoot multiplication, clonal instability, poor rooting frequency and high cost of production are major impediments challenging the micropropagation of orchids and other ornamental plants. These problems can be solved with the proper usage of plant growth regulators (PGRs) in the medium. The highest shoot proliferation rate of 21 shoots/explant was recorded in Murashige and Skoog (MS) medium containing 1 mg/l meta-topolin and 0.8 mg/l Putrescine. To date, this is the best frequency of shoot induction for Dendrobium nobile and one of the highest among other orchids. Higher rooting frequency was also recorded with the highest rooting of 10.1 roots/shoot achieved in plants grown in half strength MS media supplemented with 2 mg/l of indole butyric acid and 0.5 mg/l of phloroglucinol. The plantlets were successfully acclimatized in the greenhouse with a survival rate of 82.3% exhibiting normal developmental patterns. The regenerated plantlets were assessed for genetic stability using the molecular markers namely SCoT and IRAP revealing high degree of genetic stability within the micropropagated plants of D. nobile. Being a highly medicinal orchid, the antioxidant potentials of the mother and the micropropagated plants were assessed using DPPH, FRAP and metal chelating assays which revealed a significantly higher antioxidant activity in the micropropagated plants. Rapid multiplication rate, higher genetic stability and significantly higher antioxidant power reported in the present study on D. nobile ensure the use of this micropropagation protocol for ex-situ conservation and commercial exploitation which could also be extended to other important orchid species.

Plant Cell, Tissue and Organ Culture (PCTOC), 2015

Nardostachys jatamansi (D. Don) DC., a small, perennial, rhizomatous herb of immense medicinal im... more Nardostachys jatamansi (D. Don) DC., a small, perennial, rhizomatous herb of immense medicinal importance since ancient times, is restricted to specialized habitats of alpine Himalayas ranging from 3000 to 5200 m asl. The species has been recently listed as critically endangered under IUCN Red list of threatened species due to over exploitation of its rhizomes for medicinal uses, habitat degradation, trade and other biotic and anthropogenic interferences. An efficient protocol using both indirect and direct shoot organogenesis has been optimized for N. jatamansi. Best callusing was achieved from the cut ends of leaf and petiole explants within 15 days of culture in MS medium supplemented with 1.5 mg/l α-naphthalene acetic acid and 1.0 mg/l meta-Topolin. Culturing the explants at low temperature (13 ± 1 °C) resulted in better callus growth, shoot regeneration, hyperhydricity control and improvement in photosynthetic pigment content in regenerated shoots. Also, direct organogenesis from shoot tip and petiole explants was achieved in MS medium containing 1.0 mg/l meta-Topolin. Optimum rooting was achieved in the same medium supplemented with 1.0 mg/l indole acetic acid wherein averages of 4.52 roots/shoot were induced. Genetic stability of in vitro-derived plantlets was assessed and compared to mother plant using molecular markers and flow cytometry. Intron Splice Junction (ISJ) and Start Codon Targeted polymorphism (SCoT) marker based profiling revealed uniform banding profile in case of direct shoot organogenesis (DSO)-derived plants while callus mediated organogenesis (CMO)-derived plants showed slight variations as compared to mother plant. The genome size of N. jatamansi was found to be 2C = 1.40 ± 0.01 pg and therefore 684.6 Mbp (1C). Although organogenic calli showed mixoploidy but no major phenotypic and genetic rearrangements were detected by flow cytometry in callus-derived plants. Significantly higher antioxidant activity was observed in callus-derived plants as compared to mother and DSO-derived plants. Plant parts, regeneration pathways and various solvent systems greatly affected the yields of total phenolics, flavonoids, alkaloids, tannins contents present in the in vitro raised plantlets.

Cryo letters

The present investigation was aimed at developing a protocol for long-term preservation of germpl... more The present investigation was aimed at developing a protocol for long-term preservation of germplasm of Pinus kesiya Royle ex. Gord. through vitrification. Some of the critical components affecting explant tolerance to cryopreservation, such as effects of preculture, vitrification solutions, exposure time to vitrification solutions, volume of vitrification solution and its toxicity, washing of vitrified tissues after thawing, were analysed. The results showed that shoot regrowth of P. kesiya shoot-tips was considerably affected when exposed to cryoprotectants for longer periods of time (longer than 10 min). Among different vitrification solutions studied, maximum survival (76 percent) of shoot-tips was achieved with mVSL (using 0.6 ml of the solution) in MS basal medium containing 4.0 mg l-1 N6-benzyladenine (BA).

South African Journal of Botany, 2017

The present scenario of urbanization and commercialization has adversely affected orchid's popula... more The present scenario of urbanization and commercialization has adversely affected orchid's population; as a consequence they are diminishing from the nature very rapidly. Paphiopedilum insigne (lady's slipper orchid) is one such orchid of horticultural importance. Apart from being listed as endangered in IUCN red data list; it finds a place in Appendix I of CITES in the global platform. In the present study, capsules b180 days after pollination (DAP) were found to be immature and 180 DAP was found optimal for seed germination. Capsules N 240 DAP were found to have mature seeds that were treated prior to germination and TTC tested for viability. Seeds derived from 180 DAP capsules showed the highest germination of 88.5% in modified Burgeff medium (BG1) with initiation in 26 days. Incorporation of plant growth regulators like 5 μM kinetin (KN) + 10 μM indole-3acetic acid (IAA) in 1/2 MS medium influenced the stage-wise development of the seedlings in a short duration. Mature seeds stored at −196°C for 360 days followed by pre-treatment with 3% NaOCl showed viability of 70.5% and recorded germination of 79.2%. Sixty-nine percent of the plantlets were successfully hardened and acclimatized in the green house.

South African Journal of Botany, 2017

Orchids have been used traditionally in various herbal preparations of which Dendrobium thyrsiflo... more Orchids have been used traditionally in various herbal preparations of which Dendrobium thyrsiflorum deserves special mention. However, in spite of being such an important medicinal plant taxa, information on the genetic diversity of the orchids is limited. In order to establish an association with antioxidant activity of D. thyrsiflorum, five geographically distinct populations of D. thyrsiflorum were analyzed. Total phenolics, flavonoids and alkaloid contents along with antioxidant activity measured by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays revealed a significant level of variability across populations. Higher phytochemical activity was recorded in the representatives from Sikkim as compared to those from Mizoram. The genetic information obtained from fifty genotypes sampled from five natural populations using nine AFLP markers exhibited a total of 1207 scorable peaks of which 1188 peaks were polymorphic with high genetic diversity [percentage polymorphic bands (PPB)-98.50%; Shannon's index (I)-0.42 and Nei's Gene Diversity index (h) = 0.28]. Analysis of Molecular Variance (AMOVA) revealed that variation amongst the populations was significantly higher than within the populations. Both UPGMA and STRUCTURE analyses were employed to estimate the genetic relationships of D. thyrsiflorum germplasm. Interestingly, both methods revealed similar grouping patterns. Further, statistical analysis of molecular data revealed that four out of these nine AFLP markers tested were found to be correlated with the antioxidant activity measured by DPPH assay. With no available genetic information like linkage maps and Quantative trait loci (QTL) available, the present research finding can be utilized for conservation strategy formulation of this important medicinal orchid with high antioxidant activity.

Indian Journal of Experimental Biology, 1993