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Different dilutions, that is, 25, 50, 75, and 100%, of tannery effluent (TE) were chosen for the present study to assess the phytotoxic effects on Vigna mungo L. For amelioration purposes, different levels and combinations of iron and zinc were supplied to the plants along with 50% TE that is chosen on the basis of prior test under Petri dish culture. Cytotoxic and biochemical analysis and plant tolerance index (PTI) of plant were observed. Mitotic index deceased with increase in effluent concentration whereas abnormality % was increased. The pigments (chlorophyll a, total, and carotenoids) were decreased with increasing treatment levels of TE at both growth stages. However, carotenoid content increased significantly at all dilution levels of TE after first growth stage. Chlorophyll b was increased significantly after 35 days of growth but decreased after 70 days. Theprotein contentswere also significantly decreased with increase in all TE treatments and increased significantly in zinc recovery treatments. Activities of catalase and peroxidase enzymeswere significantly affected and increased significantly with effluent treatments. PTI showed an enhanced tolerance capacity of plant with treatment of iron and zinc. A negative correlation was found (r = -0.97) between plant height and different dilutions of effluent whereas it was positively correlated (r = 0.95) with iron and zinc treatments. The study represents the ameliorative effect of iron and zinc for phytotoxic damage in V. mungo caused by tannery effluent. [ABSTRACT FROM AUTHOR]

Establishment of symbiotic association at the appropriate developmental stage helped maintain continued growth which is vital for the long-term ex vitro survival of the orchid. In the present study, symbiotic association was carried out using different developmental stages of Dendrobium chrysanthum and pathogenic Rhizoctonia isolates (obtained from orchids and non-orchid hosts) in different culture media. Isolate 2162 supported highest symbiotic germination on OMA-S (oat meal agar medium without nutrients + sucrose), whereas, stable symbiotic association with plantlets was obtained with isolate 4634 on OMA-NC (oat meal agar medium + cellulose). Isolate Dc-2S2 obtained from the host plant did not promote seed germination nor did it form association with protocorms or plantlets. This study, for the first time identifies a combination of compatible fungal isolate, suitable culture medium, and appropriate developmental stage at which symbiotic association in vitro can be deemed successful for the medicinally important orchid, D. chrysanthum. [ABSTRACT FROM AUTHOR]

A comprehensive reassessment of IndianNymphaea(Nymphaeaceae) based on morphology, RAPD and nucleotide sequence data of the ITS,trnKintron,matKandrbcLgene was conducted. Although considerable morphological variations have been reported, pollen colour and rhizome shape are two characters which have not been mentioned in previous studies. The transformation from yellow to white coloured pollen may have evolved independently and is probably associated with a strong selective pressure acted upon by the animal pollinators on white pollen ofN. pubescensandN. rubra. Rhizome shape could easily discriminate among subgenera; the difference in shape (triangular, globular and cylindrical) probably highlights the success in their distribution. Our studies using RAPD revealed high genetic variability among individuals ofN. caerulea. This may be attributed to the breeding system followed, which could be an outcrossing species. But the lack of genetic diversity inN. tetragonais probably due to founder events, whereby a solitary founder individual from China could have resulted in the establishment of this single population of ∼25–30 individuals with no detectable variations. Molecular cloning of the ITS region ofN. rubra, necessitated by the presence of additional signals in the sequencing chromatogram, confirmed the origin of this plant taxon through hybridization involvingN. lotusandN. pubescensas the parental species. [ABSTRACT FROM AUTHOR]

Understanding the genetic resources and diversity is very important for the breeding programs and improvement of several economically important orchids like Cymbidium. Karyomorphological studies have been carried out on seven Cymbidium species, C. aloifolium (Linnaeus, 1753), C. devonianum Paxton, 1843, C. elegans Lindley, 1828, C. iridioides D. Don, 1825, C. lowianum Rchb. f.,1877, C. tigrinum Parish ex Hook. f., 1864, and C. tracyanum L. Castle,1890, most of them endangered/threatened in their natural habitat. As reported earlier, the somatic chromosome number (2n = 40) has been observed in all the seven species. Distinct inter-specific variation was recorded in the arm ratio of few homologous pairs in the complements. Symmetrical or almost symmetrical karyotypes were prevalent; however significant asymmetry was reported in C. iridioides and C. tracyanum. The significance of karyotypic variation in speciation of the genus Cymbidium has been discussed. This study provides useful chromosome landmarks and evidence about genome evolution, heteromorphic chromosomes based heterozygosity, basic chromosome number and ploidy level in the genus Cymbidium. [ABSTRACT FROM AUTHOR]

A method for the storage and high frequency conversion of Cymbidium devonianum protocorm-like bodies (PLBs) is reported. To study the effect of nutrient level on storage, PLBs were encapsulated in calcium alginate beads supplemented with 1.0x, 0.5x, 0.25x, or 0.125x Murashige and Skoog (MS) basal medium containing 0.3% (w/v) sucrose, without agar in the encapsulating matrix, and stored at room temperature (25° ± 2°C) in the dark. Beads containing 0.25x MS were also kept at different temperatures (0°C, 4°C, 8°C, or room temperature) in the dark to ascertain the optimal temperature for storage. One set of controls (i.e., non-encapsulated PLBs) was maintained for each treatment. The survival and subsequent percentage conversion values of PLBs were assessed at 30 d storage intervals after culturing on MS regeneration medium. Compared to the controls, all encapsulated PLBs showed improved storage at room temperature. In all treatments, non-encapsulated PLBs did not survive, but turned brown and died. Encapsulated PLBs in 0.25x MS medium could be stored for 90 d at room temperature without any significant loss in viability. However, a significant decrease in the survival percentage was recorded after longer storage times. Encapsulated PLBs containing 0.25x medium could be stored at 4°C and 8°C for 120 d and 180 d, respectively, without loss of viability. As storage times increased beyond 180 d, the survival percentage of encapsulated PLBs decreased. The conversion of encapsulated PLBs led to the emergence of regenerated plantlets. Initially, small green globular outgrowths from the PLBs were observed on the surface of the beads. These outgrowths multiplied to form clusters of PLBs which then regenerated into plantlets. In both studies, more prolonged storage of encapsulated PLBs increased the time interval for germination and plantlet regeneration on MS regeneration medium. Similarly, decreases in both basal MS strength in the matrix, and in storage temperature, resulted in an increase in the time required for germination and plantlet regeneration. Plantlets that regenerated from stored, encapsulated PLBs were hardened-off, and a high survival percentage (90%) was obtained in a glasshouse. [ABSTRACT FROM AUTHOR]

In vitro seed germination of Nepenthes khasiana Hook. f was accomplished in order to conserve this rare, unique and endemic pitcher plant of India. Seed germination was studied on different nutrient media, viz. MS (Murashige and Skoog), 1/2 MS, 1/4 MS, B[sub5] (Gamborg et al.), 1/2 B[sub5], 1/4 B[sub5], NN (Nitsch and Nitsch), 1/2 NN, and 1/4 NN to ascertain the nutritional requirements of germinating seeds. Seventy-percent germination of seeds was observed on 1/4 MS medium. Pitchers were found to have developed after 150 d of in vitro culture in seedlings cultured on 1/4 MS medium devoid of growth regulators. Growth regulators in the medium were also found to have a pronounced effect on the development of pitchers on in vitro-raised seedlings. Well-developed healthy pitchers were observed after 120 d of culture on 1/4 MS medium supplemented with 2.68 μM naphthalene acetic acid. [ABSTRACT FROM AUTHOR]

• An efficient in vitro propagation protocol developed for Nardostachys jatamansi from rhizome segments. • Low temperature and high light intensities profoundly affected morphogenesis. • In vitro -grown shoots maintained at conventional culture room resulted in impaired antioxidant enzyme activities, increased cell membrane damage, lipid peroxidation and endogenous H 2 O 2 accumulation with reduced photosynthetic pigment contents. Habitat modifications induced by rapid climate change and anthropogenic activities over the years have led to the extinction or confinement of many plant species in their geographic ranges. Temperature and light are the major determinants in controlling plant growth; each plant species having specific temperature and light requirements for their development and proper functioning of the photosynthetic activity. An efficient in vitro propagation protocol via callus-mediated organogenesis from rhizome segments has been developed for Nardostachys jatamansi (D. Don) DC. or 'Jatamansi', an IUCN Red-listed critically endangered plant species of immense medicinal importance. To understand the temperature and light sensitivity, and oxidative stress response of this plant, the micro-shoots were raised in vitro in the culture room (24 ± 2 °C, 50 µmol m−2 s−1 PPFD) and growth chamber (13 ± 2 °C, 850 µmol m−2 s−1 PPFD) mimicking the natural habitats. Maximum shoot regeneration (84.5%) and number of shoots (16.8 ± 0.2) per explant were observed in MS medium supplemented with 1.0 mg/l meta-Topolin and 0.5 mg/l indole acetic acid under low temperature and higher light intensity in the growth chamber. The genetic fidelity was assessed using flow cytometry and no major genetic abnormalities was observed among the regenerants. The activities of antioxidant enzymes like superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase under same culture conditions were also recorded to have increased which revealed their active involvement against oxidative stress. On the other hand, a significant decline in these enzyme activities was observed in cultures incubated in culture room indicating impaired detoxification which could be due to their inactivation at high temperature and low light intensity. It was also observed that prolonged culture of in vitro -grown shoots in the culture room led to increased cell membrane damage, lipid peroxidation and higher endogenous H 2 O 2 accumulation with reduced level of photosynthetic pigment contents, exhibiting severe oxidative stress. The in vitro -grown shoots were better maintained under conditions mimicking the natural conditions of growth which substantiated the understanding of survival strategies of this critically endangered plant species. [ABSTRACT FROM AUTHOR]

Clonal propagation is an important biotechnological tool for the conservation of rare, endangered and threatened as well as commercially important plant species of which orchids are an important representative. In the present research, an attempt was made to develop a fast, clonally stable as well as phytochemically enriched regeneration protocol for propagating Dendrobium aphyllum, an important medicinal orchid using transverse thin cell layer (t-TCL) explants. Murashige and Skoog (MS) medium supplemented with 15 µM meta-topolin along with 10 µM TDZ and 10 µM AgNO3 was found to be most conducive for shoot proliferation. After 8 weeks of culture, an average of 39.41 shoots/explant proliferated; till date this is the best shooting frequency for D. aphyllum and one of the best amongst the orchids. The highest rooting frequency of 82.34% was accomplished in half-strength MS medium supplemented with 15 µM IBA. The plantlets were successfully acclimatized in greenhouse exhibiting normal developmental patterns and flowering occurred after 6 months of acclimatization with 3-4 flowers/stalk irrespective of the flowering season. The genetic homogeneity of the micropropagated plants was ascertained using IRAP and ISSR markers. A comparative assessment of the antioxidant activity (mother and micropropagated plant) was performed using DPPH and FRAP assays which was recorded to be higher amongst the in vitro-regenerated plants. A rapid, genetically stable regeneration protocol coupled with comprehensively higher phytochemical yield is reported in the present study on D. aphyllum. The results of this study confirm the use of in vitro propagation protocol for sustainable commercial utilization as well as conservation of medicinal orchid bio-resources within a limited time period. [ABSTRACT FROM AUTHOR]

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 < 180 days after pollination (DAP) were found to be immature and 180 DAP was found optimal for seed germination. Capsules > 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-3-acetic 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. [ABSTRACT FROM AUTHOR]

Malaxis acuminata D. Don., a small, terrestrial orchid, is endemic to tropical Himalayas at an altitude of 1200–2000 m asl. The dried pseudobulbs are important ingredients of century old ayurvedic drug ‘Ashtavarga’ and a polyherbal immune-booster nutraceutical ‘Chyavanprash’, known to restore vigour, vitality and youthfulness. Considering tremendous medicinal importance of this threatened orchid species, a detailed study was undertaken for the first time to address its antioxidant potential, secondary metabolite contents and biological activities against skin-aging related enzymes (anti-collagenase, anti-elastase, anti-tyrosinase and xanthine oxidase) and anti-inflammatory activity (5-lipoxygenase and hyaluronidase) in different plant parts of wild and in vitro -derived plants of M. acuminata . Methanolic leaf and stem extracts were further evaluated for in vitro photoprotective activity against UV-B and UV-A radiations. Furthermore, secondary metabolite profiling of various plant parts was carried out by Gas Chromatography Mass Spectrometry (GC–MS). A significantly higher antioxidant potential (DPPH, metal chelating and ABTS •+ ) with a comparative higher yield of secondary metabolites was observed in in vitro -derived plantlets as compared to the wild plants. Among various solvent systems used, methanolic leaf and stem extracts showed promising inhibitory activity against major skin aging-related enzymes and anti-inflammatory potential. Methanolic leaf and stem extracts of both wild and in vitro -derived plants showed promising photoprotective activity against UV-B and UV-A radiations in vitro with comparatively higher sun protection factor (SPF). Furthermore, GC–MS analysis of methanolic extracts of leaves and stems of wild as well as in vitro -derived plantlets revealed presence of many bioactive metabolites such as, dietary fatty acids, α-hydroxy acids, phenolic acids, sterols, amino acids, sugars and glycosides which substantially explain the use of M. acuminata as one of the potential rejuvenator and anti-aging ingredient in many Ayurvedic formulations. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Dendrobium nobile is an important medicinal orchid having profound importance in traditional herbal drug preparations and pharmacopeias worldwide. Due to various anthropogenic pressures the natural populations of this important orchid species are presently facing threats of extinction. In the present study, genetic and chemical diversity existing amongst 6 natural populations of D. nobile were assessed using molecular markers, and the influence of genetic factors on its phytochemical activity especially antioxidant potential was determined. Molecular fingerprinting of the orchid taxa was performed using ISSR and DAMD markers along with the estimation of total phenolics, flavonoids and alkaloid contents. Antioxidant activity was also measured using DPPH and FRAP assays which cumulatively revealed a significant level of variability across the sampled populations. The representatives from Sikkim in Northeast India revealed higher phytochemical activity whereas those from Mizoram showed lesser activity. Analysis of molecular variance (AMOVA) revealed that variation amongst the populations was significantly higher than within the populations. The data generated by UPGMA and Bayesian analytical models were compared in order to estimate the genetic relationships amongst the D. nobile germplasm sampled from different geographical areas of Northeast India. Interestingly, identical grouping patterns were exhibited by both the approaches. The results of the present study detected a high degree of existing genetic and phytochemical variation amongst the populations in relation to bioclimatic and geographic locations of populations. Our results strongly establish that the cumulative marker approach could be the best suited for assessing the genetic relationships with high accuracy amongst distinct D. nobile accessions. [ABSTRACT FROM AUTHOR]