Botany

Permanent URI for this collection

https://hdl.handle.net/20.500.14540/124

Browse

Now showing 1 - 20 of 251

ADSORPTIVE REMOVAL OF ALUMINIUM (III) USING CHEMICALLY MODIFIED SUGARCANE BAGASSE FROM AQUEOUS SOLUTION
(Amrit Campus, 2023-08-14) NEPAL, DIWASH
A major concern for both humans and aquatic life can result from the presence of several metal ions in an aquatic environment that exceeds the allowed limit. The most efficient way to remove minute levels of hazardous metals from wastewater is through adsorption. The primary goal of this thesis work is to chemically modify sugarcane bagasse in order to create a low-cost, highly effective adsorbent for the removal of Al (III) from an aqueous solution. Both xanthated and charred sugarcane bagasse have been prepared as adsorbents. Adsorbents are characterised using FTIR, EDS, and SEM. For analysis, batch experimental method was carried out. Utilizing both CSB and XSB, the effect of pH, Al (III) concentration and contact time have been investigated using both CSB and XSB adsorbents. For both adsorbents, a 150-minutes maximum duration and a pH of 4 are found to be ideal. The Langmuir isotherm model is best fitted for equilibrium sorption data, and maximum adsorption capacities of CSB and XSB are determined to be 50.9 mg/g and 81.0 mg/g, respectively. Studies on kinetic modelling showed that a pseudo second-order kinetic model best fit the experimental data. These findings show that XSB can be an alternative bio-adsorbent for the elimination of Al(III) from an aqueous solution.
Agroforestry Practices and Their Contribution to Biodiversity and Rural Livelihoods in Bundikali Rural Municipality of Nawalparasi District, Nepal
(Department of botany, 2020) Bhattarai, Rabindra
Research related to the field application of agroforestry practices and socio-economic factors related to it are still scarce. In the present investigation, tree species diversity, livelihood and carbon sequestration were studied in the traditional agroforest of Budikali Rural municipality of Nawalparasi district. A quadrat size of 20× 20m (400m vi 2 ) was set up and tree inside the plot were listed. The sample HHs were 100 (8.09 %). Participatory Rural Appraisal was used to obtain data from the family farmers. The collected data were analyzed by using Statistical Package for Social Science (SPSS) and MS- Excel where frequency distributions, standard deviation were mostly used. Shannon-Winner (S-W) diversity index was used to analyze farm tree biodiversity. The major castes/ethnic groups in the study area were Magar, Kami, Chhetri, Bhramin, Damai, Newar, Darai, Sarki, and Gharti. The sample households (HHs) had a minimum of 0.101 hectares and a maximum of 5.23 hectares of land. The average land hold of households was 0.61± 0.58 hectares. Respondents, 24% of them had small size LSU, 59% medium size, 16 % large size. Khet land, Bari land, Kharbari land, Woodlot are four landuse type in agroecosystem. Total 74-tree species belonging to 37 families. Total 1003 tree individuals were recorded, with the density of 250.75 tree/ ha. The tree species in AF mainly used for fruits (23%), fodder and fuelwood (12.16%), fuelwood (12.16%), timber wood (12.16%). S-W index (H) = 3.87, Hmax = 0.9003, the result showed that species richness and evenness were very high in the study area. (= 3.67). Based on land use type there were high species richness and evenness of tree in Khet land (3.82) followed by Bari land, Kharbari land and woodlot respectively. There were highest number of trees 188 in DBH class 20-29 in Bari land. Based on land use type carbon stock was higher in woodlot (30.09±18.80 tons/ha) followed by Kharbari land (28.72±11.95 tons/ha), Bari land (28.36±14.35 tons/ha), and Khet land (20.47±15.51 tons/ha). The study has discovered that AF trees subsidize several products like fuelwood, fruits, medicine, fodder and biodiversity conservation. AF can play extensive role in reducing atmospheric concentration of CO2 by storing carbon in above and belowground biomass and growing biomass for biopower and biofuels and thereby replacing fossil fuel. Hence, this study recommends a strong need to strengthen promotion of AF and promotion to policy makers. Keywords: Agroforestry, Livelihood, Treediversity, Carbonstock
Agroforestry System and Their Carbon Stock in Terai and Mid-Hill Regions of Central Nepal
(Department of Botany, 2015) Kafle, Shashi
Trees and forests play a critical role in human livelihood as well as in ecosystem functioning. Agricultural emissions from crop and livestock production grew from 4.7 billion tons of CO eq. per year in 2001 to over 5.3 billion tons in 2011 due to agriculture fermentation. Compensation in loss of biodiversity, concern of food security, improvement in the living standard by generating income and the global issue of climate change related with carbon sequestration can be addressed with the scientific knowledge of agroforestry system. It can directly store carbon in tree components and potentially slows down the deforestation rate by reducing the need to clear forest land for agriculture. In the country like Nepal which is very suitable for agriculture, the agroforestry practice can be highly demanding for the overall growth of the nation. The study was carried out in Terai and mid-hill physiographic region. This study focuses mostly on the species grown in the home garden for the various purposes and to determine the total carbon stock of these two regions. The plot of 20×20m 2 was set up and the trees inside the plot were listed, counted and the various parameters like dbh, angle of elevation and distance between the observer and tree were measured for biomass carbon stock. The study was conducted in 30 home-gardens from Terai and 50 from midhill. Total 171 species were recorded in the study. Shannon's index was 1.247 in Terai and 1.216 in mid-hill. Simpson's index was 0.0915 in Terai and 0.087 in mid-hill. The total mean tree trunk volume was found to be 17.46 m 3 /ha. The average total biomass was significantly greater in Terai (21.314 t/ha) than in mid-hill (11.203 t/ha). The mean of total biomass carbon stock was found to be 10.255 tons C / ha and 5.24 tons C / ha for Terai and mid-hill respectively. The soil was collected from 0-20 cm depth. 80 soil samples were air dried and brought to laboratory for further analysis of soil carbon stock. The study found the soil bulk density to be 1.38 g/cm 3 in Terai and 1.076 g/cm in midhill region. The soil carbon stock was found to be 61.17 t C ha -1 in Terai and 67.608 t C ha -1 in mid-hill. The biomass carbon stock and soil carbon stock were summed up to obtain the total carbon stock. However, the study found no significant difference in the total carbon stock between the two regions i.e. 71.433 t C/ha in Terai and 72.856 t C/ha in mid-hill. 2 3 Though agroforestry does not contribute as much as the forest, however, it can store enough significant amount of carbon when designed in a proper way. Thus, agroforestry system can be proved to be one of the best alternatives to cope with the alarming problem of biodiversity loss, food security and climate change. Starting from a small area around the home, it can create its impact to the global scale. Keywords: Species diversity, Uses, Biomass carbon stock, Soil carbon stock.
AIR POLLUTION TOLERANCE INDEX OF SOME FODDER PLANT SPECIES AROUND SONAPUR CEMENT FACTORY IN DANG, WESTERN NEPAL
(Amrit Campus, 2024-01-28) Basnet, Kalpana
The study aims to find out the air pollution tolerant index of some fodder plant species around the Sonapur cement factory in Dang, Nepal. Commonly available and dominant five fodder plant species (Melia azedarach, Leucaena leucocephala, Garuga pinnata, Dalbergia sissoo, Bambusa nutans) were selected from three different distances i.e. (0-300) m, (300- 600) m, (600-1000) m at four directions (east, west, north and south). Matured leaf samples were collected for the biochemical studies of air pollution tolerance index (APTI). The APTI values of different plant leaves were calculated considering the biochemical parameters like relative water content (RWC), total leaf chlorophyll content (TChl), leaf extract pH and ascorbic acid (AA). Additionally, specific leaf area (SLA) was also measured. The correlation of SLA with APTI and different biochemical parameters were also calculated. The highest APTI value of the studied plants ranged from twelve to sixteen, indicating their moderate tolerance to air pollution. The APTI values of fodder plants increased significantly (p=0.05) at the distance near the factory at (0-300) m. Among them the highest APTI was found in L. leucocephala and was followed by G. pinnata in the east direction, M. azedarach in north direction, D. sissoo in south direction and B. nutans in west direction. The value of SLA, total chlorophyll content and pH decreased whereas relative water content and ascorbic acid increased near the cement factory in most of studied plants. SLA of studied plants showed significantly negative correlation (p<0.05) with APTI. This study recommends plants like L. leucocephala, G. pinnata, Melia azedarach, D. sissoo, B. nutans, which scored high APTI value at different directions, for further plantation around the cement factory.
Allelopathic Influences of Artemisia Dubia Wall. Ex. Besser on Seed Germination of Parthenium Hysterophorus L.
(Department of Botany, 2008) Sharma, Manisha
Screening plant produced phytotoxins (allelochemicals) through bioassay is an accepted strategic tool employed for the discovery of potential pesticides for weed management. The present laboratory based study was undertaken to serve the purpose of preliminary screening of phytotoxicity of Artemisia dubia against an invasive composite Parthenium hysterophorus. Allelopathic effect of aqueous (leachate and decomposed) extract, solvent extract (hexane, chloroform, methanol and water), soil amended extract with leaf, stem and root and essential oil of donor plant Artemisia dubia was studied on germination and seedling vigour of Parthenium hysterophorus. Extraction and quantification of different parts in different solvent was done by percolation method while hydro distillation method was followed for essential oil extraction. Bioassay was done by allowing P. hysterophorus seed to germinate in petri dishes (for solvent, aqueous and essential oil) and disposable plastic plates (for plant parts amended soil) in laboratory condition against varied concentrations of prepared extracts of Artemisia dubia. Yield of crude extract (solvent and aqueous) was high for leaf compared to stem and root. All the tested extract (aqueous, solvent, essential oil and soil amended with plant parts) from different plant parts significantly checked the germination of Parthenium hysterophorus in higher concentration with the effect being more pronounced due to leaf of Artemisia dubia. Linear growth of root and shoot also followed the same pattern. The order of allelopathic influence was leaf > stem > root in all the cases and it was concentration dependent. Length of root was retarded while stem length experienced no effect, sometime elongation (stem and root extract of leachate, stem extract of hexane and chloroform) and sometime retardation (aqueous decomposed extract of leaf, leaf amended soil and essential oil). Aqueous decomposed leaf extract, soil amended with leaf parts and essential oil were found to be most inhibitory. These results provide ample evidence that allelopathic potential exist in Artemisia dubia and this can be exploited for the control of Parthenium hysterophorus.
Allelopathic Interaction Studies on Parthenium hysterophorus L.
(Department of Botany, 2007) Paudel, Vivek Ranjan
The increase in concentration of allelochemicals, both from plant and seeds of Parthenium, caused decrease in the germination of Raphanus seeds. The seed germination was inhibited up to 100% in the presence of Plant diffusates (PD) and up to 86.66% in the presence of seed diffusates (SD). These allelochemicals also reduced the glucose level in germinating seeds of Raphanus sativus. The glucose level reduced up to 55% in 100 % PD grown seeds and up to 37% in 100% SD grown seeds. Extracts (essential oils) from Eucalyptus citriodora, Cymbopogon citratus and Cinnamomum camphora were used to analyze their effects in germination and seedling development of the weed. Cymbopogon oil at 8 ml l-1, Eucalyptus and Cinnamomum oils at 12 ml l-1 and all above concentrations of all extracts arrested the seed germination of the weed completely. The oil extracts irrespective from their sources were found significantly effective (P < 0.05) in arresting the seed germination and seedling length of Parthenium hysterophorus in laboratory conditions.
Allelopathic Potential and Phytochemical Screening of Some Medicinal Plants of Nepal
(Department of Botany, 2013) Sharma, Swasti
The laboratory tests were conducted to evaluate the allelopathic potential and phytochemical study of the four selected medicinal plants Ageratum conyzoides, Eclipta prostrata, Cannabis sativa and Woodfordia fructicosa . The aqueous extract bioassay of the plants with leaf, stem and root were conducted on the two test seeds wheat and pea by filter paper method. Germination, seedling growth and biomass production were observed under the allelopathic study wheras under phytochemical study qualitative or presence or absence and quantitative or crude amount of the phytochemicals present were also estimated. Data analysis was done by SPSS version 16. For the allelopathic studies the germination and seedling growth of wheat and pea test species under the different concentrations 2% ,4% ,6% ,8% and 10% of the leaf, stem and root extracts of the plants under study were carried out. Increased concentration of the aqueous extracts of the plants increased the inhibitory rate or decreased the germination and seedling growth. Generally leaf extract showed lower germination rate than the other parts. There was significant difference for the plumule length and rootlegth of wheat from that of control except for the radicle length of the C. sativa root extract. In pea, no significant difference was seen for A. conyzoides root, C. sativa stem and root and E. prostrata stem extract. Biomass production was maximum in W. fructicosa and least in A. conyzoides stem extracts in pea .In wheat maximum in C. sativa and minimum in E. prostrata extracts. Wheat was found sensitive to E. prostrata and W. fructicosa extracts wheras pea plant was found more sensitive to A. conyzoides and C. sativa extracts. Alkaloid, flavonoid, saponin, tannin, phenol, glycoside and essential oil were the phytochemicals present in the plant extracts. Key words: Allelopathic potential, Phytochemical study, medicinal, bioassay, germination, seedling, biomass production, sensitive, crude
Antibacterial Activity and Phytochemical Screening of Some Medicinal Plants of Nepal
(Department of Botany, 2009) Pandey, Madhaba Prasad
Eighteen different medicinal plants which were being used to treat the bacterial diseases in Nepal were selected. The medicinal plants were extracted in methanol by soaking method. The Drymaria cordata gave the highest yield (20%) whereas Urtica dioica gave lowest yield (4%). The methanol extract of these plants were evaluated for antibacterial activity against medically important bacteria viz. Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Proteus vulgaris, Escherichia coli, and Staphylococcus aureus. The in vitro antibacterial activity was performed by agar disc diffusion method. Among 18 medicinal plants tested, in the present study, all plants showed activity against at least two bacteria. Phyllanthus amarus and Rhus javanica inhibited all the tested bacteria. Similarly, Drymaria cordata was effective against 83% of tested bacteria. Nine plants (Bauhinia purpurea, Ageratum conyzoides, Urtica dioica, Lantana camara, Cinnamomum tamala, Melia azedarach, Vitex negundo, Oxalis corniculata, and Zizyphus mauritiana) inhibited the growth of 67% and five plants (Euphorbia hirta, Taraxacum officinale, Achyranthes bidentata, Mimosa pudica, and Cissampelos pareira) were effective against only 50% of screened bacteria and remaining one plant Ficus religiosa inhibited growth of 33% of the screened bacteria. The most susceptible bacteria were Staphylococcus aureus whose growth was inhibited by 17 out of 18 plants screened whereas Escherichia coli were found to be the most resistant bacteria being susceptible to only five plants. The gram-positive bacteria were found to be more susceptible as compared to gram-negative bacteria. Phytochemical screening was also performed on all these plants on aqueous and alcoholic extract by their color reaction with different reagents and chemicals to detect the presence of alkaloids, glycosides, saponins, terpenoids, and tannins. Most of the plants contain these secondary metabolites but on varying concentration. Among the screened plants, 67% of plants contain alkaloids, 78% plants found to contain glycosides, saponins and terpenoids each and 72% plants showed the presence of tannins. The medicinal plants which were used against bacterial disease were found to have antibacterial principles and were found to be rich in different phytochemicals.
Antibacterial Activity of Selected Medicinal plants of Nepal
(Department of Botany, 2013) Joshi, Govinda Ballab
Not available
Antibacterial activity of selected orchid species of Nepal
(Department of Botany, 2023) Dulal, Sajan
Orchidaceae, a highly advanced and widely spread family of monocotyledonous plants. Orchids have been found to contain a rich source of natural compounds with significant therapeutic activities against various disease. So this study mainly focused on antibacterial activity to generate natural medicines to substitute synthetic drugs. The orchid plants were collected from various regions of Nepal and subsequent extract preparation and laboratory work conducted at the Annapurna Research Center. A total of fifteen orchid species were selected for the purpose of this study. The different parts of orchids were used for extraction using methanol through a combination of the Percolation and intermittent sonication methods. After that in vitro antibacterial evaluation was conducted using the agar well diffusion technique with different concentration. Out of 15 species, the highest yield was obtained from Habenaria marginata 15%, and the lowest was from Coelogyne stricta 1%. In the qualitative analysis, various reagents were used to quantify tannins, flavonoids, glycosides, phenols and alkaloids. A qualitative phytochemical screening indicate that alkaloids and flavonoids were present in the extracts of all the orchid species that were tested. Both Phenol and Carbohydrate were absence in Coelogyne stricta and Eria graminifolia. The antibacterial activity of the methanol extracts from these plants was evaluated against medically significant bacteria. Enterococcus faecalis, Acinetobacter baumannii, Escherichia coli and Shigella sonnei were Gram negative whereas Staphylococcus aureus was Gram positive bacteria. All 15 plants showed activity against at least one bacterium. The two orchid plants, Coelogyne stricta and Otochilus albus, exhibited broad-spectrum activity by showing a high zone of inhibition against all tested bacteria with zone of inhibition (20mm) and (21mm) against Acinobacter baumannii respectively. Similarly, The MIC values for the tested orchid extracts range from 1.25 mg/ml to 2.5 mg/ml, while the MBC values range from 0.3125 mg/ml to 0.625 mg/ml. So Otochilus albus exhibits strong antibacterial properties against Acinobacter baumannii species, and its corresponding MIC and MBC values provide further evidence of its antibacterial effectiveness. Therefore, it is worthy to conduct additional investigations into this specific species to reveal its potential benefits. Furthermore, there is scope for conducting additional laboratory experiments and research work to develop new pharmaceutical products. Keywords: Orchids, Phytochemical compounds, Antibacterial activity, MBC, MIC
Antibacterial Activity of Some Folklore Medicinal Plants of Nepal
(Department of Botany, 2011) Khadka, Prachand
Plants have been a good source of food and medicine since human civilization. The plants, which are used by human to cure various diseases and to relieve diseases, are called medicinal plants. In the present study, thirteen medicinal plants namely Piper longum, Achyranthes aspera, Oroxylum indicum, Acmella clava, Swertia chirayita, Bauhinia variegata, Phyllanthus emblica, Justicia adhatoda, Mentha Spicata, Azadirachta indica, Curculigo orchioides, Withania somnifera and Thalictrum foliolosum were screened for potential antibacterial activity against pathogenic bacterial strains viz Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhi, Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis and Staphylococcus aureus. All the parts of medicinal plants used were kept in methanol solvent by soaking method. The Azadirachta indica gave the highest yield (23.50%) whereas Achyranthes aspera gave lowest yield (5.60%) of crude extract. The methanol extracts of these plants were evaluated for antibacterial activity by agar disc diffusion method Among thirteen medicinal plants tested, all plants showed activity against at least two bacteria. Phyllanthus emblica, Swertia chirayita, Withania somnifera and Thalictrum foliolosum inhibited all the tested bacteria. Similarly three plants viz. Acmella clava, Bauhinia variegata and Mentha spicata inhibited 86% of tested bacteria, three plants Achyranthes aspera, Oroxylum indicum and Azdirachta indica were effective against 71% of screened bacteria, Piper longum was effective against 57% of tested bacteria, Curculigo orchioides was effective against only 43% of tested bacteria and Justicia adhatoda inhibited only 29% of tested bacteria. Among the tested bacteria, most resistant bacteria was Escherichia coli whose growth were inhibited by only 8 out of 13 plants extract where as Bacillus sublilis was most susceptible bacteria whose growth was inhibited by all plants extracts. Gram-ve bacteria were more resistant than Gram +ve bacteria. The screening of crude extracts made from tested plants used by traditional healers showed that these screened plants were potentially competent to control the bacterial growth.
Antibacterial and Antioxidant Properties of Selected Medicinal Plants from Law Land Nepal
(Department of Botany, 2015) Bhatta, Laxmi
Medicinal plants , as source of remedies, are widely used as alternative therapeutic tool for the prevention or treatment of many diseases The aim of the present study was to evaluate the antibacterial and antioxidant activity of the methanolic extract of selected medicinal plants of central Nepal. Twelve medicinal plants were studied on the basis of their ethnobotanical uses in the treatment of various ailments especially diarrhoea and dysentery. Antibacterial screening against four pathogenic microbes‟ viz., Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillius substilis was determined by agar well diffusion method and zone of inhibition was observed. Out of twelve plants tested for antimicrobial activity, eight plant species showed antibacterial activity by inhibiting one or more microorganisms. The methanolic extract of Mangifera indica, Bombax ceiba, Bauhinia vahlii, Cassia fistula, Syzygium cumini, showed significant inhibition against all the tested bacteria while, Psidium guajava, Elephantopus scaber and Azadirachta indica showed inhibition against few pathogenes. But medicinal plants such as Cassia occidentalis, Uraria lagopoides, Moringa oleifera and Costus speciosus did not show antibacterial activity against selected bacteria. Total phenolic and flavonoid content were determined by Folin-Ciocalteu and aluminium chloride calorimetric method respectively. The antioxidant activity was determined by 2, 2diphenyl-1-picrylhyrazyl (DPPH) free radical and ascorbic acid was taken as standard. Syzygium cumini, Bombax ceiba, Elephantopus scaber, Uraria lagopoides and Bauhinia vahlii showed lower IC 50 value than standard ascorbic acid where as Cassia occidentalis, Mangifera indica, Moringa oleifera, Azadirachta indica, Cassia fistula, Psidium guagava and Costus specious showed higher value than standard ascorbic acid. Moringa oleifera showed the highest phenolic content whereas all the plant extracts showed comparable amount of Flavonoid content. The results of the present study suggest that the selected plants can be used as a source of antioxidants and antibacterial for pharmacological preparations as very well evidenced by the present work.
Antibacterial and Antioxidant Property of Selected Medicinal Plants of Daman VDC, Makawanpur District
(Department of Botany, 2016) Adhikari, Usha
Altogether fifteen plants used to treat stomach troubles like indigestion, diarrhea and dysentery were selected for the study purpose. The medicinal plants were extracted in methanol by Percolation with intermittent Sonication method. Bergenia ciliata had the highest yield (20.03%) while Cautleya spicata had the lowest yield (2.90%). The methanol extracts of these plants were evaluated for antibacterial activity against medicinally important bacteria viz. Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus and also evaluated for the antioxidant activity. The in vitro antibacterial activity was performed by agar well diffusion method. Among the 15 plants tested, in the present study, all plants except one (Achyranthes bidentata) showed activity against at least one bacterium. Bergenia ciliata, Coriaria napalensis, Potentilla fulgens, Pyracantha crenulata, Pyrus pashia and Rubus ellipticus inhibited all the tested bacteria at 50 µg/ml and 100 µg/ml. Lindera neesiana inhibited all the tested bacteria at 100 µg/ml only. Callicarpa macrophylla inhibited only 3 of the tested bacteria at 150 µg/ml while Galium aparine and Uraria picta inhibited Gram +ve bacteria only. Adiantum philippense, Anemone vitifolia, Campanuma paillida and Cautleya spicata inhibited Bacillus subtilis only. Most of the extracts showed activity against Gram +ve bacteria than Gram -ve bacteria. Highest phenolic content was obtained for Potentilla fulgens (90.73 ± 0.71 mg GAE/g) while the lowest was shown by Achyranthes bidentata (2.21 ± 0.19 mg GAE/g). Similarly, highest content of flavonoid was obtained for Adiantum philippense (21.19 ± 0.28 mg QE/g dry plant) and Cautleya spicata (21.19±0.52 mg QE/g dry plant) and lowest for Bergenia ciliata (1.78 ± 0.11 mg QE/g dry plant). Antioxidant activity of the methanolic extract was determined using DPPH method. Maximum IC 50 value was obtained for Achyranthes bidentata i.e. 127.55 and minimum for Bergenia ciliata i.e. 40.56. Thus, Bergenia ciliata was considered to be the best antioxidant among the sampled plant samples.
Antifungal Activities of Essential Oils and Crude Extracts of Some Aromatic Plants Against Fusarium Rot of Trichosanthes Dioica Roxb
(Department of Botany, 2007) Wagle, Bina
The infected Pointed gourds samples were collected from the local market of Kathmandu Valley. The fungus isolated from the infected Pointed gourds was identified as Fusarium solani, which was responsible for the storage fruit rot disease. Pathogenicity test was carried out for the confirmation of disease by transferring the inoculum from the pure culture of Fusarium solani to healthy Pointed gourds. For the control, the essential oils and extracts from five aromatic plants viz. Zanthoxylum armatum, Mentha arvensis, Amomum subulatum, Valeriana jatamansi and Cymbopogon flexuosus were used to assess their fungitoxic activities against the test fungus. Each essential oils was diluted to different concentrations of 0.625, 1.25, 2.5, 5.0 and 10.0µlml-1 (in 80% Acetone) and the extracts were diluted in to 0.625, 1.25, 2.5, 5.0, 10, 20, 30, 40, 50 & 100 µlml-1 (in distilled water). The value of minimum inhibitory concentration (MIC) and percentage of mycelial growth inhibition of the essential oils and extracts were obtained as, the oil and extract of Cymbopogon flexuosus showed the highest fungitoxicity (100%) at the concentration of 5.0 and 50 µlml-1, similarly the oils and extracts of Zanthoxylum armatum, Mentha arvensis, Amomum subulatum and Valeriana jatamansi were found to be 10 and 100 µlml-1 respectively. The percentages of mycelial growth inhibition were found to be different, according to their different concentration of each essential oils and extracts. The highest percentage of mycelial growth inhibition were found to be oils of Cymbopogon flexuosus followed by Amomum subulatum, Zanthoxylum armatum, Mentha arvensis and Valeriana jatamansi respectively and similarly extracts of Cymbopogon flexuosus followed by Zanthoxylum armatum, Amomum subulatum, Valeriana jatamansi and Mentha arvensis respectively. Thus comparative fungitoxicities of five different essential oils and extracts were observed against Fusarium solani.
Antifungal activities of some medicinal plant extracts and Trichoderma spp. against stemphylium vesicarium of allium sativum
(Department of Botany, 2010) Shrestha, Sajana
The extracts of eight aromatic plants viz. Cuscuta reflexa, Syzygium aromaticum, Allium cepa, Cinnamomum zeylanicum, Solanum xanthocarpum, Phyllanthus emblica, Cinnamomum camphora and Equisetum diffusum were assessed in-vitro for antifungal activity against Stemphylium vesicarium; the causal organism of leaf blight of garlic. Pathogenicity test was confirmed by inoculating the pathogen into healthy garlic plant. The assessment for fungitoxicity was carried out by poisoned food technique using five different concentrations (20%, 40%, 60%, 80% & 100%) against the test fungus in terms of percentage of mycelial growth inhibition. Among the test plants, the extracts of Cuscuta reflexa, Syzygium aromaticum and Allium cepa were able to inhibit the mycelial growth completely. Trichoderma spp. was tested to determine its effect on mycelia growth of S. vesicarium on PDA medium. The mycelia growth was totally inhibited by Trichoderma spp. showing its fungitoxic properties.
Antifungal Activity of Essential Oil of Some Medicinal Plants against (Dry Rot of Potato) Fusarium oxysporum Schlecht
(Department of Botany, 2009) Poudel, Rita
Potato samples were collected from the Kalimati Vegetable Markets of Kathmandu. The fungus, isolated from the infected potato tubers was identified as Fusarium oxysporum Schlecht, which causes dry rot disease of potato tubers in storage. Pathogenecity test was carried out for the conformation of disease. It was confirmed by inoculating the pathogen in to the healthy tubers. Cinnamomum tamala, Nardostachys grandiflora, Eucalyptus citriodora and Cymbopogon citratus were hydro-distilled in laboratory for the extraction of essential oils. The other two essential oils of Mentha arvensis and Acorus calamus were obtained from the HPPCL. Each essential oil was diluted to the different concentrations of 40.0µlml -1 , 20.0µlml -1 , 10.0µlml , 2.5µlml -1 , 1.25µlml -1 and 0.625µlml -1 in 80% acetone. Fungitoxicity was assessed by poisoned food technique. Essential oil of Eucalyptus citriodora showed the highest fungitoxicity (100%) at the concentration of 20.0µlml -1 , while essential oil of Cymbopogon citratus, Nardostachys grandiflora and Acorus calamus showed the highest fungitoxicity (100%) at the concentration of 40.0µlml -1. Similarly, essential oils of Cinnamomum tamala and Mentha arvensis showed the highest fungitoxicity (90.59% and 67.60% respectively) at the concentration of 40.0µlml -1 . The Minimum Inhibitory Concentration (MIC) of different essential oils was obtained. The MIC of Eucalyptus citriodora was 20.0µlml -1 i.e. the complete inhibition of colony growth of Fusarium oxysporum was seen at 20.0µlml -1 concentration. Similarly, the MIC of Cymbopogon citratus, Nardostachys grandiflora and Acorus calamus was found 40.0µlml -1 against the mycelial growth of Fusarium oxysporum. Thus, comparative antifungal activities of 6 different essential oils were observed against Fusarium oxysporum (the causal agent of dry rot disease of potato tubers in storage). -1 , 5.0µlml -1
Antifungal Activity of Some Plant Essential Oils against Alternaria brassicicola (Schw.) Wiltshire
(Department of Botany, 2012) Gautam, Ritu
The essential oil of six medicinal plants viz. Zanthoxylum armatum (DC), Juniperus recurva Buch-Ham.ex.D.Don, Cymbopogan martini (Roxb) W. Watson, Cymbopogan citratus (DC.)Tra, Mentha arvensis L. and Gaultheria fragrantissima Wall. were assessed in vitro for antifungal activity against, Alternaria brassicicola: the causal organism of leaf spot of cauliflower. Pathogenecity test was conformed by inoculating the Pathogen into healthy cauliflower leaf. The assessment of fungitoxicity was carried out by poisoned food technique using five different concentration (2.5 µlml 5 -1 , 5 µlml -1 , 10 µlml -1 , 20 µlml -1 , 40 µlml -1 ) against the test fungi in terms of mycelial growth inhibition. Among the choosen oil samples, oils of Mentha arvensis, Cymbopogan martini and Cymbopogan citratus were found able to inhibit the mycelial growth of Alternaria brassicicola completely.
Antifungal effects of some plant essential oils against Alternaria alternata (Fr.) Keissl. and Aspergillus niger van Tiegh. from grapes
(2015) Bhattarai, Bina; Sanjay Kumar Jha
The essential oil of six plants viz. Murraya koenigii (L.) Spreng., Eucalyptus citriodora Hook., Artemisia indica Willd., Cinnamomum camphora (L.) J. Presl., Cinnamomum tamala (Buch.-Ham.) Nees and Eberm and Lantana camara L. were assessed in vitro for the antifungal activity against Alternaria alternata (Fr.) Keissl. and Aspergillus niger van Tiegh., causing postharvest rots in grapes. The test fungi were isolated from infected grapes obtained from local markets. The essential oils were extracted through hydro distillation process using Clevenger oil extracting apparatus. For screening of antifungal activity treatments at concentration of 20, 40, 80, 160 and 320 µl/ml and controls were set to determine percentage inhibition of mycelial growth of two test fungi using poisoned food technique. All the tested oils exhibited significant antifungal effect (P<0.05) over tested fungi. Among all six essential oils, Cinnamomum camphora showed the most effective antifungal activity against Aspergillus niger which inhibited the mycelial growth by 81.58 % and 100 % at 20 and 80 µl/ml oil concentration respectively. Furthermore, Cinnamomum tamala showed best antifungal effect in controlling Alternaria alternata among all six oils which inhibited the mycelial growth by 93.11 % at 20 µl/ml and by 100 % at 80 µl/ml oil concentrations.
Antifungal Effects of Some Plant Essential Oils Against botrytis Cinerea
(Department of Botany, 2006) Neupane, Ashok
Botrytis cinerea causes the gray mold fruit rot of strawberry. The causalpathogen was isolated from the infected strawberry fruit. Pathogenecity test was carried out for the confirmation of disease. Thymus linearis, Artemisiagmelinii and Tanacetum gracile were collected from Manang as part of the NUFU funded project.Artemisia indica and Murraya koenigii were collectedfrom the local garden of Central Department of Botany TU. These all fiveplants were hydrodistilled in the lab for the extraction of essential oils. Eachessential oil was diluted to different concentrations of 10,000 ppm, 5,000 ppm,2,500 ppm, 1,250 ppm and 625 ppm in 80% acetone. The essential oil ofArtemisia gmelinii was further diluted to 12,500 ppm, 25,000 ppm, 50,000ppm, 75,000 ppm and 1,00000 ppm for finding out the minimum inhibitory concentration (MIC). The essential oil of Artemisia indica was further diluted in to 20,000 ppm, 40,000 ppm, 60,000 ppm and 80,000 ppm respectively. Fungitoxicity was assessed by poisoned food technique. Essential oil of Thymus linearis showed the highest fungitoxicity (100%) at the concentrationof 10,000-ppm. The minimum inhibitory concentration (MIC) of differentessential oils was calculated. MIC of Thymus linearis was 10,000 ppm, i.e. at 10,000-ppm concentration; complete inhibition of colony growth of Botrytiscinereais seen. MIC of Artemisia indica was found to be 60,000 ppm and MIC of Artemisia gmelinii was found to be 75,000 ppm against Botrytis cinerea.
Antimicrobial Activities and Phytochemical Screening of Some Invasive Alien Species of Nepal
(Department of Botany, 2014) Das, Ritu Kumari
In the present study, the antimicrobial activities and phytochemical screening of three Invasive Alien Species were studied. The crude extracts of the alien species (Ageratina adenophora, Ipomoea carnea ssp. fistulosa and Xanthium strumarium) were prepared by using distilled water and methanol as solvents. The antimicrobial activity against six pathogenic bacteria, three gram negative: Klebsiella pneumoniae (ATCC 15380), Proteus mirabilis (ATCC 49132), Escherichia coli (ATCC 25922) and three gram positive: Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25932) and five phytopathogenic fungi: Alternaria brassicae, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici and Sclerotium rolfsii of different concentrations (50 mg/ml, 100 mg/ml, 150 mg/ml, 200 mg/ml, 250 mg/ml) of selected plant extracts was studied. The highest (16.48%) crude extract was obtained in A. adenophora in distilled water and the lowest (6.2%) in methanolic extract of X. strumarium. The phytochemical screening depicted the presence of terpenoids, saponins, cardiac glycosides, flavonoids, reducing compounds, tannins, phlabotannins and alkaloids. Seven replicates were used for each tested microbes. The antibacterial activity of extracts was determined by disc diffusion method and zone of inhibition (ZOI) was measured. Gram negative bacteria was found more resistant than gram positive bacteria. The most susceptible bacteria was S. aureus while the most resistant bacteria was E. coli. Methanolic extract was found more effective than distilled water. The antifungal activity of extracts was determined by poisoned food technique and linear mycelium growth reduction (LMGR) percentage was calculated. The distilled water extracts inhibited the growth of fungal mycelium while methanolic extracts completely inhibited (100%) the growth of some selected fungi at higher concentrations. Fusarium oxysporum was the most susceptible fungus while A. brassicae and B. cinerea were the most resistant fungi. Between bacteria and fungi, bacteria was found more susceptible than fungi against both distilled water and methanol extracts of selected IAS. Key words: IAS, Antimicrobial property, ZOI, LMGR, Phytochemical Screening.