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2008 - 20093
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Subject: Botany × End date: 2009 × Start date: 2007 ×
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    ThesisItemOpen Access
    Screening of some selected bryophytes for antimicrobial activity
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2009-06) Gahtori, Dheeraj; Chaturvedi, Preeti
    Mounting pressure of teeming population and shrinking land resources have necessitated the production of more food per unit area. However the indiscriminate use of synthetic pesticides for meeting the increasing food demand and created several problems of pest resistance, food contamination by toxic residues and environmental pollution. To reduce the dependence on synthetic pesticides there is an urgent need to search for plant based natural products. In the present study the different organic and aqueous extracts of four bryophytes- Marchantia polymorpha, Plagiochasma appendiculatum, Dicranum undulatum and Isopterygium elegans have been investigated in vitro for their bioactivity against four different fungal pathogens, viz., Sclerotium rolfsii, Rhizoctonia solani, Fusarium oxysporum and Tilletia indica and five different bacteria viz., Xanthomonas oryzae pv. Oryzae, Salmonella enterica, Pasteurella multocida, Escherichia coli O157 and Melissococcus plutonius (all G-ve). Disc diffusion and microbroth techniques were used for evaluation of antimicrobial activity of the extracts. All the microorganisms were found to be sensitive against at least one of the organic extracts while all the aqueous extracts were found to be ineffective. Organic extracts of all four bryophytes (M. polymorpha, P. appendiculatum, D. undulatum and I. elegans) were effective against F. oxysporum and T. indica. Organic extracts of all bryophytes except, I. elegans, were effective for all the tested bacterial pathogens. These results clearly indicate that bryophytes may prove to be a very good and new source of antimicrobial agents and can encourage to develop a novel broad spectrum antimicrobial herbal formula in future.
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    ThesisItemOpen Access
    Diversity of flowering plants in Pantnagar Agriculture Complex: Native and non native elements
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2009-06) Joshi, Kanchan; Rawat, D.S.
    ‘Earth Summit’ at Rio de Janeiro (Brazil) in 1992 considered biodiversity as an important resource and laid immense stress on its accurate assessment and conservation. Assessment of biodiversity at local level is essentially required for better management and considering this a study of floristic diversity of Pantnagar Agricultural complex was carried out during July 2008-June 2009. A complete list of flowering plants of Pantnagar was prepared on the basis of plant collection in the area during study period, previous floristic reports and other reliable sources. The results obtained show that 662 species of flowering plant within 453 genera and 112 families grow in Pantnagar. Dicots constitute the major part of this floristic diversity being 80.21% with 531 spp within 364 genera and 92 families. Monocots are 18.4% and represented by 122 spp. within 83 genera and 15 families Gymnosperms are represented by 9 spp (1.35%, all cultivated taxa) within 6 genera and 5 families. The dominant families are Poaceae (51 spp; 35 genera), Asteraceae (49 spp; 38 genera), Papilionaceae (42 spp; 27 genera) Euphorbiaceae (26 spp; 13 genera) Malvaceae (23 spp; 10 genera), Solanaceae (19 spp; 11 genera), Lamiaceae (19 spp; 12 genera). Acanthaceae (18 spp; 14 genera), Caesalpiniaceae (18 spp; 6 genera) and Scrophulariaceae (17 spp; 11 genera) together forming 282 species (42.59%) and 179 genera (39.51%). Plants cultivated/planted for different purposes in the area makes major part of floristic diversity and are represented by 348 species (52.57%) Naturalized and indigenous taxa are represented by 154 spp. and 160 spp. respectively. Analysis of nativity indicate that out of total 662 spp., 147 spp. (22.2%) are of American origin, 55 spp. (18.30%) of African, 49 spp. (7.40%) of European, 10 spp. (1.51%) of Australian, 30 spp. (4.53%) of Pantropical, 1 spp. (0.15%) of neotropical, 77 spp. (11.63%) of wides and 293 spp. (44.2%) of Asian origin (these 293 spp. also include 160 spp. of indigenous nature i.e. native to Indian region). The study indicate that destruction of native vegetation for agriculture and urbanization has led to drastic reduction in native flora on the one hand and at other hand it has promoted colonization of the area by invasive alien species which is evident by the presence of 61 spp. of invasive species (of India) and 6 spp. of World’s worst invasive alien species in this area.
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    ThesisItemOpen Access
    Effect of certain environmental factors on seed germination and seedling growth in four different medicinal plant species
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-07) Lajja Vati; Rao, P.B.
    Herbs have always been the principal form of medicine in India and presently they are becoming more popular throughout the developed world. From the ancient times, herbs have been used for pain relieving and health care needs. They have provided the entire medicament to man and domestic animals for a wide spectrum of ailments and to sooth his aches and pains. The present study deals with the effect of certain environmental factors i.e., light, water and temperature on seed germination and watering frequency and shade on seedling growth of four medicinal plant species viz., Andrographis paniculata (Burm.) ex Nees. Datura stramonium Linn. Psoralea corylifolia Linn., and Withania somnifera (L.) Dunal, the seeds were subjected to different stresses (water, temperature and light quality) and the results indicated that per cent seed germination decreased with increasing water stress. However, germination was absent in W. somnifera at high water stress (-15 bar). With increasing in temperature, seed germination was increased in all species and the maximum per cent seed germination was occurred in high temperature (30/35 0C). The maximum seed germination of all the species occurred in direct light in all the species except W. somnifera, in which it was in both direct light and red light. The seedlings of A. paniculata, D. stramonium, P. corylifolia and W. Somnifera were raised in polyethylene bags and subjected to different watering frequencies (daily, 7, 14 and 21 days intervals) and different light intensities (100%, 86%, 50% and 25% of full sun light) and continued upto four months. The observations (height, number of leaves and branches, root length, dry weight of leaves, stem, shoot, root and total seedling) were made with one month interval either direct measurement or by harvesting seedlings. The values of all parameters decreased with decreasing moisture in all the species i.e., from daily to 21 days watering intervals, except root length, in which it increased with decreasing moisture in all the species. The values of all parameters decreased with increasing light intensity in all the species except W. somnifera, in which the height, number of leaves and branches was decreased with decreasing light intensity (increasing shade level). The root length, showed poor growth with increasing shade in all the species. These results indicated that root length was highly affected by moisture and shade.