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Subject: Botany × End date: 2009 × Start date: 2009 ×
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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.