Academy of Life science

Āgra, India

Academy of Life science

Āgra, India
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Chauhan S.,Academy of Life science | Chauhan S.V.S.,Academy of Life science | Galetto L.,National University of Cordoba
South African Journal of Botany | Year: 2017

This study reports the influence of habitat on floral (flower and nectar characteristics, phenology) and pollination biology (flower visitors and breeding system) on Callistemon citrinus (syn. Callistemon lanceolatus), an Australian species of family Myrtaceae. In India, this small ornamental tree is cultivated in gardens, avenues and road sides and flowers throughout the year. At Agra (Uttar Pradesh, northern India) this species flowers twice a year (February–May and August–November). Flowers open early in the morning and can be characterized as protandrous for a brief period. Fresh open flowers presented ca. 25% of total produced nectar. Nectar sugar composition consisted of only glucose and fructose. A wide array of visitors (honey bees (Apis dorsata), butterflies, wasps, ants, moth, hover flies, several birds and Indian palm squirrel) visit flowers either for pollen or nectar or for facilitating self- and cross-pollination by their intra- and inter-tree movements. Among these, honey bees are dominant in number and in the amount of pollen on their body, while butterflies, ants, wasps, sunbirds, parrots, oriental white-eye sparrow and squirrels forage only for nectar and can be considered occasional pollinators or nectar thieves. Although flowers are highly visited, nectar in standing crop showed that flower visitors did not consume the total nectar produced. Nectar replenishment decreased with age in both bagged- and exposed flowers, showing the capability of secreting nectar after removal during the entire flower lifetime. Experimental hand-pollinations showed that naturalized C. citrinus fruits matured through autogamy, geitonogamy or xenogamy as was reported for native Australian populations. C. citrinus displays an interesting reproductive strategy, shows phenotypic plasticity of flowering periodicity and interacts with a generalized pollinator system, attracts a wide array of animal species with a conspicuous amount or replenished nectar after removals, and uses both compatibility strategies – xenogamy and autogamy – to ensure successful pollination and seed production at native or naturalized habitats. © 2017 SAAB

Agarwal M.,Bsa College | Chauhan S.,Academy of Life science
Medicinal Plants | Year: 2015

In the present study antibacterial activity of aqueous and alcoholic extracts of stem bark and leaves of Dolichandwne falcata (Wall, ex DC.) Seem (Bignoniaceae) was tested against MDR isolates DKU-156 and JAL-1236 of M. tuberculosis, reference susceptible strain M. tuberculosis H37Rv as well as fast growing mycobacterial pathogen M. fortuitum (TMC-1529). The leaves and bark collected between spring and summer season were dried and extracts was prepared using three portions of the dried powdered bark and leaves. It was soaked separately in 500 ml of distilled water and ethanol (98%) for 72 h and refluxed and filtrates were concentrated under vacuum at 40° C to obtain the dry extracts. Reference drug susceptible strain M. tuberculosis H37Rv as control, multi-drug resistant isolates DKU-156, JAL-1236 and fast growing mycobacterial pathogen M. fortuitum (TMC-1529) were used during the present investigation. Antimicrobial assays were performed in Lowenstein Jensen (L-J) medium and Middlebrook 7H9 broth in BacT/ALERT 3D system (Sigma-Aldrich, St. Louis, USA). The aqueous and alcoholic extracts of stem bark and leaves were incorporated in the media. Susceptibility testing of MDR isolates was also performed against streptomycin in the same batch of media for comparison of cfu on drug free controls. The results of the present investigation clearly showed that the aqueous extracts of stem bark were more effective as compared to aqueous and leaf extracts and alcoholic stem bark and leaf extracts. © 2015, All rights reserved.

Chauhan S.,Academy of Life science | Chauhan S.V.S.,Academy of Life science
Medicinal Plants | Year: 2014

The family Orchidaceae is one of the largest families of Angiosperms. It is cosmopolitan in distribution. Apart from being highly ornamental for it’s colourful and fragrant flowers and varied economic importance, the members of the family commonly called as orchids are of great medicinal importance. They have been used as a source of herbal remedies in China since 2800 BC. With increasing uses of herbal drugs, the demand for medicinal plants has increased many folds. Large number of orchids from north-eastern states of India is pirated to other parts not only for ornamental but for medicinal uses. This has caused great threat for extinction of orchids. Both in-situ and ex-situ conservation of orchids needs urgent attention. In the present review, medicinal properties of 24 genera and 56 species have been described. © 2014, All rights reserved.

Chauhan S.,Dr. B.R. Ambedkar University | Chauhan S.V.S.,Academy of Life science
Medicinal Plants | Year: 2012

The leaf and stem bark extracts from some species of Bignoniaceae (Adenochalyma alliaceum, Crescentia cujute, Millingtonia hortensis, Pyrostegia venusta and Tabebuia argentia), were found to show antibacterial activities towards the Gram-positive bacteria (Bacillus subtilis and Staphyloccus aureus), Gram negative (Escherichia coli) and yeast (Candida albicans). The extract of Tabebuia argentia was found to be the most active against the Grampositive bacteria.

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