Natural Product Radiance 262 Research Article Introduction Pteridophytes (fern and fern allies) by virtue of their possessing great variety and fascinating foliage have drawn the attention and admiration of horticulturists and plant lovers for centuries. About 191 genera and more than 1000 species of pteridophytes are reported from India 1 . Medicinal value of them is known to man for more than 2000 years. Sushruta and Charaka (ca. 100 A.D.) mentioned medicinal uses of Marsilea minuta Linn. and Adiantum capillus-veneris Linn. in their Samhitas. Sharma and Vyas 2 studied ethnobotanical aspects of various pteridophytes of Rajasthan. They found that tribal people use various species of Athyrium for curing diseases. Gehlot and Bohra 3 studied antibacterial activities of leaf extracts of some ferns from Pachmarhi hills. Kaushik and Dhiman 4 conducted ethnobotanical studies of some common medicinal pteridophytes. Antibacterial and antifungal activities of various species of pteridophytes against various human pathogenic organisms were studied by the authors 5-8 . The screening and scientific evaluation of plant extract for their antimicrobial substance may prove beneficial for the mankind. Further, synergistic interaction among crude extracts or phytoconstituents in vitro may be useful in the preparation of improved polyherbal or drugs formulations. In the present investigation an attempt has been made to test in vitro antibacterial activity of Athyrium pectinatum found in Rajasthan against some human and plant pathogenic bacteria like, Agrobacterium tumefaciens, Escherichia coli, Salmonella arizonae, Salmonella typhi and Staphylococcus aureus. Athyrium pectinatum (Wall.) Presl. (Family — Athyriaceae) has creeping and branched rhizome; scales brown, lanceolate and up to 7 to 15 mm in length; stipes fragile, straw coloured, 10-35 cm long, lamina variable, broadly lanceolate to sub-deltoid with acuminate apex, decompoundly pinnate and finely dissected, pinnae stalked, distantly placed, 6-15 × 2-4.5 cm ascending with slender, naked, greenish rachides, pinnules, up to 15 × 6 mm, sub-deltoid, cut down into ultimate oblong, narrow segments with dentate margin, secondary rachides minutely pubescent, veins forked; sori minute, indusium thin, membranous; spores dark brown. The plant is common in Mt. Abu area and is frequently used by the Bheels for medicinal purpose. The young leaves are used as vegetable. The rhizome is considered as a strong anthelmintic 2 . Materials and Methods Collection and identification of plants The specimens of plant were collected from Mt. Abu in Rajasthan during the month of August 2001 and their identity was confirmed through literature available in the Department of Botany, J.N. Vyas University, Jodhpur. Antibacterial activity of Athyrium pectinatum (Wall.) Presl. Pradeep Parihar 1 *, Leena Parihar 1 and Achaleshwar Bohra 2 1 Department of Microbiology and Biotechnology Dr. Tanveer Malawat College of Biosciences, Bikaner-334 003, Rajasthan, India 2 Microbiology Laboratory, Department of Botany, J. N. Vyas University, Jodhpur- 342 001, Rajasthan *Correspondent author, E-mail: pradeepparihar2002@yahoo.com Received 4 July 2005; Accepted 13 October 2005 Abstract Aqueous and alcoholic extracts of plant parts of Athyrium pectinatum (Wall.) Presl. were tested against the growth of some human and plant pathogenic bacteria like, Agrobacterium tumefaciens, Escherichia coli, Salmonella arizonae, Salmonella typhi and Staphylococcus aureus. Nearly all the extracts were found effective against these bacteria. The positive results so obtained were compared with that of the reference standard antibiotic (Tetracycline). It was found that extracts when mixed in equal proportion with the antibiotic were more effective against bacteria than the antibiotic alone. Keywords: Antibacterial activity, Athyrium pectinatum, Ferns, Pteridophytes. IPC code; Int. cl. 7 — A61P 31/04 Natural Product Radiance, Vol. 5(4), 2006, pp.262-265