ANTIBACTERIAL SCREENING OF A FEW MEDICINAL FERNS AGAINST ANTIBIOTIC RESISTANT PHYTO PATHOGEN

Centella asiatica is a medicinal plant. It is severely affected by leaf spot disease caused by a harmful, antibiotic resistant phyto pathogen Xanthomonas campestris pv. centellae (X. c. pv. c). Farmers used synthetic pesticides to control the disease. When pesticides are applied to control this pathogen, pesticides may cause environmental hazards and health problems in man. But traditionally plants are used to prevent or control the plant diseases in agriculture. It is an eco- friendly, biocontrol, traditional method. Hence the aim of the present study is to control the pathogen in biocontrol method by screening the phytochemicals and antibacterial activity of petroleum ether, chloroform, benzene, methanol and aqueous extracts of fronds of five ferns (Pteridophytes) Adiantum caudatum, Angiopteris evecta, Pteris confusa, Pteris argyraea and Lygodium microphyllum against X. c. pv. c. The methanol extracts of all the ferns gave successful result against the tested bacteria. Phytochemical analysis of all the extracts revealed that antibacterial activity is due to the presence of alkaloids, flavonoids and phenolic compounds. According to the results of MIC (Minimum Inhibitory Concentration) and RPI (Relative Percentage Inhibition) values, Angiopteris evecta could be used as potential plant for the management of pathogenic bacteria, X. c. pv. c which is known to cause diseases on many vegetables and cash crops particularly Centella asiatica.