Isolation of Bacteria from Rhizosphere, Phylloplane and Caulosphere of Brinjal (Solanum melongena L.)

Abstract

Rhizosphere, phylloplane and caulosphere is the region where a complex community of microbes, mainly bacteria and fungi are present. The microbe- plant interaction in these regions can be beneficial, neutral, variable, or deleterious for plant growth. The bacteria that exert beneficial effects on plant development are termed plant growth promoting bacteria. To isolate the bacteria from rhizosphere, phylloplane and caulosphere of brinjal (Solanum melongena L.). The seeds of 16 cultivars of brinjal (Solanum melongena L.) viz., Arka keshav, Arka shirish, Arka kusumaker, and IIHR accession numbers 389,386,387,377 Tc, BB44, 391, 433, 434, 427, 447, 448, 476 and 487 that were used in the initial screening experiment were obtained from the Department of Vegetable crops, IIHR, Hessaraghatta, Bangalore. Brinjal (Solanum melongena L.) plants of different varieties were collected from seven locations around Bangalore viz., Hessaraghatta, Yelahanka, Kengeri, Madi vala, Hebbal, Tirumalapura and Attibele were also screened for the presence of associative bacteria. Associative microorganisms isolated from the rhizosphere, phylloplane and shoot regions of brinjal (Solanum melongena L.), revealed the presence of three morphologically different colonies. 80% of 16 cultivars of the brinjal (Solanum melongena L.) screened showed the presence of associative bacterial colonies. In this study diazotrophic BBI were obtained from the rhizoplane, phylloplane and stem of 16 cultivars of brinjal (Solanum melongena L.) that were screened. The dominant pearl-colored colonies isolated from all varieties of brinjal plants that were screened was identified and showed maximum nitrogen fixing ability compared with that of the other colonies. The phylloplane of brinjal (Solanum melongena L.) plants from seven different locations around Bangalore showed the presence of the dominant pearl-colored colonies. Moderate growth of bacteria was observed in root, stem and leaf bits sterilized up to 35 minutes. Even on surface sterilized roots which were homogenized and inoculated on growth media, dense growth of bacteria was observed there by establishing the presence of bacteria inside the root system. For the first time the presence of growth promoting bacteria on the rhizosphere and endorhizosphere of brinjal (Solanum Melongena L.) cultivars was established.