Abstract

ISOLATION AND CHARACTERIZATION OF STREPTOMYCES SPP. FROM TURMERIC PLANTATION SOILS FOR ANTAGONISTIC ACTIVITY AGAINST PYTHIUM APHANIDERMATUM, A CAUSAL PATHOGENIC ORGANISM OF RHIZOME ROT DISEASE OF TURMERIC PLANTS

M. Nithya*, P. Ponmurugan and B. Mythili Gnanamangai

ABSTRACT

An attempt was made to isolate and characterize subsequently identify Streptomyces spp. from turmeric plantation soils collected from different agroclimatic zones of Tamil Nadu, India for the present study with respect to the production of bioactive secondary metabolites. Soil samples were collected from different places such as Coimbatore, Dharmapuri, Erode, Salem and Viluppuram districts of Tamil Nadu in which 100 soil samples were collected and subjected to screen for the isolation of Streptomyces spp. The results indicated that the population density of Streptomyces spp. in turmeric soils was found to be more in Coimbatore (14.7x103 cfu /gm soil dry wt) region followed by Erode (13.7) and lesser in Viluppuram (9.0) region. The population density of Streptomyces spp. was interrelated with the nutrient status of turmeric soils which is positive correlated. A total of 25 isolates of Streptomyces were obtained from soil samples on starch-casein agar and subjected to purify them for their antagonistic activity against rhizome rot disease causing pathogenic microorganism Pythium aphanidermatum. Based on the morphological, biochemical and physiological parameters, a total of five potential isolates were picked up and identified as Streptomyces spp. Based on the in vitro performance, CS12 isolate was promising in terms of antibiotics production when compared to other isolates of Streptomyces. The results on antagonistic studies indicated that the pathogen’s growth was suppressed significantly in the in vitro studies and it was found to be of potential antagonist against P.aphanidermatum.

Keywords: Turmeric soils, Actinomycetes, Streptomyces, Antagonistic activity, Pythium aphanidermatum.