R. Rangeshwaran ¹, A. R. Wasnikar ², R. D. Prasad ¹, N. Anjula ¹, C. R. Sunanda ¹

Affiliations
1 Project Directorate of Biological Control (ICAR), Post Bag No. 2491, H. A. Farm Post, Bellary Road, Hebbal, Bangalore 560 024, Karnataka, IN
2 Department of Plant Pathology, Jawaharlal Nehru Krishi Vishwa Vidhyalaya, Jabalpur 482 004, M. P., IN

Abstract

Twentyfive endophytic bacteria were isolated from internal tissues of ischolar_main and stem portions of chickpea, sunflower, niger, chilli and capsicum plants. The endophytes were screened in dual culture on Potato Dextrose Agar (PDA) and Tryptic Soya Agar (TSA) against Fusarium oxysporum f. sp. ciceri, Fusarium udum, Rhizoctonia solani and Sclerotium rolfsii. Ten isolates exhibited inhibition of the pathogens. Maximum percent inhibition (37.93) of F. oxysporum f. sp. ciceri was obtained on PDA with B. subtilis (PDBCEN 3). On TSA percent inhibition was maximum (52.21) with isolate PDBCEN-7. Testing against F. udum in dual culture test revealed that Pseudomonas sp. (PDBCEN 8) showed maximum (40.45%) inhibition on PDA. Pseudomonas sp. (PDBCEN-2) was highly effective on TSA and showed maximum (56.9%) inhibition zone. Against R. solani, maximum inhibition (44.96%) was recorded with endophyte PDBCEN 7. On TSA all the ten endophytic bacteria were effective in restricting the growth of test fungus. Percent inhibition of S. rolfsii was maximum (40.93%) with Pseudomonas sp. (PDBCEN 6) on PDA. On TSA percent inhibition was maximum (46.73%) with P. fluorescens (PDBCEN 1). The endophytic isolates were able to promote better growth of chickpea but the vigour index varied between the isolates. We could not correlate high pathogen inhibition under in vitro with high vigour index.

Keywords

Biological Control, Endophytic Bacteria, Wilt Pathogens.

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R. K. Srivastava ¹, R. D. Prasad ², R. Rangeshwaran ², A. R. Wasnikar ³, S. P. Singh ², N. S. Rao ²

Affiliations
1 Crop Research Station, Narendra Deva University of Agriculture and Technology, Bahraich 271 801, U. P., IN
2 Project Directorate of Biological Control (ICAR), P. B. No. 2491, H. A. Farm Post, Hebbal, Bangalore 560 024, Karnataka, IN
3 Department of Plant Pathology, Jawaharlal Nehru Krishi Vishwa Vidhyalaya, Jabalpur 482 004, M. P., IN

Abstract

Eight Trichoderma isolates were tested for their bioefficacy against seed, ischolar_main and seedling rot incited by Rhizoctonia solani by adopting an in vivo test method (blotter test). Vigor index ranging from 169.5 to 2239.4 and disease incidence ranging between 10 to 86 percent were recorded in various treatments. All bioagents were graded based on disease grading key proposed for their rating. The clear differentiation of efficacy of various Trichoderma species against R. solani obtained with the in vivo bioefficacy test method adopted (blotter test) in the present study shows suitability of this method for routine screening of fungal biocontrol agents against seed and soil borne plant pathogens.

Keywords

Fungal Antagonists, in vivo Bioassay, Plant Pathogens.

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