1. C. falcatum mycelia growth (mm) on tenth day
Screening of antagonistic endophytic bacteria against Colletotrichum falcatum causing red rot in Sugarcane crop
Beenu Shastri, Rajesh Kumar *
Department of Environmental Microbiology, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow , U.P.
INTRODUCTION
RESULTS
Total 51 endophytes bacteria have been isolated from root and stalk of sugarcane variety.
Among them , Isolates 1148-B5, 1148-S11, and 1148-S12 gave strongest inhibition against C. falcatum.
Sugarcane (Saccharum officinarum) occupied a prized position in the agrarian economy of India. It is affected with one of the devastating disease known as red rot .
Red rot disease is the “Cancer” of sugarcane (Khan et al., 2011). It is caused by fungal pathogen C. falcatum.
In India, the estimated loss in sugarcane crop production due to fungal diseases is about 18-31% (Jayashree et al., 2010).
Endophytic bacteria could be better alternative against the problem of crop losses due to red rot pathogen.
They accompaniment certain metabolic properties such as plant growth promotion, controlling phytopathogen or helping host plant to defeat stress response (Compant et al., 2005).
Studies also suggested relevant information that endophytic bacteria showed significant control of disease occurring in various crops of rice and potatoes (Sturz, 1995, Hurek et al., 1994).
Prevalence of endophytic PGPR strains in sugarcane has been established and their antagonistic activity against red rot pathogen demonstrated.
Hence, the present study aims to screen the endophytic bacterial community from the tissues of sugarcane variety against the red rot fungus C. falcatum.
Sugarcane variety
Co 1148
Potent antagonistic isolates from Co 1148
Antagonism
against C. falcatum
Table. 1. showing % age inhibition of antagonistic isolates .
S. No
Isolates
C. falcatum mycelia growth (mm) on tenth day
% Inhibition 1
Control
74±4 - 2
1148 -B5
12±2
81.5 ± 5 3
1148 -S11
9±1
85 ± 2.5 4
1148-S12
10±2
84.4 ± 5
OBJECTIVES
To collect healthy asymptomatic sugarcane variety from the field of IISR, Lucknow.
To isolate the endophytic bacteria from the roots and stalk tissues of healthy sugarcane variety.
Screening of antagonistic activity of isolated endophytes against red rot pathogen C. falcatum in vitro.
Further, evaluation of isolated potent antagonistic bacteria for plant growth promotory activities in vitro.
Morphological and Biochemical characterization
1148- B5
1148- S11
1148- S12
Gram staining of isolates
1148-S11
1148-B5
1148-S12
Control
Citrate Utilisation
Urease Production
Cellulase
Amylase
Caseinase
METHODOLOGY
Isolation of endophytic bacteria from the healthy sugarcane variety Co1148 on LB agar plate with a modified method (Sturz et al.,1998; Surette et al., 2003; Viswanathan et al., 2003).
Dual culture antagonism of isolated endophyte against C. falcatum on PDA plate (Viswanathan et al., 2003).
Morphological and biochemical characterization of potent antagonistic isolates (Vincent 1970).
PGP characterization for screening of isolates.
Phosphate solubilization (Pikovaskaya, 1948)
IAA production (Loper and Schroth , 1986)
HCN production (Bakker and Schippers ,1987)
PGP Characterization of Isolates
1148– B5
1148- S11
1148- S12
Control
1148-B5
1148-S11
1148-S12
Phosphate solubilization
IAA production
HCN production
CONCLUSION
Isolates 1148-B5, 1148-S11 and 1148-S12 exhibited strong antagonism against red rot fungus C. falcatum with above 80% inhibition in vitro.
Isolated endophytic bacteria showed promising result for phosphate solubilisation, IAA production and HCN production.
Thus, on the basis of screening these isolates taken for future work which might work as biocontrol agent and plant growth promoter.
SIGNIFICANCE
Bacterial communities inside the sugarcane for the management of red rot disease would be explored.
Endophytic bacteria avoid the unfavourable biotic and abiotic conditions of environment by residing in the intercellular spaces of plant. Therefore, it could be a holistic approach for biocontrol purpose .
Plant growth promotion in sugarcane crop might increases due to plant mineral uptake and improved plant water relationship associated with colonization of endophytic strains .
REFERENCES
Compant, S., B. Reiter, A. Sessitsch, J. Nowak, C. Clément, and E. A. Barka (2005) Appl. Environ Microb. 71,
Jayashree, J., A. Selvi, and N.V. Nair (2010) J. Plant Breed. 1,
Sturz, A.V., B.R. Christie, and B.G. Matheson (1998) Can. J. Microbiol. 44,162–167.
Surette, M.A., A.V. Sturz, R. Rajasekaran, R.R. Lada, and J. Nowak (2003) Plant Soil. 253,381–390.
Viswanathan, R., R. Rajitha, R. A. Sundar, and V. Ramamoorthy (2003) Sugar Tech. 5, 25 – 29.
International Seminar on
Recent Trends and Experimental Approaches in Science , Technology and Nature, IISR , Lucknow.