Screening and characterization of antifungal clusterbean (Cyamopsis tetragonoloba) rhizobacteria

• Published in: Biocontrol science and technology Vol. 18; no. 1-2; pp. 139 - 156
• Main Authors: Bajoria, S, Varshney, A.K, Pareek, R.P, Mohan, M.K, Ghosh, P
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 2008
• Subjects: Achromobacter xylosoxidans; Arachis hypogaea; Bacillus; Bacillus subtilis; biological control; biological control agents; Cicer arietinum; Cyamopsis tetragonoloba; disease control; functional diversity; fungal antagonists; fungal diseases of plants; Fusarium oxysporum; guar gum; Macrophomina phaseolina; microbial genetics; microbial growth; molecular sequence data; nucleotide sequences; pathogenicity; phylogeny; plant pathogenic fungi; proteinases; Pseudomonas aeruginosa; Pumilus; Ralstonia; rhizobacteria; Rhizobiales; ribosomal RNA; salt tolerance; India
• ISSN: 0958-3157; 1360-0478
• DOI: 10.1080/09583150701818972

About 377 guar (Cyamopsis tetragonoloba) rhizobacteria were isolated from cultivated soils of north-west India (Thar Desert) and their antifungal activity against Macrophomina phaseolina (strains of groundnut, mungbean and guar) and Fusarium oxysporum (strains of chickpea and cumin) was examined. Isolates were characterised for generic types and physiological/functional diversity. About 19% isolates representing 24% locations were inhibitory to fungal growth. Isolates 009071, 009073, 009078 and 102354 recorded maximum inhibition of pathogenic fungi on plates. Isolate 034206 gave highest %RI, 009073 showed maximum protease activity and 102354 gave highest salt tolerance. Net house and field screening results revealed that isolates 004052, 009071, 009073, 001001, 094340 and 102354 had potential for biocontrol of disease. Partial sequencing of 16S rRNA gene of 61 isolates showed that 85% of isolates belonged to genus Bacillus. Phylogenetically, however, there were four clusters in the Bacillus group comprising of Bacillus subtilis, B. cereus, B. pumilus and B. sphaericus. One isolate was identified as B. flexus, while six isolates were Bacillus spp. Four isolates were identified as Achromobacter xylosoxidans, two as Bacterium (unclassified bacteria), and one each as Ochrobactrum intermedium, Pseudomonas aeruginosa and Ralstonia sp.