Genetic characterization of <i>Burkholderia cepacia</i> strain from Northeast India: A potential bio-control agent

Abstract

This paper reports the characterization of naturally occurring rhizobacteria from NE India for the control of wilt and damping-off diseases in French beans. French bean (<i>Phaseolus vulgaris</i> L.) is one of the most important food legumes for direct human consumption which was originated from South and Central America. In NE India wilt and damping-off in beans are serious diseases which are mainly caused by <i>Fusarium spp</i> and <i>Rhizoctonia solani</i>. Out of 625 bacterial isolates obtained from French bean growing fields of Manipur, 15 potential isolates were selected, whose inhibition zone width were more than 15 mm. Strain IBSD-LKBI exhibited strong antagonistic activity and can inhibit both the pathogens. Besides, this strain also produced extracellular hydrolytic enzymes (protease, chitinase, <i>β</i>-1, 3-glucanase), secondary metabolites (Siderophore, HCN). It also produces plant growth promoting hormone (IAA) and can solubilize organic phosphate. <i>Burkholderia cepacia</i> IBSD-LKBI exhibited the highest plant growth promotion and BCA. After 60 days of treatment, plant height, root length, fresh weight and % of disease suppression were significantly (P < 0.05) higher than in control plants. Productions of secondary metabolites were detected using gene specific primer. This bacterium was phenotypically characterized and sequence data of 16S rDNA revealed the closest identity with <i>Burkholderia cepacia</i> (98%). Multiple sequence alignment & phylogram with closely related sequence accessions using MEGA Software revealed this naturally occurring biocontrol bacteria belongs to <i>Burkholderia cepacia</i> complex genomovar I based on the Biolog identification system with 16S rDNA gene sequence analysis. This organism is one of the new reports from NE India for the control of wilt and damping-off diseases in French beans

Screening of Groundnut Plant Associated Rhizobacteria for Multiple Plant Beneficial Plant Growth Promoting Traits

“…Therefore their antagonistic activity would be related to the production of the inhibitory substances such as HCN, ammonia and chitinase. Similar observation was also obtained in various study where it have reported that production of fungal cell wall degrading enzymes (glucanase, chitinase, protease) and secondary metabolites (Siderophore and HCN) are common mechanisms associated with bacterial antifungal activities [38,39].…”

Screening of bacterial strains for developing effective pesticide-tolerant plant growth-promoting microbial consortia from rhizosphere soils of vegetable fields of eastern Uttar Pradesh, India

“…All strains have the ability to synthesize IAA production in broth culture in the presence of tryptophan. Burkholderia cepacia IBSD-LKBI produced significant level of IAA at the rate of 58.4 lg/ml in culture filtrate (Devi et al 2012). The conversion of tryptophan into IAA is the most important mechanism of soil microbes (Mohite 2013).…”

The Abilities of Endophytic and Biofertilizing Bacteria and Their Combinations to Suppress Bacterial Wilt Disease (Ralstonia solanacearum) of Chili

“…The ability of Psolubilizing bacteria Burkholderia or Pseudomonas cepacea to control plant diseases was also reported in other experiments. They were able to suppress Phytophthora disease in chili [16], damping off disease and Fusarium diseases in French bean [15].…”

“…Azotobacter chroococcum is Nitrogen fixing bacteria that can produce exopolysaccharide [11] and has been reported to increase the growth of lettuce [12]. Some PGPR that has potential as biofertilizer can also showed suppressive effects on plant diseases [13][14][15][16].…”