title: Plant growth-promoting traits of biocontrol potential bacteria isolated from rice rhizosphere.
abstract: Seven isolates of bacteria (SRI-156, SRI-158, SRI-178, SRI-211, SRI-229, SRI-305 and SRI-360) were earlier reported by us as having potential for biocontrol of charcoal rot of sorghum and plant growth promotion (PGP) of the plant. In the present study, the seven isolates were characterized for their physiological traits (tolerance to salinity, pH, temperature and resistance to antibiotics and fungicides) and further evaluated in the field for their PGP of rice. All the seven isolates were able to grow at pH values between 5 and 13, in NaCl concentrations of up to 8% (except SRI-156 and SRI-360), temperatures between 20 and 40°C and were resistant to ampicillin (>100 ppm; except SRI-158 and SRI-178) but sensitive (<10 ppm) to chloramphenicol, kanamycin, nalidixic acid, streptomycin (except SRI-156 and SRI-211) and tetracycline. They were tolerant to fungicides benlate and captan, except SRI-158 and SRI-178, bavistin and sensitive to thiram (except SRI-156 and SRI-211) at field application level. In the field, four of the seven isolates (SRI-158, SRI-211, SRI-229 and SRI-360) significantly enhanced the tiller numbers, stover and grain yields, total dry matter, root length, volume and dry weight over the un-inoculated control. In the rhizosphere soil at harvest, all the isolates significantly enhanced microbial biomass carbon (except SRI-156), microbial biomass nitrogen and dehydrogenase activity (up to 33%, 36% and 39%, respectively) and total N, available P and% organic carbon (up to 10%, 38% and 10%, respectively) compared to the control. This investigation further confirms that the SRI isolates have PGP properties.
authors: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, 502 324 Andhra Pradesh, India.
authors: Subramaniam
authors: S
authors: Gopalakrishnan
authors: Hd
authors: H
authors: Upadhyaya
authors: Srinivas
authors: S
authors: Vadlamudi
authors: Pagidi
authors: P
authors: Humayun
authors: Meesala Sree
authors: MS
authors: Vidya
authors: Gottumukkala
authors: G
authors: Alekhya
authors: Amit
authors: A
authors: Singh
authors: Rajendran
authors: R
authors: Vijayabharathi
authors: Ratna Kumari
authors: RK
authors: Bhimineni
authors: Murali
authors: M
authors: Seema
authors: Abhishek
authors: A
authors: Rathore
authors: Om
authors: O
authors: Rupela
keywords: Biocontrol; Field evaluation; Plant growth promotion (PGP); Rhizosphere bacteria; Rice
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