title: Evaluation of Streptomyces spp. for their plant-growth-promotion traits in rice.
abstract: Five strains of Streptomyces (CAI-17, CAI-68, CAI-78, KAI-26, and KAI-27) were previously reported to have potential for charcoal rot control and plant growth promotion (PGP) in sorghum. In this study, those 5 Streptomyces strains were characterized for their enzymatic activities and evaluated for their PGP capabilities on rice. All the Streptomyces strains were able to produce lipase and β-1,3-glucanase; grew in NaCl (up to 8%), at pH 5-13, and at temperatures 20-40 °C; and were resistant to ampicillin, sensitive to nalidixic acid, and highly sensitive to chloramphenicol, kanamycin, streptomycin, and tetracycline. They were highly tolerant to the fungicide bavistin but were highly sensitive to benlate, benomyl, and radonil. When evaluated on rice in the field, Streptomyces significantly enhanced tiller and panicle numbers, stover and grain yields, dry matter, root length, volume and dry weight, compared with the control. In the rhizosphere at harvest, microbial biomass carbon and nitrogen, dehydrogenase activity, total nitrogen, available phosphorus, and % organic carbon were also found significantly higher in Streptomyces-treated plots than in the control plots. This study further confirms that the selected Streptomyces have PGP activities.
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502 324, Andhra Pradesh, India.
authors.forename: Subramaniam
authors.initials: S
authors.lastname: Gopalakrishnan
authors.forename: Srinivas
authors.initials: S
authors.lastname: Vadlamudi
authors.forename: Shravya
authors.initials: S
authors.lastname: Apparla
authors.forename: Prakash
authors.initials: P
authors.lastname: Bandikinda
authors.forename: Rajendran
authors.initials: R
authors.lastname: Vijayabharathi
authors.forename: Ratna Kumari
authors.initials: RK
authors.lastname: Bhimineni
authors.forename: Om
authors.initials: O
authors.lastname: Rupela
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D043326:Glucan 1,3-beta-Glucosidase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000254:growth & development / Q000382:microbiology*; D010758:Phosphorus / Q000378:metabolism; D054712:Salinity; D012988:Soil Microbiology; D013302:Streptomyces / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D013696:Temperature
chemical_list: D000890:Anti-Infective Agents; D010758:Phosphorus; D002244:Carbon; D008049:Lipase; D002480:Cellulase; D043326:Glucan 1,3-beta-Glucosidase; D009584:Nitrogen