title: Isolation, characterization, and evaluation of multi-trait plant growth promoting rhizobacteria for their growth promoting and disease suppressing effects on ginger.
abstract: In this study, 100 PGPR strains isolated from different varieties of ginger (Zingiber officinale Rosc.) were first characterized for their morphological, biochemical, and nutrient mobilization traits in vitro. The PGPR were also screened in vitro for inhibition of Pythium myriotylum causing soft rot in ginger. Results revealed that only five PGPR showed >70% suppression of P. myriotylum. These 5 PGPR viz., GRB (Ginger rhizobacteria) 25--Burkholderia cepacia, GRB35--Bacillus amyloliquefaciens; GRB58--Serratia marcescens; GRB68--S. marcescens; GRB91--Pseudomonas aeruginosa were used for further growth promotion and biocontrol studies in the green house and field. The green house study revealed that GRB35 (B. amyloliquefaciens) and GRB68 (S. marcescens) registered markedly higher sprouting (96.3%) and lower disease incidence (48.1%) and greater rhizome yield (365.6 g pot(-1) and 384.4 g pot(-1), respectively), while control registered the lowest sprouting (66%), maximum soft rot incidence (100%) and lowest rhizome yield (134.4 g pot(-1)). In the field experiments also, GRB68 (S. marcescens) and GRB35 (B. amyloliquefaciens) registered the greatest sprouting (80% each), markedly lower soft rot incidence (5.2% and 7.3%, respectively) and higher yield (5.0 and 4.3 kg(3)m(-2), respectively) compared to chemicals like Streptomycin sulphate (73.0%, 18.5% and 2.3 kg(3)m(-2), respectively), Metalaxyl-Mancozeb (73.0%, 14.0% and 3.8 kg(3)m(-2), respectively) and control (73.0%, 25.1% and 2.2 kg 3m(-2), respectively). Overall, the results suggested that for growth promotion and management of soft rot disease in ginger, GRB35 B. amyloliquefaciens and GRB68 S. marcescens could be good alternatives to chemical measures. Since, the latter has been reported to be an opportunistic human pathogen, we recommend the use of B. amyloliquefaciens for integration into nutrient and disease management schedules for ginger cultivation.
authors: ICAR-Indian Institute of Spices Research, P.O. Box 1701, Marikunnu P.O., Calicut 673012, Kerala, India. Electronic address: rdinesh2005@gmail.com.
authors: Raghavan
authors: R
authors: Dinesh
authors: ICAR-Indian Institute of Spices Research, P.O. Box 1701, Marikunnu P.O., Calicut 673012, Kerala, India.
authors: Muthuswamy
authors: M
authors: Anandaraj
authors: ICAR-Indian Agricultural Research Institute, New Delhi, India.
authors: Aundy
authors: A
authors: Kumar
authors: ICAR-Indian Institute of Spices Research, P.O. Box 1701, Marikunnu P.O., Calicut 673012, Kerala, India.
authors: Yogiyar Kundil
authors: YK
authors: Bini
authors: ICAR-Indian Institute of Spices Research, P.O. Box 1701, Marikunnu P.O., Calicut 673012, Kerala, India.
authors: Kizhakke Purayil
authors: KP
authors: Subila
authors: Plant Pathology and Microbiology (PLPM), Texas A&M University, College Station, TX, USA.
authors: Ravindran
authors: R
authors: Aravind
mesh_terms: D000898:Antibiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D020939:Zingiber officinale / Q000254:growth & development / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D011775:Pythium / Q000502:physiology*; D058441:Rhizosphere; D012988:Soil Microbiology
keywords: Bacillus amyloliquefaciens; Plant growth promoting rhizobacteria; Pythium myriotylum; Serratia marcescens; Zingiber officinale Rosc