Cold tolerance and plant growth promotion potential of Serratia marcescens strain SRM (MTCC 8708) isolated from flowers of summer squash (Cucurbita pepo)

AIM: To determine the cold tolerance and plant growth promotion potential of Serratia marcescens strain SRM (MTCC 8708). METHODS AND RESULTS: Serratia marcescens strain SRM was isolated from the flowers of summer squash plants, showing no apparent symptoms of yellow vine disease. It was evaluated for growth and plant growth promotion attributes at 15 and 4 degrees C. At 15 degrees C, the isolate was able to solubilize 76.6 microg ml(-1) of P and produce Indole Acetic Acid, IAA (11.1 microg ml(-1)). HCN and siderophore production were also detected at 15 degrees C. The isolate retained all the plant growth promotion traits at 4 degrees C. Seed bacterization with the isolate significantly enhanced plant biomass and nutrient uptake of wheat seedlings grown in cold temperatures. CONCLUSION: Serratia marcescens strain SRM is a promising cold-tolerant isolate that can significantly influence wheat seedling growth at cold temperatures. SIGNIFICANCE AND IMPACT OF THE STUDY: This strain can be employed as a bioinoculant in cold temperature conditions.