English

Abstract

The role of plant growth promoting rhizobacteria for growth and rooting in Rosa damascena Mill. cuttings was evaluated in this study. Fifteen distinctive and fast growing rhizobacterial colonies (strains) were chosen to inoculate the Rosa cuttings by dipping in them. Growth parameters like shoot length, new shoot fresh weight, new shoot dry weight, root length, root fresh weight and root dry weight showed highly significant results while mortality percentage of cutting was non-significant. Results of the pot experiments revealed that most of the isolates showed growth promoting activities in Rosa cuttings except the isolates B5 which was proved to be growth limiting strain as it gave 20‒40% less result for all parameters. The most prominent results were produced by isolated strains F6 (Pseudomonas fluorescens), LSI19 (Rhizobium leguminosarum) and LC4 (Vibrios vulnificus). Isolate LSI19 showed maximum shoot length, new shoot fresh and dry weights with an increase (over un-inoculated control) of 51.6%, 55.2% and 48.0%, respectively. Root growth was positively influenced by isolate F6 with maximum root length and root fresh and dry weights (173.0%, 68.7% and 124.7%, respectively). All the other strains enhanced cutting growth characters up to 30‒60% compared to control. Strains LSI19, F6 and LC4 were proved to be superior strains in all growth attributes. Results on the bases of total score obtained by each strain in all growth parameters showed that strains LSI19, F6 and LC4 got first three positions. Therefore, these three strains (LSI19, F6 and LC4) were selected for further studies. © 2016 Friends Science Publishers