Effects of Plant Growth Promoting Rhizobaceria on growth and yield of tef (Eragrostis tef Zucc. Trotter) under greenhouse condition

Abstract

The aim of this study was to assess the effect of Plant Growth Promoting Rhizobacteria (PGPR) on growth and yield of tef. About 160 bacteria were isolated from rhizosphere of tef (Eragrostis tef Zucc. Trotter) and characterized on the basis of PGPR and biochemical features. Four best isolates (AURB15, AURB34, AURB56 and AURB65) were selected and further characterized by physiological methods and identified to species level using API kit method. The selected isolates were then evaluated by inoculation on to two tef varieties (DZ-Cr-37 and DZ-01-974) at greenhouse condition. The isolates displayed diverse morphological, physiological, biochemical and PGPR characteristics. They showed growth in wide range of temperature, pH and NaCl. The isolates were found to belong to three genera and four species. Isolate AURB15 (Pseudomonas fluorscens) was observed to significantly increase mean root dry weight (39%), root shoot ratio (42%) and yield (45%) of the tef variety DZ-Cr-37; like wise isolate AURB65 (Bacillus subtilis) better increased mean root dry weight (28%), root shoot ratio (19%) and yield (44%) of tef variety DZ-01-974. Comparable mean shoot dry weight, % nitrogen and total protein (p>0.05) was recorded by inoculation the isolates. Where as inoculation of two isolates, AURB34 (Burkholderia cepacia) and AURB56 (Bacillus coagulans) on DZ-01-974 did not increase mean root dry weight, root shoot ratio and yield of DZ-01-974. The increase in mean root dry weight, root shoot ratio and yield of tef varieties DZ-Cr-37 and DZ-01-974 by AURB15 (Pseudomonas fluorscens) and AURB65 (Bacillus subtilis) suggests that the isolates have better potential for further field testing and application in improving yield of the tef varieties. © 2011 Academic Journals Inc.