The Influence of Klebsiella oxytoca on the Germination of Brassica spp.

Germination of Brassica integrifolia and B. rapachinensis was investigated in the presence of Klebsiella oxytoca isolated from soil. Morphological properties, ammonium production, phosphates and potassium solubilization index, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, cellulose activity, and the production of gibberellic acid (GA) in the isolates were determined. Three isolates were chosen to test their effects on the germination of Brassica spp. The highest shoot (2.29 cm) and root length (1.64 cm) of B. rapachinensis seed were recorded for single inoculation with strain H1-702. Results showed that H1-702 was also the best treatment for stimulation of germination in B. integrifolia where shoot length, root length and percentage of germination were 1.70 cm, 2.58 cm and 97%, respectively. Interestingly, the average shoot length of B. integrifolia (1.66 cm) was lower than that -of' B. rapa chinensis (1.94 cm), while its average root length was nearly double that of B. rapachinensis at 2.49 cm and 1.37 cm, respectively. Hence, at germination, leafy B. integrifolia tended to have increased root length, while the B. rapachinensis petiole grew shoots at this stage. 16S Rrna sequence analysis, after comparison of the nucleotide databases, indicated that the isolate H1-702 had 99.93% similarity with Klebsiella oxytoca. Results indicated that Klebsiella oxytoca has the potential to promote plant growth.