Glomus mosseae associated bacteria and their influence on stimulation of mycorrhizal colonization, sporulation, and growth promotion in guava (Psidium guajava L.) seedlings

• Published in: Biological agriculture & horticulture 2012-12, Vol.28 (4), p.267-279
• Main Authors: Panneerselvam, Periyasamy, Mohandas, Sukhada, Saritha, Boya, Upreti, Kaushal Kishore, Poovarasan, Monnappa, Ajay, Sulladmath, Vijay Virupakshayya
• Format: Article
• Language: English
• Subjects: alkaline phosphatase; Bacillus subtilis; bacteria; biomass; Brevibacillus; chlorophyll; co-inoculation; cropping systems; fungi; glomalin; Glomus mosseae; growth promotion; guava; guavas; high performance liquid chromatography; indole acetic acid; leaf area; leaves; mycorrhiza associated bacteria; phenol; polymerase chain reaction; Pseudomonas aeruginosa; Pseudomonas putida; Psidium guajava; rhizosphere; ribosomal RNA; roots; seedlings; shoots; solubilization; spores; sporulation; vesicular arbuscular mycorrhizae; zinc
• ISSN: 2165-0616; 0144-8765; 2165-0616
• DOI: 10.1080/01448765.2012.741108

Arbuscular mycorrhiza (AM) associated bacteria were isolated from G. mosseae spores from different guava cropping systems in southern India. Seven bacteria were isolated and evaluated for their performance in stimulation of AM fungal colonization and spore proliferation in the roots of guava seedlings. Of the seven isolates, four G. mosseae associated bacterial isolates were selected based on their efficiency in stimulation of AM root colonization and spore production. They were identified as Pseudomonas putida (HM590706), Pseudomonas aeruginosa (HM590705), Brevibacillus sp. (HM590700), and Bacillus subtilis (HM590703) by polymerase chain reaction amplification of 16S rRNA. Ability of the four isolates to produce indole acetic acid and GA₃ was analysed by high performance liquid chromatography and their P and Zn solubilization potential was assessed in vitro. Of these isolates, P. putida was selected for further studies for growth promotion attributes and ability to stimulate AM fungal colonization and spore proliferation in guava seedlings. Further evaluation indicated that application of G. mosseae along with P. putida produced significantly higher leaf, stem, shoot, and root dry masses, total biomass, and total leaf area than other treatments followed by G. mosseae and P. putida alone. Application of G. mosseae with P. putida significantly increased the contents of leaf chlorophyll, phenol, and total glomalin, acid and alkaline phosphatase activities, AM fungal colonization, and spore population in the rhizosphere of guava seedlings compared with either G. mosseae or P. putida alone. The results obtained show that combined inoculation of G. mosseae with its associated bacterium, P. putida, significantly improved AM fungal colonization and spore proliferation in addition to enhancement of the growth promotion in guava seedlings. These findings have a significant impact for the raising of guava seedling root stocks for commercial multiplication.