Impact of microorganism inoculation on growth and Si accumulation in rubber seedlings.

Microbial agents present in soil rhizosphere play a key role in reducing intensive use of inorganic fertilizers, which cause environmental pollution and negatively affect soil fertility. To improve plant growth, microbial agents with silicon (Si) can be used in combination with chemical fertilizers. In this glasshouse study, co-inoculants Enterobacter sp. UPMSSB7, mycorrhizae (Glomus mosseae) and addition of Si were evaluated for growth improvement of rubber seedlings. Results of this study indicated that co-inoculation significantly (P < 0.01) improved stem height, chlorophyll content, leaf area, root and shoot dry weight, total root length, root surface area, and root volume as compared to control treatment. The co-inoculation significantly (P < 0.01) increased Si content in shoot and root as well as leaf nutrients content (N, P, and K) as compared to control treatment. Si alone had no effect on seedling growth and nutrients content. The population of Enterobacter sp. UPMSSB7 in rhizosphere of seedlings as a result of co-inoculation, was not significantly different from Enterobacter sp. UPMSSB7 with Si treatment. The mycorrhizae root colonization and spore density were significantly (P < 0.01) increased in co-inoculation, compared to control and single inoculations with Si. Thus, our results suggested that co-inoculants Enterobacter sp. and mycorrhizae could be an eco-friendly approach for growth promotion of rubber seedlings. [ABSTRACT FROM AUTHOR]