Abstract
Low-cost forest management using highly effective microorganisms to promote seedling and tree growth is an important issue in reforestation in Indonesia and other tropical rain forest zones. To survey effective plant growth-promoting rhizobacteria (PGPR) for dipterocarp seedlings and/or saplings, forty-four bacterial strains were isolated from rhizoplane of several Dipterocarpaceae seedlings and saplings in Carita plantation forest located in the western part of Java Island followed by test for their effectiveness on the growth of Shorea selanica. Some isolated rhizobacteria demonstrated growth-promoting activity on dipterocarp seedlings. In the primary bioassay, these rhizobacteria indicated positive, negative or no effect on the plant growth, and 16S rRNA gene sequences of some important isolates were determined for their tentative identification. The most prominent strain isolated from Shorea leprosula was Erwinia. Other effective isolates were tentatively identified as, Rhizobium, Enterobacter, Duganella, an Alcaligeneceae bacterium, an Oxalobacteraceae bacterium, and some yeasts.
