Potential of indole acetic acid producing rhizobacteria to Promote the growth and increase the yield of edamame,A vegetable soybean (glycine max)

Abstract

Five isolates of indole acetic acid (IAA) producing rhizobacteria have been isolated from rhizospheres of plants grown in Bali, Indonesia. Based on 16s rRNA gene analysis those isolates were identified as Stenotrophomonas maltophilia Sg3 Proteus mirabilis BjB17, Providencia rettgeri AlDp5, Bacillus thuringiensis TNJbx.3.3, Bacillus cereus GR12. All of these isolates significantly (P<0.05) increased relative growth rate (RGR), net assimilation rate, leaf size, chlorophyll content of leaf, dry weight of roots and shoots, number of root nodules of edamame, a vegetable soybean.  Treatment with rhizobacteria was also significantly (p<0.05) increased number of pod plant^-1,  weight of pods plant^-1, pod weight, and protein content in the seed. Five isolates of IAA producing rhizobacteria treatment increased the number of pod plant^-1 ranged from 42.06% to 54.48%, weight of pods plant^-1 ranged from 69.62% to 91.08%, pod weight ranged from 13.91% to 28.53% when compared to control. In general, Stenotrophomonas maltophilia Sg3 showed the highest ability to promote the growth and increase the yield of edamame. These results suggested that this isolate is the most promising bio-stimulant to increase productivity of edamame in Indonesia.