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bioRxiv · 10.1101/310797

Diversity of Culturable Endophytic bacteria from Wild and Cultivated Rice showed potential Plant Growth Promoting activities

Borah, M.·Das, S.·Boruah, H.·Boro, R.·Barooah, M.
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Abstract

In this paper, we report the endophytic microbial diversity of cultivated and wild Oryza sativa plants including their functional traits related to multiple traits that promote plant growth and development. Around 255 bacteria were isolated out of which 70 isolates were selected for further studies based on their morphological differences. The isolates were characterized both at biochemical and at the molecular level by 16s rRNA gene sequencing. Based on 16S rRNA gene sequencing the isolates were categorized into three major phyla, viz, Firmicutes (57.1 %), Actinobacteria (20.0 %) and Proteobacteria (22.8 %). Firmicutes was the dominant group of bacteria of which the most abundant genus was Bacillus. The isolates were further screened in vitro for plant growth promoting activities which revealed a hitherto unreported endophytic bacterial isolate, Microbacteriaceae bacterium RS01 11 as the highest secretor of a phytohormone, IAA (28.39 {+/-} 1.39 g/ml) and GA (67.23 {+/-} 1.83 g/ml). Bacillus subtilis RHS 01 displayed highest phosphate solubilizing activity (81.70 {+/-} 1.98 g/ml) while, Microbacterium testaceum MK LS01, and Microbacterium trichothecenolyticum MI03 L05 exhibited highest potassium solubilizing activity (53.42{+/-}0.75g/ml) and zinc solubilizing efficiency (157.50%) respectively. Bacillus barbaricus LP20 05 produced highest siderophore units (64.8 %). Potential plant growth promoting isolated were tested in vivo in pot culture under greenhouse conditions. A consortium consisting of Microbacteriaceae bacterium RS01 11, Bacillus testaceum MK LS01 and Bacillus subtilis RHS promoted plant growth and increased the yield 3.4 fold in rice when compared to control T0 when tested in pot culture and reduce application rates of chemical fertilizer to half the recommended dose. Our study confirms the potentiality of the rice endophytes isolated as good plant growth promoter and effective biofertilizer.

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Borah, M., Das, S., Boruah, H., Boro, R., Barooah, M.. 2018-04-30. Diversity of Culturable Endophytic bacteria from Wild and Cultivated Rice showed potential Plant Growth Promoting activities. https://doi.org/10.1101/310797

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