| dc.description.abstract | Plants are associated with vast and diverse group of microorganisms including bacteria,
and fungus. Endophytic bacteria were used as biofertilizers and biocontrol agents for increasing
croup cultivation. The purposes of present study was isolation and biomolecular characterization
of diazinon pesticide degrading endophytes from rice plants and to evaluate there plant growth
promoting properties. Synthetic, colorless liquid organophosphorus pesticide diazinon was used
as sole carbon source in minimal salt media for isolation of target endophytes from the roots, shood
and leaves of healthy Oryza sativa plants from two different aman rice field. By Screening of
morphological characteristics F1LD1, F1LD2, F1LD3, F1SD1, F1SD2, F1SD3, F1RD1, F1RD2,
F1RD3, F1RD4 were collected from field 1 and F2D1L, F2D2L,F2D3L, F2D1S, F2D2S,F2D3S,
F2D1R, F2D2R,F2D3R, F2D4R were collected from field 2. They were characterized based on
biochemical reaction, different cellulytic enzyme production, bioremediation, antagonism, invitro
and invivo growth promotion potentials. All of them 12 endophytes were primarily selected for
morphological characteristics by 16S gene sequence and 9 different genera of endophytic isolates
were found as Pantoea sp(F1SD1), Burkholderia sp (F1RD4), Klebsiella sp (F1RD4),
Pseudomonas sp (F2D1R), Bacillus sp (F2D2R), Enterobacter sp (F1LD2), Shigella sp (F2D3L),
Kosakonia sp (F2D2L) and Serratia sp (F2D1S). In biochemical reaction oxidase catalase and
triple suger iron agar test were shows positive reaction on the other hand indole gives negative
reaction by all of isolates. Except F1RD4, F2D3L and F2D1R all other endophyte were give urease
test positive. Thirteen of the isolates shows negative test for methyl red (MR) test, whereas
fourteen of the isolates shows positive test for Voges- proskauer (VP). Seventeen of the isolates
given MIU test positive on the other hand three isolates are given negative result are they F1RD1,
F1RD2 and F2D1R. To assay fermentation of sucrose, lactose dextrose and maltose majority of
endophytes were shows ablity to uses this carbohydrate as carbon source, only F1RD1 against
sucrose and F2D1R against maltose shows negative result. All isolates produced xylanase, amylase
and protease enzymes by liquefaction of the target medium but non of them can produce pectinase
enzyme. Without F1RD2, F2D2L and F2D1S all other produce cellulose enzyme. The dye
degradation assay represent that all isolated endophytes can survive 1% dye containing MSM
medium by using avitera blue, bromothymol blue, toluidine blue, trypan blue and congo red as
their sole carbon source. The FTIR spectrum of diazinon degradation by isolated endophytes give
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significant bioremediation potential. The significant antagonistics activity of isolated endophyts
were also shows against huuman pathogenic bacteria S. Aureus and S. epidermidis. Out of the
twenty isolates eighteen isolates can fix atmospheric nitrogen in the nitrogen free media. Eight of
the isolates, LD2-F1, LD3-F1, SD3-F1, D1L-F2, D2L-F2, D1S-F2, D3S-F2 and D3R-F2 showed
high growth with clear holo gone in Jensen’s medium. Without F1RD4 and F2D2R stain, all other
isolated endophytes were capable of producing a halo/clear zone due to solubilization of inorganic
phosphate in Pikovasky agar medium. F1RD2, F2D1S, F2D2S and F2D3S were can’t produce
ACC deaminase plant hormone where as the IAA production ranged were investigate as 0.865–
8.718 mg/ml after the incubation of 72 hours. The seed germination % and vigorus index were
significantly increased between the endophytes group than the control group. In vivo pot
experiment of high yield rice variety BRRI dhan-28 by treatment of isolated endophytes shows
high impact growth among shoot, root and dry weight. Pesticide degrading endophytes isolated
from rice plants having a vital role to improve plant growth and could be used as biofertilizer and
pesticide management tool to promote sustainable agriculture. | en_US |
