TITLE:
Isolation, Screening and Molecular Characterization of Multifunctional Plant Growth Promoting Rhizobacteria for a Sustainable Agriculture
AUTHORS:
Kay Thi Oo, Theint Theint Win, Aye Aye Khai, Pengcheng Fu
KEYWORDS:
PGPR, Rhizobacteria, Maize, Green-Gram, Siderophore, IAA
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.6,
June
22,
2020
ABSTRACT: The use of PGPR as a multifunctional biofertilizer
or biostimulant is an alternative way to prevent soil pollution and preserve
agricultural for sustainable economy. In this study, 102 bacterial strains were
isolated from rhizospheric soil of different crop fields. Among them, 15
bacterial isolates rich of NPK were selected to screen for PGP activity. It was
found that 4 out 15 isolates were able to fix atmospheric nitrogen, 14 could
solubilize phosphate and 5 could solubilize potassium. They were further examined
for the production of hydrolytic enzymes (amylase, cellulose, chitinase, etc.),
plant hormone (IAA) and plant defense substances (HCN, siderophore, etc.). All
PGPR isolates were able to produce IAA, siderophore and ammonia while 2
isolates could produce HCN. Among them, 73.33% of selected isolates produced
amylase, 80% produced cellulase, 66.67% produced pectinase, 93.33% produced
chitinase and β-glucanase. For salt stress tolerance, all the isolates grew well
in 5% NaCl while only 4 tolerated 9% NaCl. Among all isolates, 2 have
antifungal activity and 5 have antibacterial activity. The best 6 isolates and
consortium were tested to promote plant growth in green-gram and maize
germination. Seed germination of green-gram and maize was observed the best in Acromobacter insolitus S3 compared with
other treatments. Pseudomonas plecoglossicida B3 was found the best in fresh weight for both crops. The highest
root formation was observed in Acromobacter insolitus S3 treatment in maize and Enterobacter hormaechei W1 treatment in
green-gram.