TY - JOUR
T1 - The effect of salt-tolerant antagonistic bacteria from tomato rhizosphere on plant growth promotion and damping-off disease suppression under salt-stress conditions
AU - Gaya Karunasinghe, Thamodini
AU - Hashil Al-Mahmooli, Issa
AU - Al-Sadi, Abdullah Mohammed
AU - Velazhahan, Rethinasamy
N1 - Publisher Copyright:
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2020/1/2
Y1 - 2020/1/2
N2 - A total of 24 morphologically distinct salt-tolerant bacteria were isolated from the tomato rhizosphere soil and tested in vitro against Pythium aphanidermatum, causing damping-off disease in tomato. Among them, five bacterial isolates viz., BTR1.0, BTR1.1, BTR4.4, BTR7.0 and BTR8.6 were found to inhibit the mycelial growth of P. aphanidermatum. The maximum antagonistic effect was shown by BTR1.0 followed by BTR7.0 and BTR1.1. Based on the MALDI Biotyper analysis, these bacterial isolates were identified as Serratia marcescens (BTR1.0 and BTR1.1), Pseudomonas aeruginosa (BTR7.0 and BTR8.6) and Alcaligenes faecalis (BTR4.4). Analysis of plant growth stimulating activity of bacterial strains revealed that A. faecalis BTR4.4 recorded the highest vigour index followed by S. marcescens BTR1.0. The biocontrol activity of bacterial antagonists against tomato damping-off was tested under salt-water irrigation. Among the bacterial strains tested, S. marcescens BTR1.1 was found to be highly effective under non-saline water irrigation, which suppressed the disease by 68% compared to infected control. However, at 50 mM NaCl concentration, S. marcescens strain BTR1.0, P. aeruginosa strain BTR7.0 and A. faecalis BTR4.4 provided a significant level of control of the disease. At 100 mM NaCl concentration, no significant effect of the bacterial strains on the disease incidence was observed.
AB - A total of 24 morphologically distinct salt-tolerant bacteria were isolated from the tomato rhizosphere soil and tested in vitro against Pythium aphanidermatum, causing damping-off disease in tomato. Among them, five bacterial isolates viz., BTR1.0, BTR1.1, BTR4.4, BTR7.0 and BTR8.6 were found to inhibit the mycelial growth of P. aphanidermatum. The maximum antagonistic effect was shown by BTR1.0 followed by BTR7.0 and BTR1.1. Based on the MALDI Biotyper analysis, these bacterial isolates were identified as Serratia marcescens (BTR1.0 and BTR1.1), Pseudomonas aeruginosa (BTR7.0 and BTR8.6) and Alcaligenes faecalis (BTR4.4). Analysis of plant growth stimulating activity of bacterial strains revealed that A. faecalis BTR4.4 recorded the highest vigour index followed by S. marcescens BTR1.0. The biocontrol activity of bacterial antagonists against tomato damping-off was tested under salt-water irrigation. Among the bacterial strains tested, S. marcescens BTR1.1 was found to be highly effective under non-saline water irrigation, which suppressed the disease by 68% compared to infected control. However, at 50 mM NaCl concentration, S. marcescens strain BTR1.0, P. aeruginosa strain BTR7.0 and A. faecalis BTR4.4 provided a significant level of control of the disease. At 100 mM NaCl concentration, no significant effect of the bacterial strains on the disease incidence was observed.
KW - Alcaligenes faecalis
KW - biocontrol
KW - damping-off
KW - Lycopersicon esculentum
KW - Pseudomonas aeruginosa
KW - Serratia marcescens
UR - http://www.scopus.com/inward/record.url?scp=85073924001&partnerID=8YFLogxK
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U2 - 10.1080/09064710.2019.1668956
DO - 10.1080/09064710.2019.1668956
M3 - Article
AN - SCOPUS:85073924001
SN - 0906-4710
VL - 70
SP - 69
EP - 75
JO - Acta Agriculturae Scandinavica Section B: Soil and Plant Science
JF - Acta Agriculturae Scandinavica Section B: Soil and Plant Science
IS - 1
ER -