1.Effectiveness of indigenous fluorescent pseudomonads in suppressing Rhizoctonia solani root rot disease and promoting plant growth in chilli seedlings
Ng Lee Chuen ; Rul-Hajar Muda ; Khairulmazmi Ahmad
Malaysian Journal of Microbiology 2021;17(2):200-211
Aims:
This study aimed to isolate and evaluate the indigenous fluorescent Pseudomonas spp. with bio-control potential
against Rhizoctonia solani and promoting growth in chilli seedlings.
Methodology:
A total of 120 fluorescent bacterial were isolated from the healthy chilli rhizosphere soil from the seven
major chilli cultivation localities in Terengganu, Malaysia. Only 115 Gram negative fluorescent isolates were further invitro screened for antagonistic activities against R. solani and plant growth-promoting properties. The 50 most effective
fluorescent Pseudomonads antagonist against R. solani with minimum percentage inhibition of radial growth (PIRG) of
65% were selected. Hierarchical cluster analysis was further conducted with two dendrograms derived from SPSS
Statistic 20 to facilitate the comparison between these 50 isolates for antagonistic and growth-promoting properties. A
total of 40 fluorescent isolates within the most potential cluster were further selected and identified using 16S rRNA
sequencing. Thirty four fluorescent isolates were identified as Pseudomonas spp. and six isolates as Burkholderia spp.
The top 13 ranked fluorescent Pseudomonas spp. from the scoring index were evaluated for seed germination and vigor
index in chilli seedlings. There was no significant difference in germination rate between fluorescent Pseudomonas
inoculated with control. However, vigor index of chilli seeds pre-inoculated with fluorescent P. putida (B5C1), P.
aeruginosa (B3C56) and P. putida (B5C7) were significantly increased with 4684.9, 4657.3 and 4401.0 over control (P ≤
0.05).
Conclusion, significance and impact of study
These selected fluorescent isolates: P. putida (B5C1), P. aeruginosa
(B3C56) and P. putida (B5C7) have the potential to be developed as biofungicide against R. solani and as growthpromoter in chilli production system.
Pseudomonas fluorescens
;
Rhizoctonia
;
Seedlings