scholarly journals Suppression of soil borne fungal pathogens associated with apple replant disease by cyclic application of native strains of Pseudomonas aeruginosa

2017 ◽  
Vol 9 (4) ◽  
pp. 2105-2109
Author(s):  
Ranjna Sharma ◽  
Joginder Pal ◽  
Sheetal Rana ◽  
Mohinder Kaur

Plant growth promoting fluorescent Pseudomonas aeruginosa strains An-E and An- F were used for the suppression of replant disease organisms which were isolated from replant site of apple in Shimla district of Hima-chal Pradesh. Full and half concentration of individual and consortial strains were used for the experiment. Among all the treatments, full concentration of compatible consortial strains were quite effective in decreasing the deleterious rhizobacterial (197-99 cfu/g) and fungal population (7-0 cfu/g). Total rhizobacterial count starts decreasing after each cyclic application of fluorescent P. aeruginosa strains An-E and An-F due to root colonization property of these plant growth promoting strains in the replant site of apple. Establishment of Pseudomonas aeruginosa strains at replant site was inversely correlated with decreasing deleterious bacterial and fungal population in the replant site. 70 per cent survival of apple rootstocks was recorded in full concentration of consortial treatment (An-E and An- F) as compared to control after three years of plantation. Four major fungal pathogens viz. Dematophor anecatrix, Phytophthora cactorum, Pythium ultimum and Fusarium oxysporum were isolated and identified from National centre for fungal taxonomy, New Delhi. These strains can be further exploited and recommended for the management of replant problem of apple.


2021 ◽  
Vol 44 (2) ◽  
pp. 69-84
Author(s):  
Farhana Tasnim Chowdhury ◽  
Nazia Rifat Zaman ◽  
Mohammad Riazul Islam ◽  
Haseena Khan

Plant growth promoting rhizobacteria (PGPR) residing in soil rhizosphere provide enormous beneficial effects to a plant host producing diverse secondary metabolites and enzymes useful for plant growth and protection. Siderophores, antibiotics, volatile compounds and hydrolytic enzymes are the major molecules secreted by the PGPRs, which have substantial antifungal properties and can provide plant protection. These compounds are responsible for the lysis and hyperparasitism of antagonists against deleterious fungal pathogens. Siderophore-producing PGPRs function by depriving the pathogen of iron nutrition. Antibiotics have been reported to be involved in the suppression of different fungal pathogens by inducing fungistasis, inhibition of spore germination, lysis of fungal mycelia. The PGPRs also secrete a wide range of low molecular weight volatile organic compounds (VOCs) that inhibit mycelial growth, sporulation, germination of phytophathogenic fungi, etc. Hydrolytic enzymes, mostly chitinase, protease and cellulose, lyse the cell wall of fungi. Therefore, plant growth-promoting rhizobacteria can be considered as an effective, eco-friendly, and sustainable replacement to the chemical fungicides. There are many PGPRs that perform very well in controlled conditions but not in field conditions, and hence the commercializing of hese products is not easy.  Development of formulations with increased shelf life, a broad spectrum of action and consistent performance under field conditions can pave the way for commercializing the PGPRs at a faster rate. Journal of Bangladesh Academy of Sciences, Vol. 44, No. 2, 69-84, 2020





2008 ◽  
Vol 54 (4) ◽  
pp. 248-258 ◽  
Author(s):  
Russell K. Hynes ◽  
Grant C.Y. Leung ◽  
Danielle L.M. Hirkala ◽  
Louise M. Nelson

The use of beneficial soil microorganisms as agricultural inputs for improved crop production requires selection of rhizosphere-competent microorganisms with plant growth-promoting attributes. A collection of 563 bacteria originating from the roots of pea, lentil, and chickpea grown in Saskatchewan was screened for several plant growth-promoting traits, for suppression of legume fungal pathogens, and for plant growth promotion. Siderophore production was detected in 427 isolates (76%), amino-cyclopropane-1-carboxylic acid (ACC) deaminase activity in 29 isolates (5%), and indole production in 38 isolates (7%). Twenty-six isolates (5%) suppressed the growth of Pythium sp. strain p88-p3, 40 isolates (7%) suppressed the growth of Fusarium avenaceum , and 53 isolates (9%) suppressed the growth of Rhizoctonia solani CKP7. Seventeen isolates (3%) promoted canola root elongation in a growth pouch assay, and of these, 4 isolates promoted the growth of lentil and one isolate promoted the growth of pea. Fatty acid profile analysis and 16S rRNA sequencing of smaller subsets of the isolates that were positive for the plant growth-promotion traits tested showed that 39%–42% were members of the Pseudomonadaceae and 36%–42% of the Enterobacteriaceae families. Several of these isolates may have potential for development as biofertilizers or biopesticides for western Canadian legume crops.



2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Bushra Uzair ◽  
Rehana Kausar ◽  
Syeda Asma Bano ◽  
Sammer Fatima ◽  
Malik Badshah ◽  
...  

The use of microbial technologies in agriculture is currently expanding quite rapidly with the identification of new bacterial strains, which are more effective in promoting plant growth. In the present study 18 strains of Pseudomonas were isolated from soil sample of Balochistan coastline. Among isolated Pseudomonas strains four designated as SP19, SP22, PS24, and SP25 exhibited biocontrol activities against phytopathogenic fungi, that is, Rhizopus microsporus, Fusarium oxysporum, Aspergillus niger, Alternaria alternata, and Penicillium digitatum; PS24 identified as Pseudomonas aeruginosa by 16srRNA gene bank accession number EU081518 was selected on the basis of its antifungal activity to explore its potential as plant growth promotion. PS24 showed multiple plant growth promoting attributes such as phosphate solubilization activity, indole acetic acid (IAA), siderophore, and HCN production. In order to determine the basis for antifungal properties, antibiotics were extracted from King B broth of PS24 and analyzed by TLC. Pyrrolnitrin antibiotic was detected in the culture of strain PS24. PS24 exhibited antifungal activities found to be positive for hydrogen cyanide synthase Hcn BC gene. Sequencing of gene of Hcn BC gene of strain PS24 revealed 99% homology with the Pseudomonas aeruginosa strain PA01. The sequence of PS24 had been submitted in gene bank accession number KR605499. Ps. aeruginosa PS24 with its multifunctional biocontrol possessions can be used to bioprotect the crop plants from phytopathogens.





Sign in / Sign up

Export Citation Format

Share Document