Biofungicidal potential of selected plant extracts against fruit rot pathogens of banana, tomato and mango
Fruit rot caused by several fungal pathogens can be considered as a threat to economic loss due to quality defect and quantity loss, besides constitute health risk to the consumers due to mycotoxin contamination produced by the pathogens. Frequent and unselective use of fungicide to control the p...
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| Format: | Thesis |
| Language: | English English |
| Published: |
2022
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/112146/1/FS%202022%2066%20-%20IR.pdf http://psasir.upm.edu.my/id/eprint/112146/ |
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| Summary: | Fruit rot caused by several fungal pathogens can be considered as a threat to economic
loss due to quality defect and quantity loss, besides constitute health risk to the
consumers due to mycotoxin contamination produced by the pathogens. Frequent and
unselective use of fungicide to control the pathogens has ended up to resistant
development of the pathogens and increase toxic accumulation in fruits. Previous studies
reported that plant extracts might contain variety of bioactive constituents that able to
control the pathogen’s growth. Hence, the aims of this study were to screen antifungal
activity of selected plant extracts against Fusarium oxysporum, Fusarium proliferatum,
Colletotrichum gloeosporioides and Lasiodiplodia theobromae under in vitro condition,
to examine morphological and cytological changes of the pathogens treated with selected
plant extracts using scanning (SEM) and transmission (TEM) electron microscope, to
evaluate the efficacy of the selected plant extracts against fruit rot disease and to identify
phytochemical constituents of the selected plant extracts using Ultra High Performance
Liquid Chromatography Mass Spectrometer (UHPLC MS/MS). The plant extracts of
Pilea microphylla, Peperomia pellucida, Persicaria odorata, Cymbopogon citratus,
Tamarindus indica, Garcinia mangostana and Averrhoa bilimbi were prepared using
different types of solvents and in vitro screening was conducted using poisoned food
bioassay. Eight out of 48 plant extracts showed high significant inhibition effect against
mycelial growth of F. oxysporum and F. proliferatum, while no extracts showed high
significant inhibition effect against C. gloeosporioides growth and no extracts showed
significant inhibition effect against L. theobromae when compared to positive controls.
The eight effective extracts were further used to examine their inhibition effect on
conidial germination. The results showed G. mangostana pericarp and A. bilimbi fruit
ethanolic extracts significantly lowered the conidial germination of F. oxysporum
(14.33%) and (20.00%), F. proliferatum (28.33%) and (39.75%), C. gloeosporioides
(14.67%) and (20.00%) and L. theobromae (18.89%) and (28.57%) when compared to
the controls. Shrivelled mycelia were observed via SEM on pathogens treated with both
plant extracts indicating morphological changes were occurred in the cell compared to
the controls in which the mycelia were in normal form. Alterations in hyphae cellular
structures of the treated pathogens were observed via TEM, indicating cytological
changes occurred in the cell membrane when compared to the controls in which the
hyphae cells were in normal form. The selected plant extracts at different concentrations
showed varied degrees in disease severity reduction percentages against all pathogens,
especially to F. oxysporum and F. proliferatum that were inoculated on different type of
fruits; banana, tomato and mango. G. mangostana pericarp ethanolic extract at
concentration of 100 mg/mL exhibited the equivalent efficacy in supressing fruit rot
disease in both banana and tomato fruits, while A. bilimbi fruit ethanolic extract at
concentration of 100 mg/mL showed significant reduction in fruit rot development on
mango when compared to fungicide carbendazim. Significant changes on fruit quality of
banana and tomato were displayed by the treatment of G. mangostana pericarp ethanolic
extract, while A. bilimbi fruit ethanolic extract treatment showed significant changes in
fruit quality of mango, when compared to the control fruits. Identification of
phytochemical constituents was exhibited the presence of some of vital component
groups which contributed to the antifungal activity of the extracts. UHPLC MS/MS
spectral analysis displayed 50 metabolites in the negative ion mode, while 68 metabolites were identified in the positive ion mode of G. mangostana pericarp ethanolic extractcor respondingly. Meanwhile, 59 metabolites were tentatively identified in the negativeion mode, whereas 109 metabolites were identified in the positive ion mode of A. bilimbi fruit ethanolic extract respectively. The equivalent and greater effect of G. mangostana pericarp and A. bilimbi fruit ethanolic extracts when compared to fungicide carbendazim was due to the presence of phytochemical compounds that possessed antifungal
properties. This innovation has potential to be applied as an eco-friendly and gentle
approach to control fruit rot disease. |
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