KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/kmitl/1

Browse

Search Results

Now showing 1 - 7 of 7

Some of the metrics are blocked by your
consent settings
Sensitivity of Phytophthora palmivora Causing Durian Diseases to Metalaxyl-M and Dimethomorph in Southern and Eastern Thailand
(2025-05-14)
Kongtragoul, Pornprapa
;
Charoensiri, Sasidara
;
Rimchon, Somkiat
;
Knight, Susan
Metalaxyl-M (Met-M) and dimethomorph (Dim) are two systemic fungicides commonly used in Thailand to treat durian rot diseases caused by Phytophthora palmivora, a pathogen that significantly affects durian production. Fungicides have long been used by Thai durian farmers to control this infection, but managing the disease has become increasingly challenging in recent years. Monitoring fungicide resistance evolution is essential for effective disease management. In 2020 and 2022, eighty-one and sixty isolates, respectively, were collected from naturally infected durians in southern and eastern Thailand. All isolates were identified as P. palmivora through sporangium formation. Furthermore, 23 out of the 141 isolates were confirmed as P. palmivora based on sequencing of the internal transcribed spacer (ITS) and 5.8S regions of rDNA. All isolates were tested for mycelium growth sensitivity to Met-M and Dim. EC50 values were used to classify sensitivity into three categories: sensitive (S) at EC50 < 1 mgL-1, moderately resistant (MR) at EC50 between 1 and 100 mgL-1, and resistant (R) at EC50 > 100 mgL-1. In southern Thailand, 58% of the isolates were Met-MRDimS, and 41.25% were Met-MSDimS. In eastern Thailand, 36.67% were Met-MMRDimS, and 41.67% were Met-MSDimS. These findings indicate that the populations of P. palmivora in the durian orchards in southern and eastern Thailand consisted of a mixture of sensitive, moderately resistant, and resistant strains.
1
Some of the metrics are blocked by your
consent settings
Fungicide resistance of Phytophthora palmivora causing durian diseases in eastern and southern Thailand and the in vitro alternative control by cajeput leaf extracts
(2023-03-01)
Somnuek, S.
;
Kongtragoul, P.
;
Jaenaksorn, T.
The results showed that 24 and 25 of 40 collected isolates of Phytophthora palmivora were resistant to metalaxyl and mancozeb, respectively with the 50% effective concentration (EC<inf>50</inf>) higher than 100 mg/L. Meanwhile, all isolates were resistant to fosetyl-al with EC<inf>50</inf> higher than 1000 mg/L. Moreover, mapping between the survey areas and all Phytophthora isolates with the resistant levels to the 3 tested fungicides was depicted. Interestingly, 20 of 40 isolates showed multiple fungicide resistance to all tested fungicides with different modes of action, thereby selecting for the in vitro evaluation of the cajeput extract effect. Lower than expected, only 9 out of 20 multiple fungicide resistance isolates were shown to be significantly sensitive to the 10000, 20000 and 40000 ppm of cajeput extract based on paper disc assay.
2
Some of the metrics are blocked by your
consent settings
A new nanofibre derived from Trichoderma hamatum K01 to control durian rot caused by Phytophthora palmivora
(2023-01-01)
Phal, Pheaktra
;
Soytong, Kasem
;
Poeaim, Supattra
Phytophthora rot of durian var Monthong caused by Phytophthora palmivora has been proven to be a serious threat to durian plantations in Thailand. The research was targeted to isolate the causal pathogen and prove its pathogenicity by Koch’s postulate. Morphology and molecular phylogeny have confirmed the identification of pathogenic and antagonistic fungi. Evaluation of antagonistic fungus against plant pathogen in vitro and greenhouse conditions, morphology and molecular phylogenetic identification confirmed antagonistic species Trichoderma hamatum K01 and pathogenic isolate P. palmivora PYSC01. The crude metabolite of T. hamatum K01, namely TK01-MeOH gave the most substantial inhibitory effect to inhibit colony growth and sporangia formation at ED<inf>50</inf> (50% effective dose) values of 288 and 118 µg/mL, respectively. Moreover, nanofibre namely nano-TK01M exhibited the best antifungal activity in inhibiting colony growth and sporangia formation at ED<inf>50</inf> values of 11 and 3 µg/mL, respectively. Nano-TK01M treated on durian leaves induced the synthesis of scopoletin, which is known as a defense mechanism and marker of plant resistance or plant immunity. Moreover, the application of nano-TK01M significantly reduced disease incidence, the same as metalaxyl. Additionally, nano-TK01M treatment was the most effective in enhancing plant physiological parameters, including the synthesis of chlorophyll, carotenoid contents and promoted plant growth, compared to both metalaxyl and non-treated control. T. hamatum K01 produced antifungal metabolite pyrone 6-pentyl-2H-Pyran-2-one and sorbicillin. It is reported for the first time that pyrone and sorbicillin could be expressed as bioactive compounds in reduction of the disease incidence of durian rot caused by P. palmivora. The finding confirmed that nano-TK01M from T. hamatum K01 exhibited the most effective in controlling plant pathogen, which could be promoted as agricultural input for plant disease management, and it is also a nontoxic fungicide for living life and eco-friendly.
Some of the metrics are blocked by your
consent settings
Antifungal effect of zinc oxide nanoparticles against disease in durian caused by Phytophthora palmivora
(2021-06-01)
Ritmontree, S.
;
Kongtragoula, P.
Durian (Durio zibethinus) is one of the most important economic fruit crops in Thailand with high international demand. However, this commercially important crop is affected by the fungus, Phytophthora palmivora which causes fruit, stem and root rot disease and significant economic losses. Zinc oxide nanoparticles (ZnO-NPs) have recently shown capability as an antimicrobial agent being biocompatible, economic, and having a low toxicity. Their potent ability can stimulate the production of excess reactive oxygen species, the release of zinc ions, and the induction of cell apoptosis. The objective of this study was to investigate the antifungal effect of ZnO-NPs, with 25-50 nm size range, at concentrations of 0, 500, 1000 and 2000 μg mL-1 on growth inhibition of P. palmivora denominated as Phy001 and Phy002. A poisoned food technique with potato dextrose agar (PDA) was used in the study together with an investigation of the inhibition of infection on durian leaves. The results showed that ZnO-NPs at a concentration of 2,000 μg mL-1 could significantly inhibit mycelial growth of Phy001 and Phy002 by 56.6 and 53.6%, respectively. Moreover, the nanoparticles could reduce the disease severity on durian leaves in both isolates by 50.5 and 43.7%, respectively. These results suggest that the use of ZnO-NPs could be a satisfactory and environmentally safe alternative to the current fungicides that are used to control durian disease caused by P. palmivora.
1
Some of the metrics are blocked by your
consent settings
Nano-particles from Chaetomium brasiliense to control Phytophthora palmivora caused root rot disease in durian var Montong
(2018-12-01)
Tongon, R.
;
Soytong, K.
;
Kanokmedhakul, S.
;
Kanokmedhakul, K.
The antagonistic fungus, Chaetomium brasiliense was tested to control Phytophthora palmivora causing rot disease of Durian (Durio zibithenus L.) var Montong by crude extracts and Nano-particles derived from Ch. brasiliense. Crude extracts of antagonistic fungus was tested for antifungal biological activities. The crude extracts from antagonistic fungus with hexane, ethyl acetate and methanol were tested against P. palmivora. Crude ethyl acetate from Ch. brasiliense gave significantly against P. palmivora which the ED <inf>50</inf> values was 17.46 µg/ml. Testing Nano-particles were tested for antifungal activities. The results showed nano - particles from Ch. brasiliense gave effectively significantly inhibition of colony growth and spore production which the ED <inf>50</inf> values were 1.08 µg/ml, and 8.68 µg/ml respectively. Application of Nano - particles to control the P. palmivora causing root rot disease of durian in pot experiment was successfully done. The results showed nano-particles from Ch. brasiliense reduced the root rot disease on durain of 40%. The nano-particles from Ch. brasilense gave significiantly high plant growth which were 79.5 cm when compared to the non-trated control.
Some of the metrics are blocked by your
consent settings
Nano-particles derived from Chaetomium elatum against Phytophthora rot of durian
(2018-12-01)
Thongkham, D.
;
Soytong, K.
;
Kanokmedhakul, S.
;
Kanokmedhakul, K.
Durian are the economically fruit trees in Thailand. The important problem of durian is root rot disease caused by Phytophthora palmivora. This study was used Chaetomium elatum to control the P. palmivora causing root rot disease of durian by dual culture method, crude extract test and nano particles test derived from Ch. elatum. Dual-culture test showed that Ch. elatum gave efficiency to inhibit of spore and colony growth of P. palmivora which were 46.13 and 38.89%, respectively. Testing efficacy of crude extract from Ch. elatum to control P. palmivora found that crude ethyl acetate from Ch. elatum gave significantly highest against pathogen of P. palmivora at the concentration of 1000 ppm which the ED <inf>50</inf> of 175.31 ppm. Nano particles testing, nano particles of crude hexane, ethyl acetate and methanol from Ch. elatum showed the ED <inf>50</inf> values of 3.49, 3.47 and 3.41 ppm.
2
Some of the metrics are blocked by your
consent settings
Biological control of Phytophthora palmivora causing root rot of pomelo using Chaetomium spp.
(2015-01-01)
Hung, Phung Manh
;
Wattanachai, Pongnak
;
Kasem, Soytong
;
Poaim, Supatta
Phytophthora diseases have become a major impediment in the citrus production in Thailand. In this study, an isolate of Phytophthora denominated as PHY02 was proven to be causal pathogen of root rot of Pomelo (Citrus maxima) in Thailand. The isolate PHY02 was morphologically characterized and identified as Phytophthora palmivora based on molecular analysis of an internal transcribed spacer rDNA sequence. This work also presents in vitro evaluations of the capacities of Chaetomium spp. to control the P. palmivora PHY02. As antagonists, Chaetomium globosum CG05, Chaetomium cupreum CC3003, Chaetomium lucknowense CL01 inhibited 50~61% mycelial growth, degraded mycelia and reduced 92~99% sporangial production of P. palmivora PHY02 in bi-culture test after 30 days. Fungal metabolites from Chaetomium spp. were tested against PHY02. Results showed that, methanol extract of C. globosum CG05 expressed strongest inhibitory effects on mycelial growth and sporangium formation of P. palmivora PHY02 with effective dose ED50 values of 26.5 μg/mL and 2.3 μg/mL, respectively. It is interesting that C. lucknowense is reported for the first time as an effective antagonist against a species of Phytophthora.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results