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Papers by Yasmeen Siddiqui

Journal of Soil Science and Plant Nutrition

Horticulture, Environment, and Biotechnology, 2020

Antifungal activities of the methanolic crude extracts of Garcinia atroviridis fruits were evalua... more Antifungal activities of the methanolic crude extracts of Garcinia atroviridis fruits were evaluated against Colletotrichum capsici, the causal pathogen of anthracnose of chilli.The antifungal activity of crude methanolic fruit extracts of G. atroviridis using poison food technique recorded 100% inhibition at minimum inhibitory concentration (MIC) values above 500 μg mL⁻ ¹.Similarly, percentage inhibition of 70.5% was calculated in agar well at 900 μg mL-1 which was at par with fungicide,Dithane® M-45 (73.8%) at 1000 μg mL⁻ ¹. It was accompanied by a significant reduction in cellulolytic and pectinolyticenzymes production by C. capsici at different concentrations. Several bioactive compounds in the crude extracts were identified using bioautography and LCMS. Amongst all, fatty acid (dodecanoic acid), hydrocoumarins, anthraquinones and benzofuran were prominent in suppression of C. capsici as evident from inhibition zone of 0.45 cm, 0.5 cm, 0.47 cm and 0.7 cm, respectively. Exposing ...

Agronomy, 2021

Fusarium oxysporum f. sp. niveum (Fon) is the causative agent of Fusarium wilt disease of waterme... more Fusarium oxysporum f. sp. niveum (Fon) is the causative agent of Fusarium wilt disease of watermelon; it is the most serious soil-borne pathogen around the globe. The yield loss is around 30–80% or even more, and is presently a major hindrance to watermelon cultivation worldwide. Initially, the infected watermelon plant shows symptoms like loss of turgor pressure of the leaves and vines that can be recovered at night. The progress of the disease in contaminated transplants turns into dull green to yellow and finally necrotic. When the fungus continues to colonize the xylem vessel, it usually forms more tyloses, finally limiting water movement and causing wilt. The correct identification of the pathogen is necessary for proper disease control. As such, the selection of a molecular marker could serve as an effective means of screening the pathogen. Additionally, different methods have also been reported for the identification of Fon. Therefore, this review focused on the comprehensive...

The Plant Pathology Journal, 2020

Current Plant Biology, 2019

Scientia Horticulturae, 2020

International Journal of Agriculture and Biology, 2009

Fungicidal activity of humic acids isolated from empty fruit bunch of oil palm compost EFB-HA and... more Fungicidal activity of humic acids isolated from empty fruit bunch of oil palm compost EFB-HA and commercial grade humic acid Co-HA were evaluated on the conidial germination and mycelial growth of Choanephora cucurbitarum. EFB-HA and Co-HA significantly (P ≤ 0.05) inhibited the mycelial growth and conidial germination of C. cucurbitarum in vitro compared to control. The inhibition in mycelial growth increased with increase in humic acid concentrations tested, suggesting the presence of fungicidal activity. The maximum inhibition of conidial germination (71.96% after 24 h) was exerted by EFB-HA at the highest concentration (1000 mg L -1 ). It was concluded that the efficiency of HA studied in controlling fungal growth was apparently related not only to their concentration and the pathogen examined, but also to HA origin and nature and in particular, HA structural and functional properties, especially COOH group content.

Compost tea is gaining importance as an alternative to chemical fertilizers and pesticides. The m... more Compost tea is gaining importance as an alternative to chemical fertilizers and pesticides. The microbial population in the compost tea contributes toward its effectiveness. An attempt was made to enhance the biological activity of compost tea by fortification with microbial substrates. Humic acid and yeast extract (4:7 w/w 100 g-1 compost) when used as microbial starter during brewing of compost tea significantly (P less than or equal to 0.05) enhanced the microbial population. There was a ten to hundred fold percentage increase for total bacteria, fungi and actinomycetes compared to control. The stability of microbial enriched compost tea was maintained up to four months of storage based on significantly higher number of viable cell counts when compared to compost tea without substrates (control). The viable microbial cell counts over a storage period of six months was 8.5x10(9), 4.6x10(6), 3.5x10(4), 3.9x10(4), 1.4x10(5), 4.8x10(4) and 7.3x10(5) for other bacteria.

Plant Disease

Fusarium wilt disease incited by Fusarium oxysporum f. sp. niveum (FON) is the utmost devastating... more Fusarium wilt disease incited by Fusarium oxysporum f. sp. niveum (FON) is the utmost devastating soil-inhabiting fungal pathogen limiting watermelon (Citrullus lanatus) production in Malaysia and globally. The field disease survey of fusarium wilt was carried out during December 2019 and November 2020, in three major production areas (3 farmer fields per location) in Peninsular Malaysia namely, Mersing, Serdang and Kuantan and disease incidence of 30 and 45%, was recorded for each year, respectively. Infected watermelon plants showed symptoms such as vascular discoloration, brown necrotic lesions to the soil line or the crown, one-sided wilt of a plant, or a runner or the whole plant. Infected root and stem tissues, 1-2 cm pieces were surface sterilized with 0.6% NaOCl for 1 minute followed by double washing with sterile water. The disinfected tissues were air-dried and transferred onto semi-selective Komada’s medium (Komada 1975) and incubated for 5 days. The fungal colonies produ...

Forests

Basal stem rot (BSR) caused by a wood degrading fungus, Ganoderma boninense, is the major constra... more Basal stem rot (BSR) caused by a wood degrading fungus, Ganoderma boninense, is the major constraint in palm oil production. It degrades the wood components and causes palms to collapse, leading to heavy losses. Inefficacy in controlling this disease could be caused by the lack of understanding in how the pathogen establishes itself on the host concerning wood decay stages. This study aimed to understand and determine the role of benzoic acid on the suppression of G. boninense and production of ligninolytic enzymes responsible for wood decay. Further, the alteration in wood component structure due to G. boninense infection and its prevention were studied. Benzoic acid treatment resulted in more than 80% of inhibition in G. boninense growth. SEM and HR-TEM analysis confirmed the antifungal activity of benzoic acid by disruption of mycelial morphology and cellular ultrastructure. Moreover, the membrane permeability assay recorded enhanced cell mortality in benzoic acid treated myceliu...

Plants

The threat of Ganoderma boninense, the causal agent of basal stem rot disease, in the oil palm in... more The threat of Ganoderma boninense, the causal agent of basal stem rot disease, in the oil palm industry warrants finding an effective control for it. The weakest link in the disease management strategy is the unattended stumps/debris in the plantations. Hence, this study aimed to determine whether the selected phenolic compounds could control G. boninense in inoculated oil palm woodblocks and restrict wood biodegradation. Results indicated a significant reduction in the wood mass loss when treated with all the phenolic compounds. Surprisingly, syringic and vanillic acids behaved ambivalently; at a lower concentration, the wood mass loss was increased, but it decreased as the concentrations were increased. In all four phenolic compounds, the inhibition of mass loss was dependent on the concentration of the compounds. After 120 days, the mass loss was only 31%, with 63% relative degradation of lignin and cellulose, and 74% of hemicellulose and wood anatomy, including silica bodies, we...

Saudi Journal of Biological Sciences

Molecules

The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most ... more The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indica...

Journal of Soil Science and Plant Nutrition

Horticulture, Environment, and Biotechnology, 2020

Antifungal activities of the methanolic crude extracts of Garcinia atroviridis fruits were evalua... more Antifungal activities of the methanolic crude extracts of Garcinia atroviridis fruits were evaluated against Colletotrichum capsici, the causal pathogen of anthracnose of chilli.The antifungal activity of crude methanolic fruit extracts of G. atroviridis using poison food technique recorded 100% inhibition at minimum inhibitory concentration (MIC) values above 500 μg mL⁻ ¹.Similarly, percentage inhibition of 70.5% was calculated in agar well at 900 μg mL-1 which was at par with fungicide,Dithane® M-45 (73.8%) at 1000 μg mL⁻ ¹. It was accompanied by a significant reduction in cellulolytic and pectinolyticenzymes production by C. capsici at different concentrations. Several bioactive compounds in the crude extracts were identified using bioautography and LCMS. Amongst all, fatty acid (dodecanoic acid), hydrocoumarins, anthraquinones and benzofuran were prominent in suppression of C. capsici as evident from inhibition zone of 0.45 cm, 0.5 cm, 0.47 cm and 0.7 cm, respectively. Exposing ...

Agronomy, 2021

Fusarium oxysporum f. sp. niveum (Fon) is the causative agent of Fusarium wilt disease of waterme... more Fusarium oxysporum f. sp. niveum (Fon) is the causative agent of Fusarium wilt disease of watermelon; it is the most serious soil-borne pathogen around the globe. The yield loss is around 30–80% or even more, and is presently a major hindrance to watermelon cultivation worldwide. Initially, the infected watermelon plant shows symptoms like loss of turgor pressure of the leaves and vines that can be recovered at night. The progress of the disease in contaminated transplants turns into dull green to yellow and finally necrotic. When the fungus continues to colonize the xylem vessel, it usually forms more tyloses, finally limiting water movement and causing wilt. The correct identification of the pathogen is necessary for proper disease control. As such, the selection of a molecular marker could serve as an effective means of screening the pathogen. Additionally, different methods have also been reported for the identification of Fon. Therefore, this review focused on the comprehensive...

The Plant Pathology Journal, 2020

Current Plant Biology, 2019

Scientia Horticulturae, 2020

International Journal of Agriculture and Biology, 2009

Fungicidal activity of humic acids isolated from empty fruit bunch of oil palm compost EFB-HA and... more Fungicidal activity of humic acids isolated from empty fruit bunch of oil palm compost EFB-HA and commercial grade humic acid Co-HA were evaluated on the conidial germination and mycelial growth of Choanephora cucurbitarum. EFB-HA and Co-HA significantly (P ≤ 0.05) inhibited the mycelial growth and conidial germination of C. cucurbitarum in vitro compared to control. The inhibition in mycelial growth increased with increase in humic acid concentrations tested, suggesting the presence of fungicidal activity. The maximum inhibition of conidial germination (71.96% after 24 h) was exerted by EFB-HA at the highest concentration (1000 mg L -1 ). It was concluded that the efficiency of HA studied in controlling fungal growth was apparently related not only to their concentration and the pathogen examined, but also to HA origin and nature and in particular, HA structural and functional properties, especially COOH group content.

Compost tea is gaining importance as an alternative to chemical fertilizers and pesticides. The m... more Compost tea is gaining importance as an alternative to chemical fertilizers and pesticides. The microbial population in the compost tea contributes toward its effectiveness. An attempt was made to enhance the biological activity of compost tea by fortification with microbial substrates. Humic acid and yeast extract (4:7 w/w 100 g-1 compost) when used as microbial starter during brewing of compost tea significantly (P less than or equal to 0.05) enhanced the microbial population. There was a ten to hundred fold percentage increase for total bacteria, fungi and actinomycetes compared to control. The stability of microbial enriched compost tea was maintained up to four months of storage based on significantly higher number of viable cell counts when compared to compost tea without substrates (control). The viable microbial cell counts over a storage period of six months was 8.5x10(9), 4.6x10(6), 3.5x10(4), 3.9x10(4), 1.4x10(5), 4.8x10(4) and 7.3x10(5) for other bacteria.

Plant Disease

Fusarium wilt disease incited by Fusarium oxysporum f. sp. niveum (FON) is the utmost devastating... more Fusarium wilt disease incited by Fusarium oxysporum f. sp. niveum (FON) is the utmost devastating soil-inhabiting fungal pathogen limiting watermelon (Citrullus lanatus) production in Malaysia and globally. The field disease survey of fusarium wilt was carried out during December 2019 and November 2020, in three major production areas (3 farmer fields per location) in Peninsular Malaysia namely, Mersing, Serdang and Kuantan and disease incidence of 30 and 45%, was recorded for each year, respectively. Infected watermelon plants showed symptoms such as vascular discoloration, brown necrotic lesions to the soil line or the crown, one-sided wilt of a plant, or a runner or the whole plant. Infected root and stem tissues, 1-2 cm pieces were surface sterilized with 0.6% NaOCl for 1 minute followed by double washing with sterile water. The disinfected tissues were air-dried and transferred onto semi-selective Komada’s medium (Komada 1975) and incubated for 5 days. The fungal colonies produ...

Forests

Basal stem rot (BSR) caused by a wood degrading fungus, Ganoderma boninense, is the major constra... more Basal stem rot (BSR) caused by a wood degrading fungus, Ganoderma boninense, is the major constraint in palm oil production. It degrades the wood components and causes palms to collapse, leading to heavy losses. Inefficacy in controlling this disease could be caused by the lack of understanding in how the pathogen establishes itself on the host concerning wood decay stages. This study aimed to understand and determine the role of benzoic acid on the suppression of G. boninense and production of ligninolytic enzymes responsible for wood decay. Further, the alteration in wood component structure due to G. boninense infection and its prevention were studied. Benzoic acid treatment resulted in more than 80% of inhibition in G. boninense growth. SEM and HR-TEM analysis confirmed the antifungal activity of benzoic acid by disruption of mycelial morphology and cellular ultrastructure. Moreover, the membrane permeability assay recorded enhanced cell mortality in benzoic acid treated myceliu...

Plants

The threat of Ganoderma boninense, the causal agent of basal stem rot disease, in the oil palm in... more The threat of Ganoderma boninense, the causal agent of basal stem rot disease, in the oil palm industry warrants finding an effective control for it. The weakest link in the disease management strategy is the unattended stumps/debris in the plantations. Hence, this study aimed to determine whether the selected phenolic compounds could control G. boninense in inoculated oil palm woodblocks and restrict wood biodegradation. Results indicated a significant reduction in the wood mass loss when treated with all the phenolic compounds. Surprisingly, syringic and vanillic acids behaved ambivalently; at a lower concentration, the wood mass loss was increased, but it decreased as the concentrations were increased. In all four phenolic compounds, the inhibition of mass loss was dependent on the concentration of the compounds. After 120 days, the mass loss was only 31%, with 63% relative degradation of lignin and cellulose, and 74% of hemicellulose and wood anatomy, including silica bodies, we...

Saudi Journal of Biological Sciences

Molecules

The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most ... more The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indica...