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Bacillus cereus strain Bc-cm103 shows nematicidal activity and, therefore, has been used as a biological control agent to control the root-knot nematode Meloidogyne incognita. However, it remains unknown whether volatile organic compounds (VOCs) produced by B. cereus strain Bc-cm103 are effective in biocontrol against M. incognita. Therefore, in this study, we investigated the activity of Bc-cm103 VOCs against M. incognita. The B. cereus strain Bc-cm103 significantly repelled the second-stage juveniles (J2s) of M. incognita. In vitro evaluation of VOCs produced by the fermentation of Bc-cm103 in a three-compartment Petri dish revealed the mortality rates of M. incognita J2s as 90.8% at 24 h and 97.2% at 48 h. Additionally, evaluation of the ability of Bc-cm103 VOCs to suppress M. incognita infection in a double-layered pot test showed that root galls on cucumber roots decreased by 46.1%. Furthermore, 21 VOCs were identified from strain Bc-cm103 by solid-phase microextraction gas chromatography–mass spectrometry, including alkanes, alkenes, esters, and sulfides. Among them, dimethyl disulfide (30.63%) and S-methyl ester butanethioic acid (30.29%) were reported to have strong nematicidal activity. Together, these results suggest that B. cereus strain Bc-cm103 exhibits fumigation activity against M. incognita.
Nan Yin; Rui Liu; Jian-Long Zhao; Raja Asad Ali Khan; Yan Li; Jian Ling; Wei Liu; Yu-Hong Yang; Bing-Yan Xie; Zhen-Chuan Mao. Volatile Organic Compounds of Bacillus cereus Strain Bc-cm103 Exhibit Fumigation Activity against Meloidogyne incognita. Plant Disease 2021, 105, 904 -911.
AMA StyleNan Yin, Rui Liu, Jian-Long Zhao, Raja Asad Ali Khan, Yan Li, Jian Ling, Wei Liu, Yu-Hong Yang, Bing-Yan Xie, Zhen-Chuan Mao. Volatile Organic Compounds of Bacillus cereus Strain Bc-cm103 Exhibit Fumigation Activity against Meloidogyne incognita. Plant Disease. 2021; 105 (4):904-911.
Chicago/Turabian StyleNan Yin; Rui Liu; Jian-Long Zhao; Raja Asad Ali Khan; Yan Li; Jian Ling; Wei Liu; Yu-Hong Yang; Bing-Yan Xie; Zhen-Chuan Mao. 2021. "Volatile Organic Compounds of Bacillus cereus Strain Bc-cm103 Exhibit Fumigation Activity against Meloidogyne incognita." Plant Disease 105, no. 4: 904-911.
The efficacy of traditional control measures for the management of plant pathogens is decreasing, and the resistance of these pathogens to pesticides is increasing, which poses a serious threat to global food security. The exploration of novel and efficient management measures to combat plant disease is an urgent need at this time. In this study, fungal metabolites from three Trichoderma spp. (T. harzianum, T. virens and T. koningii) were prepared on three different growth media (STP, MOF and supermalt (SuM)). The fungal metabolites were tested in vitro and in vivo from March–April 2020 under greenhouse conditions in a pot experiment utilizing completely randomized design to test their management of the bacterial wilt disease caused by R. solanacearum in tomato plants. The effect of the fungal metabolites on bacterial cell morphology was also investigated through scanning electron microscopy (SEM) analysis. In vitro investigation showed that the fungal metabolites of T. harzianum obtained on the STP medium were the most effective in inhibiting in vitro bacterial growth and produced a 17.6 mm growth inhibition zone. SEM analysis confirms the rupture of the cell walls and cell membranes of the bacterium, along with the leakage of its cell contents. Generally, fungal metabolites obtained on an STP medium showed higher activity than those obtained on the other two media, and these metabolites were then evaluated in vivo according to three application times (0 days before transplantation (DBT), 4 DBT and 8 DBT) in a greenhouse trial to examine their ability to manage R. solanacearum in tomato plants. Consistent with in vitro results, the results from the greenhouse studies showed a level of higher anti-bacterial activity of T. harzianum metabolites than they did for the metabolites of other fungi, while among the three application times, the longest time (8 DBT) was more effective in controlling bacterial wilt disease in tomato plants. Metabolites of T. harzianum applied at 8 DBT caused the maximum decrease in soil bacterial population (1.526 log cfu/g), resulting in the lowest level of disease severity (area under disease progressive curve (AUDPC) value: 400), and maximum plant freshness (with a resulting biomass of 36.7 g, a root length of 18.3 cm and a plant height of 33.0 cm). It can be concluded that T. harzianum metabolites obtained on an STP medium, when applied after 8 DBT, can suppress soil bacterial population and enhance plant growth, and thus can be used as a safe, environmentally-conscious and consumer-friendly approach to managing bacterial wilt disease in tomato plants and possibly other crops.
Yancui Guo; Zhenyu Fan; Xiong Yi; Yuhong Zhang; Raja Khan; Zhiqiang Zhou. Sustainable Management of Soil-Borne Bacterium Ralstonia solanacearum In Vitro and In Vivo through Fungal Metabolites of Different Trichoderma spp. Sustainability 2021, 13, 1491 .
AMA StyleYancui Guo, Zhenyu Fan, Xiong Yi, Yuhong Zhang, Raja Khan, Zhiqiang Zhou. Sustainable Management of Soil-Borne Bacterium Ralstonia solanacearum In Vitro and In Vivo through Fungal Metabolites of Different Trichoderma spp. Sustainability. 2021; 13 (3):1491.
Chicago/Turabian StyleYancui Guo; Zhenyu Fan; Xiong Yi; Yuhong Zhang; Raja Khan; Zhiqiang Zhou. 2021. "Sustainable Management of Soil-Borne Bacterium Ralstonia solanacearum In Vitro and In Vivo through Fungal Metabolites of Different Trichoderma spp." Sustainability 13, no. 3: 1491.
Background Ralstonia solanacearum causes bacterial wilt disease in tomato and other crops resulting in huge economic losses worldwide. Several measures have been explored for the control of R. solanacearum, but the desired control level of the disease through sustainable and ecofriendly way is still awaited. Main body In this study, fungal metabolites produced by Trichoderma harzianum were investigated in the form of crude extract for the management of R. solanacearum both in vitro and in planta in tomato plants. In in vitro investigation, fungal metabolites were checked for their antibacterial potential at different concentrations (30, 60, 90, 120, 150, and 180 mg ml−1) and bacterial cell morphology was observed under scanning electron microscopy (SEM). In a greenhouse experiment, different application times (0, 3, and 6 days before transplantation DBT) and doses (0, 3, 6, and 9%) of the fungal metabolites were tested for their effects on soil bacterial population, disease severity and plant growth of tomato plants. The in vitro evaluation showed a strong antibacterial activity of fungal metabolites in concentration dependent manner. The highest concentration 180 mg ml−1 produced maximum inhibition zone (20.2 mm) having non-significant difference with the inhibition zone (20.5 mm) produced by the standard antibiotic streptomycin. The SEM analysis revealed severe morphological destructions of bacterial cells. In case of greenhouse experiment, the highest decrease in soil bacterial population, lowest disease severity, and maximum increase in plant growth parameters were obtained by highest dose (9%) and longest application time (6 DBT). Conclusion The fungal metabolites produced by T. harzianum could be used as low-cost, environment-friendly, and sustainable management strategy for the control of R. solanacearum in tomato plants.
Liu Yan; Raja Asad Ali Khan. Biological control of bacterial wilt in tomato through the metabolites produced by the biocontrol fungus, Trichoderma harzianum. Egyptian Journal of Biological Pest Control 2021, 31, 1 -9.
AMA StyleLiu Yan, Raja Asad Ali Khan. Biological control of bacterial wilt in tomato through the metabolites produced by the biocontrol fungus, Trichoderma harzianum. Egyptian Journal of Biological Pest Control. 2021; 31 (1):1-9.
Chicago/Turabian StyleLiu Yan; Raja Asad Ali Khan. 2021. "Biological control of bacterial wilt in tomato through the metabolites produced by the biocontrol fungus, Trichoderma harzianum." Egyptian Journal of Biological Pest Control 31, no. 1: 1-9.
Ixeris chinensis (Thunb.) Nakai is an important medicinal plant, young seedlings are also used as a wild vegetable in China. In recent years, I. chinensis has been cultivated in Shandong and Hebei Provinces, China. In August 2018, I. chinensis plants growing in greenhouses of Langfang City (116°36′28.62″ N; 39°36′36.44″ E), Hebei Province, exhibited typical symptoms caused by root-knot nematodes (RKN; Meloidogyne spp.). The plants grown slowly, leaves were small and few, and color became lighter. Galls and egg masses were visible on roots, and white, pear-shaped adult females observed inside the roots. The number of galls per plant (n = 15) was 62.87 ± 11.88 (42-95) and egg masses 16.53 ± 4.70 (9-26). Nematodes were extracted from soil and root samples (n = 15) using standard procedures (Barker 1985) and RKN found in 100% samples. Morphological and molecular studies were conducted on second-stage juveniles (J2), eggs, and females with eggs. Females (n = 30) were pear-shaped, 505.81 to 799.81 μm (665.03 ± 76.48) in length, and 276.81 to 584.50 μm (397.98 ± 70.42) in width, with round perineal pattern and the dorsal arch is relatively high, squarish and with wavy striae. Body length of J2 (n = 20) varied from 349.39 to 416.51 μm (382.15 ± 16.99), body width was 14.13 to 17.97 μm (15.68 ± 1.19), stylet length 11.52 to 14.89 μm (13.48 ± 0.92), tail length 36.12 to 52.15 μm (42.69 ± 4.46), hyaline tail terminus length 8.91 to 15.30 μm (12.49 ± 2.03) and presented well developed esophageal glands. Eggs (n = 20) were oval with length/width 84.05 ± 4.14/38.21 ± 1.84 μm. These morphological characteristics were similar to the description of M. incognita according to Zeng et al. (2014) and Whitehead (1968). The sizes of observed females in I. chinensis plant are smaller compared with M. incognita isolate characterized by Zeng et al. (2014), but they are similar with Whitehead (1968). Species identification was further confirmed by PCR with M. incognita-specific primers Mi-F/Mi-R (5′-GTGAGGATTCAGCTCCCCAG-3′, 5′-ACGAGGAACATACTTCTCCGTCC-3′) (Meng et al. 2004) and 28S rDNA D2/D3 region primers MF/MR (5′-GGGGATGTTTGAGGCAGATTTG-3′, 5′-AACCGCTTCGGACTTCCACCAG -3), (Hu et al. 2011). A 995-bp and a 478-bp DNA fragment were obtained with primers Mi-F/Mi-R and MF/MR, respectively. Fragments were, sequenced (MK410954 and MK410953, respectively) and compared with available sequences on NCBI. Sequences were 100% identical to the JN005841, JN005843, JN005844, JN005845, and AF435794, MH332653, MH332652 M. incognita sequences, respectively. Morphological and molecular characterization supports the identification of the isolate found on I. chinensis as M. incognita. Ixeris chinensis (Thunb.) Nakai seedlings (n = 15, 5-6 leaves stage), grown in sterilized soil individually, were also inoculated, with 1,200 M. incognita J2 (Pi) per seedling, using a sterilized micropipet and maintained at 25-28°C in a greenhouse. The test was repeated three times independently. After 7 weeks, plants were uprooted, the number of galls (196.3 ± 2.5), egg masses (43.6 ± 0.5) and final population density, evaluated from the eggs and J2s collected from per plant roots, (Pf; 6905.6 ± 81.0) recorded and the reproduction factor (Rf = Pf/Pi; 5.76 ± 0.1) calculated. I. chinensis was considered a good host for M. incognita in Langfang. Previous reports showed that I. chinensis was moderately resistant to M. incognita (Tsay et al. 2004). Our results are somewhat in contradiction probably due to the differences on environmental conditions or genetic diversity of RKN or I. chinensis. Meloidogyne incognita is the most frequent RKN species in China, with a wide distribution and range of host plants and causes severe yield losses. To our knowledge, this is the first report of Ixeris chinensis (Thunb.) Nakai as a host of M. incognita in Hebei Province, China.
Rui Liu; Nan Yin; Raja Asad Ali Khan; Zhenchuan Mao. First Report of the Root-Knot Nematode Meloidogyne incognita Infecting Ixeris chinensis in Hebei Province, China. Plant Disease 2020, 104, 3267 .
AMA StyleRui Liu, Nan Yin, Raja Asad Ali Khan, Zhenchuan Mao. First Report of the Root-Knot Nematode Meloidogyne incognita Infecting Ixeris chinensis in Hebei Province, China. Plant Disease. 2020; 104 (12):3267.
Chicago/Turabian StyleRui Liu; Nan Yin; Raja Asad Ali Khan; Zhenchuan Mao. 2020. "First Report of the Root-Knot Nematode Meloidogyne incognita Infecting Ixeris chinensis in Hebei Province, China." Plant Disease 104, no. 12: 3267.
In vitro and screen house experiments were conducted to investigate the effectiveness of thirteen phytochemicals from Artemisia elegantissimia and A. incisa on root knot nematode, Meloidogyne incognita in tomato (Lycopersicon esculentum L.) cv. Rio Grande. A positive control (Carbofuran) and negative control (H2O) were also used for comparison. Effectiveness of phytochemicals against juveniles (J2s) mortality and egg hatch inhibition were evaluated after 24, 48 and 72 hours of incubation at three concentrations viz; 0.1, 0.2 and 0.3 mg/mL in vitro conditions. Amongst thirteen phytochemicals, Isoscopletin (Coumarin), Carbofuran and Apigenin (Flavonoid) showed the highest mortality and egg hatch inhibition of M. incognita at all intervals. Inhibition of eggs and J2s mortality were the greatest (90.0%) and (96.0%) at 0.3 mg/mL concentration. Application of phytochemicals caused reduction in number of galls, galling index, and egg masses on tomato plant and enhanced plant growth parameters under screen house conditions. Gall numbers (1.50), galling index (1.00), number of juveniles (4.83) and egg masses (4.00) were greatly reduced and plant growth parameters such as; plant height (28.48 cm), fresh (72.13 g) and dry shoot weights (35.99 g), and root fresh (6.58 g) and dry weights (1.43 g) were increased significantly by using Isoscopletin. In structure activity relationship, juveniles of M. incognita, exhibited variations in their shape and postures upon death when exposed to different concentrations of phytochemicals of Artemisia spp. The present study suggests that Artemisia based phytochemicals possess strong nematicidal effects and can be used effectively in an integrated disease management program against root knot nematodes.
Raja Asad Ali Khan; I. Naz; S. Hussain; S. Ullah; M. U. Rashid; I. Siddique. Phytochemical management of root knot nematode (Meloidogyne incognita) kofoid and white chitwood by Artemisia spp. in tomato (Lycopersicon esculentum L.). Brazilian Journal of Biology 2020, 80, 829 -838.
AMA StyleRaja Asad Ali Khan, I. Naz, S. Hussain, S. Ullah, M. U. Rashid, I. Siddique. Phytochemical management of root knot nematode (Meloidogyne incognita) kofoid and white chitwood by Artemisia spp. in tomato (Lycopersicon esculentum L.). Brazilian Journal of Biology. 2020; 80 (4):829-838.
Chicago/Turabian StyleRaja Asad Ali Khan; I. Naz; S. Hussain; S. Ullah; M. U. Rashid; I. Siddique. 2020. "Phytochemical management of root knot nematode (Meloidogyne incognita) kofoid and white chitwood by Artemisia spp. in tomato (Lycopersicon esculentum L.)." Brazilian Journal of Biology 80, no. 4: 829-838.
Bacterial wilt (BW) disease caused by Ralstonia solanacearum species complex is a devastating plant disease that inflicts heavy losses to the large number of economic host plants it infects. In this study, the potential of dried powder of the arid-land medicinal shrub Rhazya stricta to control BW of tomato was explored. Both, in vitro and in planta studies were conducted, using different concentrations of dried powder of plant parts, and applied (surface mulched or mixed) to infested soil at 0, 10, and 20 days before transplanting (DBT). Aqueous extract of leaves (16% w/v) was found to be as effective as streptomycin (100 ppm) in inhibiting the in vitro growth of R. solanacearum. As evident from the scanning electron micrograph, 16% aqueous extract of leaves produced severe morphological changes, such as rupture of the bacterial cell walls. Results from the greenhouse experiments demonstrated that the higher powder dose (succulent shoot), namely, 30 g/kg of soil mixed with infested soil 20 DBT, was found to be the most effective in controlling BW. It increased root length (cm), shoot length (cm), and plant fresh biomass (g) by 55, 42, and 40%, respectively, over control plants. Mixing of plant powder with the artificially infested (35 ml of 108 CFU/ml per kilogram of soil) pot soil was better than surface mulching. The 30 g/kg of soil dose mixed with soil increased root length (cm), shoot length (cm), and plant fresh biomass (g) of treated plants by 67, 36, and 46%, respectively, over control plants. A 37% decrease in disease severity over the control was observed with drench application of 30 g of powder per kilogram of soil applied once at 20 DBT. Our results indicated that the dried powder (30 g/kg of soil) of leaves or succulent shoots of R. stricta, thoroughly mixed with soil, 20 DBT, could act as an effective control method against BW.
Raja Asad Ali Khan; Syed Sartaj Alam; Sania Hayat; Musharaf Ahmad; Asad Ali; Ishrat Naz; Yan Li. Eco-friendly Management of Bacterial Wilt in Tomato Using Dried Powder of the Wild Arid-Land Medicinal Shrub Rhazya stricta. Plant Disease 2020, 104, 2613 -2621.
AMA StyleRaja Asad Ali Khan, Syed Sartaj Alam, Sania Hayat, Musharaf Ahmad, Asad Ali, Ishrat Naz, Yan Li. Eco-friendly Management of Bacterial Wilt in Tomato Using Dried Powder of the Wild Arid-Land Medicinal Shrub Rhazya stricta. Plant Disease. 2020; 104 (10):2613-2621.
Chicago/Turabian StyleRaja Asad Ali Khan; Syed Sartaj Alam; Sania Hayat; Musharaf Ahmad; Asad Ali; Ishrat Naz; Yan Li. 2020. "Eco-friendly Management of Bacterial Wilt in Tomato Using Dried Powder of the Wild Arid-Land Medicinal Shrub Rhazya stricta." Plant Disease 104, no. 10: 2613-2621.
Muhammad Zubair; Raja Asad Ali Khan; Asad Ali; Najeeb Ullah; Shawana Ahmad; Moazam Hyder; Musharaf Ahmad; Aamar Mushtaq; Khalid Pervaiz Akhtar. First Report of Tomato leaf curl New Delhi virus in Physalis minima in Pakistan. Plant Disease 2020, 104, 1878 .
AMA StyleMuhammad Zubair, Raja Asad Ali Khan, Asad Ali, Najeeb Ullah, Shawana Ahmad, Moazam Hyder, Musharaf Ahmad, Aamar Mushtaq, Khalid Pervaiz Akhtar. First Report of Tomato leaf curl New Delhi virus in Physalis minima in Pakistan. Plant Disease. 2020; 104 (6):1878.
Chicago/Turabian StyleMuhammad Zubair; Raja Asad Ali Khan; Asad Ali; Najeeb Ullah; Shawana Ahmad; Moazam Hyder; Musharaf Ahmad; Aamar Mushtaq; Khalid Pervaiz Akhtar. 2020. "First Report of Tomato leaf curl New Delhi virus in Physalis minima in Pakistan." Plant Disease 104, no. 6: 1878.
Phytopathogenic fungi, causing significant economic and production losses, are becoming a serious threat to global food security. Due to an increase in fungal resistance and the hazardous effects of chemical fungicides to human and environmental health, scientists are now engaged to explore alternate non-chemical and ecofriendly management strategies. The use of biocontrol agents and their secondary metabolites (SMs) is one of the potential approaches used today. Trichoderma spp. are well known biocontrol agents used globally. Many Trichoderma species are the most prominent producers of SMs with antimicrobial activity against phytopathogenic fungi. Detailed information about these secondary metabolites, when grouped together, enhances the understanding of their efficient utilization and further exploration of new bioactive compounds for the management of plant pathogenic fungi. The current literature provides the information about SMs of Trichoderma spp. in a different context. In this review, we summarize and group different antifungal SMs of Trichoderma spp. against phytopathogenic fungi along with a comprehensive overview of some aspects related to their chemistry and biosynthesis. Moreover, a brief overview of the biosynthesis pathway, action mechanism, and different approaches for the analysis of SMs and the factors affecting the regulation of SMs in Trichoderma is also discussed.
Raja Asad Ali Khan; Saba Najeeb; Shaukat Hussain; Bingyan Xie; Yan Li. Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Fungi. Microorganisms 2020, 8, 817 .
AMA StyleRaja Asad Ali Khan, Saba Najeeb, Shaukat Hussain, Bingyan Xie, Yan Li. Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Fungi. Microorganisms. 2020; 8 (6):817.
Chicago/Turabian StyleRaja Asad Ali Khan; Saba Najeeb; Shaukat Hussain; Bingyan Xie; Yan Li. 2020. "Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Fungi." Microorganisms 8, no. 6: 817.
Bacterial wilt disease caused by Ralstonia solanacearum is a devastating plant disease that inflicts heavy losses to the large number of economic host plants it infects. The potential of dried powder of the Conyza canadensis to control bacterial wilt (BW) of tomato was explored in vitro and in planta. Three application times (16 days before transplanting (DBT), 8 DBT and 0 DBT), three plastic-mulch durations (10 days plastic mulching (DPM), 5DPM and 0DPM) and four doses viz. 0 g, 8 g, 16 g and 24 g of the plant powder were evaluated. SEM analysis was also conducted to observe the change in bacterial cell morphology. Ethanol extract of dried C. canadensis in different concentrations inhibited the in vitro growth of R. solanacearum by as much as 98% of that produced by ampicillin. As evident from the scanning electron micrograph, the highest concentration produced severe morphologic changes, such as rupture of the bacterial cell walls and cell contents leaked out. Results from application time and dose experiment demonstrated that the highest powder dose viz. 24 g kg−1 mixed with infested soil 16 DBT gave maximum root length (34.0 ± 2.5 cm), plant height (74.3 ± 4.7 cm), fresh biomass (58.3 ± 4.3 g), reduction in bacterial population (1.52 log10) and resulted in lowest AUDPC value (1156.6). In case of mulching duration and dose experiment the maximum root length (39.6 ± 3.2 cm), plant height (78.3 ± 5.8 cm), fresh biomass (65.6 ± 4.9 g) reduction in bacterial population (1.59 log10) and lowest AUDPC value (1251.6) was achieved through the application of highest powder dose viz. 24 g kg−1 and longest plastic mulching duration of 10 DPM. The better results of highest dose and longer application time can be explained on the basis of higher amounts of anti-microbial plant bio-active compounds in highest dose and the longer exposure time of the pathogen to these chemicals. The better results of longer mulching duration are due to faster and more complete decomposition (because of 10-days-long plastic-mulch-provided increased solar heat) of the dried powder which produced more amounts of volatile and non-volatile bactericidal compounds. Our results clearly suggest that the use of 24 g kg−1 dried plant powder of C. canadensis plastic-mulched for two weeks could be used as a reliable component of the integrated disease management program against BW.
Ke Chen; Raja Asad Ali Khan; Wen Cao; Meng Ling. Sustainable and Ecofriendly Approach of Managing Soil Born Bacterium Ralstonia solanacearum (Smith) Using Dried Powder of Conyza canadensis. Pathogens 2020, 9, 327 .
AMA StyleKe Chen, Raja Asad Ali Khan, Wen Cao, Meng Ling. Sustainable and Ecofriendly Approach of Managing Soil Born Bacterium Ralstonia solanacearum (Smith) Using Dried Powder of Conyza canadensis. Pathogens. 2020; 9 (5):327.
Chicago/Turabian StyleKe Chen; Raja Asad Ali Khan; Wen Cao; Meng Ling. 2020. "Sustainable and Ecofriendly Approach of Managing Soil Born Bacterium Ralstonia solanacearum (Smith) Using Dried Powder of Conyza canadensis." Pathogens 9, no. 5: 327.
Losses in crops caused by plant pathogenic bacteria and parasitic nematode are increasing because of a decrease in efficacy of traditional management measures. There is an urgent need to develop nonchemical and ecofriendly based management to control plant diseases. A potential approach of controlling plant disease in the crops is the use of biocontrol agents and their secondary metabolites (SMs). Luckily fungi and especially the genus Trichoderma comprise a great number of fungal strains that are the potential producer of bioactive secondary metabolites. In this study secondary metabolites from ten Trichoderma spp. were evaluated for their antibacterial and nematicidal potential against phytopathogenic bacteria Ralstonia solanacearum, Xanthomonas compestris and plant parasitic nematode Meloidogyne incognita. Five different growth media were evaluated for the production of SMs. It was shown that SMs of different Trichoderma spp. obtained on different growth media were different in the degree of their bioactivity. Comparison of five growth media showed that SMs produced on solid wheat and STP media gave higher antibacterial activity. SMs of T. pseudoharzianum (T113) obtained on solid wheat media were more effective against the studied bacteria followed by SMs from T. asperelloides (T136), T. pseudoharzianum (T129) and T. pseudoharzianum (T160). Scanning electron microscopy (SEM) was further conducted to observe the effect of SMs on bacterial cell morphology. As evident from the SEM, SMs produced severe morphological changes, such as rupturing of the bacterial cell walls, disintegration of cell membrane and cell content leaking out. SMs from T. viridae obtained on liquid STP and solid wheat media showed the highest percent of M. incognita juveniles (J2s) mortality and inhibition in egg hatching of M. incognita. The results of our study suggest that T. pseudoharzianum (T113) and T. viridae could be selected as an effective candidate for SMs source against phytopathogenic bacteria and M. incognita respectively.
Raja Asad Ali Khan; Saba Najeeb; Zhenchuan Mao; Jian Ling; Yuhong Yang; Yan Li; Bingyan Xie. Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Bacteria and Root-Knot Nematode. Microorganisms 2020, 8, 401 .
AMA StyleRaja Asad Ali Khan, Saba Najeeb, Zhenchuan Mao, Jian Ling, Yuhong Yang, Yan Li, Bingyan Xie. Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Bacteria and Root-Knot Nematode. Microorganisms. 2020; 8 (3):401.
Chicago/Turabian StyleRaja Asad Ali Khan; Saba Najeeb; Zhenchuan Mao; Jian Ling; Yuhong Yang; Yan Li; Bingyan Xie. 2020. "Bioactive Secondary Metabolites from Trichoderma spp. against Phytopathogenic Bacteria and Root-Knot Nematode." Microorganisms 8, no. 3: 401.
Because of its known anti-bacterial properties, we explored the potential of Xanthium strumarium, an invasive, enormous mass-producing weed, for the control of Ralstonia solanacearum which causes bacterial wilt (BW) of tomato. Both in-vitro and in-planta experiments were conducted, using different concentrations of the dried powders of the plant parts applied to infested soil at different times. Addition of a 20% (w/v) aqueous extract of leaf powder or succulent shoot powder to wells cut in nutrient agar inhibited growth of R. solanacearum. In in-planta experiments, 4.5% (w/w) leaf powder applied to artificially infested soil 10 days before transplant (DBT), produced the best effect and enhanced root length, shoot length, and plant fresh bio-mass by 64%, 37%, and 42%, respectively, as compared to inoculated control. Leaf powder also lowered the area under disease progress curve (AUDPC) by 38%, and the pathogen counts (g−1 dry soil) by 1.202 log10 units. Succulent shoot powder (4.5% w/w) applied 20 DBT proved to be better than other application times and increased root length, shoot length, and plant fresh bio-mass by 55%, 42%, and 57%, respectively, as compared to inoculated control. Succulent shoot powder also decreased AUDPC by 35%, and the pathogen counts (g−1 dry soil) by 1.294 log10 units. Our data strongly suggest that 4.5% (w/w) of leaf or succulent shoot powder, applied 20 DBT, can be an effective component of the integrated disease management (IDM) against BW.
Raja Asad Ali Khan; M. Ahmad; I. Naz; S. Najeeb; L. Yanlin; S. S. Alam. Sustainable management of bacterial wilt of tomato using dried powder of Xanthium strumarium L. Journal of Plant Pathology 2019, 102, 421 -431.
AMA StyleRaja Asad Ali Khan, M. Ahmad, I. Naz, S. Najeeb, L. Yanlin, S. S. Alam. Sustainable management of bacterial wilt of tomato using dried powder of Xanthium strumarium L. Journal of Plant Pathology. 2019; 102 (2):421-431.
Chicago/Turabian StyleRaja Asad Ali Khan; M. Ahmad; I. Naz; S. Najeeb; L. Yanlin; S. S. Alam. 2019. "Sustainable management of bacterial wilt of tomato using dried powder of Xanthium strumarium L." Journal of Plant Pathology 102, no. 2: 421-431.
Aqueous extracts and green manures of different parts of Adhatoda vasica, a wild medicinal shrub plant, were tested in vitro and in vivo for the control of bacterial wilt (BW) in tomato. Higher concentration (14%, w/v) of aqueous extracts of leaf, succlent shoot and stem were more effective than the lower concentrations and inhibited the in vitro growth of the pathogen by 94, 89, and 65% respectively, of the growth inhibition produced by streptomycin (200 ppm). Green manure dose of 30 g kg−1 soil strongly suppressed the BW pathogen, reduced disease severity and promoted the yield-contributing plant growth parameters. Green manure of leaves, when applied to soil 4 weeks before the transplantation of tomato seedlings, controlled BW more effectively and significantly increased plant growth parameters as compared to the green manures of other parts of the plant and other application times. It can be clearly concluded from our data that Adhatoda vasica leaves green manure dose of 30 g kg−1 soil (or possibly higher) could be included as an effective and nature-friendly component of the integrated disease management (IDM) against BW and possibly other similar diseases. Wässrige Extrakte und Gründünger aus verschiedenen Teilen von Adhatoda vasica, einer wilden medizinischen Strauchpflanze, wurden in vitro und in vivo zur Kontrolle der bakteriellen Tomatenwelke getestet. Höhere Konzentrationen (14 %, w/v) von wässrigen Extrakten aus Blättern, Spross und Stiel waren wirksamer als niedrigere Konzentrationen und hemmten das Wachstum des Pathogens in vitro um 94 %, 89 % bzw. 65 % der Wachstumshemmung durch Streptomycin (200 ppm). Die Gründüngerdosis von 30 g/kg Boden unterdrückte den Erreger der Bakterienwelke stark, verringerte den Schweregrad der Erkrankung und förderte die ertragbringenden Pflanzenwachstumsparameter. Die Gründüngung mit Blättern bei Applikation auf den Boden 4 Wochen vor der Verpflanzung der Tomatensämlinge kontrollierte die bakterielle Welke wirksamer und erhöhte die Pflanzenwachstumsparameter signifikant im Vergleich zur Gründüngung mit anderen Pflanzenteilen und zu anderen Anwendungszeiten, Aus unseren Daten lässt sich eindeutig schließen, dass eine Gründüngung mit 30 g Adhatoda-vasica-Blättern/kg Boden (oder möglicherweise höher) als wirksamer und naturverträglicher Bestandteil des integrierten Krankheitsmanagements gegen bakterielle Welke und möglicherweise andere ähnliche Krankheiten aufgenommen werden könnte.
Raja Asad Ali Khan; Najeeb Ullah; Syed Sartaj Alam; Asad Ali; Ishrat Naz; Bilal Ahmad; Musharaf Ahmad; Inam Ullah. Management of Ralstonia solanacearum (Smith) Wilt in Tomato Using Green Manure of the Medicinal Plant Adhatoda vasica (L.) Nees. Gesunde Pflanzen 2019, 72, 129 -138.
AMA StyleRaja Asad Ali Khan, Najeeb Ullah, Syed Sartaj Alam, Asad Ali, Ishrat Naz, Bilal Ahmad, Musharaf Ahmad, Inam Ullah. Management of Ralstonia solanacearum (Smith) Wilt in Tomato Using Green Manure of the Medicinal Plant Adhatoda vasica (L.) Nees. Gesunde Pflanzen. 2019; 72 (2):129-138.
Chicago/Turabian StyleRaja Asad Ali Khan; Najeeb Ullah; Syed Sartaj Alam; Asad Ali; Ishrat Naz; Bilal Ahmad; Musharaf Ahmad; Inam Ullah. 2019. "Management of Ralstonia solanacearum (Smith) Wilt in Tomato Using Green Manure of the Medicinal Plant Adhatoda vasica (L.) Nees." Gesunde Pflanzen 72, no. 2: 129-138.
The potential of finely ground dried powder of different parts (leaves, succulent shoot and stem) of the desert medicinal plant, Withania coagulans, (L) Dunal to control bacterial wilt (BW) of tomato was explored using four different doses (0 g, 10 g, 20 g, and 30 g Kg−1 soil) and three different (0 days before transplanting DBT, or 10 DBT and 20 DBT) application timings. Both, in-vitro and in-vivo experiments were conducted. In in-vitro studies, each of the three concentrations (5%, 10%, and 20% w/v) of aqueous extracts of leaves, succulent shoot and stems inhibited the growth of the BW pathogen, Ralstonia solanacearum. The aqueous extract (20% w/v) of dried powder of leaves produced the maximum zones of inhibition (ZI) (20.8 mm) followed by that of succulent shoot (19.2 mm) and stem (16 mm) while the minimum ZI (11.2 mm,) was produced by the aqueous extracts of (5% w/v) stem powder. Consistent with the in-vitro results, the effect of the ground powders of the medicinal plant was found to be dose- and plant-part-dependent in in-vivo studies as well. Dried powder of leaves performed better than those of succulent shoot and stems. Leaves powder used at 30 g kg−1 soil under in-vivo conditions, reduced area under disease progress curve (AUDPC) by 37.54%, pathogen population g−1 of the infested soil by 45.04%, enhanced shoot length by 37.45%, root length by 63.36%, and plant fresh biomass by 38.62% as compared to untreated inoculated control plants. Dried powder of succulent shoot (tender shoots plus leaves) used at 30 g/kg soil, ranked second in terms of controlling bacterial wilt. It reduced AUDPC by 32.33%, pathogen population g−1of soil by 32.66%, augmented shoot and root lengths by 35%, and 62.39%, respectively and plant fresh biomass by 38.41% as compared to control plants. Lower doses of dried powders of all parts of the medicinal plant gave inferior results. Similarly, the application time of 20 DBT was found to be better than 10 DBT and 0 DBT. It achieved a reduction of 32.91% in AUDPC, and an augmentation of 41.32%, 54.42%, 54.53% in shoot length, root length and plant fresh biomass, respectively in comparison to untreated inoculated plants. Therefore, it is concluded that dried powder of leaves or succulent shoots of W. coagulans applied at the rate of 30 g kg−1 soil, 20 DBT, can be included as an effective component of integrated disease management (IDM) against BW.
S. Najeeb; M. Ahmad; Raja Asad Ali Khan; I. Naz; A. Ali; Syed S. Alam. Management of bacterial wilt in tomato using dried powder of Withania coagulan (L) Dunal. Australasian Plant Pathology 2019, 48, 183 -192.
AMA StyleS. Najeeb, M. Ahmad, Raja Asad Ali Khan, I. Naz, A. Ali, Syed S. Alam. Management of bacterial wilt in tomato using dried powder of Withania coagulan (L) Dunal. Australasian Plant Pathology. 2019; 48 (2):183-192.
Chicago/Turabian StyleS. Najeeb; M. Ahmad; Raja Asad Ali Khan; I. Naz; A. Ali; Syed S. Alam. 2019. "Management of bacterial wilt in tomato using dried powder of Withania coagulan (L) Dunal." Australasian Plant Pathology 48, no. 2: 183-192.
Plant diseases are threat to global food security. The excessive use of agrochemicals is the leading cause of pesticides resistance and toxicity to beneficial life forms. The quest for innocuous and alternate antimicrobial agent is crucial in order to overcome the pathogen resistance and the birth of nanotech offers pledge to combat pathogenic organisms. In this study, a facile benign biogenic approach was adopted for the synthesis of biocompatible iron oxide nanoparticles (Fe2O3−NPs) via Skimmia laureola leaf extract and the synthesized nanoparticles were evaluated for their antibacterial efficacy against bacterial wilt pathogen Ralstonia solanacearum in vitro and in planta. Physico-chemical characterization of the synthesized nanoparticles was performed through UV–Visible spectroscopy, Fourier Transform Infrared Spectroscopic, X-Ray Diffraction, Energy Dispersive X-ray Spectroscopy and Scanning Electron Microscopy. The results revealed polydisperse nanoparticles in the size range of 56 nm to 350 nm. The culture media containing 6 mg/mL of Fe2O3−NPs dramatically inhibited the bacterial growth in vitro. Scanning electron microscopy revealed degenerative characteristics including degraded, shriveled and concentrated cell walls. Diseases severity was effectively reduced with 6% w/v of Fe2O3−NPs treated root zone in planta. Plant shoots, root length and fresh biomass were enhanced with Fe2O3−NPs treatments. The results indicated that the biosynthesized Fe2O3−NPs have the potential to control agriculturally important phytopathogen Ralstonia solanacearum in vitro and in planta.
Tariq Alam; Raja Asad Ali Khan; Ahmad Ali; Hassan Sher; Zahid Ullah; Mohammad Ali. Biogenic synthesis of iron oxide nanoparticles via Skimmia laureola and their antibacterial efficacy against bacterial wilt pathogen Ralstonia solanacearum. Materials Science and Engineering: C 2018, 98, 101 -108.
AMA StyleTariq Alam, Raja Asad Ali Khan, Ahmad Ali, Hassan Sher, Zahid Ullah, Mohammad Ali. Biogenic synthesis of iron oxide nanoparticles via Skimmia laureola and their antibacterial efficacy against bacterial wilt pathogen Ralstonia solanacearum. Materials Science and Engineering: C. 2018; 98 ():101-108.
Chicago/Turabian StyleTariq Alam; Raja Asad Ali Khan; Ahmad Ali; Hassan Sher; Zahid Ullah; Mohammad Ali. 2018. "Biogenic synthesis of iron oxide nanoparticles via Skimmia laureola and their antibacterial efficacy against bacterial wilt pathogen Ralstonia solanacearum." Materials Science and Engineering: C 98, no. : 101-108.
Raja Asad Ali Khan; Bilal Ahmad; Musharaf Ahmad; Asad Ali; Ishrat Naz; Muhammad Fahim. Management of Ralstonia solanacearum (Smith) Yabuuchi wilt in tomato (Solanum Lycopersicum L.) with dried powder of the medicinal plant Withania somnifera (L.) Dunal. Pakistan Journal of Botany 2018, 51, 1 .
AMA StyleRaja Asad Ali Khan, Bilal Ahmad, Musharaf Ahmad, Asad Ali, Ishrat Naz, Muhammad Fahim. Management of Ralstonia solanacearum (Smith) Yabuuchi wilt in tomato (Solanum Lycopersicum L.) with dried powder of the medicinal plant Withania somnifera (L.) Dunal. Pakistan Journal of Botany. 2018; 51 (1):1.
Chicago/Turabian StyleRaja Asad Ali Khan; Bilal Ahmad; Musharaf Ahmad; Asad Ali; Ishrat Naz; Muhammad Fahim. 2018. "Management of Ralstonia solanacearum (Smith) Yabuuchi wilt in tomato (Solanum Lycopersicum L.) with dried powder of the medicinal plant Withania somnifera (L.) Dunal." Pakistan Journal of Botany 51, no. 1: 1.