[Objectives]The paper was to explore the prevention and therapeutic schedule of tobacco black shank.[Methods]Different concentrations of 25 g/L fludioxonil·37.5 g/L metalaxyl-M,10 billion/mL Bacillus amyloliquefa...[Objectives]The paper was to explore the prevention and therapeutic schedule of tobacco black shank.[Methods]Different concentrations of 25 g/L fludioxonil·37.5 g/L metalaxyl-M,10 billion/mL Bacillus amyloliquefaciens,110 g/L amino acids·24 g/L manganese zinc,120 g/L calcium·20 g/L magnesium,and 4%metalaxyl-M·64%mancozeb were employed to assess their efficacy in controlling tobacco black shank.The disease index was subsequently evaluated.[Results]25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+110 g/L amino acids·24 g/L manganese zinc(transplanting dosage)or 120 g/L calcium·20 g/L magnesium(sealing dosage)(transplanting dosage:750 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2,sealing dosage:1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2)resulted in a notable impact on the prevention of tobacco black shank.The incidence in the treated area was 10.78%,a 35.72%reduction compared to the control.The estimated yield was 99700 yuan/hm 2,a 34.91%increase compared to the control.25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+120 g/L calcium·20 g/L magnesium+4%metalaxyl-M·64%mancozeb(control dosage:1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2+1.5×103 g/hm 2,1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2+1.5×103 g/hm 2,with an interval of 7 d between applications)demonstrated a significant efficacy in controlling tobacco black shank.At 7 d following the second application,the relative preventive efficacy was observed to be 88.99%.Additionally,the estimated yield was 109900 yuan/hm 2,representing an increase of 244.51%compared to the control.[Conclusions]During the transplanting and sealing stages,25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+110 g/L amino acids·24 g/L manganese zinc(transplanting dosage)or 120 g/L calcium·20 g/L magnesium(sealing dosage)may be employed to enhance the growth of tobacco plants and mitigate the occurrence of tobacco black shank.Additionally,25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+120 g/L calcium·20 g/L magnesium+4%metalaxyl-M·64%mancozeb can be utilized for the treatment of tobacco black shank during the initial incidence stage.展开更多
The water extract of dry mycelium ofPenicillium chrysogenum （DME） was used to induce resistance in Virginia tobacco plants against Phtophthora parasitica var. nicotianae. Results showed that the efficacy of DME in c...The water extract of dry mycelium ofPenicillium chrysogenum （DME） was used to induce resistance in Virginia tobacco plants against Phtophthora parasitica var. nicotianae. Results showed that the efficacy of DME in controlling black shank disease depended on both DME solution concentration and its＇ treatment methodology. Soil application of 1.5-5% DME 72 hr before inoculation with Phtophthora parasitica vat. nicotianae provided highly significant protection against black shank, relative to the control without DME treatment. Optimized tobacco plant treatment with 2.5% DME significantly increased peroxidase （POD） and polyphenol oxidase （PPO） activity levels in the upper leaf sections of the tobacco plants. DME had no direct antifungal activity on the growth of Phtophthora parasitica var. nicotianae in vitro, suggesting that disease control with DME treatment resulted from the induced propagation of natural defense mechanisms in the tobacco plants.展开更多
Tobacco black shank is one of the devastating diseases of tobacco. In recent years, this disease widely occurred in most tobacco-growing areas, which caused disastrous losses and has severely threatened the sustainabl...Tobacco black shank is one of the devastating diseases of tobacco. In recent years, this disease widely occurred in most tobacco-growing areas, which caused disastrous losses and has severely threatened the sustainable development of flue-cured tobacco. In order to lay a theoretical foundation for the better control of tobacco black shank, the occurrence characteristics and integrated control strategis of this disease were systematically discussed according to the aspects of agricultural control, chemical control, biological control, etc.展开更多
The resistance of 15 flue-cured tobacco varieties were identified by artificial inoculation of black shank. The results showed that K326, Yunyan 202 and NC102 belonged to resistance variety against black shank, and th...The resistance of 15 flue-cured tobacco varieties were identified by artificial inoculation of black shank. The results showed that K326, Yunyan 202 and NC102 belonged to resistance variety against black shank, and the resistance successively were K326 〉 Yunyan 202 〉 NC102 ; Yunyan 87, Cuibi 5, Yunyan 85, Yunyan 97 and Cuibi 7 belonged to moderate resistance variety against black shank, and the resistance successively were Yunyan 87 ~ Cuibi 5 ~ Yunyan 85 〉 Yunyan 97 〉 Cuibi 7 ; Cuibi 12, NC82, PYH06 and Cuibi 14 belonged to moderate susceptible variety against black shank, and the resistance successively were Cuibi 12 ~ NC82 ~ PVH06 ~ Cuibi 14; Cuibi 1 and Hongda belonged to high susceptible variety against black shank, and the resistance successively were Cuibi 1 〉 09011 〉 Hongda. The disease dynamics of flue-cured tobacco varieties were positively correlated with variety susceptibility, namely the earlier infection in susceptible variety, the faster the disease progression.展开更多
Investigations into the potential application of nanoparticles acting as nanofungicides in sustainable agriculture are rapidly expanding due to the high antimicrobial properties of these compounds,which do not risk in...Investigations into the potential application of nanoparticles acting as nanofungicides in sustainable agriculture are rapidly expanding due to the high antimicrobial properties of these compounds,which do not risk inducing pathogen resistance to fungicides.A detailed understanding of the impact of copper oxide nanoparticles(CuO NPs)on soil-borne phytopathogenic fungi is yet to be obtained.This study aimed to explore the in vitro antifungal activity and control efficacy of CuO NPs applied via irrigation with respect to tobacco black shank(TBS)disease caused by Phytophthora nicotianae.The results revealed that CuO NPs greatly interfered with the reproductive growth process of this fungus,repressing hyphal growth,spore germination and sporangium production.Additionally,morphological damage,intracellular ROS accumulation and increased SOD enzyme activity in hyphae were the antifungicidal mechanisms of these NPs.In pot experiments,treatment with CuO NPs at 100 mg L^(–1)significantly suppressed TBS development,compared with the effect on control plants,and the control efficacy reached 33.69%without inducing phytotoxicity.Exposure to CuO NPs significantly activated a series of defense enzymes,and resistance genes in tobacco can further explain the mechanisms by which CuO NPs suppressed fungal infection.The Cu content in both the leaves and roots of P.nicotianae-infested plants increased by 50.03 and 27.25%,respectively,after treatment with 100 mg L^(–1)CuO NPs,compared with that of healthy plants.In particular,a higher Cu content was observed in infected roots than in leaves.Therefore,this study showed the potential of CuO NPs applied as nanofungicides and as nanoinducers of fungus resistance genes for the management of TBS through inhibition of pathogen infection and stimulation of plant defenses.展开更多
文摘[Objectives]The paper was to explore the prevention and therapeutic schedule of tobacco black shank.[Methods]Different concentrations of 25 g/L fludioxonil·37.5 g/L metalaxyl-M,10 billion/mL Bacillus amyloliquefaciens,110 g/L amino acids·24 g/L manganese zinc,120 g/L calcium·20 g/L magnesium,and 4%metalaxyl-M·64%mancozeb were employed to assess their efficacy in controlling tobacco black shank.The disease index was subsequently evaluated.[Results]25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+110 g/L amino acids·24 g/L manganese zinc(transplanting dosage)or 120 g/L calcium·20 g/L magnesium(sealing dosage)(transplanting dosage:750 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2,sealing dosage:1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2)resulted in a notable impact on the prevention of tobacco black shank.The incidence in the treated area was 10.78%,a 35.72%reduction compared to the control.The estimated yield was 99700 yuan/hm 2,a 34.91%increase compared to the control.25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+120 g/L calcium·20 g/L magnesium+4%metalaxyl-M·64%mancozeb(control dosage:1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2+1.5×103 g/hm 2,1.5×103 mL/hm 2+1.2×104 mL/hm 2+1.5×103 mL/hm 2+1.5×103 g/hm 2,with an interval of 7 d between applications)demonstrated a significant efficacy in controlling tobacco black shank.At 7 d following the second application,the relative preventive efficacy was observed to be 88.99%.Additionally,the estimated yield was 109900 yuan/hm 2,representing an increase of 244.51%compared to the control.[Conclusions]During the transplanting and sealing stages,25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+110 g/L amino acids·24 g/L manganese zinc(transplanting dosage)or 120 g/L calcium·20 g/L magnesium(sealing dosage)may be employed to enhance the growth of tobacco plants and mitigate the occurrence of tobacco black shank.Additionally,25 g/L fludioxonil·37.5 g/L metalaxyl-M+10 billion/mL B.amyloliquefaciens+120 g/L calcium·20 g/L magnesium+4%metalaxyl-M·64%mancozeb can be utilized for the treatment of tobacco black shank during the initial incidence stage.
文摘The water extract of dry mycelium ofPenicillium chrysogenum （DME） was used to induce resistance in Virginia tobacco plants against Phtophthora parasitica var. nicotianae. Results showed that the efficacy of DME in controlling black shank disease depended on both DME solution concentration and its＇ treatment methodology. Soil application of 1.5-5% DME 72 hr before inoculation with Phtophthora parasitica vat. nicotianae provided highly significant protection against black shank, relative to the control without DME treatment. Optimized tobacco plant treatment with 2.5% DME significantly increased peroxidase （POD） and polyphenol oxidase （PPO） activity levels in the upper leaf sections of the tobacco plants. DME had no direct antifungal activity on the growth of Phtophthora parasitica var. nicotianae in vitro, suggesting that disease control with DME treatment resulted from the induced propagation of natural defense mechanisms in the tobacco plants.
基金Supported by Project of Yunnan Tobacco Company of Science and Technology(2014YN20)
文摘Tobacco black shank is one of the devastating diseases of tobacco. In recent years, this disease widely occurred in most tobacco-growing areas, which caused disastrous losses and has severely threatened the sustainable development of flue-cured tobacco. In order to lay a theoretical foundation for the better control of tobacco black shank, the occurrence characteristics and integrated control strategis of this disease were systematically discussed according to the aspects of agricultural control, chemical control, biological control, etc.
基金Supported by General Project of Panzhihua Branch of Sichuan Tobacco Company"Breeding and Application of Cuibi Series Varieties"(PZHYC20130016)
文摘The resistance of 15 flue-cured tobacco varieties were identified by artificial inoculation of black shank. The results showed that K326, Yunyan 202 and NC102 belonged to resistance variety against black shank, and the resistance successively were K326 〉 Yunyan 202 〉 NC102 ; Yunyan 87, Cuibi 5, Yunyan 85, Yunyan 97 and Cuibi 7 belonged to moderate resistance variety against black shank, and the resistance successively were Yunyan 87 ~ Cuibi 5 ~ Yunyan 85 〉 Yunyan 97 〉 Cuibi 7 ; Cuibi 12, NC82, PYH06 and Cuibi 14 belonged to moderate susceptible variety against black shank, and the resistance successively were Cuibi 12 ~ NC82 ~ PVH06 ~ Cuibi 14; Cuibi 1 and Hongda belonged to high susceptible variety against black shank, and the resistance successively were Cuibi 1 〉 09011 〉 Hongda. The disease dynamics of flue-cured tobacco varieties were positively correlated with variety susceptibility, namely the earlier infection in susceptible variety, the faster the disease progression.
基金financial support by the National Natural Science Foundation of China(32001934)the Key Science and Technology Project of Sichuan Tobacco Company,China(SCYC202114)。
文摘Investigations into the potential application of nanoparticles acting as nanofungicides in sustainable agriculture are rapidly expanding due to the high antimicrobial properties of these compounds,which do not risk inducing pathogen resistance to fungicides.A detailed understanding of the impact of copper oxide nanoparticles(CuO NPs)on soil-borne phytopathogenic fungi is yet to be obtained.This study aimed to explore the in vitro antifungal activity and control efficacy of CuO NPs applied via irrigation with respect to tobacco black shank(TBS)disease caused by Phytophthora nicotianae.The results revealed that CuO NPs greatly interfered with the reproductive growth process of this fungus,repressing hyphal growth,spore germination and sporangium production.Additionally,morphological damage,intracellular ROS accumulation and increased SOD enzyme activity in hyphae were the antifungicidal mechanisms of these NPs.In pot experiments,treatment with CuO NPs at 100 mg L^(–1)significantly suppressed TBS development,compared with the effect on control plants,and the control efficacy reached 33.69%without inducing phytotoxicity.Exposure to CuO NPs significantly activated a series of defense enzymes,and resistance genes in tobacco can further explain the mechanisms by which CuO NPs suppressed fungal infection.The Cu content in both the leaves and roots of P.nicotianae-infested plants increased by 50.03 and 27.25%,respectively,after treatment with 100 mg L^(–1)CuO NPs,compared with that of healthy plants.In particular,a higher Cu content was observed in infected roots than in leaves.Therefore,this study showed the potential of CuO NPs applied as nanofungicides and as nanoinducers of fungus resistance genes for the management of TBS through inhibition of pathogen infection and stimulation of plant defenses.
