A field study was carried out on the grey disorder in fine-cured tobacco (Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobaccoand...A field study was carried out on the grey disorder in fine-cured tobacco (Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobaccoand dead roots. Grey disorder leaves produced low quality lamina, which was low in N, nicotine, reducedsugar and K contents. In this study’ soil available Mn and leaf Mn contents were in a relatively low level andshould not be an important factor in the occurrence of grey disorder in fine-cured tobacco.展开更多
Plasmopam viticola, a causal agent of grapevine downy mildew, is a widely distributed pathogen, which can cause destructive disease in field-grown grapevines. Although fungicides are used to treat the disease, fungici...Plasmopam viticola, a causal agent of grapevine downy mildew, is a widely distributed pathogen, which can cause destructive disease in field-grown grapevines. Although fungicides are used to treat the disease, fungicide-resistant strains have been emerging. In this study, we developed graphene oxide （GO）-Fe3O4 nanocomposites, which could effectively repress the germination of sporangia and inhibit the development of downy mildew. 50 μg mL^-1 GO-Fe3O4 showed excellent protective and fungiddal activities. 250 μg mL^-1 GO-Fe3O4 on grapevine leaves in the field could significantly decrease the severity of downy mildew, suggesting its potent curative effect. Moreover, GO-Fe3O4 had no significant toxic effects on grapevine plants even at the concentration twice that of the highest dosage （1000 μg mL^-1） used in this study. Our work suggested that GO-Fe3O4 would offer an important opportunity to develop new approach for controlling plant diseases.展开更多
文摘A field study was carried out on the grey disorder in fine-cured tobacco (Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobaccoand dead roots. Grey disorder leaves produced low quality lamina, which was low in N, nicotine, reducedsugar and K contents. In this study’ soil available Mn and leaf Mn contents were in a relatively low level andshould not be an important factor in the occurrence of grey disorder in fine-cured tobacco.
基金supported by the National Natural Science Foundation of China (31501680 and 21277055)the Natural Science Foundation of Hebei Province (C2014407061 and C2014407008)PhD Research Startup Foundation of Hebei Normal University of Science and Technology (2013YB005)
文摘Plasmopam viticola, a causal agent of grapevine downy mildew, is a widely distributed pathogen, which can cause destructive disease in field-grown grapevines. Although fungicides are used to treat the disease, fungicide-resistant strains have been emerging. In this study, we developed graphene oxide （GO）-Fe3O4 nanocomposites, which could effectively repress the germination of sporangia and inhibit the development of downy mildew. 50 μg mL^-1 GO-Fe3O4 showed excellent protective and fungiddal activities. 250 μg mL^-1 GO-Fe3O4 on grapevine leaves in the field could significantly decrease the severity of downy mildew, suggesting its potent curative effect. Moreover, GO-Fe3O4 had no significant toxic effects on grapevine plants even at the concentration twice that of the highest dosage （1000 μg mL^-1） used in this study. Our work suggested that GO-Fe3O4 would offer an important opportunity to develop new approach for controlling plant diseases.
