Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost application.The results showed that the rice...Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost application.The results showed that the rice grown after oilseed rape had significantly lower Cd and Pb concentrations in both straw and grains.Cd and Pb concentrations in the grains of the rice rotated with oilseed rape decreased by approximately 46-80% and 17-86%,respectively,although the Cd and Pb removal by oilseed rape ranged only from 2.39-3.67 and 0.032-0.13% of the total content in soil.Compost amendment also decreased the bioavailability of Cd and Pb in the soil and reduced Cd and Pb uptake by oilseed rapes and rice.The concentrations of Cd and Pb significantly decreased in the exchangeable and carbonate fractions and Pb concentration decreased in the organic matter and sulfide fractions in the contaminated soil after planting oilseed rapes.展开更多
The oilseed rape growing in the lower reaches of Yangtze River in China belongs to winter varieties and suffers the risk of freezing injury.In this research,a typical freezing injury event occurred in Anhui Province w...The oilseed rape growing in the lower reaches of Yangtze River in China belongs to winter varieties and suffers the risk of freezing injury.In this research,a typical freezing injury event occurred in Anhui Province was taken as a case study,the freezing damage degree of oilseed rape was assessed,and its development characteristics based on the vegetation metrics derived from MODIS and MERIS data were investigated.The oilseed rape was mapped according to the decline of greenness from bud stage to full-bloom period,with the phenological phases identified adopting time-series analyses.NDVI was more sensitive to freezing injury compared with other commonly used vegetation indices(VIs)calculated using MODIS bands,e.g.,EVI,GNDVI and SAVI.The freezing damage degree employing the difference between post-freeze growth and the baseline level in adjacent damage-free growing seasons was determined.The remote sensing-derived damage levels were supported by their correlation with the cold accumulated temperatures at the county level.The performance of several remote sensing indicators of plant biophysical and biochemical parameters was also investigated,i.e.,the photosynthetic rate,canopy water status,canopy chlorophyll content,leaf area index(LAI)and the red edge position(REP),in response to the advance of the freezing damage.It was found that the photosynthetic rate indicator—Photochemical Reflectance Index(PRI)responded strongly to freezing stress.Freezing injury caused canopy water loss,which could be detected though the magnitude was not very large.MERIS-LAI showed a slow and lagging response to low temperature and restored rapidly in the recovery phase;additionally,REP and the indicator of canopy chlorophyll content—MERIS Terrestrial Chlorophyll Index(MTCI),did not appear to be influenced by freezing injury.It was concluded that the physiological functions,canopy structure,and organic content metrics showed a descending order of vulnerabilities to freezing injury.展开更多
The general increase of the cultivation and trade of Bt transgenic plants resis- tant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased...The general increase of the cultivation and trade of Bt transgenic plants resis- tant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape （Brassica napus L.）, including transgenic lines. In environmental risk assessments （ERAs） for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non-target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or natural- ization of spilled seed in Sicily （Italy）. Diurnal Lepidoptera, which are pollinators, can be exposed directly to the insecticidal proteins as larvae （mainly of Pieridae） through the host and through the pollen that can deposit on other host plants. Adults can be exposed via pollen and nectar. The flight periods of butterflies were recorded, and they were found to overlap for about 90% of the flowering period ofB. napus for the majority of the species. In addition, B. napus has a high potential to hybridise with endemic taxa belonging to the B. oleracea group. This could lead to an exposure of non-target Lepidoptera if introgression of the Bt gene into a wild population happens. A rank of the risk for butterflies and wild relatives of oilseed rape is given. We conclude that, in environmental risk assessments, attention should be paid to plant-insect interaction especially in a biodiversity hotspot such as Sicily.展开更多
基金supported by the National Natural Science Foundation of China (40971261)the Special Fund for Argo-Scientific Reserch in the Public Interest,China (200903015).
文摘Pot experiments were conducted under greenhouse condition to investigate whether Cd and Pb uptake by rice could be reduced when it was rotated with oilseed rape and compost application.The results showed that the rice grown after oilseed rape had significantly lower Cd and Pb concentrations in both straw and grains.Cd and Pb concentrations in the grains of the rice rotated with oilseed rape decreased by approximately 46-80% and 17-86%,respectively,although the Cd and Pb removal by oilseed rape ranged only from 2.39-3.67 and 0.032-0.13% of the total content in soil.Compost amendment also decreased the bioavailability of Cd and Pb in the soil and reduced Cd and Pb uptake by oilseed rapes and rice.The concentrations of Cd and Pb significantly decreased in the exchangeable and carbonate fractions and Pb concentration decreased in the organic matter and sulfide fractions in the contaminated soil after planting oilseed rapes.
基金the National Natural Science Foundation of China(No.41171276)。
文摘The oilseed rape growing in the lower reaches of Yangtze River in China belongs to winter varieties and suffers the risk of freezing injury.In this research,a typical freezing injury event occurred in Anhui Province was taken as a case study,the freezing damage degree of oilseed rape was assessed,and its development characteristics based on the vegetation metrics derived from MODIS and MERIS data were investigated.The oilseed rape was mapped according to the decline of greenness from bud stage to full-bloom period,with the phenological phases identified adopting time-series analyses.NDVI was more sensitive to freezing injury compared with other commonly used vegetation indices(VIs)calculated using MODIS bands,e.g.,EVI,GNDVI and SAVI.The freezing damage degree employing the difference between post-freeze growth and the baseline level in adjacent damage-free growing seasons was determined.The remote sensing-derived damage levels were supported by their correlation with the cold accumulated temperatures at the county level.The performance of several remote sensing indicators of plant biophysical and biochemical parameters was also investigated,i.e.,the photosynthetic rate,canopy water status,canopy chlorophyll content,leaf area index(LAI)and the red edge position(REP),in response to the advance of the freezing damage.It was found that the photosynthetic rate indicator—Photochemical Reflectance Index(PRI)responded strongly to freezing stress.Freezing injury caused canopy water loss,which could be detected though the magnitude was not very large.MERIS-LAI showed a slow and lagging response to low temperature and restored rapidly in the recovery phase;additionally,REP and the indicator of canopy chlorophyll content—MERIS Terrestrial Chlorophyll Index(MTCI),did not appear to be influenced by freezing injury.It was concluded that the physiological functions,canopy structure,and organic content metrics showed a descending order of vulnerabilities to freezing injury.
文摘The general increase of the cultivation and trade of Bt transgenic plants resis- tant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape （Brassica napus L.）, including transgenic lines. In environmental risk assessments （ERAs） for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non-target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or natural- ization of spilled seed in Sicily （Italy）. Diurnal Lepidoptera, which are pollinators, can be exposed directly to the insecticidal proteins as larvae （mainly of Pieridae） through the host and through the pollen that can deposit on other host plants. Adults can be exposed via pollen and nectar. The flight periods of butterflies were recorded, and they were found to overlap for about 90% of the flowering period ofB. napus for the majority of the species. In addition, B. napus has a high potential to hybridise with endemic taxa belonging to the B. oleracea group. This could lead to an exposure of non-target Lepidoptera if introgression of the Bt gene into a wild population happens. A rank of the risk for butterflies and wild relatives of oilseed rape is given. We conclude that, in environmental risk assessments, attention should be paid to plant-insect interaction especially in a biodiversity hotspot such as Sicily.
