Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321&#...Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321' were transformed respectively by two efficient plant expression plasmids pBinMoBc and pBinoBc via Agrobacterium tumefaciens . In pBinMoBc, cry 1Ac3 gene, which encodes the Bt toxin, is under the control of chimeric OM promoter. In pBinoBc, it is under control of CaMV 35S promoter. After co_cultivation with Agrobacterium tumefimpfaciens LBA4404 (containing pBinMoBc or pBinoBc), kanamycin_resistant selection, somatic embryos were induced and regenerated plants were obtained. Then the regenerated plantlets were grafted to untransformed stocks in greenhouse to produce descendants. The integration of cry 1Ac3 gene and its expression in T 2 generation of transgenic cotton plants were confirmed by Southern hybridization and Western blotting. The analyses of insect bioassay indicated that the transgenic plants of both constructions have significant resistance to the larvae of cotton bollworm ( Heliothis armigera ) and that cry 1Ac3 gene driven by chimeric OM promoter could endue T 2 generation cotton with high pest_resistant ability, implicating that it has a profound application in genetic engineering to breed new pest_resistant cotton varieties.展开更多
The contents of the soil microbial biomass nitrogen (SMBN) in the soils sampled from the Loess Plateau of China were determined using chloroform fumigation aerobic incubation method (CFAIM), chloroform fumigation anae...The contents of the soil microbial biomass nitrogen (SMBN) in the soils sampled from the Loess Plateau of China were determined using chloroform fumigation aerobic incubation method (CFAIM), chloroform fumigation anaerobic incubation method (CFANIM) and chloroform fumigation-extraction method (CFEM).The N taken up by ryegrass on the soils was determined after a glasshouse pot experiment. The flushes of nitrogen (FN) of the soils obtained by the CFAIM and CFANIM were higher than that by the CFEM, and there were significantly positive correlations between the FN obtained by the 3 methods. The N extracted from the fumigated soils by the CFAIM, CFANIM and CFEM were significantly positively correlated with the N uptake by ryegrass. The FN obtained by the 3 methods was also closely positively correlated with the plant N uptake. The contributions of the SMBN and mineral N and mineralized N during the incubation period to plant N uptake were evaluated with the multiple regression method. The results showed that the N contained in the soil microbial biomass might play a noticeable role in the N supply of the soils to the plant.展开更多
A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to fo...A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to focus the effect of percolation pattern on accumulation of cupper （Cu） and cadmium （Cd） in rice plants in contaminated paddy filed with soil dressing models. Percolation pattern has significant effect on soil environment, especially redox potential that may influence mobilization of Cd, Cu and other elements. In open system percolation models, the plowsole and subsoil were in oxidative condition （600 mV）, whereas reduction condition （-200 mV） was measured in closed system percolation models. Accumulations of Cu and Cd in all parts of rice plants （roots, grains, stems and leaves） were found higher in an open system percolation with the paddy field model comparatively than in a closed system percolation. The soil redox （Eh） condition influenced by the percolation pattern might be one of the main factors for uptake and accumulation of Cu and Cd in rice plants. The plant height and stem number were found lower in open system percolation comparatively to closed system percolation. In the yields section, the average panicle length, number of panicle and rice grain/hill and weight of grain/hill were lower in open system percolation than the closed system percolation.展开更多
Carbon stable isotope techniques were extensively employed to trace the dynamics of soil organic carbon(SOC)across a land-use change involving a shift to vegetation with different photosynthetic pathways.Based on the ...Carbon stable isotope techniques were extensively employed to trace the dynamics of soil organic carbon(SOC)across a land-use change involving a shift to vegetation with different photosynthetic pathways.Based on the isotopic mass balance equation,relative contributions of new versus old SOC,and SOC turnover rate in corn fields were evaluated world-wide.However,most previous research had not analyzed corn debris left in the field,instead using an average corn plant δ^(13)C value or a measured value to calculate the proportion of corn-derived SOC,either of which could bias results.This paper carried out a detailed analysis of isotopic fractionation in corn plants and deduced the maximum possible bias of SOC dynamics study.The results show approximately 3‰ isotopic fractionation from top to bottom of the corn leaf.The ^(13)C enrichment sequence in corn plant was tassel﹥stalk or cob﹥root﹥leaves.Individual parts accounting for the total dry mass of corn returned distinct values.Consequently,the average δ^(13)C value of corn does not represent the actual isotopic composition of corn debris.Furthermore,we deduced that the greater the fractionation in corn plant,the greater the possible bias.To alleviate bias of SOC dynamics study,we suggest two measures:analyze isotopic compositions and proportions of each part of the corn and determine which parts of the corn plant are left in the field and incorporated into SOC.展开更多
Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the e...Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA derived from lignite on growth and macronutrient uptake of wheat （Triticum acstivum L.） grown in earthen pots under greenhouse conditions. The soils used in the pot experiment were a calcareous Haplustalf and a non-calcareous Haplustalf collected from Raisalpur and Guliana, respectively, in Punjab Province, Pakistan. The experiment consisted of four treatments with HA levels of 0 （control without HA）, 30, 60, and 90 mg kg^-1 soil designated as HA0, HA1, HA2, and HA3, respectively. In the treatment without HA （HA0）, nitrogen （N）, phosphorus （P）, and potassium （K） were applied at 200, 100, and 125 mg kg^-1 soil, respectively. Significant differences among HA levels were recorded for wheat growth （plant height and shoot weight） and N uptake. On an average of both soils, the largest increases in plant height and shoot fresh and dry weights were found with HA2 （60 mg kg^-1 soil）, being 10%, 25%, and 18%, respectively, as compared to the control without HA （HA0）. Both soils responded positively towards HA application. The wheat growth and N uptake in the non-calcareous soil were higher than those of the calcareous soil. The HA application significantly improved K concentration of the non-calcareous soil and P and NO3-N of the calcareous soil. The highest rate of HA （90 mg kg^-1 soil） had a negative effect on growth and nutrient uptake of wheat as well as nutrient accumulation in soil, whereas the medium dose of HA （60 mg kg^-1 soil） was more efficient in promoting wheat growth.展开更多
文摘Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321' were transformed respectively by two efficient plant expression plasmids pBinMoBc and pBinoBc via Agrobacterium tumefaciens . In pBinMoBc, cry 1Ac3 gene, which encodes the Bt toxin, is under the control of chimeric OM promoter. In pBinoBc, it is under control of CaMV 35S promoter. After co_cultivation with Agrobacterium tumefimpfaciens LBA4404 (containing pBinMoBc or pBinoBc), kanamycin_resistant selection, somatic embryos were induced and regenerated plants were obtained. Then the regenerated plantlets were grafted to untransformed stocks in greenhouse to produce descendants. The integration of cry 1Ac3 gene and its expression in T 2 generation of transgenic cotton plants were confirmed by Southern hybridization and Western blotting. The analyses of insect bioassay indicated that the transgenic plants of both constructions have significant resistance to the larvae of cotton bollworm ( Heliothis armigera ) and that cry 1Ac3 gene driven by chimeric OM promoter could endue T 2 generation cotton with high pest_resistant ability, implicating that it has a profound application in genetic engineering to breed new pest_resistant cotton varieties.
基金the National Natural Science Foundation of China(Nos.49890330,39770425 and 30070429) the National Key Basic Research Support Foundation of China(No.G1999011707).
文摘The contents of the soil microbial biomass nitrogen (SMBN) in the soils sampled from the Loess Plateau of China were determined using chloroform fumigation aerobic incubation method (CFAIM), chloroform fumigation anaerobic incubation method (CFANIM) and chloroform fumigation-extraction method (CFEM).The N taken up by ryegrass on the soils was determined after a glasshouse pot experiment. The flushes of nitrogen (FN) of the soils obtained by the CFAIM and CFANIM were higher than that by the CFEM, and there were significantly positive correlations between the FN obtained by the 3 methods. The N extracted from the fumigated soils by the CFAIM, CFANIM and CFEM were significantly positively correlated with the N uptake by ryegrass. The FN obtained by the 3 methods was also closely positively correlated with the plant N uptake. The contributions of the SMBN and mineral N and mineralized N during the incubation period to plant N uptake were evaluated with the multiple regression method. The results showed that the N contained in the soil microbial biomass might play a noticeable role in the N supply of the soils to the plant.
文摘A greenhouse experiment was conducted using stratified paddy field models, which were prepared by polluted soil with 12.5 cm soil dressing. The paddy models were assembled with open and closed percolation system to focus the effect of percolation pattern on accumulation of cupper （Cu） and cadmium （Cd） in rice plants in contaminated paddy filed with soil dressing models. Percolation pattern has significant effect on soil environment, especially redox potential that may influence mobilization of Cd, Cu and other elements. In open system percolation models, the plowsole and subsoil were in oxidative condition （600 mV）, whereas reduction condition （-200 mV） was measured in closed system percolation models. Accumulations of Cu and Cd in all parts of rice plants （roots, grains, stems and leaves） were found higher in an open system percolation with the paddy field model comparatively than in a closed system percolation. The soil redox （Eh） condition influenced by the percolation pattern might be one of the main factors for uptake and accumulation of Cu and Cd in rice plants. The plant height and stem number were found lower in open system percolation comparatively to closed system percolation. In the yields section, the average panicle length, number of panicle and rice grain/hill and weight of grain/hill were lower in open system percolation than the closed system percolation.
基金financially supported by National Natural Science Foundation of China(Grant No.2013CB95670241573012+1 种基金4157113004141261058)
文摘Carbon stable isotope techniques were extensively employed to trace the dynamics of soil organic carbon(SOC)across a land-use change involving a shift to vegetation with different photosynthetic pathways.Based on the isotopic mass balance equation,relative contributions of new versus old SOC,and SOC turnover rate in corn fields were evaluated world-wide.However,most previous research had not analyzed corn debris left in the field,instead using an average corn plant δ^(13)C value or a measured value to calculate the proportion of corn-derived SOC,either of which could bias results.This paper carried out a detailed analysis of isotopic fractionation in corn plants and deduced the maximum possible bias of SOC dynamics study.The results show approximately 3‰ isotopic fractionation from top to bottom of the corn leaf.The ^(13)C enrichment sequence in corn plant was tassel﹥stalk or cob﹥root﹥leaves.Individual parts accounting for the total dry mass of corn returned distinct values.Consequently,the average δ^(13)C value of corn does not represent the actual isotopic composition of corn debris.Furthermore,we deduced that the greater the fractionation in corn plant,the greater the possible bias.To alleviate bias of SOC dynamics study,we suggest two measures:analyze isotopic compositions and proportions of each part of the corn and determine which parts of the corn plant are left in the field and incorporated into SOC.
基金Supported by the University of Azad Jammu and Kashmir,Muzaffarabad,Pakistan
文摘Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA derived from lignite on growth and macronutrient uptake of wheat （Triticum acstivum L.） grown in earthen pots under greenhouse conditions. The soils used in the pot experiment were a calcareous Haplustalf and a non-calcareous Haplustalf collected from Raisalpur and Guliana, respectively, in Punjab Province, Pakistan. The experiment consisted of four treatments with HA levels of 0 （control without HA）, 30, 60, and 90 mg kg^-1 soil designated as HA0, HA1, HA2, and HA3, respectively. In the treatment without HA （HA0）, nitrogen （N）, phosphorus （P）, and potassium （K） were applied at 200, 100, and 125 mg kg^-1 soil, respectively. Significant differences among HA levels were recorded for wheat growth （plant height and shoot weight） and N uptake. On an average of both soils, the largest increases in plant height and shoot fresh and dry weights were found with HA2 （60 mg kg^-1 soil）, being 10%, 25%, and 18%, respectively, as compared to the control without HA （HA0）. Both soils responded positively towards HA application. The wheat growth and N uptake in the non-calcareous soil were higher than those of the calcareous soil. The HA application significantly improved K concentration of the non-calcareous soil and P and NO3-N of the calcareous soil. The highest rate of HA （90 mg kg^-1 soil） had a negative effect on growth and nutrient uptake of wheat as well as nutrient accumulation in soil, whereas the medium dose of HA （60 mg kg^-1 soil） was more efficient in promoting wheat growth.
