Expression of insecticidal protein for transgenic Bacillus thuringiensis (Bt) cotton is unstable and related to nitrogen metabolism. The objective of this study was to investigate the relationship between leaf carbo...Expression of insecticidal protein for transgenic Bacillus thuringiensis (Bt) cotton is unstable and related to nitrogen metabolism. The objective of this study was to investigate the relationship between leaf carbon nitrogen ratio (C/N) and insecticidal efficacy of two Bt cotton cultivars. C/N ratio and Bt protein content were both measured at peak square period and peak boll period respectively under 5-7 d high temperature and different nitrogen fertilizer rates on the Yangzhou University Farm and the Ludong Cotton Farm, China. All plants were grown in field. The results showed that the C/N ratio enhanced slightly and the Bt protein content remained stable at peak square period, but significant increases for the C/N ratio and decreases markedly for the leaf Bt protein concentration were detected at the peak boll period. The similar patterns at the two growth periods were found for the leaf C/N ratio and Bt protein content by different N fertilizer treatments. When nitrogen rate was from 0 to 600 kg ha-l, the C/N ratio was reduced by 0.017 and 0.006 for Sikang 1 and Sikang 3 at peak square period, compared to the 1.350 to 1.143 reduction for Sikang 1 and Sikang 3 at peak boll period, respectively. Correspondingly, the leaf Bt protein contents were bolstered by 2.6-11.8 and 26.9-36.9% at the two different growth periods, respectively. The results suggested that enhanced C/N ratio by high temperature and nitrogen application may result in the reduction of inseetiocidal efficacy in Bt cotton, especially in peak boll period.展开更多
Two-year field experiments were conducted at Linqing, Yellow River valley of China, to study the plant response to the removal of early fruiting branches in transgenic Bt (Bacillus thuringiensis) cotton (Gossypium ...Two-year field experiments were conducted at Linqing, Yellow River valley of China, to study the plant response to the removal of early fruiting branches in transgenic Bt (Bacillus thuringiensis) cotton (Gossypium hirsutum L.) from 2003 to 2004. Plants were undamaged and treated by removing two basal fruiting branches (FB) at squaring to form the control and the removal treatment, respectively. The plant height, leaf area (LA), dry weight of fruiting forms (DWFF), the number of fruiting nodes (NFN), photosynthetic (Pn) rate, and levels of leaf chlorophyll (Chl), N, P, K, and Cry lAc protein in main- stem leaves were measured at a 10- or 20-d interval after FB removal, and the sink/source ratio as indicated by NFN/LA and DWFF/LA was determined. FB removal significantly increased the plant height, LA, and plant biomass in both years. Lint yields were increased 7.5 and 5.2% by removal compared with their controls in 2003 and 2004, respectively. Significant increases in boll size (5.7 and 5.1%) were also observed in removal than in control for both years. Either NFN/LA or DWFF/LA was significantly reduced by removal before 40 d after removal; however, both NFN/LA and DWFF/LA were significantly enhanced by FB removal at 80 d after removal compared to the untreated control. There was no significant difference in fiber quality in the first two harvests between removal and control, but fiber strength and micronarie in the third harvest were significantly improved by FB removal. In terms of leaf Chl, Pn rate, levels of total N, P, and K in late season, leaf senescence was considerably delayed by FB removal. Levels of CrylAc protein in the fully expanded young leaves were considerably higher in FB-excised plants than in control, indicating FB removal enhanced CrylAc expression. It is suggested that the yield and quality improvement with FB removal may be attributed to the increased NFN/LA or DWFF/LA in late season and delayed leaf senescence, respectively. FB removal can be a potential practice incorporated into the intensive cultivation system for enhancing transgenic Bt cotton production.展开更多
A field experiment was conducted in order to evaluate the economics of different genotypes of cotton planted under various planting densities at Agronomic Research Area, University of Agriculture Faisalabad during the...A field experiment was conducted in order to evaluate the economics of different genotypes of cotton planted under various planting densities at Agronomic Research Area, University of Agriculture Faisalabad during the summer season in 2013. Sowing was done manually with the help of dibbling method on both sides of the bed in standing water, with bed distance of 75 cm. The crop was sown in May and the experiment comprised of following FH-142, FH-114 at various densities (S1 = 10 cm, S2 = 15 cm, S3 =20 cm, S4 = 25 cm, S5 = 30 cm). Data regarding net field benefit, benefit cost ratio, dominance analysis, and marginal rate of return were collected. The experimental results showed that maximum NFB of (Rs. 222,575), (Rs. 202,483) was achieved in FH-142 and FH-114 when planted at a plant spacing of 20 cm and 15 cm respectively. While the maximum benefit cost ratio (BCR) of 1.76 was found in genotype FH-142 at plant spacing of 20 and 25 cm and FH-114 depicted maximum BCR of 1.62 and 1.61 when planted at plant spacing of 15 and 20 cm, respectively. Dominance analysis of FH-142 planted at 10 and 15 cm while FH-114 at plant spacing of 10, 15 and 20 cm was dominated due to their lower net field benefits as compared to other treatments, while maximum marginal rate of return (1494%, 788%) by planting FH-142, FH-114 was obtained at 30 cm and 25 cm recorded respectively.展开更多
基金supported by the National Natural Science Foundation of China(31171479)the Key Laboratory Foundation of Jiangsu Province,China(10KJA210057)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,China,the Doctoral Advisor Foundation of Education Department of China(20113250110001)the Project of National Agricultural Modern Industrial Technology System Post Experts,China(CARS-18-20)the Graduate Student Scientific Research Innovation Projects of Jiangsu Province,China(CXLX11_1019)
文摘Expression of insecticidal protein for transgenic Bacillus thuringiensis (Bt) cotton is unstable and related to nitrogen metabolism. The objective of this study was to investigate the relationship between leaf carbon nitrogen ratio (C/N) and insecticidal efficacy of two Bt cotton cultivars. C/N ratio and Bt protein content were both measured at peak square period and peak boll period respectively under 5-7 d high temperature and different nitrogen fertilizer rates on the Yangzhou University Farm and the Ludong Cotton Farm, China. All plants were grown in field. The results showed that the C/N ratio enhanced slightly and the Bt protein content remained stable at peak square period, but significant increases for the C/N ratio and decreases markedly for the leaf Bt protein concentration were detected at the peak boll period. The similar patterns at the two growth periods were found for the leaf C/N ratio and Bt protein content by different N fertilizer treatments. When nitrogen rate was from 0 to 600 kg ha-l, the C/N ratio was reduced by 0.017 and 0.006 for Sikang 1 and Sikang 3 at peak square period, compared to the 1.350 to 1.143 reduction for Sikang 1 and Sikang 3 at peak boll period, respectively. Correspondingly, the leaf Bt protein contents were bolstered by 2.6-11.8 and 26.9-36.9% at the two different growth periods, respectively. The results suggested that enhanced C/N ratio by high temperature and nitrogen application may result in the reduction of inseetiocidal efficacy in Bt cotton, especially in peak boll period.
文摘Two-year field experiments were conducted at Linqing, Yellow River valley of China, to study the plant response to the removal of early fruiting branches in transgenic Bt (Bacillus thuringiensis) cotton (Gossypium hirsutum L.) from 2003 to 2004. Plants were undamaged and treated by removing two basal fruiting branches (FB) at squaring to form the control and the removal treatment, respectively. The plant height, leaf area (LA), dry weight of fruiting forms (DWFF), the number of fruiting nodes (NFN), photosynthetic (Pn) rate, and levels of leaf chlorophyll (Chl), N, P, K, and Cry lAc protein in main- stem leaves were measured at a 10- or 20-d interval after FB removal, and the sink/source ratio as indicated by NFN/LA and DWFF/LA was determined. FB removal significantly increased the plant height, LA, and plant biomass in both years. Lint yields were increased 7.5 and 5.2% by removal compared with their controls in 2003 and 2004, respectively. Significant increases in boll size (5.7 and 5.1%) were also observed in removal than in control for both years. Either NFN/LA or DWFF/LA was significantly reduced by removal before 40 d after removal; however, both NFN/LA and DWFF/LA were significantly enhanced by FB removal at 80 d after removal compared to the untreated control. There was no significant difference in fiber quality in the first two harvests between removal and control, but fiber strength and micronarie in the third harvest were significantly improved by FB removal. In terms of leaf Chl, Pn rate, levels of total N, P, and K in late season, leaf senescence was considerably delayed by FB removal. Levels of CrylAc protein in the fully expanded young leaves were considerably higher in FB-excised plants than in control, indicating FB removal enhanced CrylAc expression. It is suggested that the yield and quality improvement with FB removal may be attributed to the increased NFN/LA or DWFF/LA in late season and delayed leaf senescence, respectively. FB removal can be a potential practice incorporated into the intensive cultivation system for enhancing transgenic Bt cotton production.
文摘A field experiment was conducted in order to evaluate the economics of different genotypes of cotton planted under various planting densities at Agronomic Research Area, University of Agriculture Faisalabad during the summer season in 2013. Sowing was done manually with the help of dibbling method on both sides of the bed in standing water, with bed distance of 75 cm. The crop was sown in May and the experiment comprised of following FH-142, FH-114 at various densities (S1 = 10 cm, S2 = 15 cm, S3 =20 cm, S4 = 25 cm, S5 = 30 cm). Data regarding net field benefit, benefit cost ratio, dominance analysis, and marginal rate of return were collected. The experimental results showed that maximum NFB of (Rs. 222,575), (Rs. 202,483) was achieved in FH-142 and FH-114 when planted at a plant spacing of 20 cm and 15 cm respectively. While the maximum benefit cost ratio (BCR) of 1.76 was found in genotype FH-142 at plant spacing of 20 and 25 cm and FH-114 depicted maximum BCR of 1.62 and 1.61 when planted at plant spacing of 15 and 20 cm, respectively. Dominance analysis of FH-142 planted at 10 and 15 cm while FH-114 at plant spacing of 10, 15 and 20 cm was dominated due to their lower net field benefits as compared to other treatments, while maximum marginal rate of return (1494%, 788%) by planting FH-142, FH-114 was obtained at 30 cm and 25 cm recorded respectively.