[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser ...[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser and He-Ne laser at three dosage levels separately. A randomized complete block design with three replications was adopted. The biological effects of laser-induced mutation on fibrous roots of Ll-generation yellow skin onion were investigated with biostatistics and physiological and biochemical methods. [Result] Significant variations in the biological effects caused by various laser treatments were observed in the length, quantity, fresh weight and activity of onion fibrous roots. Specifically, the variation in fibrous root length induced by different types of laser reached 5% significance level; significant variation was observed in fibrous roots of different onion cultivars induced by laser, while the variation among each treatment did not reach 5% sig- nifieance level ; the variation in fibrous root quantity induced by different dosage levels of laser reached 5% significance level ; laser radiation showed stimulating effect on root activity of onion. [ Conclusion] This study provided reference for laser-induced breeding of yellow skin onion.展开更多
Rapid socio-economic changes in China,such as land conversion and urbanization,are creating new scopes for the application of precision agriculture(PA).An experiment to assess the economic benefits of two precision ag...Rapid socio-economic changes in China,such as land conversion and urbanization,are creating new scopes for the application of precision agriculture(PA).An experiment to assess the economic benefits of two precision agriculture methods was applied for one year–precision seeding and precision seeding with land leveling.Whilst the results for this were positive,of itself it did not provide evidence of longer terms gains.The costs of land leveling are accrued in a single year but the benefits could carry over into subsequent years.Thus,in this case if the PA method provides carry over benefits to future years,the economic assessment would incorrectly assign all the costs to a single year of benefits i.e.the benefit-cost ratio would be underestimated.To gauge whether there was carry over benefits in future years we looked at NDVI and GUI as proxies for future year benefits.For the single year experiment,our results showed that:(1)Winter wheat yield was increased 23.2%through the integration of precision seeding and laser leveling technologies.(2)Both the single technology and the integrated technologies significant reduced the concentration of soil ammonium nitrogen at the depths of 60 cm;(3)The benefit/cost ratio's of the treatments exceeded that of the baseline by approximately 10%which translated to an increase of several hundred US$per hectare.The NDVI analysis showed that the effect of laser land leveling could last to the next two years.When considering the multi-year impact of land leveling,the benefit/cost ratio of PSLL will increase to 23.5%and 22.9%with and without laser land leveling subsidies.Making clear the eco-nomic benefits of using PA technologies will likely promote application of the technologies in the region.展开更多
采用213 nm-纳秒激光剥蚀系统对生物基体样品的剥蚀颗粒进行研究,优化了激光剥蚀条件。在剥蚀能量为25%,束斑直径为200μm,剥蚀速率为20μm/s,频率为20 Hz,载气为700 m L He+700 m L Ar时,信号强度及稳定性最佳。以^(31)P为内标元素,最...采用213 nm-纳秒激光剥蚀系统对生物基体样品的剥蚀颗粒进行研究,优化了激光剥蚀条件。在剥蚀能量为25%,束斑直径为200μm,剥蚀速率为20μm/s,频率为20 Hz,载气为700 m L He+700 m L Ar时,信号强度及稳定性最佳。以^(31)P为内标元素,最佳剥蚀条件下,考察了56个元素的相对分馏因子。结果表明,生物基体的剥蚀颗粒相较于NIST 610玻璃标样更大,达到3μm;生物基体中元素分馏效应相较于玻璃基体小,大多数元素的相对分馏因子达到1.0±0.1。探讨了生物基体中元素分馏机理,分析了生物基体相较于玻璃基体剥蚀颗粒大,而相对分馏因子未明显增大的原因。一方面可能是粒径3μm的颗粒进入电感耦合等离子体后能原子化;另一方面,大的剥蚀颗粒的富集效应相对较小。进一步对分馏效应的影响因素进行研究,发现分馏效应与激光剥蚀能量、激光频率和扫描速率相关,并且与元素的氧化物沸点负相关,与氧化物键能和电离能正相关。展开更多
基金Supported by Natural Science Foundation of Sichuan Education Department(2008ZA033)
文摘[ Objective] This study aimed to investigate the biological effects of laser-induced mutation on fibrous roots of yellow skin onion. [ Method] Wet seeds of two yellow skin onion cultivars were irradiated by CO2 laser and He-Ne laser at three dosage levels separately. A randomized complete block design with three replications was adopted. The biological effects of laser-induced mutation on fibrous roots of Ll-generation yellow skin onion were investigated with biostatistics and physiological and biochemical methods. [Result] Significant variations in the biological effects caused by various laser treatments were observed in the length, quantity, fresh weight and activity of onion fibrous roots. Specifically, the variation in fibrous root length induced by different types of laser reached 5% significance level; significant variation was observed in fibrous roots of different onion cultivars induced by laser, while the variation among each treatment did not reach 5% sig- nifieance level ; the variation in fibrous root quantity induced by different dosage levels of laser reached 5% significance level ; laser radiation showed stimulating effect on root activity of onion. [ Conclusion] This study provided reference for laser-induced breeding of yellow skin onion.
基金funded by the National Key Research and Development Program of China(2017YFE0122500).
文摘Rapid socio-economic changes in China,such as land conversion and urbanization,are creating new scopes for the application of precision agriculture(PA).An experiment to assess the economic benefits of two precision agriculture methods was applied for one year–precision seeding and precision seeding with land leveling.Whilst the results for this were positive,of itself it did not provide evidence of longer terms gains.The costs of land leveling are accrued in a single year but the benefits could carry over into subsequent years.Thus,in this case if the PA method provides carry over benefits to future years,the economic assessment would incorrectly assign all the costs to a single year of benefits i.e.the benefit-cost ratio would be underestimated.To gauge whether there was carry over benefits in future years we looked at NDVI and GUI as proxies for future year benefits.For the single year experiment,our results showed that:(1)Winter wheat yield was increased 23.2%through the integration of precision seeding and laser leveling technologies.(2)Both the single technology and the integrated technologies significant reduced the concentration of soil ammonium nitrogen at the depths of 60 cm;(3)The benefit/cost ratio's of the treatments exceeded that of the baseline by approximately 10%which translated to an increase of several hundred US$per hectare.The NDVI analysis showed that the effect of laser land leveling could last to the next two years.When considering the multi-year impact of land leveling,the benefit/cost ratio of PSLL will increase to 23.5%and 22.9%with and without laser land leveling subsidies.Making clear the eco-nomic benefits of using PA technologies will likely promote application of the technologies in the region.
文摘采用213 nm-纳秒激光剥蚀系统对生物基体样品的剥蚀颗粒进行研究,优化了激光剥蚀条件。在剥蚀能量为25%,束斑直径为200μm,剥蚀速率为20μm/s,频率为20 Hz,载气为700 m L He+700 m L Ar时,信号强度及稳定性最佳。以^(31)P为内标元素,最佳剥蚀条件下,考察了56个元素的相对分馏因子。结果表明,生物基体的剥蚀颗粒相较于NIST 610玻璃标样更大,达到3μm;生物基体中元素分馏效应相较于玻璃基体小,大多数元素的相对分馏因子达到1.0±0.1。探讨了生物基体中元素分馏机理,分析了生物基体相较于玻璃基体剥蚀颗粒大,而相对分馏因子未明显增大的原因。一方面可能是粒径3μm的颗粒进入电感耦合等离子体后能原子化;另一方面,大的剥蚀颗粒的富集效应相对较小。进一步对分馏效应的影响因素进行研究,发现分馏效应与激光剥蚀能量、激光频率和扫描速率相关,并且与元素的氧化物沸点负相关,与氧化物键能和电离能正相关。
