Cerium oxide nanoparticles(CeO_(2) NPs)are likely to have dramatic impacts on plant performances,yet the effects of CeO_(2) NPs on seed germination and seedling growth have not been fully explored.In this study,the se...Cerium oxide nanoparticles(CeO_(2) NPs)are likely to have dramatic impacts on plant performances,yet the effects of CeO_(2) NPs on seed germination and seedling growth have not been fully explored.In this study,the seed germination and seedling growth of subshrub species Vitex negundo under different concentrations of CeO_(2) NPs(low-1 mg/L,medium-100 mg/L,high-500 mg/L)have been discussed.Results showed that:(1)The seed germination rate reduces by 11.25%and 2.5%under the low and medium concentrations of CeO_(2) NPs,respectively,but increased by 7.08%under the high concentration;(2)CeO_(2) NPs had significant effects on the growth traits(root length,shoot height and biomass)of seedlings,being the highest under the medium concentration and the lowest under the highest concentration;(3)The superoxide dismutase activity was the maximum(355.91 U/g),but the protein concentration was the minimum(3.85 ug/mL)under the high concentration of CeO_(2) NPs.Our results indicated that the effects of CeO_(2) NPs on seed germination and seedling growth are concentration-dependency,i.e.,low and medium concentrations inhibited while high concentration promoted seed germination,however,seedling growth showed opposite responses.Therefore,appropriate CeO_(2) NPs concentrations are beneficial to the seed germination and seedling growth of Vitex negundo and improve the physiological performance of seedlings and enhance their adaptability to environmental adversity.展开更多
Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly we...Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly weathered rocky slope (38°). Root number, length and diameter were recorded and single root specimens were classified and tested for tensile strength. The results show that root anchorage is different between the two constructions by bolts and wire. Under limited soil condition, root anchorage ability is 80% lower than when there is sufficient soil due to the reduction of the diameter and number of all second-order lateral roots, as well as the reduction of the tensile strength of the embedded second-order and first-order lateral roots on limited soil. We conclude that the distribution and anchorage of Vitex negundo L. is affected by limited soil availability on rocky slopes.展开更多
氮沉降的增加,可能会对土壤养分造成更为显著的影响,目前关于大气氮沉降对植物"肥岛"效应中土壤养分的影响鲜有报道。于河南省太行山南麓地区,以NH_4NO_3为供施氮源,按土层深度采集土样,以模拟氮沉降方法(3个水平,无氮CK、低...氮沉降的增加,可能会对土壤养分造成更为显著的影响,目前关于大气氮沉降对植物"肥岛"效应中土壤养分的影响鲜有报道。于河南省太行山南麓地区,以NH_4NO_3为供施氮源,按土层深度采集土样,以模拟氮沉降方法(3个水平,无氮CK、低氮2g N m^(-2)a^(-1)处理、中氮12g N m^(-2)a^(-1)处理和高氮24g N m^(-2)a^(-1)处理),分析了氮沉降对太行山荆条灌木(Vitex negundo L.var.)"肥岛"土壤中有机质、全氮和速效磷含量的影响。结果表明:灌木"肥岛"中全氮和速效磷含量,总体表现出随氮沉降量增长而增加的趋势;氮沉降显著增加了土壤表层有机质、氮、磷的含量;高氮沉降与CK相比引起的各土层间养分差异更显著;随着氮沉降水平的增加,冠幅内外和土层间养分差异增大,土壤养分的增长率随之加大;氮沉降在一定程度内加剧了"肥岛"的富集效应,且氮沉降量越大,这种富集效应越显著。这些研究结果可为研究灌木"肥岛"对外源氮的响应机制及保育作用提供参考。展开更多
基金This study was supported by the Science and Technology Innovation Foundation of Henan Agricultural University(30601458)the Scientific Research Foundation for the Doctor of Henan Agriculture University(30500848).
文摘Cerium oxide nanoparticles(CeO_(2) NPs)are likely to have dramatic impacts on plant performances,yet the effects of CeO_(2) NPs on seed germination and seedling growth have not been fully explored.In this study,the seed germination and seedling growth of subshrub species Vitex negundo under different concentrations of CeO_(2) NPs(low-1 mg/L,medium-100 mg/L,high-500 mg/L)have been discussed.Results showed that:(1)The seed germination rate reduces by 11.25%and 2.5%under the low and medium concentrations of CeO_(2) NPs,respectively,but increased by 7.08%under the high concentration;(2)CeO_(2) NPs had significant effects on the growth traits(root length,shoot height and biomass)of seedlings,being the highest under the medium concentration and the lowest under the highest concentration;(3)The superoxide dismutase activity was the maximum(355.91 U/g),but the protein concentration was the minimum(3.85 ug/mL)under the high concentration of CeO_(2) NPs.Our results indicated that the effects of CeO_(2) NPs on seed germination and seedling growth are concentration-dependency,i.e.,low and medium concentrations inhibited while high concentration promoted seed germination,however,seedling growth showed opposite responses.Therefore,appropriate CeO_(2) NPs concentrations are beneficial to the seed germination and seedling growth of Vitex negundo and improve the physiological performance of seedlings and enhance their adaptability to environmental adversity.
基金founded by Major Project of Chinese National Programs for Fundamental Research and Development (Grant No.2007CB416603)
文摘Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly weathered rocky slope (38°). Root number, length and diameter were recorded and single root specimens were classified and tested for tensile strength. The results show that root anchorage is different between the two constructions by bolts and wire. Under limited soil condition, root anchorage ability is 80% lower than when there is sufficient soil due to the reduction of the diameter and number of all second-order lateral roots, as well as the reduction of the tensile strength of the embedded second-order and first-order lateral roots on limited soil. We conclude that the distribution and anchorage of Vitex negundo L. is affected by limited soil availability on rocky slopes.
文摘氮沉降的增加,可能会对土壤养分造成更为显著的影响,目前关于大气氮沉降对植物"肥岛"效应中土壤养分的影响鲜有报道。于河南省太行山南麓地区,以NH_4NO_3为供施氮源,按土层深度采集土样,以模拟氮沉降方法(3个水平,无氮CK、低氮2g N m^(-2)a^(-1)处理、中氮12g N m^(-2)a^(-1)处理和高氮24g N m^(-2)a^(-1)处理),分析了氮沉降对太行山荆条灌木(Vitex negundo L.var.)"肥岛"土壤中有机质、全氮和速效磷含量的影响。结果表明:灌木"肥岛"中全氮和速效磷含量,总体表现出随氮沉降量增长而增加的趋势;氮沉降显著增加了土壤表层有机质、氮、磷的含量;高氮沉降与CK相比引起的各土层间养分差异更显著;随着氮沉降水平的增加,冠幅内外和土层间养分差异增大,土壤养分的增长率随之加大;氮沉降在一定程度内加剧了"肥岛"的富集效应,且氮沉降量越大,这种富集效应越显著。这些研究结果可为研究灌木"肥岛"对外源氮的响应机制及保育作用提供参考。
