The seeds of Pinus tabulaeformis Carr.were dried from 64 g·kg-1 to 53 g·kg-1,41 g·kg-1,32 g·kg-1 and 25 g·kg-1 moisture content in a desiccator with silica gel.The seed vigor and physiological...The seeds of Pinus tabulaeformis Carr.were dried from 64 g·kg-1 to 53 g·kg-1,41 g·kg-1,32 g·kg-1 and 25 g·kg-1 moisture content in a desiccator with silica gel.The seed vigor and physiological characteristics after accelerated aging were measured.The results showed that the seed germination energy,germination percentage,germination index and vigor index separately decreased 6.8%,14.5%,1.39 and 4.18;The germination percentage and vigor of ultra-dried seeds were higher than those of seeds with 64 g·kg-1 moisture content;The activities of dehydrogenase and α-amylase of ultra-dried seeds were higher than those of seeds with 64 g·kg-1 moisture content after aging,while the relative conductivity was lower than that of the latter.It is feasible that Pinus tabulaeformis Carr.seeds to be stored with 32 g·kg-1 moisture content.展开更多
[目的]为研究间作绿豆对核桃苗根系生长、根系水分运输和光合特性的影响,[方法]采用砂培方法,在温室内将1年生核桃嫁接苗和绿豆进行间作。[结果]显示:间作绿豆增加了土壤全氮含量(0.014%0.021%),不添加氮素间作绿豆,核桃苗根系总表面积...[目的]为研究间作绿豆对核桃苗根系生长、根系水分运输和光合特性的影响,[方法]采用砂培方法,在温室内将1年生核桃嫁接苗和绿豆进行间作。[结果]显示:间作绿豆增加了土壤全氮含量(0.014%0.021%),不添加氮素间作绿豆,核桃苗根系总表面积、根系总长度、根系直径和根系总体积均显著增加,而正常供应氮素间作绿豆,核桃苗根系生长降低。核桃苗根系单位面积的导水率与土壤氮素含量显著相关,添加氮素与否间作绿豆后,根系单位面积导水率分别升高0.102×10-5m L·cm-1·min-1·MPa-1和0.057×10-5m L·cm-1·min-1·MPa-1;而不添加氮素间作绿豆整株根系导水率增加0.043 m L·cm-1·min-1·MPa-1,正常供应氮素间作绿豆后,核桃苗整株根系导水率反而降低0.034 m L·cm-1·min-1·MPa-1;核桃苗气孔导度对各处理响应和根系整株导水力有相同趋势,不添加氮素间作绿豆核桃光合能力升高至对照水平,光饱和点达1 567.17μmol·m-2·s-1,最大净光合速率达12.84μmol·m-2·s-1,光补偿点和暗呼吸速率降低;而正常供应氮素间作绿豆核桃苗光合能力降低。[结论]间作绿豆改善了核桃苗的生长环境,有益于增加核桃苗的根系吸收面积、水分运输以及光合代谢;但在氮素充足的土壤中,间作绿豆非但无益于核桃苗,反而降低核桃苗的水分供应,影响其气体交换和光合能力。展开更多
疏伐是一项重要的林业管理措施,其可以通过降低森林密度、减少树木对资源的竞争来提高树木的生长（Martín-Benito et al.,2010）。然而,在疏伐后的若干年内这种生长释放作用经常不能体现出来（Yang,1989;Youngblood,1991）,而且疏...疏伐是一项重要的林业管理措施,其可以通过降低森林密度、减少树木对资源的竞争来提高树木的生长（Martín-Benito et al.,2010）。然而,在疏伐后的若干年内这种生长释放作用经常不能体现出来（Yang,1989;Youngblood,1991）,而且疏伐带来微环境的突然改变还可能引起存留树木的生长停滞、甚至顶端坏死（Bladon et al.,2006;2007）。展开更多
文摘The seeds of Pinus tabulaeformis Carr.were dried from 64 g·kg-1 to 53 g·kg-1,41 g·kg-1,32 g·kg-1 and 25 g·kg-1 moisture content in a desiccator with silica gel.The seed vigor and physiological characteristics after accelerated aging were measured.The results showed that the seed germination energy,germination percentage,germination index and vigor index separately decreased 6.8%,14.5%,1.39 and 4.18;The germination percentage and vigor of ultra-dried seeds were higher than those of seeds with 64 g·kg-1 moisture content;The activities of dehydrogenase and α-amylase of ultra-dried seeds were higher than those of seeds with 64 g·kg-1 moisture content after aging,while the relative conductivity was lower than that of the latter.It is feasible that Pinus tabulaeformis Carr.seeds to be stored with 32 g·kg-1 moisture content.
文摘[目的]为研究间作绿豆对核桃苗根系生长、根系水分运输和光合特性的影响,[方法]采用砂培方法,在温室内将1年生核桃嫁接苗和绿豆进行间作。[结果]显示:间作绿豆增加了土壤全氮含量(0.014%0.021%),不添加氮素间作绿豆,核桃苗根系总表面积、根系总长度、根系直径和根系总体积均显著增加,而正常供应氮素间作绿豆,核桃苗根系生长降低。核桃苗根系单位面积的导水率与土壤氮素含量显著相关,添加氮素与否间作绿豆后,根系单位面积导水率分别升高0.102×10-5m L·cm-1·min-1·MPa-1和0.057×10-5m L·cm-1·min-1·MPa-1;而不添加氮素间作绿豆整株根系导水率增加0.043 m L·cm-1·min-1·MPa-1,正常供应氮素间作绿豆后,核桃苗整株根系导水率反而降低0.034 m L·cm-1·min-1·MPa-1;核桃苗气孔导度对各处理响应和根系整株导水力有相同趋势,不添加氮素间作绿豆核桃光合能力升高至对照水平,光饱和点达1 567.17μmol·m-2·s-1,最大净光合速率达12.84μmol·m-2·s-1,光补偿点和暗呼吸速率降低;而正常供应氮素间作绿豆核桃苗光合能力降低。[结论]间作绿豆改善了核桃苗的生长环境,有益于增加核桃苗的根系吸收面积、水分运输以及光合代谢;但在氮素充足的土壤中,间作绿豆非但无益于核桃苗,反而降低核桃苗的水分供应,影响其气体交换和光合能力。
文摘疏伐是一项重要的林业管理措施,其可以通过降低森林密度、减少树木对资源的竞争来提高树木的生长（Martín-Benito et al.,2010）。然而,在疏伐后的若干年内这种生长释放作用经常不能体现出来（Yang,1989;Youngblood,1991）,而且疏伐带来微环境的突然改变还可能引起存留树木的生长停滞、甚至顶端坏死（Bladon et al.,2006;2007）。
