The effect of auxins （IAA or IBA at 100, 200, 500 mg.L J） on rooting and sprouting parameters differed significantly （p 〈 0.05）. Rooting and sprouting percentages were higher in some treatments while other parame...The effect of auxins （IAA or IBA at 100, 200, 500 mg.L J） on rooting and sprouting parameters differed significantly （p 〈 0.05）. Rooting and sprouting percentages were higher in some treatments while other parameters were significantly higher in other treatments. The results of the present study revealed that rooting was significantly （p 〈 0.05） affected by the length of cuttings, as well as the position of shoots and type of cuttings. On average, 86.0 per cent rooting was observed in the 30-cm long cuttings com- pared to the other two lengths of cuttings, i.e., 20 and 25 cm, irrespective of any auxin treatment. In a control set, without any auxin treatment, a maximum of 60.0% rooting was recorded in the 30-cm long cuttings and a minimum of 40.0% of the cuttings rooted in the 20-cm long cuttings. Similarly, cuttings collected from the lower and upper portions of shoots resulted in 72.5 and 52.5 per cent rooting respectively, irrespective of auxin treatments. Maximum rooting was observed in the lower portion （40.0%） of cutting com- pared to the upper portion （30.0%） in the control set without auxin treatment. Leafless branches produced maximum （72.0%） rooting compared to the leafy cuttings （35.0%）, irrespective of the auxin treatment. The leafy cuttings produces a minimum of 15.0% sprout- ing and rooting in the control set.展开更多
Stress in plants refers to adverse changes in their functioning.The occurrence and intensity of a stress can be assessed by alterations in plant traits,termed stress indicators.The ultimate goal of this study was to t...Stress in plants refers to adverse changes in their functioning.The occurrence and intensity of a stress can be assessed by alterations in plant traits,termed stress indicators.The ultimate goal of this study was to test whether six morpho-physiological plant traits,frequently used as stress indicators,respond consistently across species to various environmental stressors,with the aim of detecting universal stress indicators in forest tree species.We examined changes in vertical increment,leaf/needle size,shoot length,needle longevity,photosynthetic efficiency and fluctuating asymmetry in three common European tree species,mountain birch(Betula pubescens var.pumila),Norway spruce(Picea abies)and Scots pine(Pinus sylvestris)along three environmental gradients(elevation,pollution and seashore)from forests to stressful open environments.Data were collected in 2003,2004 and 2005 from 297 trees growing naturally across 36 sites in north-western Russia.Fluctuating asymmetry was the only trait that did not vary among sites with differing levels of environmental stress.Leaf/needle size and shoot length occasionally changed along stress gradients,but the magnitude and direction of these changes differed by gradient type and species,resulting in no significant overall stress effect for either trait.In contrast,photosynthetic efficiency,vertical increment and needle longevity consistently decreased from low-stress to high-stress sites.The overall effect was significant for each of these three traits despite the magnitudes of these decreases differed depending on the gradient type and location,species,study year and individual tree.Replication at spatial,temporal and taxonomic levels ensured the robustness and reliability of our results that photosynthetic efficiency,vertical growth and needle longevity reliably captured a general stress syndrome and may serve as stress indicators in forest species.展开更多
[Objective] This study was to investigate the allelopathic effects of J.curcas leaf leachates on seedling growth and antioxidative enzymes,and thus to reveal physiologically allelopathic effects of J.curcas trees on u...[Objective] This study was to investigate the allelopathic effects of J.curcas leaf leachates on seedling growth and antioxidative enzymes,and thus to reveal physiologically allelopathic effects of J.curcas trees on undergrowth plants.[Method] The allelopathic effects of leaf leachates of Jatropha curcas amended into soil were determined on the growth,proline and malondialdehyde（MDA） contentas well as superoxide dismutase（SOD）,catalase（CAT）,ascorbate peroxidase（APX）,guaiacol peroxidase（POD） in roots of marigold（Tagetes erecta） seedlings.[Results] The application of leaf leachates of J.curcas in the soil significantly inhibited the shoot and root length of marigold compared to un-amended soils.The leaf leachates increased the O-2,H2O2,MDA and proline content in the roots of marigold seedlings.The effects increased with the ascending of leaf leachates concentration.In addition,superoxide dismutase（SOD） and guaiacol peroxidase（POD） were not remarkably affected by the leachates at lower concentrations,but at higher concentration,SOD activity was ascended.Similarly,the activities of CAT and APX were also significantly increased with the increase of leachates concentrations.[Conclusion] These results show that J.curcas can release the phytotoxic compound（s） into soil,which are inhibitory to certain test species by interfering with physiological process.展开更多
文摘The effect of auxins （IAA or IBA at 100, 200, 500 mg.L J） on rooting and sprouting parameters differed significantly （p 〈 0.05）. Rooting and sprouting percentages were higher in some treatments while other parameters were significantly higher in other treatments. The results of the present study revealed that rooting was significantly （p 〈 0.05） affected by the length of cuttings, as well as the position of shoots and type of cuttings. On average, 86.0 per cent rooting was observed in the 30-cm long cuttings com- pared to the other two lengths of cuttings, i.e., 20 and 25 cm, irrespective of any auxin treatment. In a control set, without any auxin treatment, a maximum of 60.0% rooting was recorded in the 30-cm long cuttings and a minimum of 40.0% of the cuttings rooted in the 20-cm long cuttings. Similarly, cuttings collected from the lower and upper portions of shoots resulted in 72.5 and 52.5 per cent rooting respectively, irrespective of auxin treatments. Maximum rooting was observed in the lower portion （40.0%） of cutting com- pared to the upper portion （30.0%） in the control set without auxin treatment. Leafless branches produced maximum （72.0%） rooting compared to the leafy cuttings （35.0%）, irrespective of the auxin treatment. The leafy cuttings produces a minimum of 15.0% sprout- ing and rooting in the control set.
基金supported by the Research Council(formerly Academy)of Finland(projects 122133,214824,362731,and researcher posts of M.V.Kozlov)EC through the BALANCE project carried out under contract EVK2-2002-00169,and the University of Turku。
文摘Stress in plants refers to adverse changes in their functioning.The occurrence and intensity of a stress can be assessed by alterations in plant traits,termed stress indicators.The ultimate goal of this study was to test whether six morpho-physiological plant traits,frequently used as stress indicators,respond consistently across species to various environmental stressors,with the aim of detecting universal stress indicators in forest tree species.We examined changes in vertical increment,leaf/needle size,shoot length,needle longevity,photosynthetic efficiency and fluctuating asymmetry in three common European tree species,mountain birch(Betula pubescens var.pumila),Norway spruce(Picea abies)and Scots pine(Pinus sylvestris)along three environmental gradients(elevation,pollution and seashore)from forests to stressful open environments.Data were collected in 2003,2004 and 2005 from 297 trees growing naturally across 36 sites in north-western Russia.Fluctuating asymmetry was the only trait that did not vary among sites with differing levels of environmental stress.Leaf/needle size and shoot length occasionally changed along stress gradients,but the magnitude and direction of these changes differed by gradient type and species,resulting in no significant overall stress effect for either trait.In contrast,photosynthetic efficiency,vertical increment and needle longevity consistently decreased from low-stress to high-stress sites.The overall effect was significant for each of these three traits despite the magnitudes of these decreases differed depending on the gradient type and location,species,study year and individual tree.Replication at spatial,temporal and taxonomic levels ensured the robustness and reliability of our results that photosynthetic efficiency,vertical growth and needle longevity reliably captured a general stress syndrome and may serve as stress indicators in forest species.
基金Supported by National Key Technologies R&D Program of China(2008BAK51B01-7-3)~~
文摘[Objective] This study was to investigate the allelopathic effects of J.curcas leaf leachates on seedling growth and antioxidative enzymes,and thus to reveal physiologically allelopathic effects of J.curcas trees on undergrowth plants.[Method] The allelopathic effects of leaf leachates of Jatropha curcas amended into soil were determined on the growth,proline and malondialdehyde（MDA） contentas well as superoxide dismutase（SOD）,catalase（CAT）,ascorbate peroxidase（APX）,guaiacol peroxidase（POD） in roots of marigold（Tagetes erecta） seedlings.[Results] The application of leaf leachates of J.curcas in the soil significantly inhibited the shoot and root length of marigold compared to un-amended soils.The leaf leachates increased the O-2,H2O2,MDA and proline content in the roots of marigold seedlings.The effects increased with the ascending of leaf leachates concentration.In addition,superoxide dismutase（SOD） and guaiacol peroxidase（POD） were not remarkably affected by the leachates at lower concentrations,but at higher concentration,SOD activity was ascended.Similarly,the activities of CAT and APX were also significantly increased with the increase of leachates concentrations.[Conclusion] These results show that J.curcas can release the phytotoxic compound（s） into soil,which are inhibitory to certain test species by interfering with physiological process.
