In this paper, root-shoot relationships of seedlings of Manchurican ash (Fraxinus mandchurica) in pots is studied in green house. The results show that roots and shoots have the co-ordination of growth and roots and s...In this paper, root-shoot relationships of seedlings of Manchurican ash (Fraxinus mandchurica) in pots is studied in green house. The results show that roots and shoots have the co-ordination of growth and roots and shoots of ash have the same growth dynamics. There are very close relationships between toall root mass and total shoot mass, between fine root mass and leaf mass in this experiments. At the end growing season, ash root-shoot mass ratio and fine root-leaf mass ratio are 1 .85 and 2.01 respectively. These ratios are difference during growth season. There are larger roots than shoots on seedling stage. Low nitrogen and phosphorus produce higher root-shoot ratio, and high nutrient concentrations decrease the ratios.展开更多
The role of acetylcholine (ACh) on plant root- shoot communication was investigated using the root-split system of Vicia faba L. In the experiments, slight osmotic stress caused the decrease of ACh content in root tip...The role of acetylcholine (ACh) on plant root- shoot communication was investigated using the root-split system of Vicia faba L. In the experiments, slight osmotic stress caused the decrease of ACh content in root tips and the xylem sap transported up per time unit from root tip to the shoot when the water potential of the shoot was kept un-changed. It also caused the decrease of ACh content in the abaxial epidermis. The decrease was highly correlative to the changes of transpiration rate, suggesting that the decrease of ACh content probably functions as a signal to regulate stomatal behavior. The effect of osmotic stress might be mainly through the inhibition of the ACh synthesis in root tip; thus further influences the ACh content in root tip, xy-lem sap and abaxial epidermis and resulting in the changes of stomatal behavior. These results provide new evidence that plants transduce positive and negative signals among roots and shoots to coordinate stomatal behavior and adapt to variable environments.展开更多
为明确不同氮肥运筹对玉米根冠协调发育的影响,基于长期定位氮肥试验平台,设置4个氮素处理(N3:300 kg N/hm^(2);N2:225 kg N/hm^(2);N1:150 kg N/hm^(2);N0:0 kg N/hm^(2)),2023-2024年以郑单958和先玉3352个玉米品种为试验材料,分析玉...为明确不同氮肥运筹对玉米根冠协调发育的影响,基于长期定位氮肥试验平台,设置4个氮素处理(N3:300 kg N/hm^(2);N2:225 kg N/hm^(2);N1:150 kg N/hm^(2);N0:0 kg N/hm^(2)),2023-2024年以郑单958和先玉3352个玉米品种为试验材料,分析玉米关键生育期根冠特征。结果表明,增施氮肥显著提高玉米产量及地上部和地下部的生物量,但N2与N3处理间产量差异不显著,N3、N2、N1处理成熟期干物质积累量较N0分别增加了106.5%~164.3%、87.4%~125.7%、71.8%~87.4%;根系干重峰值出现在吐丝后15 d左右,N3、N2、N1处理较N0处理分别增加了33.67%~49.67%、17.87%~21.89%、9.69%~18.38%。根冠比动态呈单峰曲线,峰值出现在出苗后45 d左右,随施氮量增加而降低,N2处理较N1、N0处理分别降低11.1%和25.7%,较N3处理增加4.1%。研究结果表明,氮肥投入影响玉米产量的增加,当施氮量超过225 kg N/hm^(2)时,增产效应趋于饱和。合理的氮肥运筹(中氮,N2)通过优化物质分配比例,协调根冠生长,在保障产量提升的同时提高了肥料利用效益,为玉米氮肥精准调控及可持续生产提供了依据。展开更多
草地作为我国陆地生态系统重要的碳库,对我国气候调节和实现碳达峰碳中和具有重要意义。综合以往草地植被碳储量估算的相关文献,本文综述了草地植被碳储量代表性估算方法,并分析了不同估算结果的差异性来源。结果表明:自21世纪以来我国...草地作为我国陆地生态系统重要的碳库,对我国气候调节和实现碳达峰碳中和具有重要意义。综合以往草地植被碳储量估算的相关文献,本文综述了草地植被碳储量代表性估算方法,并分析了不同估算结果的差异性来源。结果表明:自21世纪以来我国草地植被碳储量的估算值之间差异较大,碳储量的估算结果介于0.56~4.66 Pg,均值为2.22 Pg,碳密度估算结果介于216~1148 g C·m^(-2),均值为654.23 g C·m^(-2);草地植被枯落物碳储量占比介于0.1%~8.6%,均值为5.6%,枯落物的忽略会导致碳储量估算总量偏低;采用全球单位碳密度估算方法同其他估算方法之间存在显著性差异(P<0.05);草地植被地上部、地下部和枯落物的含碳率分别为39.3%、36.6%和30.7%,植被地上部含碳率与枯落物含碳率之间呈显著性差异(P<0.05),采用较为普遍的碳转换系数45%会导致草地植被碳储量估算总量偏大;不同草地类型根茎比差异较大,介于0.76~41.80,均值为9.16。综上,草地植被碳储量的估算方法、数据源、重要参数的不同,导致了草地植被碳储量估算总量之间的差异。展开更多
[Objective] This study was to investigate the effect of atrazine stress on the growth of Pennisetum hydridum. [Method] Pot experiments were conducted to study the effects of atrazine stress （20, 50, 100, 200, 500 mg...[Objective] This study was to investigate the effect of atrazine stress on the growth of Pennisetum hydridum. [Method] Pot experiments were conducted to study the effects of atrazine stress （20, 50, 100, 200, 500 mg/kg） on plant height, biomass, root-shoot ratio and chlorophyll content of P. hydridum. [Results] Low level of atrazine stress （20 and 50 mg/kg） showed no significant effects on plant height and biomass of P. hydridum. Moderate level of atrazine stress （100 and 200 mg/kg） did not show significant effect on plant height, but did on the biomass of P. hydridum. Biomass of P. hydridum stressed by 100 and 200 mg/kg of atrazine was decreased by 34.1% and 36.4% compared with control, respectively. High level of atrazine stress （500 mg/kg） brought significant decrease in plant height（by 40.6%） and biomass（20.0%） of P. hydridum. All levels of atrazine stress showed no significant effects on root-shoot ratio and chlorophyll content of P. hydridum. [Conclusion] Pennisetum hydridum has strong tolerance to atrazine stress.展开更多
文摘In this paper, root-shoot relationships of seedlings of Manchurican ash (Fraxinus mandchurica) in pots is studied in green house. The results show that roots and shoots have the co-ordination of growth and roots and shoots of ash have the same growth dynamics. There are very close relationships between toall root mass and total shoot mass, between fine root mass and leaf mass in this experiments. At the end growing season, ash root-shoot mass ratio and fine root-leaf mass ratio are 1 .85 and 2.01 respectively. These ratios are difference during growth season. There are larger roots than shoots on seedling stage. Low nitrogen and phosphorus produce higher root-shoot ratio, and high nutrient concentrations decrease the ratios.
基金suppoaed by the National Key Basic Research Special Funds of China(Grant No.G1999011700).
文摘The role of acetylcholine (ACh) on plant root- shoot communication was investigated using the root-split system of Vicia faba L. In the experiments, slight osmotic stress caused the decrease of ACh content in root tips and the xylem sap transported up per time unit from root tip to the shoot when the water potential of the shoot was kept un-changed. It also caused the decrease of ACh content in the abaxial epidermis. The decrease was highly correlative to the changes of transpiration rate, suggesting that the decrease of ACh content probably functions as a signal to regulate stomatal behavior. The effect of osmotic stress might be mainly through the inhibition of the ACh synthesis in root tip; thus further influences the ACh content in root tip, xy-lem sap and abaxial epidermis and resulting in the changes of stomatal behavior. These results provide new evidence that plants transduce positive and negative signals among roots and shoots to coordinate stomatal behavior and adapt to variable environments.
文摘为明确不同氮肥运筹对玉米根冠协调发育的影响,基于长期定位氮肥试验平台,设置4个氮素处理(N3:300 kg N/hm^(2);N2:225 kg N/hm^(2);N1:150 kg N/hm^(2);N0:0 kg N/hm^(2)),2023-2024年以郑单958和先玉3352个玉米品种为试验材料,分析玉米关键生育期根冠特征。结果表明,增施氮肥显著提高玉米产量及地上部和地下部的生物量,但N2与N3处理间产量差异不显著,N3、N2、N1处理成熟期干物质积累量较N0分别增加了106.5%~164.3%、87.4%~125.7%、71.8%~87.4%;根系干重峰值出现在吐丝后15 d左右,N3、N2、N1处理较N0处理分别增加了33.67%~49.67%、17.87%~21.89%、9.69%~18.38%。根冠比动态呈单峰曲线,峰值出现在出苗后45 d左右,随施氮量增加而降低,N2处理较N1、N0处理分别降低11.1%和25.7%,较N3处理增加4.1%。研究结果表明,氮肥投入影响玉米产量的增加,当施氮量超过225 kg N/hm^(2)时,增产效应趋于饱和。合理的氮肥运筹(中氮,N2)通过优化物质分配比例,协调根冠生长,在保障产量提升的同时提高了肥料利用效益,为玉米氮肥精准调控及可持续生产提供了依据。
文摘草地作为我国陆地生态系统重要的碳库,对我国气候调节和实现碳达峰碳中和具有重要意义。综合以往草地植被碳储量估算的相关文献,本文综述了草地植被碳储量代表性估算方法,并分析了不同估算结果的差异性来源。结果表明:自21世纪以来我国草地植被碳储量的估算值之间差异较大,碳储量的估算结果介于0.56~4.66 Pg,均值为2.22 Pg,碳密度估算结果介于216~1148 g C·m^(-2),均值为654.23 g C·m^(-2);草地植被枯落物碳储量占比介于0.1%~8.6%,均值为5.6%,枯落物的忽略会导致碳储量估算总量偏低;采用全球单位碳密度估算方法同其他估算方法之间存在显著性差异(P<0.05);草地植被地上部、地下部和枯落物的含碳率分别为39.3%、36.6%和30.7%,植被地上部含碳率与枯落物含碳率之间呈显著性差异(P<0.05),采用较为普遍的碳转换系数45%会导致草地植被碳储量估算总量偏大;不同草地类型根茎比差异较大,介于0.76~41.80,均值为9.16。综上,草地植被碳储量的估算方法、数据源、重要参数的不同,导致了草地植被碳储量估算总量之间的差异。
基金Supported by Natural Science Foundation of Yunnan Province(2010CD058)~~
文摘[Objective] This study was to investigate the effect of atrazine stress on the growth of Pennisetum hydridum. [Method] Pot experiments were conducted to study the effects of atrazine stress （20, 50, 100, 200, 500 mg/kg） on plant height, biomass, root-shoot ratio and chlorophyll content of P. hydridum. [Results] Low level of atrazine stress （20 and 50 mg/kg） showed no significant effects on plant height and biomass of P. hydridum. Moderate level of atrazine stress （100 and 200 mg/kg） did not show significant effect on plant height, but did on the biomass of P. hydridum. Biomass of P. hydridum stressed by 100 and 200 mg/kg of atrazine was decreased by 34.1% and 36.4% compared with control, respectively. High level of atrazine stress （500 mg/kg） brought significant decrease in plant height（by 40.6%） and biomass（20.0%） of P. hydridum. All levels of atrazine stress showed no significant effects on root-shoot ratio and chlorophyll content of P. hydridum. [Conclusion] Pennisetum hydridum has strong tolerance to atrazine stress.
