通过对福建三明36年生的格氏栲人工林和杉木人工林林木地下C分配(TBCA)进行研究,结果表明,由分室累加法直接测定的格氏栲和杉木人工林的TBCA分别为8.426和4.040 t C.hm-2.-a 1。在格氏栲和杉木人工林TBCA组成中,根系净生产量和根系呼吸...通过对福建三明36年生的格氏栲人工林和杉木人工林林木地下C分配(TBCA)进行研究,结果表明,由分室累加法直接测定的格氏栲和杉木人工林的TBCA分别为8.426和4.040 t C.hm-2.-a 1。在格氏栲和杉木人工林TBCA组成中,根系净生产量和根系呼吸各约占50%;在根系年净生产量中,细根年净生产量和粗根年净生产量各约占75%和25%。而格氏栲和杉木人工林的细根年C归还量则均约占各自TBCA的1/3(分别为33%和36%)。在假设地下C库处于稳定状态时,由C平衡法计算的格氏栲和杉木人工林的TBCA(分别为6.039t C.hm-2.-a 1和2.987 t C.hm-2.-a 1)低于分室累加法,这与两种人工林地下C库尚未达到稳定状态有关。利用R a ich and N ade lhoffer全球模式方程推算的格氏栲和杉木人工林的TBCA(分别为9.771t C.hm-2.a-1和5.344 t C.hm-2.-a 1)则高于分室累加法,这与全球模式方程只是一种全球尺度规律有关。展开更多
Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In die late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root-borne buds, which in turn gr...Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In die late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root-borne buds, which in turn grow into ramets and taproot. On the basis of observation on numerous samples, methods to classify the age of ramets and buds for the root sucker herbaceous plant population and to estimate the ages of taproots were established according to their morphology. The age of ramets was classified based on the regeneration times of taproot buds. Ramets developed from new root sucker buds were classified as 1 a. After 1 a ramets died, the ramets reproduced from the taproots were 2 a, and so on. New buds from a root sucker were 0 a buds, other age classes of buds were consistent with that of ramets, i.e. buds produced from taproots of I a ramets were 1 a buds, and so on. In the hay clipping meadows of the Songnen Plains, for K. integrifolia population, there are three age classes of ramets, representing a steady age structure. The maximal age of taproots of ramets is 4 a. Among all age classes, the population productivity of 2 a ramets was the highest, and that of I a ramets was the lowest. The ramet productivity increased with ramet age. During the early period of growing season, the productivity of 3 a ramets was the highest, but after the middle of growing season, I a ramets showed the greatest relative growth rate. The population size and age structure in the next year could be accurately forecasted by the number of fresh roots with budlet and present population in late autumn. The potential population in the bud banks was more than two times of the present population, which may provide sufficient substitution in the future.展开更多
Ardisia mamillata Hance is a rare plant with highly ornamental and medicinal value. The traditional propagation methods for A. mamillata by seeds or cutting provided low proliferation rate. This study is to optimize t...Ardisia mamillata Hance is a rare plant with highly ornamental and medicinal value. The traditional propagation methods for A. mamillata by seeds or cutting provided low proliferation rate. This study is to optimize the propagation technique of A. mamillata by tissue culture and set up an industrial production system to provide plenty of A. mamillata seedlings for the human demand. The optimal initiation medium for A. mamillata is MS +2.0 mg/L BA +0.1 mg/L NAA +30 g/L sugar, providing76.4% initiation rate. The optimal shoot proliferation medium for A. mamillata is MS+1.0 mg/L BA+0.1 mg/L NAA+30 g/L sugar, providing 4.56 fold proliferation rate and3.10 cm shoot in height. The optimal shoot elongation medium for A. mamillata is MS+0.5 mg/L BA+0.1 mg/L NAA+30 g/L sugar, providing 2.77 fold proliferation rate and 4.27 cm shoot in height. The optimal rooting medium for A. mamillata is 1/2MS+0.1 mg/L IBA +15 g/L sugar, providing 99.7% rooting rate, 4.0 roots per individual,7.53 cm root in length and 3.94 cm shoot in height. This provides a reliable mass propagation method for A. mamillata.展开更多
本研究于2015—2016年进行野外控制试验,分析了不同施氮(N)水平(0、1、2、4、8、16 g N·m^(-2)·a^(-1))对青藏高原高寒草原根系生产、周转速率和现存量的影响及其调控因素。结果表明:随着施N量的增加,根系生产量和现存量呈线...本研究于2015—2016年进行野外控制试验,分析了不同施氮(N)水平(0、1、2、4、8、16 g N·m^(-2)·a^(-1))对青藏高原高寒草原根系生产、周转速率和现存量的影响及其调控因素。结果表明:随着施N量的增加,根系生产量和现存量呈线性或指数下降的趋势。与对照相比,16 g N·m^(-2)·a^(-1)处理根系生产量和现存量2年平均下降43.0%和45.7%。根系周转速率呈先上升后下降的趋势,2015年和2016年分别在2和4 g N·m^(-2)·a^(-1)处理达到峰值。线性混合模型结果显示,根系淀粉含量是调控根系生产量和周转速率的主要因素,分别解释二者变异的21.7%和25.4%;而根系现存量则受根系蛋白含量的影响,其解释率为20.8%。N富集对根系生产和现存量表现出抑制作用,低N促进而高N抑制根系周转速率,根系碳氮代谢指标是调控根系动态对N添加响应的主要因素。展开更多
Interspecific root/rhizosphere interactions affect phosphorus (P) uptake and the productivity of maize/faba bean and maize/wheat intercropping systems. The aim of these experiments was to determine whether manipulatio...Interspecific root/rhizosphere interactions affect phosphorus (P) uptake and the productivity of maize/faba bean and maize/wheat intercropping systems. The aim of these experiments was to determine whether manipulation of maize root growth could improve the productivity of the two intercropping systems. Two near isogenic maize hybrids (the larger-rooted T149 and smaller-rooted T222) were intercropped with faba bean and wheat, under conditions of high- and low-P availability. The larger-rooted T149 showed greater competitive ability than the smaller-rooted T222 in both maize/faba bean and maize/wheat intercropping systems. The higher competitive ability of T149 improved the productivity of the maize/faba bean intercropping system in P-sufficient conditions. In maize/wheat intercropping systems, root growth, shoot biomass, and P uptake of maize were inhibited by wheat, regardless of the P-supply. Compared with T222, the larger-rooted T149 suffered less in the intercropping systems. The total biomass of the maize/wheat intercropping system was higher for wheat/T149 than for wheat/T222 under low-P conditions. These data suggested that genetic improvement of maize root size could enhance maize growth and its ability to compete for P resources in maize/faba bean and maize/wheat intercropping systems. In addition, depending on the P availability, larger maize roots could increase the productivity of intercropping systems.展开更多
Aims Research on the effects of extreme rainfall events on ecosystem function has primarily focussed on drought or flooding events,which usually include changes to mean or total rainfall,annually or over a season.Howe...Aims Research on the effects of extreme rainfall events on ecosystem function has primarily focussed on drought or flooding events,which usually include changes to mean or total rainfall,annually or over a season.However,less is known about the effects of increased rainfall variability without change to mean or total amounts.We investigated the effects of increased variation of water supply on shoot and root biomass as well as the distribution of root biomass of four grassland plant species,grown in monoculture and mixture communities.Methods Perennial ryegrass(Lolium perenne L.,shallow-rooting grass),chicory(Cichorium intybus L.,deep-rooting forb),white clover(Trifolium repens L.,shallow-rooting legume)and red clover(Trifolium pratense L.,deep-rooting legume)were established in mesocosms.Four plants of the same species were grown in monoculture communities and one of each species grown in four-species communities.Water supply was manipulated such that;compared with a baseline level with low variation in water supply,there was a treatment with medium variation(±40%)and another with high variation(±80%).Shoot and root biomass were measured,and vertical root distribution models fitted.Important Findings Compared with the low variation treatment,shoot biomass was significantly reduced under high variation for white clover,red clover and four-species communities.Under all conditions,four-species communities produced more shoot and root biomass than predicted by species performance in monoculture(overyielding).Under increased water variation,chicory monocultures allocated a higher proportion of root biomass to deeper soil layers while the total root biomass of white clover monocultures was significantly reduced.These results indicate that increased variability of water supply can negatively affect the shoot and root biomass production of single and multi-species grasslands.There is a need for further investigation of water variation effects on the functioning of multi-species grassland systems at field scale.展开更多
基金National Key Research and Development Program of China(2019YFE0117000)National Natural Science Foundation of China(32271579)Regional Collaborative Innovation Project of Xinjiang Uygur Autonomous Region(2023E01008).
文摘通过对福建三明36年生的格氏栲人工林和杉木人工林林木地下C分配(TBCA)进行研究,结果表明,由分室累加法直接测定的格氏栲和杉木人工林的TBCA分别为8.426和4.040 t C.hm-2.-a 1。在格氏栲和杉木人工林TBCA组成中,根系净生产量和根系呼吸各约占50%;在根系年净生产量中,细根年净生产量和粗根年净生产量各约占75%和25%。而格氏栲和杉木人工林的细根年C归还量则均约占各自TBCA的1/3(分别为33%和36%)。在假设地下C库处于稳定状态时,由C平衡法计算的格氏栲和杉木人工林的TBCA(分别为6.039t C.hm-2.-a 1和2.987 t C.hm-2.-a 1)低于分室累加法,这与两种人工林地下C库尚未达到稳定状态有关。利用R a ich and N ade lhoffer全球模式方程推算的格氏栲和杉木人工林的TBCA(分别为9.771t C.hm-2.a-1和5.344 t C.hm-2.-a 1)则高于分室累加法,这与全球模式方程只是一种全球尺度规律有关。
文摘Kalimeris integrifolia Turcz. is a root sucker form perennial herb of Compositae. In die late period of growing season, fresh fleshy radicels grow up above the soil surface to develop root-borne buds, which in turn grow into ramets and taproot. On the basis of observation on numerous samples, methods to classify the age of ramets and buds for the root sucker herbaceous plant population and to estimate the ages of taproots were established according to their morphology. The age of ramets was classified based on the regeneration times of taproot buds. Ramets developed from new root sucker buds were classified as 1 a. After 1 a ramets died, the ramets reproduced from the taproots were 2 a, and so on. New buds from a root sucker were 0 a buds, other age classes of buds were consistent with that of ramets, i.e. buds produced from taproots of I a ramets were 1 a buds, and so on. In the hay clipping meadows of the Songnen Plains, for K. integrifolia population, there are three age classes of ramets, representing a steady age structure. The maximal age of taproots of ramets is 4 a. Among all age classes, the population productivity of 2 a ramets was the highest, and that of I a ramets was the lowest. The ramet productivity increased with ramet age. During the early period of growing season, the productivity of 3 a ramets was the highest, but after the middle of growing season, I a ramets showed the greatest relative growth rate. The population size and age structure in the next year could be accurately forecasted by the number of fresh roots with budlet and present population in late autumn. The potential population in the bud banks was more than two times of the present population, which may provide sufficient substitution in the future.
基金Supported by Fujian Modern Agriculture Project:The Innovation and Industrialization Techniques of Dominant Woody Flowering Plants(No.:Min Lin Ji Cai[2012]137)
文摘Ardisia mamillata Hance is a rare plant with highly ornamental and medicinal value. The traditional propagation methods for A. mamillata by seeds or cutting provided low proliferation rate. This study is to optimize the propagation technique of A. mamillata by tissue culture and set up an industrial production system to provide plenty of A. mamillata seedlings for the human demand. The optimal initiation medium for A. mamillata is MS +2.0 mg/L BA +0.1 mg/L NAA +30 g/L sugar, providing76.4% initiation rate. The optimal shoot proliferation medium for A. mamillata is MS+1.0 mg/L BA+0.1 mg/L NAA+30 g/L sugar, providing 4.56 fold proliferation rate and3.10 cm shoot in height. The optimal shoot elongation medium for A. mamillata is MS+0.5 mg/L BA+0.1 mg/L NAA+30 g/L sugar, providing 2.77 fold proliferation rate and 4.27 cm shoot in height. The optimal rooting medium for A. mamillata is 1/2MS+0.1 mg/L IBA +15 g/L sugar, providing 99.7% rooting rate, 4.0 roots per individual,7.53 cm root in length and 3.94 cm shoot in height. This provides a reliable mass propagation method for A. mamillata.
文摘本研究于2015—2016年进行野外控制试验,分析了不同施氮(N)水平(0、1、2、4、8、16 g N·m^(-2)·a^(-1))对青藏高原高寒草原根系生产、周转速率和现存量的影响及其调控因素。结果表明:随着施N量的增加,根系生产量和现存量呈线性或指数下降的趋势。与对照相比,16 g N·m^(-2)·a^(-1)处理根系生产量和现存量2年平均下降43.0%和45.7%。根系周转速率呈先上升后下降的趋势,2015年和2016年分别在2和4 g N·m^(-2)·a^(-1)处理达到峰值。线性混合模型结果显示,根系淀粉含量是调控根系生产量和周转速率的主要因素,分别解释二者变异的21.7%和25.4%;而根系现存量则受根系蛋白含量的影响,其解释率为20.8%。N富集对根系生产和现存量表现出抑制作用,低N促进而高N抑制根系周转速率,根系碳氮代谢指标是调控根系动态对N添加响应的主要因素。
基金supported by the National Natural Science Foundation of China (Grant Nos. 31121062 and 31071852)the National Basic Research Program of China (Grant No. 2009CB11860)the Special Fund for the Agricultural Profession (Grant No. 201103003)
文摘Interspecific root/rhizosphere interactions affect phosphorus (P) uptake and the productivity of maize/faba bean and maize/wheat intercropping systems. The aim of these experiments was to determine whether manipulation of maize root growth could improve the productivity of the two intercropping systems. Two near isogenic maize hybrids (the larger-rooted T149 and smaller-rooted T222) were intercropped with faba bean and wheat, under conditions of high- and low-P availability. The larger-rooted T149 showed greater competitive ability than the smaller-rooted T222 in both maize/faba bean and maize/wheat intercropping systems. The higher competitive ability of T149 improved the productivity of the maize/faba bean intercropping system in P-sufficient conditions. In maize/wheat intercropping systems, root growth, shoot biomass, and P uptake of maize were inhibited by wheat, regardless of the P-supply. Compared with T222, the larger-rooted T149 suffered less in the intercropping systems. The total biomass of the maize/wheat intercropping system was higher for wheat/T149 than for wheat/T222 under low-P conditions. These data suggested that genetic improvement of maize root size could enhance maize growth and its ability to compete for P resources in maize/faba bean and maize/wheat intercropping systems. In addition, depending on the P availability, larger maize roots could increase the productivity of intercropping systems.
基金Funding was provided through the AnimalChange project which received funding from the European Community’s Seventh Framework Programme(grant agreement no.266018).
文摘Aims Research on the effects of extreme rainfall events on ecosystem function has primarily focussed on drought or flooding events,which usually include changes to mean or total rainfall,annually or over a season.However,less is known about the effects of increased rainfall variability without change to mean or total amounts.We investigated the effects of increased variation of water supply on shoot and root biomass as well as the distribution of root biomass of four grassland plant species,grown in monoculture and mixture communities.Methods Perennial ryegrass(Lolium perenne L.,shallow-rooting grass),chicory(Cichorium intybus L.,deep-rooting forb),white clover(Trifolium repens L.,shallow-rooting legume)and red clover(Trifolium pratense L.,deep-rooting legume)were established in mesocosms.Four plants of the same species were grown in monoculture communities and one of each species grown in four-species communities.Water supply was manipulated such that;compared with a baseline level with low variation in water supply,there was a treatment with medium variation(±40%)and another with high variation(±80%).Shoot and root biomass were measured,and vertical root distribution models fitted.Important Findings Compared with the low variation treatment,shoot biomass was significantly reduced under high variation for white clover,red clover and four-species communities.Under all conditions,four-species communities produced more shoot and root biomass than predicted by species performance in monoculture(overyielding).Under increased water variation,chicory monocultures allocated a higher proportion of root biomass to deeper soil layers while the total root biomass of white clover monocultures was significantly reduced.These results indicate that increased variability of water supply can negatively affect the shoot and root biomass production of single and multi-species grasslands.There is a need for further investigation of water variation effects on the functioning of multi-species grassland systems at field scale.
