Grain filling, a crucial stage of grain yield formation in rice, is usually affected by the panicle nitrogen （N） fertilization. Field and pot culture experiments were conducted to explore the underlying mechanisms o...Grain filling, a crucial stage of grain yield formation in rice, is usually affected by the panicle nitrogen （N） fertilization. Field and pot culture experiments were conducted to explore the underlying mechanisms of N effect. Two rice cultivars with high lodging resistance were grown in the field and pot. Four panicle N fertilization treatments were conducted in 2006 and repeated in 2007. The result showed that medium level of panicle N fertilization treatment （NM） enhanced the accumulation and translocation of non-structural carbohydrate （NSC） in the stem and sheath. Compared with non-nitrogen treatment （NO）, NM promoted the translocation of labeled ^13C from stem and sheath to grain. But, low level of panicle N fertilization treatment （NL） and high level of panicle N fertilization treatment （NH） showed the negative effect. The endosperm cell, grain length, and grain width of NM increased more quickly than that of NO from 4 to 10 d after anthesis. During the early period of grain filling, sucrose-phosphate synthase （EC 2.4.1.14, SPS） activity were significantly higher for the NM treatment than those of the NL and NH treatments. Sucrose synthase （EC 2.4.1.13, SuSase） activity in the grains was substantially enhanced by NM, with the duration of higher activity being longer than those of the other treatments. At maturing stage, NM significantly increased the filled grain number, the seed-setting rate, and the grain weight compared with NL and NH. The results suggest that NM have a positive effect on the activities of enzymes of physiological importance, thereby increasing the grain size and promoting grain filling.展开更多
We investigated non-structural carbohydrates（NSC） levels and components（starch,glucose,fructose and sucrose） in the leaves of three typical co-occurring forestfloor plants,moss Eurhynchium savatieri（ES）,fern Par...We investigated non-structural carbohydrates（NSC） levels and components（starch,glucose,fructose and sucrose） in the leaves of three typical co-occurring forestfloor plants,moss Eurhynchium savatieri（ES）,fern Parathelypteris nipponica（PN） and forb Aruncus sylvester（AS） in a 30-year-old Chinese pine（Pinus tabulaeformis）plantation forest on the eastern Tibetan Plateau.We also explored their responses to three gap creation treatments（control and two gap creations of 80 and 110 m2） based on NSC levels.PN had the highest leaf NSC level of the three plants,with AS second and ES lowest.Starch was the predominant component of NSC and the contents of glucose were higher than those of fructose or sucrose for all three species.The NSC level of ES in intermediate gaps was significantly higher than at control sites.PN also had higher NSC levels in both small and intermediate gaps than in control sites.But the differences between treatments were not obvious for AS.Our results suggest that ES and PN benefit from gap formation while the two species have different NSC response sensitivities to gap size,but the leaf NSC level of AS is less sensitive to the disturbance.展开更多
为了探究长期干旱胁迫下连翘不同器官的非结构性碳水化合物(NSC)含量与水力特性的协调及响应机制。以连续3年不同水分条件处理后的连翘幼苗为研究对象,设置3个水分处理(适宜供水、中度干旱胁迫和重度干旱胁迫),研究长期干旱胁迫后连翘...为了探究长期干旱胁迫下连翘不同器官的非结构性碳水化合物(NSC)含量与水力特性的协调及响应机制。以连续3年不同水分条件处理后的连翘幼苗为研究对象,设置3个水分处理(适宜供水、中度干旱胁迫和重度干旱胁迫),研究长期干旱胁迫后连翘幼苗的光合特性、生物量的分配、NSC各组分含量、水力特性的变化及其碳水两者之间的相关关系。结果表明:(1)适宜供水、中度干旱、重度干旱胁迫下,枝条的栓塞程度分别为30.7%、41.8%和42.3%,枝条导水率分别为0.95、0.71、0.65 kg m^(-1)s-1MPa^(-1)。(2)重度干旱胁迫显著降低了净光合速率、蒸腾速率、气孔导度、水分利用效率。(3)重度干旱胁迫导致地上和粗根生物量显著降低,细根生物量和根冠比显著增加。此外,各器官的NSC含量显著降低,其根系NSC消耗量最高,根系的可溶性总糖和淀粉含量显著降低,枝条的可溶性总糖、葡萄糖和蔗糖含量增加了12.9%、31.1%和45.7%,而淀粉含量降低了40.7%。(4)枝条栓塞程度和导水率与可溶性总糖、淀粉、蔗糖和葡萄糖含量显著相关,其栓塞程度与可溶性总糖、葡萄糖和蔗糖呈正相关,而与淀粉呈负相关(P<0.01)。综上所述,干旱导致连翘枝条木质部的栓塞程度增加,导水率、光合作用和水分运输效率均显著降低,但连翘通过提高枝条内可溶性总糖、葡萄糖、蔗糖含量和降低淀粉、NSC含量以提高植物在干旱条件下的存活机率及旱后水分恢复能力,研究为半干旱区连翘培育和经营提供理论依据。展开更多
以国家植物园中水杉(Metasequoia glyptostroboides Hu et Cheng)为研究对象,对比根部淹水和非淹水生境中水杉的叶片形态特征、化学计量特征、气体交换参数及非结构性糖类的差异,分析水杉对2种生境的适应策略。结果表明:水杉根部淹水和...以国家植物园中水杉(Metasequoia glyptostroboides Hu et Cheng)为研究对象,对比根部淹水和非淹水生境中水杉的叶片形态特征、化学计量特征、气体交换参数及非结构性糖类的差异,分析水杉对2种生境的适应策略。结果表明:水杉根部淹水和非淹水生境土壤含水量差异显著(P<0.05),土壤化学计量特征中除C/N比外均具有显著差异。根部淹水生境水杉叶面积和比叶面积均显著大于根部非淹水生境,但叶干物质含量显著低于非淹水生境,这主要通过叶长的增加实现。同一径级内,根部淹水生境仅Ⅰ〔20 cm≤胸径(DBH)<30 cm〕径级水杉叶片净光合速率显著高于非淹水生境;3个径级水杉叶片胞间CO_(2)浓度在2种生境间无显著差异;气孔导度和蒸腾速率在2种生境间均存在显著差异,且除Ⅰ径级的蒸腾速率外均为根部淹水生境显著高于根部非淹水生境。同一生境内,水杉叶片净光合速率、气孔导度和蒸腾速率随着径级的增大呈上升趋势,而胞间CO_(2)浓度的变化趋势相反。同一径级内,根部淹水生境水杉叶片有机碳、全氮和全磷含量均高于根部非淹水生境,且除有机碳含量外均存在显著差异;根部淹水生境水杉叶片N/P比、C/N比和C/P比总体小于根部非淹水生境,其中,Ⅰ径级水杉叶片N/P比和C/N比在2种生境间差异显著,Ⅰ和Ⅱ(30 cm≤DBH<40 cm)径级水杉叶片C/P比在2种生境间差异显著。根部淹水生境水杉叶片非结构性糖类含量显著高于非淹水生境,主要表现为可溶性糖含量的升高。综上所述,水杉对淹水胁迫具有良好的适应能力,能够通过改变叶片形态、可溶性糖含量及气孔开放程度来保证正常的生命活动,在今后的迁地保护过程中可通过增加土壤含水量和光照帮助水杉适应环境的变化。展开更多
基金supported by the National Natural Science Foundation of China (30871482)the Scientific Research Innovation Project for Graduate Student of Jiangsu Province, China (CXO7B_184Z)
文摘Grain filling, a crucial stage of grain yield formation in rice, is usually affected by the panicle nitrogen （N） fertilization. Field and pot culture experiments were conducted to explore the underlying mechanisms of N effect. Two rice cultivars with high lodging resistance were grown in the field and pot. Four panicle N fertilization treatments were conducted in 2006 and repeated in 2007. The result showed that medium level of panicle N fertilization treatment （NM） enhanced the accumulation and translocation of non-structural carbohydrate （NSC） in the stem and sheath. Compared with non-nitrogen treatment （NO）, NM promoted the translocation of labeled ^13C from stem and sheath to grain. But, low level of panicle N fertilization treatment （NL） and high level of panicle N fertilization treatment （NH） showed the negative effect. The endosperm cell, grain length, and grain width of NM increased more quickly than that of NO from 4 to 10 d after anthesis. During the early period of grain filling, sucrose-phosphate synthase （EC 2.4.1.14, SPS） activity were significantly higher for the NM treatment than those of the NL and NH treatments. Sucrose synthase （EC 2.4.1.13, SuSase） activity in the grains was substantially enhanced by NM, with the duration of higher activity being longer than those of the other treatments. At maturing stage, NM significantly increased the filled grain number, the seed-setting rate, and the grain weight compared with NL and NH. The results suggest that NM have a positive effect on the activities of enzymes of physiological importance, thereby increasing the grain size and promoting grain filling.
基金supported by the Strategic Priority Research Program of the CAS(No.XDA05070306)the National Science&Technology Pillar Program in 12th 5-year Plan of China(No.2011BAC09B0402)
文摘We investigated non-structural carbohydrates（NSC） levels and components（starch,glucose,fructose and sucrose） in the leaves of three typical co-occurring forestfloor plants,moss Eurhynchium savatieri（ES）,fern Parathelypteris nipponica（PN） and forb Aruncus sylvester（AS） in a 30-year-old Chinese pine（Pinus tabulaeformis）plantation forest on the eastern Tibetan Plateau.We also explored their responses to three gap creation treatments（control and two gap creations of 80 and 110 m2） based on NSC levels.PN had the highest leaf NSC level of the three plants,with AS second and ES lowest.Starch was the predominant component of NSC and the contents of glucose were higher than those of fructose or sucrose for all three species.The NSC level of ES in intermediate gaps was significantly higher than at control sites.PN also had higher NSC levels in both small and intermediate gaps than in control sites.But the differences between treatments were not obvious for AS.Our results suggest that ES and PN benefit from gap formation while the two species have different NSC response sensitivities to gap size,but the leaf NSC level of AS is less sensitive to the disturbance.
文摘为了探究长期干旱胁迫下连翘不同器官的非结构性碳水化合物(NSC)含量与水力特性的协调及响应机制。以连续3年不同水分条件处理后的连翘幼苗为研究对象,设置3个水分处理(适宜供水、中度干旱胁迫和重度干旱胁迫),研究长期干旱胁迫后连翘幼苗的光合特性、生物量的分配、NSC各组分含量、水力特性的变化及其碳水两者之间的相关关系。结果表明:(1)适宜供水、中度干旱、重度干旱胁迫下,枝条的栓塞程度分别为30.7%、41.8%和42.3%,枝条导水率分别为0.95、0.71、0.65 kg m^(-1)s-1MPa^(-1)。(2)重度干旱胁迫显著降低了净光合速率、蒸腾速率、气孔导度、水分利用效率。(3)重度干旱胁迫导致地上和粗根生物量显著降低,细根生物量和根冠比显著增加。此外,各器官的NSC含量显著降低,其根系NSC消耗量最高,根系的可溶性总糖和淀粉含量显著降低,枝条的可溶性总糖、葡萄糖和蔗糖含量增加了12.9%、31.1%和45.7%,而淀粉含量降低了40.7%。(4)枝条栓塞程度和导水率与可溶性总糖、淀粉、蔗糖和葡萄糖含量显著相关,其栓塞程度与可溶性总糖、葡萄糖和蔗糖呈正相关,而与淀粉呈负相关(P<0.01)。综上所述,干旱导致连翘枝条木质部的栓塞程度增加,导水率、光合作用和水分运输效率均显著降低,但连翘通过提高枝条内可溶性总糖、葡萄糖、蔗糖含量和降低淀粉、NSC含量以提高植物在干旱条件下的存活机率及旱后水分恢复能力,研究为半干旱区连翘培育和经营提供理论依据。
文摘以国家植物园中水杉(Metasequoia glyptostroboides Hu et Cheng)为研究对象,对比根部淹水和非淹水生境中水杉的叶片形态特征、化学计量特征、气体交换参数及非结构性糖类的差异,分析水杉对2种生境的适应策略。结果表明:水杉根部淹水和非淹水生境土壤含水量差异显著(P<0.05),土壤化学计量特征中除C/N比外均具有显著差异。根部淹水生境水杉叶面积和比叶面积均显著大于根部非淹水生境,但叶干物质含量显著低于非淹水生境,这主要通过叶长的增加实现。同一径级内,根部淹水生境仅Ⅰ〔20 cm≤胸径(DBH)<30 cm〕径级水杉叶片净光合速率显著高于非淹水生境;3个径级水杉叶片胞间CO_(2)浓度在2种生境间无显著差异;气孔导度和蒸腾速率在2种生境间均存在显著差异,且除Ⅰ径级的蒸腾速率外均为根部淹水生境显著高于根部非淹水生境。同一生境内,水杉叶片净光合速率、气孔导度和蒸腾速率随着径级的增大呈上升趋势,而胞间CO_(2)浓度的变化趋势相反。同一径级内,根部淹水生境水杉叶片有机碳、全氮和全磷含量均高于根部非淹水生境,且除有机碳含量外均存在显著差异;根部淹水生境水杉叶片N/P比、C/N比和C/P比总体小于根部非淹水生境,其中,Ⅰ径级水杉叶片N/P比和C/N比在2种生境间差异显著,Ⅰ和Ⅱ(30 cm≤DBH<40 cm)径级水杉叶片C/P比在2种生境间差异显著。根部淹水生境水杉叶片非结构性糖类含量显著高于非淹水生境,主要表现为可溶性糖含量的升高。综上所述,水杉对淹水胁迫具有良好的适应能力,能够通过改变叶片形态、可溶性糖含量及气孔开放程度来保证正常的生命活动,在今后的迁地保护过程中可通过增加土壤含水量和光照帮助水杉适应环境的变化。
