不同水稻品种在不同光照条件下的光合特性及干物质积累

对12个杂交水稻品种在两类生态条件下的光合特性及干物质积累进行了研究.结果表明：水稻适应环境的能力主要由其自身因素决定,品种之间存在较大差异.品种间的净光合速率和叶绿素含量差异均比生态区域间的差异更显著.产量与总干物质量和净光合速率呈显著正相关,决定系数R2分别为0.584和0.590,与茎鞘物质输出率和茎鞘物质转换率相关不显著.与低光强地区相比,高光强地区叶片厚度和干物质积累量增加,茎鞘物质输出率和茎鞘物质转换率降低.在光照充足的条件下,产量中来自于后期光合积累物质的比例较大;在光照不足的条件下,产量中来自于前期干物质积累及其转运的比例较大.     

化学杂交剂对灌浆期小麦源流库的影响

以大穗小麦品种SN05-3和多穗小麦SN02-3为试验材料,研究了化学杂交剂BAU-9403对灌浆期小麦库、源、流的影响.结果表明,BAU-9403诱导的小麦雄性不育率大于95%,异交结实率高于92.5%;BAU-9403能够显著降低旗叶叶绿素含量和提高其净光合速率;喷药处理的干物质日生产量,茎、叶、鞘的干物质转移量及其输出率和转换率均下降;喷药处理籽粒饱满度平均减少0.222,平均灌浆速率降低0.306g/1000 grains·d-1,灌浆持续期平均缩短6.03d.BAU-9403处理的SN05-3净光合速率增加幅度、叶绿素含量及茎中干物质转移量、输出率和转换率下降幅度均高于SN02-3,而叶中干物质转移量下降幅度和鞘中的干物质输出率却低于SN02-3;SN05-3的灌浆持续期缩短幅度明显大于SN02-3,而其灌浆速率下降的程度小于SN02-3.综合分析表明,BAU-9403能够影响灌浆期小麦的光合生理特性,破坏库、源之间的平衡关系,使干物质积累和转运不畅,导致粒重下降,且品种间的反应存在差异.     

不同播期和抽穗期弱光胁迫对杂交稻生理性状及产量的影响

以耐阴性中等的杂交稻川香9838为材料,研究不同播期和抽穗期弱光胁迫对杂交稻抽穗期光合特征、渗透调节物质、保护性酶活性和产量的影响.结果表明:不同播期和抽穗期弱光胁迫对水稻抽穗期干物质积累、剑叶光合速率、抗氧化酶活性和产量均有显著影响.随播期的推迟,全生育期明显缩短,稻谷产量呈不同程度的下降趋势.与对照相比,抽穗期轻度弱光胁迫(遮光20％)能缓解水稻生育过程中面临的高温及强光照危害,进而能缓解剑叶光合速率和抽穗期干物质累积的降低,调节抗氧化酶活性,适度提高结实率;而抽穗期中度(遮光40％)、重度(遮光60％)弱光胁迫均不利于水稻生长.剑叶光合速率、丙二醛含量和超氧化物歧化酶活性对播期和抽穗期弱光胁迫较为敏感.水稻始穗1 ～5d剑叶光合速率与稻谷产量和抽穗后干物质积累量显著相关.     

不同生态环境下水稻基因型产量形成与源库特性的比较研究

以日本和IRRI的9个水稻品种为材料,分别以武香粳9号和两优培九为对照,在江苏南京和云南丽江研究了不同水稻基因型干物质积累与源库形成特征及其在不同生态环境下的差异.结果表明,生态环境对水稻产量和干物质积累量影响显著.高产水稻品种积累了高额干物质量,且干物质生产优势在中后期.高产品种的总颖花量、LAI及群体生长速率(CGR)都较高.稻谷产量随干物质积累总量的增加而提高,与齐穗后干物质积累量、总颖花量和LAI呈极显著正相关,与粒叶比呈显著正相关.与云南丽江点相比,群体LAI、单位面积颖花量和抽穗后干物质积累量少及生长速率(CGR)低是南京点稻谷产量低的关键因素.     

不同混交比例对杉木和大叶榉幼苗功能性状的影响

了解林木功能性状在不同培育模式下的变异和关联,对揭示林木生态适应性及其生态功能具有重要意义。选取了亚热带地区两种常见人工林树种杉木、大叶榉幼苗为研究对象,设置4种不同栽培模式的盆栽试验：单一杉木（4C）,单一大叶榉（4Z）和杉木、大榉树3种混栽模式（1C3Z、2C2Z、3C1Z）,研究不同混交比例对其叶、茎、根功能性状的影响。结果表明：（1）杉木总叶面积、叶干物质含量、净光合速率、蒸腾速率和气孔导度在混栽模式下显著减小,而比叶面积显著增大;根长和比根长在不同处理间无显著差异;叶、茎、根生物量和单株总生物量在混栽模式下显著低于4C处理,不同混栽模式之间差异不显著。（2）大叶榉单叶面积在3C1Z处理下最高,总叶面积随大叶榉在树种组成中所占比例的降低而逐渐增大,比叶面积在不同处理间无显著差异,叶干物质含量、净光合速率、蒸腾速率和气孔导度均在2C2Z处理下最大,而瞬时水分利用效率在2C2Z处理下最小;根长在3C1Z处理下显著增大,比根长在不同处理间无显著差异;叶、茎、根生物量和单株总生物量随大叶榉在树种组成中所占比例的降低而逐渐增大。综合来看,杉木和大叶榉混合处理中杉木种间竞争大于种内竞争,而大叶榉相反;随杉木在混栽处理中比例减少,其主要通过增加比叶面积,提高净光合速率,减少茎生物量积累来适应种间竞争关系;而大叶榉随其在混栽处理中比例的减少,显著增加叶面积和根长来提高资源利用率,减少地下资源分配,提高地上茎生物量积累。因此,树种混交比例将显著影响林木功能性状及其生物量积累,选择适宜混交比例对混交林可持续经营具有重要意义。     

不同密度混播对玉米植株13C同化物分配和产量的影响

为了探讨不同密度混播对玉米植株¹³C同化物分配和产量的影响,选用‘郑单958’(ZD)和‘登海605’(DH)为试验材料,在不同密度下(LD,67500株·hm^-2;HD,97500株·hm^-2)设置单播(SZD、SDH)与混播(M、1∶1、2∶2)处理,研究玉米品种不同密度混播对植株光合特性、¹³C同化物分配、干物质积累量和产量的影响.结果表明: 随密度增加,籽粒产量、¹³C同化物在籽粒中的分配、干物质积累量和叶面积指数均提高;而叶绿素含量和净光合速率则降低.在67500株·hm^-2下,混播较单播处理无显著优势,但在97500株·hm^-2下,两品种混播提高了叶面积指数、叶绿素含量和穂位叶净光合速率,干物质积累量增加.混播促进茎等营养器官的干物质向籽粒的转运,提高了¹³C同化物在籽粒中的分配比例.混播处理较单播产量增加,主要因为千粒重显著增加.在高密度种植条件下,混播有助于扩大光合面积,维持较高的净光合速率,提高群体干物质积累量,改善干物质的分配状况,增加同化物向籽粒的分配,最终提高夏玉米产量.可见,混播栽培可显著增加黄淮海区密植夏玉米产量.     

不同密度混播对玉米植株13C同化物分配和产量的影响

为了探讨不同密度混播对玉米植株¹³C同化物分配和产量的影响,选用‘郑单958’(ZD)和‘登海605’(DH)为试验材料,在不同密度下(LD,67500株·hm^-2;HD,97500株·hm^-2)设置单播(SZD、SDH)与混播(M、1∶1、2∶2)处理,研究玉米品种不同密度混播对植株光合特性、¹³C同化物分配、干物质积累量和产量的影响.结果表明: 随密度增加,籽粒产量、¹³C同化物在籽粒中的分配、干物质积累量和叶面积指数均提高;而叶绿素含量和净光合速率则降低.在67500株·hm^-2下,混播较单播处理无显著优势,但在97500株·hm^-2下,两品种混播提高了叶面积指数、叶绿素含量和穂位叶净光合速率,干物质积累量增加.混播促进茎等营养器官的干物质向籽粒的转运,提高了¹³C同化物在籽粒中的分配比例.混播处理较单播产量增加,主要因为千粒重显著增加.在高密度种植条件下,混播有助于扩大光合面积,维持较高的净光合速率,提高群体干物质积累量,改善干物质的分配状况,增加同化物向籽粒的分配,最终提高夏玉米产量.可见,混播栽培可显著增加黄淮海区密植夏玉米产量.     

开放式空气CO2增高对水稻物质生产与分配的影响

在大田栽培条件下,研究开放式空气CO2增加(FACE)200μmol·mol^-1的处理对水稻物质生产与分配的影响．结果表明,FACE处理使移栽至抽穗后20d的干物质积累量显著增加,使抽穗后20d至成熟期的干物质生产量显著减少,生物产量显著提高．移栽至抽穗期的干物质积累量增加是由于叶面积系数和净同化率共同提高所致;抽穗期至抽穗后20d的干物质积累量增加主要是由于叶面积系数的增加所致;抽穗后20d至成熟期的干物质生产量减少主要是由于净同化率的下降所造成．提高茎鞘占全株干物重的比例,降低叶片占全株干物重的比例,对穗占全株干物重的比例无显著影响,能显著提高水稻抽穗期茎鞘中可溶性糖、淀粉的含有率和含量,提高FACE处理的生物产量能极显著提高水稻产量(r＝0．7825)．     

不同水稻品种产量形成过程的能量积累与热值特征

通过测定晚季稻汕优63 (三系杂交稻)、两优2186（两系杂交稻）和IR64（常规稻）生长过程中的干物质和热值,研究了不同水稻品种生长过程中的热值动态和能量固定特征.结果表明,完熟期汕优63、两优2186和IR64 3种水稻的干物质积累量分别为1926.38、1933.80和1842.30 g·m^-2,能量积累量分别为31137.05、31060.63和30454.89 kJ·m^-2,不同水稻品种的干物质及能量积累量间无显著差异.在灌浆过程中,汕优63、两优2186和IR64总的能量表观转化率分别为38.95%、 28.38%和32.66%,汕优63和IR64的能量流动比两优2186顺畅,两优2186茎器官能量输出受阻.完熟期3种水稻分配到籽粒中的能量依次占53.03%、46.43%和50.11%,三系杂交稻汕优63具有能量分配优势.热值分析表明,3种水稻各生育期间的热值平均值间无显著差异;不同器官热值大小依次为：叶＞籽粒＞鞘＞茎＞根,热值范围为：叶16.81～17.25 kJ·g^-1,籽粒15.89～16.54 kJ·g^-1,鞘14.33～15.49 kJ·g^-1,茎14.23～15.15 kJ·g^-1,根11.51～13.25 kJ·g^-1,叶片的热值显著高于其它器官,而根的热值显著低于其它器官.水稻叶片热值与其碳含量、叶绿素a含量、氮含量存在显著正相关,确定系数R²分别为0.609、0.471和0.485.     

不同水分管理下优质稻花后植株碳氮流转与籽粒生长及品质的相关性

以桂华占、八桂香为材料,在干湿交替灌溉、亏缺灌溉、淹水灌溉3种水分条件下,研究优质稻花后植株碳氮流转与籽粒生长及品质的相关性。结果表明:不同水分管理下,桂华占和八桂香花后碳氮流转与籽粒的生长间存在密切相关。主要表现在:(1)茎鞘和叶片干物质转运对籽粒干物质积累的贡献率为16.86%～25.68%,花后茎叶干物质运转速度和运转率与籽粒起始灌浆势呈显著甚至极显著正相关;籽粒最大灌浆速率、活跃灌浆期、持续灌浆时间与叶片干物质运转速度和运转率呈极显著正相关,与茎鞘干物质运转速度和运转率呈极显著负相关;(2)茎鞘碳同化物转运对籽粒的产量和淀粉产量的贡献率则为干湿交替灌溉>亏缺灌溉>淹水灌溉;但叶片碳同化物转运对籽粒的产量和淀粉产量的贡献率则为淹水灌溉>亏缺灌溉>干湿交替灌溉;茎叶可溶性糖积累量的减少和籽粒直链淀粉含量和积累量增加是同步的,且茎叶可溶性糖积累量快速递减期(花后3～12d)与直链淀粉含量和积累量快速递增期(花后6～12d)同步;(3)茎鞘和叶片氮素转运对籽粒氮素积累的贡献率为44.05%～117.66%,叶片总氮转运对籽粒氮素积累的贡献率大于茎鞘,茎鞘和叶片氮同化物对籽粒氮素的贡献率以淹水灌溉处理的最大,亏缺灌溉处理的次之,干湿交替灌溉处理的最小。     

不同供镁水平对两菊芋品种幼苗生物量、光合和叶绿素荧光特性的影响

采用砂培方式研究了不同供镁水平对"南芋1号(Nanyu No.1)"和"青芋2号(Qingyu No.2)"幼苗生物量、光合特性和叶绿素荧光特性的影响。结果表明:缺镁使菊芋叶片叶绿素含量显著降低,干物质积累减少,净光合速率、蒸腾速率和光合电子传递速率显著下降、CO2同化受抑制,同时Fv/Fm、ΦPSII、qP和qN也显著下降,加重了叶片受到光抑制的程度;随着供镁水平的增加,菊芋的干物质积累,叶绿素含量,光合参数和各系列荧光参数均呈现先增加后降低的趋势;南芋1号和青芋2号在镁离子浓度分别为3和6mmol.L-1,叶片的净光合速率、Fo、Fm、Fo’、Fm’、Fv/Fm、ΦPSII、ETR达到最高值,叶绿素a、b及总叶绿素含量也最多,干物质积累量最大;南芋1号的各系列荧光参数、光合参数、叶绿素含量和干物质积累量均显著高于青芋2号。     

分期施氮与CO2浓度升高对小麦光合及其物质积累和产量的互作效应

采用开顶式气室和盆栽方法,以冬小麦品种‘小偃22’为材料,探讨了分期施氮与CO2浓度升高对小麦抽穗期和灌浆中期旗叶光合、地上部物质积累和产量的互作效应.结果显示:(1)不施氮条件下CO2浓度升高对小麦旗叶叶绿素含量(SPAD)和可溶性蛋白含量、光合能力、地上部花后干物质和氮素累积量、籽粒产量的影响不明显(P>0.05)或产生显著负效应;在施氮(300mg/kg土)条件下各指标均不同程度增加,且大多数达到显著水平.(2)与氮肥全部基施相比,分期施氮时CO2浓度升高使灌浆期旗叶光合能力、地上部花后干物质和氮素累积以及产量增加的幅度较大,其中以播前、返青期和孕穗期施氮比例为5∶3∶2时最明显.研究表明,适当分期施氮可能更有利于发挥CO2浓度升高对冬小麦的增产作用.     

花后干旱或渍水下氮素供应对小麦光合和籽粒淀粉积累的影响

防雨池栽条件下,设置渍水、干旱和对照3个土壤水分处理,每水分处理下再设置两个施氮水平,研究了花后渍水和干旱逆境下氮素水平对两个蛋白质含量不同的小麦品种光合特性和籽粒淀粉积累的影响.结果表明,与对照相比,花后渍水和干旱处理显著降低小麦旗叶净光合速率和SPAD值,干物质积累量下降.干旱处理下,增施氮肥提高旗叶光合速率和SPAD值,渍水处理下则相反.水分逆境明显降低籽粒可溶性总糖含量,且渍水处理下增施氮肥降低小麦叶片和籽粒可溶性总糖含量,干旱状态下规律相反.渍水处理下增施氮肥降低淀粉积累速率.水分逆境明显降低小麦粒重、产量和淀粉产量,且干旱处理下增施氮肥有利于籽粒重、产量和淀粉产量的提高,而渍水下增施氮肥使粒重和产量进一步降低.试验结果表明,花后渍水和干旱逆境下施用氮肥对小麦旗叶光合速率和籽粒淀粉积累有明显的调节效应.     

Relationship between leaf photosynthetic function at grain filling stage and yield in super high-yielding hybrid rice (Oryza sativa. L)

The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO2 assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in     

不同产量水平旱地冬小麦品种干物质累积和转移的差异分析

旱地小麦高产栽培中品种起着重要作用,研究不同产量水平旱地冬小麦品种干物质累积和转移的差异,对黄土高原旱区作物高产稳产有重要意义。以9个旱地冬小麦品种为材料,通过田间试验研究了不同产量水平旱地冬小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率、叶面积、SPAD值以及光合速率的差异。结果表明,不同小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率均存在明显差异。与不施肥相比,高、中、低3个产量水平小麦品种在低养分投入时,成熟期生物量分别提高29%,22%和6%,高水平时分别提高46%,39%和23%,高产品种的生物量及其对养分投入的敏感程度明显高于低产品种。不同品种的花后干物质累积量随养分投入水平提高而增加,但花前营养器官中储存物质的转移量、转移率和对籽粒的贡献率却明显随之下降。功能叶(旗叶)在灌浆期高、中、低3个产量水平品种的SPAD值在低养分投入条件下分别为20.7、17.5和13.7;高养分投入时,分别为35、26.1和16.8。高产品种西农88的光合速率为6.0μmolCO.2m-.2s-1),中产和低产品种的平均光合速率分别为4.3μmolCO.2m-.2s-1和4.0μmolCO.2m-.2s-1,高产品种功能叶(旗叶)在灌浆期能保持较高的SPAD值和光合速率,因而花后能生产较多的干物质,但其花前干物质转移量、转移率及转移干物质对籽粒的贡献率均没有明显优势。可见,花后较高的叶绿素水平、光合速率和干物质累积是旱地小麦品种高产的重要原因。选择优良品种,采取合理的栽培措施,特别是通过养分调控保持花后具较高的干物质累积量是西北旱地进一步提高冬小麦产量的重要途径。     

云锦杜鹃叶片光合作用日变化特征

自然条件下, 对云锦杜鹃光合作用日进程和光响应进行了观测, 结果表明:夏季晴天云锦杜鹃阳叶净光合速率日进程曲线为"双峰"型, 光合效率午间明显降低。胞间CO₂ 浓度的日进程基本与净光合速率相反, 中午胞间CO₂ 浓度增高表明净光合速率午间降低主要受非气孔限制因素的影响。暗呼吸速率日进程呈单峰曲线, 中午最高。阴叶净光合速率在一天的大部分时间里变化不大。一天分时段光响应试验表明, 阳叶饱和光强和表观量子效率上午较高, 下午有所降低, 而光补偿点下午有所上升。阴叶的这些光合参数在上午和下午没有明显的变化。这些研究结果表明, 强光下光抑制的发生是引起云锦杜鹃阳叶光合效率午间降低的重要原因。逐步多元回归和通径分析表明, 光合有效辐射和空气温度是直接影响净光合速率日变化的主要因子。     

Physiological Causes of Differences in Grain Yield between Varieties of Barley

In a field experiment on barley at Rothamsted with the highmean yield of 49 cwt. of grain per acre, the varieties Proctorand Herta produced 10—15 per cent, more grain than Plumage-Archeron plots that received no nitrogenous fertilizer. When nitrogenwas applied the difference was increased to about 30 per cent.,because the higher nitrogen supply caused the Plumage-Archercrop to lodge and did not increase its yield, while Proctorand Herta remained standing. The three varieties did not differ in leaf-area index nor innet assimilation rate before ear emergence, so that all hadthe same total dry weight. After ear emergence, the leaf-areaindices of Proctor and Plumage-Archer were nearly equal, butthat of Herta was smaller. Assuming that the photosyntheticefficiency of the leaves continued to be the same in all varieties,the higher grain yields of Proctor and Herta cannot be attributedto greater production of dry matter by the leaves, either beforeor after ear emergence. A pot experiment on plants with shadedears confirmed that the dry matter contributed to grain yieldby unit leaf area was nearly equal in all the varieties. The higher grain yield of Proctor and Herta than of Plumage-Archermust therefore have come from additional photosynthesis in partsof the plant other than the leaves, i.e. in the ears themselves.An attempt to demonstrate this directly in a pot experiment,by comparing the grain yields of plants with shaded or withunshaded ears, was unsuccessful because the varieties behaveddifferently in pots; Proctor and Herta produced only about 6per cent, more grain yield than Plumage-Archer, and though thedecrease in grain yield by shading the ears was slightly greaterfor Proctor and Herta, the differences were not significant. The sum of ear sizes (estimated from length and breadth measurements)per m.1 in the field experiment was greater for Proctor andHerta than for Plumage-Archer. Also the distribution of drymatter between developing ears and shoots apparently differedwith variety, so that at ear emergence the dry weight of earsper m.² was greater in the two higher yielding varieties. Theincreased amount of photosynthetic tissue in the ears of Proctorand Herta, as measured by size or weight, may not wholly explaintheir greater dry-matter production; ears of Herta may alsohave a higher photosynthetic efficiency. No differences in nutrient uptake that could account for thevarietal differences in grain yield were found. Plumage-Archerabsorbed more potassium, and Herta less phosphorus than theother varieties. About a quarter of the final content of nitrogen,and a third of the phosphorus, was absorbed after ear emergence,but the potassium content was nearly maximal at ear emergenceand later decreased. The pot experiment showed that, on the average of all varieties,26 per cent. of the dry matter in the grain at harvest originatedfrom photosynthesis in the ears, including 10 per cent, fromthe awns; 59 per cent, came from photosynthesis in the flag-leaflamina and sheath and peduncle, and 15 per cent, from partsof the shoot below the flag leaf.     

Nitrogen fertiliser rate and post-anthesis waterlogging effects on carbohydrate and nitrogen dynamics in wheat

Waterlogging is predicted to increase in both magnitude and frequency along with global warming, and will become one of the most severe adversities for crop production in many regions. Nitrogen is considered to be an effective up-regulatory nutrient for crops grown under stress and non-stress conditions. In this study, we try to evaluate N fertiliser effects on contents of carbohydrate and N dynamics, dry matter accumulation in shoot, yield under post-anthesis waterlogging. Waterlogging after anthesis significantly reduced grain yield due to decrease in thousand-kernel-weight and in grain number per spike. High N fertiliser application aggravated grain yield loss due to post-anthesis waterlogging. These yield losses were related to the decreases in dry matter accumulation, redistribution of stored photosynthate to the grain, and the conversion capacity from carbohydrate to starch in grain. The decrease in dry matter accumulation could be attributed to the reduced activities of Pn (photosynthesis) and SPS (sucrose phosphate synthase) in the flag leaf, while the low capacity in starch synthesis could be explained by the reduced activities of sucrose synthase (SS) and soluble starch synthase (SSS) in grain. Total N uptake in shoot was also reduced, which could contribute to the losses in biomass and yield by waterlogging. The decrease in Pn was inconsistent with the increase in N content in the flag leaf at high N fertiliser application under post-anthesis waterlogging.