Correlation of Leaf Nitrogen,Chlorophyll and Rubisco Contents with Photosynthesis in a Supernodulating Soybean Genotype Sakukei 4

Abstract

Soybean requires more nitrogen (N) than gramineous crops because it accumulates a large amount of N in seeds, and its photosynthetic rate per leaf N is low. The supernodulating genotype Sakukei 4 has a superior symbiotic N₂ fixation capability, and thereby is potentially high-yielding. In our previous study, Sakukei 4 was characterized by having a superior ability to maintain high leaf N content and high photosynthetic rate. The objectives of this study were to know photosynthetic characteristics of Sakukei 4 in detail, especially, the responses to CO₂ concentration and light intensity, and to elucidate how the photosynthetic characteristics of Sakukei 4 are associated with the amounts of photosynthesis-related N compounds (chlorophyll and Rubisco). The three genotypes (Sakukei 4 - supernodulating cultivar derived from Enrei, Enrei - normally nodulating cultivar, En1282-non-nodulating line derived from Enrei) were grown at various N levels in this study. The CO₂ exchange rate (CER) in Sakukei 4 was higher than, or equal to that in Enrei at wide ranges of CO₂ concentrations (150-700 μmol mol-¹) and light intensities (200-1,500 μmol m-² s-¹ PPFD). Sakukei 4 had higher leaf N (N_l), chlorophyll (Chl_L) and Rubisco (Rub_L) contents per leaf area, but lower chlorophyll and Rubisco contents per leaf N content (Chl_L/N_l, Rub_L/N_l) than Enrei. The specific leaf weight (SLW) and leaf area trended to be lower in Sakukei 4 than in Enrei. These results indicate that the superior photosynthetic rate in Sakukei 4 is attributed to higher total N, chlorophyll and Rubisco contents per leaf area, but not to high rate of allocation of total N to these N compounds.     

Nitrogen Utilization in the Supernodulating Soybean Variety “Sakukei 4” and Its Parental Varieties,“Enrei” and “Tamahomare”

Abstract

The supernodulating variety “Sakukei 4”, which has improved growth and yield, was recently developed. To evaluate its physiological traits related to the high productivity, we compared dry matter production, nitrogen (N) accumulation and N utilization in Sakukei 4 with those in the parental normally nodulating varieties, Enrei and Tamahomare, and a nonnodulating line, En1282, in pot experiments. The seed yield of Sakukei 4 was similar to that of Enrei and Tamahomare.Leaf area and relative ureide abundance in xylem sap were maintained for longer growth period in Sakukei 4 and Tamahomare than in Enrei. The total amount of nodule N₂fixation at maturity was also larger in Sakukei 4 andTamahomare than in Enrei and En1282. In En1282 and Enrei, a larger part of N accumulated in leaves and stems before seed maturation was translocated to seeds during seed filling. However, Sakukei 4 and Tamahomare, more N tended to remain in leaves and stems at maturity. These observations suggested that the physiological traits of dry-matter accumulation and N utilization in Sakukei 4 were quite similar to those in Tamahomare, despite the difference in nodulation. N use efficiency for dry matter production (NUED) was lower in Sakukei 4 than in Enrei and Tamahomare, probably due to the energy cost for sustaining a greater number and mass of nodules. This observation indicated that the low NUED of Sakukei 4 impairs its productivity and seed yield, and therefore Sakukei 4 could not exceed Enrei or Tamahomare in seed productivity.     

Characteristics of Nodulation and Nitrogen Fixation in the Improved Supernodulating Soybean (Glycine max L. Merr.) Cultivar ‘Sakukei 4’

Abstract

Supernodulating soybean lines have more than several times as many nodules as normal cultivars. They are expected to have high nitrogen-fixing ability and enhanced productivity, but their yields have been inferior to those of normal genotypes. We have recently developed a new supernodulating cultivar,‘Sakukei 4’(formerly ‘En-b0-1-2’, presently‘Kanto 100’), with improved growth and yield. The objective of the present study was to identify the characteristics of the nodulation and nitrogen-fixing ability of Sakukei 4. In pot trials, the nodule number of Sakukei 4 was 8.3 times that of a normal cultivar,‘Enrei’, and the nodule weight per plant was 2.3 to 2.8 times the value for Enrei. The acetylene reduction activity per plant in Sakukei 4 was higher than that in Enrei and conventional supernodulating genotypes, especially during the late growth stage. Compared with conventional supernodulating lines, the improved vegetative growth in shoots and roots of Sakukei 4, especially after flowering, probably enhanced its nitrogen-fixing ability per plant. We consider that its high nitrogen-fixing ability at the seed-filling stage, would help increase its yield in fields with low nitrogen fertility.     

Effects of Waterlogging on Nitrogen Fixation and Photosynthesis in Supernodulating Soybean Cultivar Kanto 100

Abstract

The supernodulating soybean (Glycine max (L.) Merr.) cultivar Kanto 100 was previously characterized by superior nitrogen (N) fixation and photosynthesis, and resulting in high yields. However, this cultivar seems to be susceptible to waterlogging during the vegetative growth stage, which frequently occurs in major soybean producing areas in East Asia. The objective of this study was to compare the effects of waterlogging on nodulation, N fixation and photosynthesis in Kanto 100 with those in its normally-nodulating ancestral cultivar Enrei. Kanto 100 and Enrei were grown in pots, and subjected to waterlogging for 10 days at three vegetative growth stages in 2003 and 2004. Waterlogging significantly reduced the number of nodules of both cultivars, but the magnitude of the reduction was more pronounced in Kanto 100. The acetylene reduction activity (ARA) of nodules and apparent photosynthetic rate (AP) of leaves were generally depressed immediately after the start of waterlogging, but both functions recovered substantially at the pod-filling stage in both cultivars. No marked cultivar difference was found in the magnitude of the reduction of ARA per plant and AP measured immediately after waterlogging and at the pod-filling stage in both years, but growth impairment was more pronounced in Kanto 100 in 2003. These results suggest that the supernodulating cultivar Kanto 100 is more susceptible to waterlogging than its normally-nodulating ancestral cultivar.     

Effect of Waterlogging During Vegetative Stage On Growth And Yield in Supernodulating Soybean Cultivar Sakukei 4

Abstract

The Supernodulating Soybean Cultivar Sakukei 4 Was Previously Characterized By Its Superior Capabilities of Nitrogen (N) Fixation and Photosynthesis, and Was Expected To Be High Yielding. Since The N Absorption By Sakukei 4 Is Largely Dependent On N Fixation, It May Be Strongly Affected By Waterlogging During The Vegetative Stage, Which Occurs Frequently in Major Soybean Producing Areas. in This Study, We investigated The Reduced Growth and Yield Resulting From Waterlogging DuringVegetative Stage and The Subsequent Recovery in Sakukei 4, in Comparison With Those in The Normally-Nodulating Cultivar Enrei and Non-Nodulating Genotype En1282. Under The Field Conditions, The Reduction of Growth and Yield By Waterlogging Was Greatest in En1282 Among The Three Genotypes, indicating That Capability of N Fixation Is Essential For The Recovery From Waterlogging-induced injury. The Waterlogging-induced Yield Reduction in Sakukei 4 Resembled That in Enrei, Although Growth Reduction Was Greater in Sakukei 4 Than in Enrei. Irrespective of Cultivar, The Yield Was Associated More Closely With The Crop Growth Rate (Cgr) During The Post-Treatment Stage Than With That During The Waterlogging Treatment. in The Pot Experiments, Yields Positively Correlated With Both Above- and Underground Plant Parts Irrespective of Cultivar, Not Significantly, But Significantly With Root Dry Weights in Enrei and With Nodule Dry Weights in Sakukei 4. These Results indicate That Sakukei 4 Exhibits A Marked Decrease in Dry Matter Production By Waterlogging, But Yield Decrease Is Compensated To A Level Similar To That of Enrei Because of Its Enhanced Nodule Growth During The Recovery Stage.     

Varietal Difference in Early Vegetative Growth during Seedling Stage in Soybean

Abstract

Rapid development after emergence is important for seedling establishment and early vegetative growth, especially at a low planting density or inferior environmental conditions. This study was conducted to understand the varietal difference in the growth parameters during the seedling stage in soybean. Twenty-seven soybean varieties originating from six countries were examined in 2009 and 2010. The pots were arranged in a completely random block design with 5 replications (10 pots per variety), and the seedlings were sampled at 14 and 28 days after sowing (DAS). The shoot dry weight at 14 and 28 DAS was highly correlated with seed size, cotyledon digestion, and leaf area. However, no positive correlation was found between shoot dry weight and photosynthetic rate at 28 DAS. Chamame, a Japanese cultivar, with the largest seed size grew rapidly, and showed the heaviest shoot dry weight, greatest cotyledon digestion, fast leaf expansion and high photosynthetic rate. However, Moyashimame, a medium-seed-size cultivar, also grew rapidly with a high photosynthetic rate. Some varieties such as Tachinagaha (Japan), Hefeng (China), Parana and Pérola (Brazil), had a large or medium seed size, and high photosynthetic rate but showed a relatively small leaf area and light shoot dry weight. These results suggested that big seeds with rapid cotyledon digestion developed a wider leaf area and therefore large dry matter production, indicating that the conversion of stored energy was more important than the leaf photosynthetic activity for early growth.     

半干旱区保护性耕作对旱作春小麦光合特性和产量形成的影响

为探究黄土高原半干旱区保护性耕作提高春小麦产量的光合生理机制,依托黄土高原半干旱区2001年建立的不同耕作措施长期定位试验,于2019年研究了传统耕作(T)、传统耕作秸秆翻入(TS)、免耕秸秆不覆盖(NT)、免耕秸秆覆盖(NTS)四种耕作措施对春小麦叶片光合相关性状、干物质积累和产量的影响。结果表明,小麦叶片叶绿素含量和叶面积指数在抽穗期达到峰值,保护性耕作延缓了花后叶片衰老,其中NTS处理的叶片叶绿素含量和叶面积指数在乳熟期均显著高于其他处理;耕作措施对开花期小麦旗叶RuBP羧化酶活性没有影响,但在灌浆期免耕和秸秆还田均提高了RuBP羧化酶活性,其中NTS处理的RuBP羧化酶活性是T处理的1.95倍;秸秆覆盖对小麦旗叶光合速率、蒸腾速率、气孔导度影响显著,NTS处理可有效改善春小麦开花期和灌浆期的光合性能,其中NTS处理的开花期旗叶光合速率、蒸腾速率、气孔导度比T处理分别提高了19.2%、30.7%、23.0%;免耕处理(NT和NTS)下花后干物质积累对籽粒贡献率较耕作处理(T和TS)提高了41.7%,秸秆还田处理(TS和NTS)花后籽粒干物质积累量及花后干物质积累对籽粒产量贡献率较不还田处理(T和NT)分别提高了71.2%和35.7%;NTS处理有效促进了小麦花后干物质积累和转运,显著增加了穗数和千粒重,使产量较T处理提高了18.7%。因此,在黄土高原半干旱区应用免耕秸秆覆盖的保护性耕作措施可促进春小麦旗叶花后光合作用、干物质积累及其向籽粒分配,延缓灌浆后期叶片衰老和叶绿素降解,协调和优化光合性能、光合时间、光合面积之间的关系,从而提高产量。     

陕西省不同年代旱地冬小麦光合与产量特征变化及其相互关系研究

为明确陕西省不同年代旱地冬小麦品种光合特征变化规律及其对产量的影响,选择曾在该省推广种植的20世纪40年代至21世纪初8个不同年代旱地冬小麦品种(蚂蚱麦,1940s;碧蚂1号,1950s;丰产3号,1960s;泰山1号,1970s;小偃6号,1980s;陕229,1990s;长武134,2000s;长旱58,2010s)为材料,设置正常供水和干旱胁迫两个水分处理,进行盆栽种植试验,对小麦不同生育期光合特征进行测定,并在收获期考种测产。结果表明,无论是干旱胁迫还是正常供水处理下,现代小麦品种(长武134和长旱158)花前旗叶净光合速率和单株叶面积都表现出显著优势,并与千粒重和产量呈显著正相关;但品种间花后光合特征差异减小,这对于现代小麦产量的提升可能产生了一定的限制作用;不同生育时期和不同水分处理下,旗叶蒸腾速率与种植年代之间相关性并不一致;干旱胁迫条件下,孕穗期和花后3d的旗叶水分利用效率都随品种更替呈明显上升的趋势;现代小麦品种在干旱处理下旗叶净光合速率等光合特征、千粒重等产量因素的优势受到影响,最终导致其产量增幅下降。未来应进一步提升现代小麦的光合优势,尤其是花前叶片净光合速率及叶面积的优势,并进一步提高千粒重,这将会是陕西省小麦节水高产和抗旱稳产的重要手段。     

大豆光合生理生态的研究——第16报 去荚对大豆比叶重和光合速率的影响

大豆生殖生长时期,去荚植株的比叶重随生育进程增加的幅度较大,但叶片光合速率和全N含量(％)在去荚后短期内低于对照,随后尤其R_7和R_8期则显著高于对照。去荚延缓了叶片衰老,提高鼓粒末期叶片的光合速率和光呼吸速率。 荚果生长在一定时间内确能提高叶片光合速率,鼓粒末期叶片光合速率的明显降低是衰老的主要征状之一。     

水钾耦合对大豆光合特性及其产物积累运转的影响

盆栽条件下,研究了不同生育时期水钾耦合对大豆光合特性及水分利用效率的影响,并对光合速率与各器官干物重进行相关分析。结果表明：苗期与花期控水时,土壤水分及水钾互作极显著影响光合速率（Pn）;结荚期控水时,水分极显著影响Pn。花期与荚期控水后测定的Pn要高于苗期的Pn。水钾耦合对光合速率（Pn）、蒸腾速率（Tr）和气孔导度（Gs）的影响趋势相似,即水分效应要优于钾肥,且一般而言同一钾肥水平下,土壤水分的影响表现为：W4>W3、W5>W2>W1。只有当土壤水分供应适宜（W3）时,钾肥的施用提高了植株的Pn、Tr和Gs。水分对植株水分利用效率（WUE）的影响要优于钾肥,且水分为正效应。苗期及开花期控水条件下,植株的Pn与根、茎、叶干物重呈极显著正相关（p<0.01）,且Pn与各器官的相关程度表现为茎>叶>根;结荚期植株Pn与根、茎、叶干物重仍呈极显著正相关（p<0.01）,与荚粒干物重呈显著正相关（p<0.05）。     

氮高效玉米杂交种的筛选及氮效率相关特性分析

选用生产中常用的8个玉米杂交种作为材料,在高氮和低氮条件下进行氮高效杂交种的筛选和氮高效指标研究。主成分分析结果表明,郑单958、金山27、郑单17为氮高效品种。通径分析表明,吸收效率对氮效率的贡献均大于利用效率,不论是否施氮,植株氮积累均以花前为主,但花后差异显著,花前氮积累对氮效率的贡献较大。不论施氮与否,完熟期全株干重、吐丝期穗三叶含氮量、花前氮积累量、穗位叶光合速率均是重要的筛选指标,不施氮肥时子粒含氮量也是重要的筛选指标。     

不同覆膜方式下超高产春玉米花粒期叶片衰老特性研究

以内单314为试验材料,在行间覆膜(SPF)、行上覆膜(UPF)及不覆膜(NPF)3种处理下,对超高产春玉米花粒期不同层位叶片的保护酶活性、光合特性及产量进行研究。结果表明,超高产春玉米花粒期不同层位叶片POD活性表现为下位叶>穗位叶>上位叶;CAT、SOD活性表现为上位叶>穗位叶>下位叶。灌浆期玉米不同层位叶片净光合速率、气孔导度、蒸腾速率变化趋势表现为穗位叶>上位叶>下位叶;乳熟期不同层位叶片净光合速率、气孔导度、蒸腾速率表现为上位叶>穗位叶>下位叶。表明在玉米花粒期,行间覆膜处理可以提高玉米上位叶及穗位叶的净光合速率、POD活性、CAT活性及SOD活性,减小气孔导度,降低叶片蒸腾速率,延缓叶片衰老,维持花粒期生理功能,保证子粒充分灌浆,提高千粒重,进而提高产量,实现超高产。     

Water relations and growth of the weed,goosegrass (Eleusine indica), under drought stress

The relative sensitivity to water stress at different growth stages of goosegrass (Eleusine indica (L.) Gaertner) was investigated by measuring water status and growth of groups of plants stressed during the vegetative stage, the reproductive stage, and during both stages. Plants were grown from seed in large pots in a controlled-environment chamber at 29/23°C and 14-h photoperiod. In all treatments, decreasing leaf water-potential was correlated with decreasing osmotic and pressure potentials. Plants stressed during the flowering stage maintained greater pressure potentials at any leaf water-potential than plants stressed during vegetative growth or stressed twice. Prestressing the plants did not induce lower leaf osmotic potentials at full turgor. However, dehydration was the main cause of low osmotic potentials measured in the leaves of the plants stressed twice. Stomatal closure occurred over a relatively large range of leaf water-potentials. The sensitivity of stomata to water stress in this species was fairly similar in the two growth stages studied. Leaves of plants stressed during the flowering stage had a smaller decline in total biomass during the stress period, and a higher rate of growth after rewatering, compared to the plants that received a stress during vegetative growth and flowering or were stressed during vegetative growth.     

Influence of Seed Treatment with Uniconazole Powder on Soybean Growth,Photosynthesis, Dry Matter Accumulation after Flowering and Yield in Relay Strip Intercropping System

Abstract

The relay strip intercropping system of wheat-corn-soybean is widely used in southwest China. However, it is hard to produce soybean stably with this system, since the growth of soybean plants is slower under shading by corn at the seedling stage, and it is compensated by accelerated growth after the symbiotic stage. Soybean plants show excessive vegetative growth due to more rain during the flowering stage, which results in fallen petals, fallen pods and lower yield. This study investigated whether seed treatment with uniconazole powder (0, 2, 4 and 8 mg kg^–1 seed) suppresses excessive vegetative growth of soybean plants during the flowering stage and delays senescence of photosynthetically active leaves at the pod-setting stage. If such events are correlated with changes in photosynthesis, they may affect dry matter accumulation and seed yield in the relay stripping system. Uniconazole promoted biomass accumulation from 31 (R₃) to 61 (R₅) days after flowering (DAF) and seed yield. Seed treatment with uniconazole raised the net photosynthetic rate, stomatal conductance, transpiration rate, and total chlorophyll and chlorophyll a contents. In contrast, uniconazole reduced leaf area index (LAI) from 1 DAF (R₁) to 46 DAF (R₄) with the increase in uniconazole concentration, whereas, uniconazole significantly increased LAI at 61 DAF, and the greatest promotion occurred at 2 mg kg^–1 treatment. The study clearly showed that uniconazole effectively suppressed excessive vegetative growth of soybean during flowering stage, delayed senescence of photosynthetically active leaves at pod-setting stage and induced higher yield, which were related to the changes in photosynthetic rate, chlorophyll content, dry matter accumulation and LAI in the relay strip intercropping system.     

不同灌溉模式对杂交水稻生育后期根系生理特性和剑叶光合特性的影响

对杂交水稻组合红莲优6和两优1193在淹水灌溉和湿润灌溉两种灌溉模式下生育后期的根系和光合生理特性进行了比较分析。结果显示,湿润灌溉增大了水稻根系密度,提高了根系活力,相关分析显示根系密度与根系活力呈正相关(r1=0.66, r2=0.68)。齐穗期剑叶叶绿素含量处理间差异不显著,但成熟期湿润灌溉显著高于淹水灌溉,推测湿润灌溉有利于剑叶功能期的延长和光合速率的提高。湿润灌溉条件下,群体生长率和相对生长率均显著高于淹水灌溉,表明湿润灌溉有利于水稻生殖生长期的干物质积累。上述结果可能是湿灌处理条件下水稻单位面积的产量极显著高于淹灌处理的主要原因。     

砂培法模拟磷素营养水平对大豆光合作用和产量的影响

以大豆品种黑农48为试验材料,采用砂培盆栽法,通过在大豆生育期间淋浇不同磷素水平的营养液,研究了施磷素水平对大豆植株光合作用及产量的影响。结果表明:随着大豆的生长CO_2的吸收速率、叶面积、光合速率逐渐增大,CO_2的吸收速率和光合速率基本在R5时期达到最大值,之后趋于逐渐下降的趋势,呈现单峰曲线变化。CO_2的吸收速率、叶面积随着磷素营养水平的增加逐渐增大,但当磷素营养水平达到21 mg·L~(-1)时,再提高磷素水平对其已无明显作用。低磷胁迫(P1处理)大豆生育中前期的光合速率明显降低,低磷胁迫后再供给较高的磷素营养对大豆光合速率有一定的激活效应,使光合速率增大。大豆株高、粒数、节数和产量都随着磷素营养水平的上升呈现逐渐增高的趋势,当磷素营养水平达到21 mg·L~(-1)时,再增加磷素营养对大豆株高和产量已无影响。低磷胁迫后再供给较高的磷素营养水平对大豆产量有一定的恢复作用。在营养生长阶段,如果缺磷极易减产,低磷胁迫时间越长产量越低。     

不同年代大豆品种根系伤流液重量变化及其与叶片光合的关系

以根系伤流液的重量作为根系活力的指标,研究了吉林省1923～2004年育成的22个大豆品种在盛花期(R2),结荚期(R4)和鼓粒期(R6)根系伤流液重量的变化及其与功能叶片净光合速率(Pn)的关系.结果表明:根系伤流液重量与品种的育成年份呈正相关变化,但年度间表现存在差异,2009年没有达到显著水平,2010年在R2、...     

夏大豆植株的光合性能研究

1986—1987年在田间条件下,研究早熟7号和早熟14号大豆植株的光合性能。结果表明:叶片的最高光合速率和平均光合速率,基部叶片>中部叶片>顶部叶片;叶面积、功能期和光合势,均为中上部叶片>顶部叶片>基部叶片。夏大豆植株叶片的平均光合速率,以苗期及开花期较高,随后呈下降趋势,鼓粒后期下降尤其明显。单株光合速率及叶面积随着生育进程呈单峰曲线变化,以结荚期最高。     

Reduction of Phosphatic and Potash Fertilizer in Sweet Corn Production by Pre-transplanting Application of Potassium Phosphate to Plug Seedlings

Abstract

To develop a new fertilizing system with a reduced amount of phosphatic fertilizer in sweet corn production, we applied potassium phosphate to the plug seedlings before transplanting to the field, and examined its effects on growth, yield, photosynthetic activity and absorption of minerals. The amount of phosphatic and potash fertilizers necessary to grow sweet corn could be reduced by the pre-transplanting KP application (PTKPA) to the plug seedlings. We considered the mechanisms involved in the reduction of P and K application rate by PTKPA as follows; 1) PTKPA increased the P content of plant, which accelerated the root establishment. 2) The advanced root establishment not only reduced the duration of water stress, but also increased absorption of the essential nutrients such as N and Mg. 3) Higher content of N and Mg led to higher chlorophyll content and possibly protein content, which activated photosynthesis during the early growth stage. 4) Improved photosynthetic activities increased NAR during the early growth stage. 5) This increase in NAR accelerated leaf expansion, increasing LAI. 6) Larger LAI during the early growth stage led to larger LAI throughout the growing stage, resulting in a higher CGR and ear yield.     

吉林省不同时期育成大豆品种叶片衰老过程中光合相关参数的研究

为了探明吉林省不同时期育成的栽培大豆品种在叶片衰老过程中光合相关参数变化,将1923-2006年划分为4个时期,第一时期为1960年以前、第二时期为1961-1980年、第三时期为1981-2000年和第四时期为2001年以后,以吉林省不同时期育成的20个栽培大豆品种为材料进行田间试验。用Li-6400光合测定仪在R2(开花期)、R4(结荚期)、R6(鼓粒期)和R7(成熟期)进行叶片光合相关参数测定。结果表明:不同时期育成大豆品种,在R4、R6和R7期净光合速率、叶绿素含量和比叶重皆表现为:第一时期第二时期第三时期第四时期。从衰老进程来看,R4~R6期,不同时期育成大豆品种的净光合速率、气孔导度、蒸腾速率及叶绿素含量下降值比皆表现为:第一时期第二时期第三时期第四时期。R6~R7期,大豆品种比叶重下降值比表现为:第一时期第二时期第三时期第四时期。这说明随着品种遗传改良,改善了大豆叶片光合相关参数,提高了叶片的光合作用,延长了光合时间,从而延缓叶片衰老,为产量的提高奠定物质基础。