甘蓝型黄籽油菜与黑籽油菜苗期生理特性的比较研究

油菜苗期的植株长势与抗性及后期产量密切相关。为探索甘蓝型黄籽油菜抗逆性较弱和产量较低的原因,以2对不同遗传来源的甘蓝型黄、黑籽油菜近等基因系为材料,研究了苗期植株的主要生理特性。结果表明,甘蓝型黄籽油菜苗期生长势弱,叶绿素含量和类胡萝卜素含量,光合速率和叶面积指数（LAI）均比相同遗传背景下的黑籽油菜低;与黑籽油菜相比,甘蓝型黄籽油菜无论是在不同的叶龄期,还是在植株的不同部位,均表现出“糖高氮低”的代谢特点,且越冬期叶片的硝态氮含量和硝酸还原酶活性也低;根颈粗和单株干物质重也明显小。甘蓝型黄籽油菜苗期生长势弱,冬前干物质积累偏少,进而影响其春后的生殖生长,这可能是其产量较低的重要原因之一。     

烟叶成熟过程中碳氮代谢关键酶对追施氮肥的响应

采用盆栽试验，通过测定烤烟成熟过程中叶片硝酸还原酶(NR)和转化酶(Inv)活性，研究了无机氮肥的追期和追量对烟叶成熟过程中叶片碳氮代谢强度及转化的影响，结果显示：在上、下部叶片成熟过程中，NR和Inv活性下降；随追氮时期推迟或追氮量增加，下部叶NR和Inv活性提高，Inv／NR降低，Inv／NR曲线峰值延后；在移栽后30d内或追氮量低于总施氮量30％时，随追氮时期推迟或追氮量增加，上部叶NR活性、Inv活性、Inv／NR降低。在本试验条件下，于移栽后30d追肥，追氮量30％，最有利于上、下部叶成熟过程中碳氮代谢的协调和适时转化。     

Responses of Root Nodule Formation and Nitrogen Fixation Activity to Nitrate in a Split-Root System in Peanut (Arachis hypogaea L.)

Peanut is an important constituent of crop rotation systems with various vegetable crops, which need large amounts of inorganic nitrogen. Nitrate inhibits nodule formation and nitrogen fixation of the peanut plants in these cropping systems. To elucidate this nitrate-induced inhibition, an experimental method using a split-root system was designed and the inhibitory level of nitrate (14 m M ) was applied to half of the roots for 5 or 30 days in pot experiments. In the application of nitrate for 5 days, the dry weight, the nitrogen content, and both the number and the fresh weight of nodules for each half of the roots were unaffected by the nitrate applied to the other half. However, the nitrate induced significantly lower nitrogenase activity in the applied half. In the application for 30 days, nitrate induced a significantly higher nitrogen content in the applied half of the roots, and the inhibitory effect on nodulation and nodule development was observed not only in the applied half but also in the other half. Thus, the inhibitory effect of long-term nitrate application on the nodulation and nitrogenase activity of peanut may be systemic, but that of short-term nitrate application, in which external nitrate may regulate nitrogen fixation, may not be systemic.     

大豆PIN-Like(PILS)基因家族的鉴定、表达分析及在根瘤共生固氮过程中的功能

植物激素生长素在植物的生长发育过程中发挥了至关重要的作用,它的稳态和浓度梯度建立控制了几乎所有器官的极性建成。生长素在特定细胞中合成、运输、感知以及代谢降解建立了符合器官发育的生长素浓度梯度。在豆科植物中,根与土壤微生物互作形成了根瘤这一特殊的器官,进行生物固氮。然而,生长素稳态控制生物固氮的功能还未知。拟南芥中的研究表明,PIN-Like (PILS)蛋白协助调节的细胞内生长素稳态,并介导下游细胞核内的生长素信号传递。本研究以大豆作为研究模型,在大豆基因组中鉴定获得19个PILS家族基因(GmPILS),不均匀分布于大豆10条染色体上。GmPILS在大豆9种组织部位中表现出多种表达模式,且具有明显的组织表达特异性。GmPILS1e和GmPILS1f在根瘤菌体区域富集表达,使用人工微RNA沉默(artificialmicro RNA interference,amiRNAi)下调GmPILS1e和GmPILS1f在根瘤的表达,导致根瘤的固氮酶活性上升,而过量表达GmPILS1f导致根瘤的固氮酶活性下降,因此GmPILS1e和GmPILS1f可能参与大豆固氮酶活性的调节。这些结果为进一步解析大豆GmPILS家族基因的功能和作用机制奠定了基础,同时也为结瘤固氮在农业育种中的应用提供了有价值的基因资源。     

Effect of Split Nitrogen Application on Growth and Yield of Wheat (T. aestivum L.) Genotypes with Different N-Assimilation Potential

A field experiment was conducted with different nitrogen regimes to assess the growth and yield performance of wheat genotypes which differ in nitrate assimilation potential. Genotypic differences in biomass accumulation were observed at different growth stages. The nitrogen treatment had little effect on biomass accumulation at early stages of growth, while at later stages of growth there was enhanced biomass accumulation when N was applied in more than two splits. On an average, genotypes with high nitrate reductase activity (the 'HNR' genotypes) accumulated 14.2 % more biomass than the genotypes with low nitrate reductase activity ('LNR' genotypes) when an extra dose (40 kg N ha⁻¹) of nitrogen was given at the time of anthesis. The application of nitrogen in more than two splits increased grain yield of both 'HNR' and 'LNR' genotypes mainly by increasing grain weight per ear. The application of an extra dose of nitrogen (40 kg N ha⁻¹) at the time of anthesis increased grain yield of 'HNR' genotypes by 38.5 % as compared to 'LNR' genotypes.     

Alternate Selection Indices for Leaf Photosynthetic Rate in Greengram (Vigna radiata [L.] Wilczek) Cultivars

Significant differences were observed for leaf net photosynthetic rate, chlorophyll content, soluble protein content, nitrate reductase activity, stomatal frequency and specific leaf mass among ten greengram cultivars. Leaf net photosynthetic rate had significant positive correlation with soluble protein, nitrate reductase activity, stomatal frequency and specific leaf mass. Leaf net photosynthetic rate had no relationship with leaf chlorophyll content in greengram.     

新山海关杨速生性的主因子分析

新山海关杨源于山海关杨实生苗,经几年观察其速生性表现突出且稳定。本试验进一步确定了影响其速生性的主因素。以扦插苗为研究对象,测定了其生长状况,蛋白质、氨基酸、叶绿素、还原糖等基本代谢物的含量以及过氧化物酶、IAA氧化酶、硝酸还原酶活性和根活力等指标。结果表明：新山海关杨与普通山海关杨相比,速生性表现明显,蛋白质、叶绿素含量及过氧化物酶、硝酸还原酶活性差异极显著;还原糖含量、IAA氧化酶活性及根活力差异显著。对以上生理生化指标进行线性相关分析,结果表明各项指标均与植株生长呈线性相关关系,其中普通山海关杨中硝酸还原酶活性与植株生长的相关系数不显著,其余均显著;而新山海关杨中还原糖含量、硝酸还原酶活性与植株生长的相关系数极显著,其余均显著。之后进行通径分析,结果表明山海关杨的主要生长因子是根活力。     

锌肥对寒地春玉米生理生化指标的影响

以黑龙江省大庆地区生产上大面积推广的玉米杂交种四单十九为研究对象,分析了6种不同锌肥水平对穗位叶的叶绿素、SOD、POD、MDA、硝酸还原酶、可溶性糖及脯氨酸含量的影响。结果表明,寒地春玉米在Zn3处理时植株长势最好,缺锌和高锌胁迫均抑制植株生长,一定的低锌比缺锌对玉米的影响更大。研究得出,随着锌浓度的升高,SoD活性增加,MDA含量降低。随着Zn2＋浓度的增大,叶绿素含量下降,硝酸还原酶活性降低。Zn3处理下脯氨酸含量最低,比Zn0减少了3．32％。Zn3处理下可溶性糖含量最高,一定的低锌和高锌胁迫可溶性糖含量均有不同程度的降低。     

Nitrate reductase and its relationship to protein and yield characteristic of triticale

Summary The optimum conditions for extraction and assay for nitrate reductase (NRase) activity in triticale were determined. NRase activity was positively correlated with plant height, grain yield and grain protein. The leaf protein, seed set or kernel weight had no significant correlation with the NRase activity. Data indicated an apparent interrelationship between NRase activity, grain protein, plant height and grain yield.     

不同氮效率茄子氮代谢相关酶活性的差异

以3个不同氮效率基因型茄子为供试材料,采用大田培养,研究了正常供氮和低氮胁迫下,茄子幼苗期到结果期的氮代谢相关酶活性,探讨氮代谢相关酶活性的差异.结果表明,与正常供氮相比,低氮胁迫下,不同氮效率基因型茄子的硝酸还原酶活性、谷氨酰胺合成酶活性均降低,且大多数指标达到显著水平.与低氮高效基因型07-860及氮双低效基因型07-857相比,氮双高效基因型07-862具有较强的氮代谢相关酶活性.在供氮水平相同条件下,通过对幼苗期至结果期不同氮效率基因型进行GS及NR活性测定,选择具有相对高活性GS及NR的氮效率基因型是对氮高效基因型的有效早期选择.     

Soybean-Rhizobium Combination for Tolerance to Low P-High Aluminum

Two greenhouse experiments were conducted to evaluate the performance of selected soybean- Bradyrhizobium combinations in a soil having low P-high aluminum stresses under controlled conditions. Growth parameters such as plant height, nodule numbers, dry weight, nitrogenase activity and seed yield were used as an index. Three selected acid (low P-high Al) tolerant ( Essex, Tracy and Bedford ) and three sensitive ( Peking, Hill and McNair 600 ) soybean ( Glycine max ) varieties were sown in each pot. Three of the most tolerant strains of Bradyrhizobium (USDA 6, 110, 122), a mixture of these strains, and a commercial inoculant (Nitragin) were used to inoculate the Hartselle sandy loam soil. The results indicated that soil acidity significantly affected the soybean Bradyrhizobium symbiosis. The combination of variety Tracy plus Nitragin (mixed-strain) produced the highest and variety Peking plus mix-strain Nitragin the lowest plant height at all pH levels. Plants inoculated with Nitragin had higher shoot dry weight and seed yields. Variety Essex in combination with Nitragin produced the highest seed yields at all pH levels. Plants inoculated with Nitragin developed significantly more nodules than the other strains except for variety Peking. There was no significant difference in total nodule numbers between tolerant and sensitive soybean varieties at all soil pH levels except for Nitragin. Shoot total N did not increase by increasing the pH level or by using different variety-strain combinations.     

甘蓝型油菜氮素高效吸收的植株形态与生理特性研究

为阐明甘蓝型油菜氮素高效吸收的形态和生理机制,利用6个氮素效率差异显著的甘蓝型油菜为供试材料,分析低氮条件下甘蓝型油菜抽薹期地上部和根系形态、叶片和根系生理特性的基因型差异及这些指标与高效氮素吸收的关系。结果表明,3个氮高效基因型在表型性状（株高、叶片数、最大叶长×宽、地上部干重、茎基粗、根长、根表面积、根体积、根平均直径和根干重）、生理（叶片可溶性糖含量、游离氨基酸总量、根系吸收总面积、活跃吸收面积、游离氨基酸总量和根系活力）和光合方面（净光合速率、气孔导度、胞间CO₂浓度、蒸腾速率和氮素光合效率）均高于3个氮低效基因型。甘蓝型油菜抽薹期根平均直径、最大叶长×宽、蒸腾速率和根系硝酸还原酶共同决定了氮素吸收效率的92.10%。     

秸秆还田对烤烟根系活力和碳氮代谢生理特性的影响

为解决长期连作及施用化肥带来的植烟土壤环境恶化问题,在粤北烟区开展了秸秆还田对烤烟根系活力和碳氮代谢生理特性影响的研究。结果表明：水稻、花生秸秆还田处理的烤烟根系活力均显著提高,且成熟期根系衰老速度延缓,施用2500 kg/hm2花生秸秆的烤烟根系活力最强。打顶前（移栽后55天）秸秆还田处理叶片中淀粉酶、硝酸还原酶活性显著高于对照,且淀粉酶活性高峰提早10天;成熟期淀粉酶、硝酸还原酶、酸性蔗糖转化酶活性则显著降低,Inv/NR比值升高。水稻秸秆还田处理的硝酸还原酶活性高于花生秸秆还田处理,且打顶前秸秆还田量高的处理高于秸秆还田量低的处理。     

减量施氮对带状套作大豆土壤通气环境及结瘤固氮的影响

为研究种植模式和施氮量对大豆土壤通气环境及结瘤固氮的影响,本研究采用二因素裂区试验设计,主区为种植模式:大豆单作(SS)、玉米/大豆带状套作(MS),副区为不同施氮量:不施氮(NN:0 kg hm^-2)、减量施氮(RN:45kghm^-2)和常量施氮(CN:60kghm^-2),监测了大豆生育期内土壤的O₂含量和土壤呼吸速率的动态变化规律,分析了各处理的土壤水稳性团聚体、容重和孔隙度差异,探讨了大豆生育期内结瘤量、固氮能力的变化特征。2年数据结果表明,与单作大豆相比,带状套作大豆可提高土壤O₂含量、>2 mm粒径团聚体的百分含量、显著增加土壤孔隙度、显著增强后期土壤呼吸的速率,显著降低<1mm粒径团聚体百分含量与土壤孔隙度;R5期根瘤干重差异不显著,但结瘤数量显著增加39.9%,固氮酶活性与固氮潜力也在此时显著高于单作大豆。各施氮量间,土壤O₂含量、0.25～1.00mm粒径的百分含量、带状套作大豆的土壤呼吸速率以RN处理最高,施氮能降低<0...     

A rapid method for assessing sodicity hazard using a cation exchange membrane

Ion exchange reactions which occur between the soil and synthetic resin surfaces have been used to approximate nutrient movement and uptake by plants. Similar exchange principles govern the proportion of sodium which will exist on the soil exchange. This study investigated the use of a cation exchange membrane (CEM) in estimating the sodicity of soil. For soils ranging in salinity from non to extremely saline, the saturated paste extractable sodium was not well related to the CEM exchangeable amounts. However, the sodium adsorption ratio (SAR) was closely related to the CEM exchangeable Na (r² = 0.95), suggesting a link between Na on the soil exchange complex and that adsorbed by the CEM. The factors which control the ion exchange dynamics of the soil exchange complex appear to similarly control cation exchange onto the CEM. This premise was used as the basis for a simplified measure of exchangeable sodium percentage (ESP). Sodium occupying the CEM, expressed as a percentage of the entire CEM capacity, showed a one to one correspondence with ESP measured using standard methods (r² = 0.91). Exchange membranes, therefore, offer a simple and rapid method of assessing soil sodicity.     

Effects of Mulch from 14 Multipurpose Tree Species (MPTs) on Early Growth and Nodulation of Cowpea (Vigna unguiculata L.)

Leaf extracts and mulch from 14 MPTs were used to study their effects on germination, initial growth and nodulation of cowpea. Aqueous leaf extracts of , , and full concentrations were added to cowpea seeds placed in Petri dishes. In the pot experiment, cowpea was planted in plastic pots filled with 1200 g of soil, and mulch was either surface-applied or incorporated into the substrate at rates equivalent to 5, 10 and 20 tons · ha⁻¹. Leaf extracts from Gliricidia sepium, Senna siamea, Milletia thoningii, Grewia pubescens and Tetrapleura tetraptera reduced cowpea germination significantly at concentrations above 25 % of the full concentration 7 days of incubation. Root length was also strongly reduced by extracts from Gmelina arborea, Senna siamea, Alchornea coordifolia, and Tetrapleura tetraptera. These inhibiting effects were also observed in the pots. Mulch incorporation significantly reduced growth and nodulation of cowpea in the pots. These reductions were more pronounced with the incorporation of mulch from fast decomposing trees such as Leucaena leococephala, Gliricidia sepium and Grewia pubescens. Although Leucaena leucocephala and Gliricidia sepium released much nitrogen, they strongly reduced cowpea growth when incorporated. This may suggest that other reasons than N immobilization caused growth reduction when the plant residues were applied to cowpea.     

花生硝酸还原酶与根瘤中固氮酶活性的研究

花生品种间根瘤量的变化有显著差异,但每克根瘤中固氮酶活性则差异不显著。固氮酶活性在全生育期出现两次高峰,分别在下针期和结荚期,而单株根瘤中固氮酶活性和单株根瘤量均在结荚期出现一次高峰。花生主茎复叶硝酸还原酶活性(NRA)在生育前期出现一次高峰,其活性的高低与品种耐肥性呈负相关。NRA 和根瘤中固氮酶活性有正相关     

渗透胁迫和盐胁迫对荞麦硝酸还原酶及亚硝酸还原酶活性的影响

以盐敏感荞麦品种TQ-0808和耐盐荞麦品种川荞1号为试验材料,采用NaCl和等渗PEG-6000处理,研究渗透胁迫和盐胁迫对不同耐盐性荞麦品种硝酸还原酶(NR)及亚硝酸还原酶(NiR)活性的影响。结果表明,高浓度盐胁迫下盐敏感荞麦品种叶片NR及NiR活性显著降低,而耐盐荞麦品种降低幅度相对较小,且高浓度盐胁迫下盐敏感荞麦品种叶片NR及NiR活性的降低幅度明显大于渗透胁迫的,说明Na⁺毒害效应发挥了主要作用。另外,两个荞麦品种叶片NR活性高低与其叶片硝酸盐含量呈正相关。     

Effect of Homobrassinolide Application on Metabolic Activity and Grain Yield of Wheat under Normal and Water-Stress Condition

Activities of nitrate reductase, glutamine synthetase along with rate of photosynthesis, chlorophyll content, soluble protein, relative water content, transpiration and diffusion resistance were estimated in wheat cv. C306 at anthesis stage under irrigated and moisture-stress condition and two levels (0.1 and 1.0 ppm) of homobrassinolide application. Yield and yield attributing parameters were recorded at harvest. Moisturestress adversely affected relative water content, transpiration, net photosynthesis, nitrate reductase and glutamine synthetase activity, chlorophyll and soluble protein content.
Homobrassinolide application increased leaf relative water content and transpiration and decreased diffusion resistance in water-stressed and recovered plants. Homobrassinolide application also had positive effect on nitrate reductase and glutamine synthetase activities, photosynthesis, chlorophyll and total soluble protein content in stressed, irrigated and revived plants. The beneficial effect was also observed on grain yield and yield attributing parameters such as grain number per ear, 1000 grain weight, ear number per plant and harvest index. It was concluded that homobrassinolide induced promotion in metabolic activity was mediated through increased enzyme protein synthesis as well as uptake of water resulting in enhanced relative water content under moisture-stress.     

水分亏缺对烤烟光合特性和氮代谢的影响

通过真空表式土壤张力计监测土壤水势,以正常氮处理的烟株为对照,对生育后期由于施肥过多而严重影响烟叶品质的烤烟K326和NC89,进行有控制的水分亏缺处理,研究以水控氮对烤烟光合特性和氮代谢的影响,探讨以水调肥改善烟叶品质的生理原因。结果表明：两种氮肥营养下,土壤水分亏缺降低了叶片的净光合速率和蒸腾速率,而施高氮较好的抑制了这种下降;适度的土壤水分亏缺抑制了硝酸还原酶的活性,降低了中上部叶全氮的含量,从而有效抑制了高氮营养下烤烟成熟期的氮代谢。