Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)

The effects of CO₂ enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO₂ concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO₂ concentration, N concentration, and CO₂×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO₂. However, at 20 mmol N/L, elevated CO₂ had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO₂ concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO₂ concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO₂ condition. Project (No. 2007CB109305) supported by the National Basic Research Program (973) of China     

Variation in glucosinolates in pak choi cultivars and various organs at different stages of vegetative growth during the harvest period

Glucosinolates (GSs) play an important role in plant defense systems and human nutrition. We investigated the content and composition of GSs in the shoots and roots of seven cultivars of pak choi. We found that ‘Si Yue Man’ had the highest total and aliphatic GS contents in the shoots and the highest benzenic GS content in the roots, ‘Shanghai Qing’ contained the highest amounts of benzenic and total GS contents in the roots, while ‘Nanjing Zhong Gan Bai’ had the lowest benzenic, indole, and total GS contents in both the shoots and roots. Therefore, the ‘Si Yue Man’ cultivar appears to be a good candidate for future breeding. Variation between the shoots and roots was also examined, and a significant correlation among the total, aliphatic, and some individual GSs was found, which is of value in agricultural breeding. GS concentrations of the leaf, petiole, and root increased dramatically during the period of rapid growth of the dry matter of the plant 10 to 20 d after transplantation, reaching peak values on Day 20 and decreasing on Day 25. We conclude that the pak choi should be harvested and consumed from 20 to 25 d after transplantation to take advantages of the high GS content in the plant.     

Influence of nitrogen and sulfur fertilization on quality of canola (<Emphasis Type="Italic">Brassica napus</Emphasis> L.) under rainfed conditions

Field experiments were conducted at Cereal Crops Research Institute, Pirsabak, Nowshera, Pakistan, during winter 2003~2004 and 2004~2005 to evaluate the effect of nitrogen and sulfur levels and methods of nitrogen application on canola (Brassica napus L. cv. Bulbul-98) under rainfed conditions. Four levels of S (0, 10, 20, and 30 kg/ha) and three levels of N (40, 60, and 80 kg/ha) and a control treatment with both nutrients at zero level were included in the experiments. Sulfur levels were applied at sowing while N levels were applied by three methods (100% soil application, 90% soil 10% foliar application, and 80% soil 20% foliar application). The experiments were laid out in randomized complete block (RCB) design having four replications. Oil content increased significantly up to 20 kg S/ha but further increase in S level did not enhance oil content. Glucosinolate content increased from 13.6 to 24.6 μmol/g as S rate was increased from 0 to 30 kg/ha. Protein content increased from 22.4% to 23.2% as S rate was increased from 0 to 20 kg/ha. Oil content responded negatively to the increasing N levels. The highest N level resulted in the highest values for protein (23.5%) and glucosinolate (19.9 μmol/g) contents. Methods of N application had no significant impact on any parameters under study.     

Leaf and root glucosinolate profiles of Chinese cabbage (Brassica rapa ssp. pekinensis) as a systemic response to methyl jasmonate and salicylic acid elicitation

Glucosinolates (GSs) are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid (JA) and salicylic acid (SA) are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage (Brassica rapa ssp. pekinensis). In this study, we applied different concentrations of methyl jasmonate (MeJA) and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Regardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS (IGS) were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that accumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin (neoGBC) did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin (GBC) to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin (4-MGBC) occurred only in the root irrespective of the type of elicitors and the site of elicitation. Thus, accumulation of IGS is a major metabolic hallmark of SA- and MeJA-mediated systemic response systems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively.     

盐胁迫对红麻种子萌发及幼苗生长的影响

研究了不同浓度的钠盐（Na2SO4和Na2CO3）胁迫对红麻种子萌发和幼苗生长的影响.结果表明：不同浓度盐胁迫对红麻种子的发芽指标和活力指数均有一定抑制作用,随浓度的增加抑制作用越强.浓度10~50 mmol/L的Na2SO4胁迫下,红麻种子的发芽势、发芽指数与对照没有显著差异,但活力指数显著低于对照,而当Na2SO4浓度为100 mmol/L时种子的发芽势、发芽指数与对照存在显著差异,Na2SO4浓度为200 mmol/L时种子不能萌发;Na2CO3浓度≥50 mmol/L时,红麻种子不能萌发.相同浓度下,Na2CO3比Na2SO4对红麻种子萌发的抑制作用更明显.     

Detection of nitrogen-overfertilized rice plants with leaf positional difference in hyperspectral vegetation index

The main objective of this work was to compare the applicability of the single leaf (the uppermost leaf L1 and the third uppermost leaf L3) modified simple ratio (mSR₇₀₅ index) and the leaf positional difference in the vegetation index between L1 and L3 (mSR_705L1-mSR_705L3) in detecting nitrogen (N)-overfertilized rice plants. A field experiment consisting of three rice genotypes and five N fertilization levels (0, 75, 180, 285, and 390 kg N/ha) was conducted at Xiaoshan, Hangzhou, Zhejiang Province, China in 2008. The hyperspectral reflectance (350–2500 nm) and the chlorophyll concentration (ChlC) of L1 and L3 were measured at different stages. The mSR_705L1 and mSR_705L3 indices appeared not to be highly sensitive to the N rates, especially when the N rate was high (above 180 kg N/ha). The mean mSR_705L1-mSR_705L3 across the genotypes increased significantly (P<0.05) or considerably from 180 to 285 kg N/ha treatment and from 285 to 390 kg N/ha treatment at all the stages. Also, use of the difference (mSR_705L1-mSR_705L3) greatly reduced the influence of the stages and genotypes in assessing the N status with reflectance data. The results of this study show that the N-overfertilized rice plants can be effectively detected with the leaf positional difference in the mSR₇₀₅ index.     

盐胁迫对不同品种小黑麦光合特性和生长的影响

分别用0,50,100,200,300 mmol/L NaC1溶液处理6个品种的小黑麦幼苗,15天后测定其净光合速率、蒸腾速率、气孔导度、胞间CO2浓度,以及根长、苗高、鲜重.结果表明,50 mmol/L NaC1处理对小黑麦的光合速率和幼苗生长有轻微促进作用,随着NaC1浓度增大,幼苗表现为光合速率、蒸腾速率、气孔导度降低,胞问CO2浓度也呈现规律性变化,幼苗生长受到抑制.综合比较以上指标,在供试的6个小黑麦品种中,抗盐性强的品种有NTH1888和NSWH11,WOH939抗盐性中等,抗盐性弱的品种为黔中3号、劲松49、澳洲黑麦.     

Factors affecting the formation of trihalomethanes in the presence of bromide during chloraminatlon

The effects of the concentration of dissolved total organic carbon(TOC),the TOC/Br-ratio,bromide ion levels,the chlorine to ammonia-N ratio(Cl:N),the monochloramine dose and the chlorine dose on the formation of trihalomethanes(THMs)(including chloroform,bromodichloromethane,chlorodibromomethane,and bromoform)from chlorination were investigated using aqueous humic acid(HA)solutions.The profile of the chloramine decay was also studied under various bromide ion concentrations.Monochloramine decayed in the presence of organic material and bromide ions.The percentage of chloroform and brominated THMs varied according to the TOC/Br-ratio.Total THMs(TTHMs)formation increased from 112 to 190 μg/L with the increase concentrations of bromide ions from 0.67 to 6.72 mg/L,but the chlorine-substituted THMs were replaced by bromine-substituted THMs.A strong linear correlation was obtained between the monochloramine dose and the formation of THMs for Cl:N ratios of 3:1 and 5:1.These ratios had a distinct effect on the formation of chloroform but had little impact on the formation of bromodichloromethane or chlorodibromomethane.The presence of bromide ions increased the rate of monochloramine decay.     

盐胁迫对转ZmPP2C2基因和野生型烟草种子萌发的影响

采用纸培法对转ZmPP2C2基因烟草和野生型烟草种子进行盐胁迫试验,设置了6个浓度梯度的NaCl溶液进行处理.结果表明:种子的发芽势、发芽率、发芽指数和活力指数总体上随盐溶液浓度的升高而降低,在盐溶液浓度为50mmol/L时,转基因烟草最低,明显低于野生型烟草.而盐溶液浓度为150mmol/L时,转基因烟草发芽势明显高于野生型烟草.叶绿素含量的变化比较复杂,在盐浓度为100mmol/L、150mmol/L时,转基因烟草随盐溶液浓度的升高下降比较明显,而野生烟草是先升高后下降.     

Ca~(2 )对杂交水稻幼苗生长及谷产量的影响

0．1～0．4mmol／LCa~(2 )能有效地促进杂交水稻幼苗的生长；提高叶片中的叶绿素含量和净光合作用速率，以及植株中的可溶性淀粉和蛋白质含量；降低叶片中的可溶性糖含量；增加植株的有效穗、结实率、千粒重和谷产量．当Ca~(2 )浓度超过0．4mmol／L时，则促进作用减弱．     

水杨酸对NaCl胁迫下大豆种子萌发和幼苗逆境生理的影响

以大豆为实验材料,采用砂培的方法,研究不同浓度SA(0.1、0.2、0.3、0.4mmol/L)对100mmol/LNaCl胁迫下大豆种子萌发和幼苗逆境生理的影响.结果表明,一定浓度的SA可以促进NaCl胁迫下大豆种子萌发、根茎生长、生物量积累,增强渗透调节,减小膜脂过氧化,但过高浓度则抑制生长、加剧膜脂过氧化.并且显示,100mmol/L NaCl胁迫下,0.2mmol/L SA对大豆种子萌发的影响效果显著,而0.3mmol/L SA对幼苗逆境生理的影响效果显著.     

Average SNR of maximum ratio transmission with selection combining

Two kinds of selection combining schemes including generalized selection combining （GSC） and generalized order selection combining （GOSC） are investigated. In the GSC scheme, L strongest diversity branches from a total of R diversity branches are selected and coherently combined by maximal ratio combining. GOSC means that the Lth strongest diversity branch from R diversity branches is selected for reception. Closed-form expressions for the average signal-to-noise ratios of maximum ratio transmission with GSC and GOSC are derived in Rayleigh fading channels.     

水杨酸对PEG胁迫下商麦5226幼苗生长的影响

以商麦5226为研究对象,研究不同浓度(0.65、0.75、0.85 mmol·L-1)外源水杨酸对水分胁迫下小麦的生理影响。结果表明,0.65-0.75 mmol·L-1外源水杨酸可以促进水分胁迫下幼苗根茎的生长,降低MDA含量和提高POD活性,提高小麦苗期的抗旱能力;但不同部位最适浓度不同,根的最适浓度为0.75 mmol·L-1,茎的最适浓度为0.65 mmol·L-1,浓度超过0.85 mmol·L-1对根茎生长有一定的抑制作用。     

Effects of nitrogen fertilization strategies on nitrogen use efficiency in physiology,recovery, and agronomy and redistribution of dry matter accumulation and nitrogen accumulation in two typical rice cultivars in Zhejiang,China

Field experiments were conducted in farmers’ rice fields in 2001 and 2002 to study the effects of nitrogen (N) management strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers’ fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution (post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer’s routine practice of Zhejiang. With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China. Project supported by the International Rice Research Institute (IRRI), Swiss Agency for Development and Cooperation (SDC), the Potash & Phosphate Institute and the Potash & Phosphate Institute of Canada (PPI-PPIC), the International Fertilizer Industry Association (IFA), the International Potash Institute (IPI), and 948 Project of the Ministry of Agriculture of China (No. 2003-Z53)     

Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts

To understand the regulation mechanism of NaCl on glucosinolate metabolism in broccoli sprouts,the germination rate,fresh weight,contents of glucosinolates and sulforaphane,as well as myrosinase activity of broccoli sprouts germinated under 0,20,40,60,80,and 100 mmol/L of NaCl were investigated in our experiment.The results showed that glucoerucin,glucobrassicin,and 4-hydroxy glucobrassicin in 7-d-old broccoli sprouts were significantly enhanced and the activity of myrosinase was inhibited by 100 mmol/L of NaCl.However,the total glucosinolate content in 7-d-old broccoli sprouts was markedly decreased although the fresh weight was significantly increased after treatment with NaCl at relatively low concentrations(20,40,and 60 mmol/L).NaCl treatment at the concentration of 60 mmol/L for 5 d maintained higher biomass and comparatively higher content of glucosinolates in sprouts of broccoli with decreased myrosinase activity.A relatively high level of NaCl treatment(100 mmol/L) significantly increased the content of sulforaphane in 7-d-old broccoli sprouts compared with the control.These results indicate that broccoli sprouts grown under a suitable concentration of NaCl could be desirable for human nutrition.     

枇杷属植物RAPD反应体系的优化与应用

采用CTAB—蛋白酶K法提取了48份枇杷种质的DNA,以西班牙枇杷品种Ullera为模板DNA,对枇杷属植物RAPD反应体系进行优化研究,结果表明:25μL反应体系中,Taq DNA聚合酶、Mg2+、引物、模板DNA和dNTPs等5种主要成分的适宜浓度或用量分别是:Mg2+为2.0 mmol/L,Taq DNA聚合酶为1.0 U,引物为0.25"mol/L,dNTPs为0.100—0.125 mmol/L,模板DNA为25—30 ng。利用该优化体系对48份枇杷种质进行RAPD随机扩增,经琼脂糖电泳获得了清晰的扩增图谱。     

抗坏血酸存在下六氮杂铜配合物修饰金电极对多巴胺的分析测定

利用自组装的方法制备了一种新型六氮杂铜配合物修饰的金电极。采用循环伏安法和电化学隧道扫描显微镜对该电极进行了表征。计算了该电极电子转移系数为0.42,标准速率常数为38S^-1。该电极可以有效地催化氧化多巴胺,当抗坏血酸浓度为1-5mmol/L时,可用于多巴胺的分析测定,检测限低至1.8×10^-8mol/L。     

水杨酸对盐胁迫下西瓜种子萌发特性的影响

采用培养皿发芽法,研究了水杨酸浸种对盐胁迫下西瓜种子萌发和幼苗生长的影响。结果表明,300mmol/L NaCl溶液浸种显著降低了西瓜种子的发芽率、发芽势、发芽指数和活力指数及胚根长和胚芽鲜重;1.0mmol/L以下浓度水杨酸浸种使盐胁迫下西瓜种子萌发和幼苗生长量随水杨酸浓度提高而显著增加;2.0 mmol/L水杨酸浸种对盐胁迫下西瓜种子萌发和幼苗生长无明显影响,3.0 mmol/L水杨酸浸种进一步降低了盐胁迫下西瓜种子萌发和幼苗生长量。结果说明,较低浓度水杨酸浸种可缓解盐胁迫对西瓜种子萌发和幼苗生长的抑制作用,减轻西瓜种子萌发期盐胁迫伤害的最适水杨酸浓度为1.0 mmol/L。     

NaCl胁迫对水稻（Oryza sativa）种子萌发和幼苗生长的影响

采用水培法,研究不同浓度（0、50、100、150、200、250、300、350、400、450、500mmol／L）的NaCl胁迫对水稻种子萌发,胚根、胚芽和幼苗生长的影响。结果表明：种子的发芽势、发芽率、都随着NaCl胁迫浓度的升高而降低,300mmol／L以上种子发芽率为0;胚根长,胚芽长也随着NaCl胁迫浓度的升高而降低,浓度大于100mmol／L时有显著（p〈0．05）影响。水稻幼苗的根长、株高、株鲜重、根干重以及茎干重也随NaCl胁迫浓度的升高呈逐渐降低的趋势,当浓度大于250mmol／L时影响尤为显著,大于300mmol／L时,植株严重失水,萎蔫,枯黄,死亡。研究结果说明NaCl胁迫对水稻种子的萌发和幼苗的生长有严重的抑制作用。     

铅、锌诱导的高羊茅叶片过氧化物酶活性变化

采用水培方法,研究了铅、锌诱导下的高羊茅叶片过氧化物酶活性变化．结果表明：高羊茅对Pb^2＋、Zn^2＋胁迫有一定的耐受能力,低浓度（0．5mmol／L）的Pb^2＋、Zn^2＋胁迫均会使高羊茅叶片POD活性随处理时间的延长先升高后下降,但10天时还保持在高于对照的水平;高浓度Pb^2＋、Zn^2＋胁迫POD活性无论开始是否上升,至10天时均下降至对照水平以下．试验同时表明高羊茅对Zn^2＋耐受能力要大于Pb^2＋．