Incidence of P,Mn and B deficiencies on the levels of the whole and individual flavonoid groups in tomato leaves

Alterations occur in the normal content of total and individual flavonoids with P, Mn and B deficiencies, in tomato leaves.

P and Mn deficiencies do not alter the total flavonoid level. Nevertheless, these deficiencies lead to different contributions of each flavonoid group (flavonols, flavones and flavanones) to the whole content.

B deficiency produces a very significant increase in total flavonoid content. Compounds that contribute the most to this accumulation are flavones.     

Mineral composition of leaves and bark in aluminum accumulators in a tropical rain forest in Indonesia

Mineral composition including AI, Ca, Mg, P, S, and Si and relationships between Al and other elements such as Ca, Mg, P, S, and Si in leaves and bark of trees in a tropical rain forest in West Sumatra were studied. Sixty five tree species and 12 unidentified trees were referred to as AI accumulators based on Chenery\s's definition (more than 1 g kg^-1 Al in leaves). For most of the Al accumulators, Al concentration in leaves was higher than in bark. However, some members of Euphorbiaceae, Melastomataceae, and Ulmaceae families showed a reverse trend. Most of the non-accumulators also showed a higher Al concentration in bark than in leaves. These results indicated that there was a difference in the mechanism of Al accumulation in tree bodies. Some of the Al accumulators showed an extremely high Al concentration (more than 10 g kg^-1) not only in the mature leaves, but also in the new leaves. Analysis of the relationships between the concentration of Al and the other 5 elements in leaves, revealed that Al accumulators could be separated into two groups at the Al concentration of 3 g kg^-1. This finding suggested that new criteria based on Al concentration (23 g kg^-1) or Al/Ca ratio in leaves could be proposed in order to define Al accumulators, apart from Chenery's criterion. Aluminium accumulators with an Al concentration in leaves lower than 3 g kg^-1 (AI accumulators <3 g kg^-1) showed the same trend as the non-accumulators in terms of these elemental relationships, while Al accumulators with an Al concentration in leaves higher than 3 g kg^-1 (AI accumulators 23 g kg^-1) showed a different trend from the non-accumulators. The Al accumulators 23 g kg^-1 and the other trees (AI accumulators < 3 g kg^-1 and non-accumulators) showed separately positive correlations between the concentrations of AI and Ca (or Mg) in the leaves. This observation seems to be opposite to general findings in plant nutrition, i.e. inhibition of Ca or Mg uptake by AI. A positive correlation between Al and S was also observed for all the trees. The Al accumulators ≥3 g kg^-1 showed positive correlations between the concentrations of Al and P (or Si) in the leaves, unlike the other trees. These findings suggested that Al stimulated P, S, or Si accumulation in leaves or Al was transported with P, S, or Si for the Al accumulators ≥3 g kg^-1. No negative relationships between Al and the other 5 elements in the leaves were observed for the Al accumulators ≥3 g kg^-1.     

氮、磷、钾用量和配比对温室黄瓜叶片相关代谢酶活性的影响

以氮、磷、钾配比1∶0.5∶1.2为对照,研究了不同氮、磷、钾用量和配比对温室无土栽培黄瓜叶片部分代谢关键酶活性的影响。结果表明,增加氮素的用量和配比,黄瓜株高、茎粗、植株干重均先升后降,硝酸还原酶活性显著增强,蔗糖合成酶、蔗糖磷酸合成酶和Mg2+、Ca2+-ATPase活性先升后降;增加磷素用量和配比,株高、茎粗、植株干重随之增大,硝酸还原酶活性先升后降,但蔗糖合成酶、蔗糖磷酸合成酶及Mg2+、Ca2+-ATPase活性显著升高;同时增加氮、磷用量和配比可显著提高硝酸还原酶、蔗糖磷酸合成酶以及Mg2+、Ca2+-ATPase的活性,但显著降低蔗糖合成酶活性;增加钾素用量和配比对黄瓜株高、茎粗和植株干重影响较小,适当增钾显著或极显著提高硝酸还原酶、蔗糖合成酶和Ca2+-ATPase的活性,Mg2+-ATPase活性升高不明显,进一步增加钾素用量和比例,上述酶活性均显著降低;增钾对蔗糖磷酸合成酶活性的影响不显著。     

镁对大豆叶片细胞膜透性和保护酶活性的影响

采用溶液培养方法研究不同的镁水平对两个大豆品种在五叶期和盛花期叶片细胞膜透性和保护酶活性的变化。结果表明,在缺镁胁迫下,大豆叶片的质膜透性(MP)和丙二醛(MDA)含量显著增加,产生的活性氧物质诱导超氧化物歧化酶(SOD)和过氧化物酶(POD)活性升高,而过氧化氢酶(CAT)活性下降;而施镁则能明显降低大豆叶片MP和MDA含量,提高CAT活性,有利于大豆抗膜脂过氧化胁迫。在施镁1～10.mg/L浓度下,大豆叶片的质膜透性和MDA以及SOD和POD活性均达最低值,而CAT活性则达最高值。说明在低镁胁迫下,大豆叶片的CAT活性受到抑制,而适量施镁则大大增强了CAT活性,有利于大豆体内活性氧的清除和抗逆境胁迫能力的提高。各处理下,大豆盛花期SOD和CAT活性明显降低,说明随着时间的延长,大豆叶片细胞内产生过多的活性氧超出了酶的防御能力,造成了酶活性伤害,而POD活性则变化不大;说明POD对活性氧具有较强的耐受性,是盛花期时起主要清除活性氧的作用的保护酶。本试验表明,大豆体内保护系统所存在的酶类在抵御逆境胁迫中相互协调,协同抗氧化。     

Short-Term Effect of Drought and Salinity on Growth and Mineral Elements in Wheat Seedlings

Both drought and salinity cause nutrient disturbance, albeit for different reasons: a decrease in the diffusion rate of nutrients in the soil and the restricted transpiration rates in plants for drought and extreme soil sodium (Na)/calcium (Ca), Na/potassium (K), and chloride (Cl)/nitrate (NO₃) ratios for salinity. The objective of this study was to examine short-term effects of drought and salinity on nutrient disturbance in wheat seedlings. Wheat was grown in a greenhouse in soil under drought and saline conditions for 26 days after sowing. At harvest, shoot biomass and length, and fresh weight and dry weight of the blade and sheath in expanded leaves 3 and 4 and expanding leaf 5 were determined. Mineral elements (K, Ca, magnesium (Mg), phosphorus (P), nitrogen (N), Na, sulphur (S), iron (Fe), zinc (Zn), and manganese (Mn)) in leaf blades and sheaths were also analyzed. At harvest, the reduction in plant height, shoot biomass, and accumulative evapotranspiration under drought was similar to that under salinity as compared with control plants. However, drought decreased the accumulation of all ions in the blade of the youngest leaf 5 compared with the control, whereas there was either an increase or no difference in all ion concentrations under saline conditions. The change in concentration for most ions in the blade and sheath of expanded leaves 3 and 4 varied among control, drought, and salinity plants, which indicated a different competition for nutrients between the sheath and blade of expanded leaves under drought and saline conditions. It can be concluded from this study that ion deficiency might occur in expanding leaves under drought but not saline conditions.     

基于边缘链码信息的番茄苗重叠叶面分割算法

针对番茄穴盘苗自动移栽机在检测幼苗特征参数时,由于叶面重叠导致提取特征参数不准确问题,提出一种基于重叠叶面边缘链码信息逐层分割算法。首先将穴盘苗原图像预处理得到的边缘二值图进行重叠叶面边缘拐点检测和链码统计,然后通过拐点配对进行叶面逐层分割,对真实分割拐点对进行线性插值,最终实现重叠叶面分割。试验结果表明,采用逐层重叠叶面分割算法具有旋转不变性,针对72孔和128孔2种穴盘规格,重叠叶面分割成功率分别为100%和96%,分割平均耗时分别为0.835和0.99 s。此分割算法分割速度快、精确度高,可满足实际工厂化全自动移栽作业要求。     

紫外辐射与复合胁迫对植物抗氧化酶系统的影响

植物抗氧化酶系统对UV-B辐射增强与复合胁迫的响应是植物抵御逆境伤害的关键机制之一。结合近年来国内外研究成果,概述了UV-B辐射对植物抗氧化酶基因表达、转录与翻译的影响,植物抗氧化酶系统对UV-B辐射与干旱、臭氧、高温、盐渍、重金属及酸雨复合胁迫的响应,以及CO2、抗坏血酸、α-萘乙酸、硒、激光辐射和稀土等调节因子对UV-B辐射下植物抗氧化酶系统的作用。     

Evaluation of an acid phosphatase assay for detection of phosphorus deficiency in leaves of maize (Zea mays L.)

Assays based on acid phosphatase activity in plant tissue show promise for rapid diagnosis of phosphorus deficiency. This study was undertaken to evaluate a simple leaf disc assay for the detection of the phosphorus deficiency in maize leaves. Leaf discs were excised from 36 to 48 day old greenhouse‐grown maize plants which had been supplied with phosphate in solution culture at levels of 5, 25 or 75 yM and which had total P concentrations in the leaves ranging from 26 to 309 mmol kg^‐1 dry wt. For acid phosphatase activity determinations, discs were incubated 15 min. at 30°C with 5 mM paranitrophenol phosphate in a pH 5.8 acetate buffer. In plants which showed visual symptoms of P‐deficiency, acid phosphatase activity was 2 to 3 times as great as in P‐suf‐ficient plants. Results were inconsistent in plants which were only moderately P‐deficient. This study indicates that the leaf disc acid phosphatase assay should be useful in confirming visual diagnosis of acute phosphorus deficiency in maize, but may not be adequately sensitive to detect moderate P deficiency.     

Beneficial effects of silicon on abiotic stress tolerance in legumes

Soil salinity, drought, metal toxicity, and ultraviolet-B radiation were major abiotic stresses that limit plant growth and productivity by disrupting the plants' cellular ionic and osmotic balance; legumes, a diverse plant family, suffered from these abiotic stresses. Although silicon (Si) is generally considered non-essential for plant growth and development, Si uptake by plants could facilitate plant growth by reducing biotic and abiotic stresses. There is however, a lack of systematic study on Si uptake benefits and mechanism on legumes because legumes reject Si uptake. Here, we reviewed the beneficial role of Si in enhancing abiotic stress tolerance in legumes and highlighted the mechanisms through which Si could improve abiotic stress tolerance in legumes. Future research needs for Si mediated alleviation of abiotic stresses in legumes are also discussed.     

两种丛枝菌根真菌对黄瓜苗期枯萎病的防效及根系抗病相关酶活性的影响

由尖孢镰刀菌引起的黄瓜枯萎病是设施黄瓜生产的主要障碍之一,丛枝菌根真菌(AM真菌)可以和包括黄瓜在内约80%的维管植物的根系形成菌根共生体,适宜的共生体组合对于寄主的生长与抗病性的提高十分有益。为明确Glomus versiforme与Glomus intraradices两种AM真菌对"津绿3号"黄瓜苗期枯萎病的防治效果。试验采用盆钵培养的方法,研究了两种AM真菌对幼苗生长及其根系3种抗病相关酶活性的影响。结果表明:两种AM真菌均可促进黄瓜幼苗的生长,并能减轻病害,但以G.versiforme的促生及生防作用更显著,接种G.versiforme处理的黄瓜幼苗株高、茎粗、叶面积及干重均显著大于对照,该处理的幼苗病情指数较对照降低26.6%。菌根化黄瓜幼苗抗病性的提高一方面与接种病原菌Fusarium oxysporum f.sp.cucumerinum前幼苗生长健壮有关;另一方面与根系抗病相关酶活性的提前诱导有关。接种F.oxysporum f.sp.cucumerinum前,G.versiforme处理的黄瓜幼苗壮苗指数显著高于G.intraradices处理与对照,分别为G.intraradices处理与对照的1.19倍与1.22倍;G.versiforme处理的黄瓜幼苗根系几丁质酶、β-1,3-葡聚糖酶与PAL酶分别比对照提前2 d、7 d、7 d被诱导,且酶活性分别为对照的1.44倍、2.16倍和92.00倍。     

接种菌剂对猪粪高温堆肥中酶活性的影响

在静态通气条件下,以猪粪为原料,以小麦秸秆作为调节物质,分别用接种复合微生物和常规堆肥两个处理研究了高温堆肥过程中酶活性的变化特征,并对其与堆料E4/E6和电导率（EC）的相互关系进行了探讨。结果表明,接种菌剂堆肥显著地提高了堆料的温度,延长了高温腐解期,有效地提高了猪粪堆肥过程中各种酶的活性和峰值。酶活性的大小因酶种类和堆肥时期的不同而各异;纤维素酶和蔗糖酶在高温期的活性高,在低温期急速下降;脲酶和多酚氧化酶活性峰值出现在堆肥后期低温阶段;脱氢酶活性峰值出现在堆肥中期,过氧化氢酶活性在整个堆肥过程中呈持续下降的趋势。接种菌剂处理和CK处理堆肥期间的EC值均与纤维素酶和脱氢酶活性呈显著的正相关（p＜0.01）;E4/E6与过氧化氢酶活性成显著正相关（p＜0.01）,说明酶活性大小是反映堆肥过程中矿质化过程和腐殖化过程生物化学进程的很好指标。     

Effect of cattle slurry in grassland on microbial biomass and on activities of various enzymes

We examined the long-term effects of cattle slurry, applied at high rates, on microbial biomass, respiration, the microbial quotient (qCO₂) and various soil enzyme activities. In March, June, July, and October 1991, slurry-amended grassland soils (0–10 cm) contained significantly higher levels of microbial biomass, N mineralization and enzyme activities involved in N, P, and C cycling. With microbial biomass as the relative value, the results revealed that the slurry treatment influenced enzyme production by the microbial biomass. High levels of urease activity were the result not only of a larger microbial biomass, but also of higher levels of enzmye production by this microbial biomass. The ratio of alkaline phosphatase and xylanase to microbial biomass was nearly constant in the different treatments. The metabolic quotient (qCO₂) declined with increased levels of slurry application. Therefore it appears that microorganisms in slurry-amended soils require less C and energy if there is no competition for nutrients. The results of this study suggest that urease activity, nitrification, and respiration (metabolic quotient) can be used as indicators of environmental stress, produced by heavy applications of cattle slurry.     

低磷胁迫对番茄叶片膜脂过氧化及保护酶活性的影响

许多土壤全磷量很高,但植物可吸收的有效磷却很低,因此作物表现缺磷.番茄是对缺磷敏感的作物,缺磷时,植株矮小,产量品质下降.目前,植物在逆境条件下的膜脂过氧化反应和保护酶系统超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的变化己广泛用于植物对逆境机理的研究[1].     

基于介电特性与IRIV-GWO-SVR算法的番茄叶片含水率检测

为了探究利用介电特性检测作物水分状况的可行性,研究了一种基于介电特性的有效、快速、精确检测番茄叶片含水率的方法。以300片不同含水率的番茄叶片为研究对象,通过LCR测量仪测定叶片在0.05~200 k Hz下的相对介电常数ε′和介质损耗因数ε″,并采用干燥法测量叶片含水率。利用迭代保留信息变量法(iteratively retains informative variables,IRIV)对介电参数进行特征变量选取,并与连续投影算法(successive projections algorithm,SPA)进行比较,利用支持向量回归机(support vector regression,SVR)分别建立叶片全变量、2种特征变量与叶片含水率的关系模型。结果表明,基于迭代保留信息变量法选取特征变量的支持向量回归模型(IRIV-SVR)具有良好的预测能力,但预测精度仍需提高,故引入灰狼优化算法(grey wolf optimizer,GWO)优化模型的参数c(惩罚因子)和g(核函数参数)。最终,经GWO优化后的模型(IRIV-GWO-SVR)的预测集决定系数R2与均方根误差RMSE分别为0.963 8,0.020 7。因此,利用介电特性结合IRIV-GWO-SVR算法预测番茄叶片含水率是可行的,同时为其他叶片含水率检测提供了一种新的方法和思路。     

锌对苦瓜叶片碳代谢及相关酶活性的影响研究

田间试验研究不同Zn肥施用量对苦瓜叶片C代谢及相关酶活性的影响结果表明 ,低Zn胁迫时苦瓜上位和下位叶片蔗糖、可溶性糖、淀粉、Zn含量、蔗糖磷酸合成酶活性和碳酸酐酶活性均显著下降 ,而酸性转化酶活性、中性转化酶活性和淀粉酶活性显著提高 ,且它们之间均呈显著和极显著相关性。     

无机包膜肥料在提高小麦氮素利用率和产量效应的研究

A field experiment with winter wheat （Triticum aestivurn L.） was conducted on a silt loam calcaric endorusti-ustic Cambosols derived from the Yellow River alluvial deposits in Henan, China, from 2001 to 2002 to evaluate N recovery and agronomic performance of different mineral coated fertilizers （MiCFs） compared to normal urea used in wheat cropping systems under field conditions. Five treatments, including CK （check, no N fertilizer）, urea and three different MiCFs at an equivalent N application rate were established in a randomized complete block design. N release from MiCFs in soil was more synchronous with the N requirement of wheat throughout the growth stages than that from urea, with grain yield of the MiCF treatments significantly higher （P 〈 0.05） than that of the treatment urea. Correspondingly, the N recovery rate was greater for all MiCFs compared to urea, increasing from 32.8% up to 50.1%. Due to its high recovery and low cost, use of the mineral coated N fertilizers was recommended instead of the polymer coated N fertilizers.     

水分胁迫对苹果属植物抗氧化酶活性的影响研究

试验研究水分胁迫对 3种苹果属植物湖北海棠、西府海棠和新疆海棠根系和叶片抗氧化酶活性的影响结果表明 ,随水分胁迫的加重 ,3种海棠抗氧化酶活性逐渐增强 ,当土壤绝对含水量降至 6 .5 %时 ,过氧化氢酶 (CAT)活性首先达高峰 ,而超氧化物歧化酶 (SOD)活性高峰则出现于土壤绝对含水量为 2 .8%时 ,之后 2种酶活性逐渐降低 ,复水后又均有所升高 ;过氧化物酶 (POD)活性高峰出现于土壤绝对含水量为 3.2 %时 ,之后逐渐下降 ,至复水后仍呈下降趋势 ;丙二醛 (MDA)含量随水分胁迫的加重而逐渐增加 ,当土壤绝对含水量降至 1 .8%时其含量最高 ,复水后则呈下降趋势。种间抗氧化能力耐旱型新疆海棠 >西府海棠 >干旱敏感型湖北海棠     

不同供镁水平对水稻叶片叶绿素荧光特性和能量耗散的影响

以高产杂交稻汕优63为材料,研究了不同供镁(Mg)水平对水稻叶片叶绿素荧光特性和抗氧化酶类活性的影响。结果表明,缺Mg使水稻叶片叶绿素含量降低,光合电子传递速率下降、CO2同化受抑制而导致Fv／Fm、PSⅡ等下降、净光合速率降低,加重了叶片受到光抑制的程度。尽管缺Mg叶片所捕获和传递到PSⅡ反应中心的光能减少,但是在强光下仍然积累了大量过剩激发能。在13:00时,对照叶片的qP下降,qN升高,过剩的激发能通过非光化学猝灭途径耗散掉以避免光合机构受到伤害,而缺Mg叶片qP下降的同时qN也显著下降,这可能是由于缺Mg使叶黄素循环受阻而阻碍了过剩激发能的耗散。缺Mg叶片中没有能够通过能量耗散系统及时耗散掉的过剩激发能导致了活性氧自由基的生成比例增加,诱导了抗氧化酶类活性不同程度的增加。大量活性氧自由基不能被抗氧化酶类及时清除掉,积累到一定程度引起了膜脂过氧化加剧而使叶绿体结构受到损伤,最终使得叶片失绿坏死。     

日光温室番茄缺镁与土壤盐分组成及离子活度的关系

研究了石灰性土壤日光温室不同栽培年限及番茄不同程度缺镁的土壤水溶盐分中离子组成、比例及Mg2+、Ca2+、K+离子活度等的变化及关系.结果表明:随着栽培年限的增加,温室土壤水溶盐分中Ca2+、K+、NO3-含量显著增加;水溶性盐分中阳离子以Ca2+为主,栽培5 a后NO3-成为阴离子主要成分;土壤中NO3-含量的增加是导致土壤盐分累积的主要因素.随番茄缺镁程度的加剧,土壤水溶性盐中Ca2+、K+、NO3-、全盐量及Ca2+/Mg2+、K+/Mg2+摩尔比均呈增加趋势,番茄出现缺镁的土壤含盐量达到盐渍化水平.随着土壤盐分含量增加,Ca2+、Mg2+活度均呈指数下降趋势,番茄缺镁的土壤溶液中Mg2+和Ca2+活度显著低于不缺镁土壤,(K+)/(Mg2+)、(Ca2+)/(Mg2+)活度比显著高于不缺镁土壤,(K+)/(Mg2+)活度比随缺镁程度加剧达显著差异,番茄缺镁的土壤溶液(K+)/(Mg2+)活度比大于1.盐分累积使Mg2+活度大幅降低以及K+富集对植物吸收Mg2+的拮抗作用是石灰性土壤上番茄缺镁的主要诱因.     

施硅对感染白粉病小麦叶片抗病相关酶活性及硅微域分布的影响

以抗/感白粉病的南农99-18/苏麦3号为试验材料,研究外源硅对接种白粉病后小麦叶片的几丁质酶、β-1,3葡聚糖酶、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)活性和叶片硅微域分布的影响,以探讨外源硅增强小麦抗白粉病的作用机理。结果表明,在不接病原菌时,施硅与否对抗/感病品种的PAL、PPO、β-1,3葡聚糖酶活性和感病品种的几丁质酶活性无显著性影响,但施硅可显著地提高抗病品种的几丁质酶活性;接种病原菌后,抗/感品种小麦叶片的几丁质酶、β-1,3葡聚糖酶、PAL和PPO活性均显著提高,而施硅处理显著地提高了感病品种的这四种酶活性和抗病品种的几丁质酶与β-1,3葡聚糖酶活性,但施硅处理对于抗病品种的PAL和PPO活性影响不显著。同时,施硅处理下,叶片硅元素相对重量都有不同程度提高,并有向刺状体基部和维管束组织富集趋势;接种病原菌后,叶片硅元素明显向病原菌侵染位点聚集,尤其有外源硅供给条件下,这种富集效应尤为显著。这意味着,硅不仅通过调节植株体内与抗病性密切相关的酶活性,而且同时可通过在侵染位点的淀积而构建了防病原菌侵入的"物理或机械屏障",以达到增强小麦的抗病性,从而抑制小麦白粉病病害发展。