外生菌根真菌Laccaria bicolor S238N增强花旗松生长及其对磷钾吸收的能力

Two variable charge soils were submerged after the addition of 30g/kg of organic matter to examine the differences in behavior between iron and manganese with respect to reduction and the distribution of different froms of the reduced elements.The reduction of manganese proceeded almost synchronously with the fall in redox potential,while the reduction of iron showed a remarkable lag behind the Eh change.Once formed,the distribution of water-soluble,exchangeable and precipitatied forms of ferrous iron was controlled by pH,CEC of the soil and total concentration of the element.For manganous ions,the proportions of water-soluble and exchangeable forms in total Mn^2 were larger than those for ferrous ions.The reduction of the two elements led to a mobilization of them,and such effect persisted even after drying of the soil,i.e.,the content of amorphous Fe became higher than that of the original soil.     

施钾对草地早熟禾根部可溶性碳水化合物及叶片氮，磷和钾含量的影响

以草地早熟禾（Poapratensis）品种男爵（Baronie）为试验材料,研究了不同施钾处理对根部0～10cm可溶性碳水化合物和叶片氮,磷和钾含量的影响。结果表明：在单施钾肥的情况下,随着施钾量的增加,越冬前草地早熟禾根系可溶性碳水化合物的含量也显著提高（P〈0．05）,这可能有助于提高植株越冬率,促进返青生长,而在同时施有氮、磷的情况下,碳水化合物含量间的差异并不显著,草地早熟禾叶片氮、钾含量也随着施钾量的增加呈显著增加的趋势（P〈0．05）。通过碳水化合物及叶片氮,磷和钾含量的测定,以N5g／m^2＋P20s3．33g／m^2＋K2O 6．68g／m^2处理对草坪返青及分蘖最佳。     

Na(+), K(+)-ATPase content in skeletal muscle of dogs with pituitary-dependent hyperadrenocorticism

Several hormones regulate Na⁺, K⁺-ATPase content in the muscle cell membrane, which is essential for maintaining muscle cell excitability. Chronic glucocorticoid excess is associated with muscle weakness and reduced endurance. We hypothesized that chronic glucocorticoid excess affects Na⁺, K⁺-ATPase content in canine skeletal muscle, and contributes to reduced endurance and muscle weakness associated with pituitary-dependent hyperadrenocorticism (PDH) in dogs. Therefore, Na⁺, K⁺-ATPase content in skeletal muscle was evaluated before and after hypophysectomy and hormone replacement (cortisone and l-thyroxin) in dogs with PDH (n = 13), and in healthy controls (n = 6). In addition, baseline and exercise-induced changes in plasma electrolyte concentrations and acid–base balance were evaluated before and after hypophysectomy in dogs with PDH. Na⁺, K⁺-ATPase content of gluteal muscle in dogs with PDH was significantly lower than in control dogs (201 ± 13 pmol/g versus 260 ± 8 pmol/g wet weight; P < 0.01). Similar differences were found in palatine muscle. After hypophysectomy and on hormone replacement, Na⁺, K⁺-ATPase was increased (234 ± 7 pmol/g wet weight). Both plasma pH and base excess in dogs with PDH (7.44 ± 0.01; 1.7 ± 0.6 mmol/l, respectively) were significantly higher (P < 0.05) than after hypophysectomy and hormone replacement (7.41 ± 0.01; −0.2 ± 0.4 mmol/l, respectively). Exercise induced respiratory alkalosis, but did not result in hyperkalemia in dogs with PDH. In conclusion, chronic glucocorticoid excess in dogs with PDH is associated with decreased Na⁺, K⁺-ATPase content in skeletal muscle. This may contribute to reduce endurance in canine PDH, although dogs with PDH did not exhibit exercise-induced hyperkalemia. Na⁺, K⁺-ATPase content normalized to values statistically not different from healthy controls after hypophysectomy and hormone replacement.     

樟叶越桔叶2个新6−O−咖啡酰葡萄糖苷的分离鉴定

为进一步挖掘樟叶越桔叶中的化学成分,采用硅胶、葡聚糖凝胶LH−20、Diaion HP20等多种柱层析方法,从其叶的80%甲醇提取物中分离得到2个新的6−O−咖啡酰葡萄糖苷,分别命名为樟叶越桔苷K（dunalianoside K,1）和樟叶越桔苷L（dunalianoside L,2）,它们的化学结构通过HRMS、¹H NMR、¹³C NMR、HSQC、HMBC和COSY等波谱分析得到确定。     

盐胁迫对红豆草幼苗生长和离子积累及分配的影响

以3周龄红豆草(Onobrychis viciaefolia)幼苗为材料,研究了不同浓度(0、5、25、50、100和200mmol·L~(-1))NaCl及50mmol·L~(-1)处理不同时间(0、1、3、5、7和9d)对其生长和离子积累及分配的影响,以期解析红豆草响应盐胁迫的生理机制。结果表明,与对照(0mmol·L~(-1))相比,5、25和50 mmol·L~(-1) NaCl对红豆草幼苗生长影响不大;而100和200mmol·L~(-1)明显抑制其生长。随着盐浓度增加,红豆草地上部和根Na+浓度呈显著增加趋势(P0.05),其中50~200mmol·L~(-1)下,地上部Na+浓度较对照增加14~39倍。特别是200mmol·L~(-1)使根Na+净吸收速率较对照增加了35倍,使整株总Na+量和地上部Na+相对分配比例分别增加了93%和45%;而显著降低了根的K+、Na+选择性运输能力。在50mmol·L~(-1) NaCl下,随着处理时间延长,地上部和根Na+浓度也呈逐渐增加趋势,但根中的Na+到7d时达到最大,然后呈下降趋势;相反,K+浓度均呈缓慢下降趋势,且根中的浓度始终高于地上部。由此可见,在5~50mmol·L~(-1) NaCl下,红豆草通过维持其体内K+、Na+稳态平衡抵御盐胁迫;而在100和200 mmol·L~(-1)下,红豆草地上部积累大量Na+,但其叶片Na+区域化及K+选择性转运能力较弱,导致植株体内Na+、K+稳态紊乱,产生离子毒害,从而抑制其生长。     

Water production functions of wheat (Triticum aestivum L.) irrigated with saline and alkali waters using double-line source sprinkler system

Expected yield losses as a function of quality and quantity of water applied for irrigation are required to formulate guidelines for the effective utilisation of marginal quality waters. In an experiment conducted during 2004-2006, double-line source sprinklers were used to determine the separate and interactive effects of saline and alkali irrigation waters on wheat (Triticum aestivum L.). The study included three water qualities: groundwater (GW; electrical conductivity of water, ECw 3.5 dS m⁻¹; sodium adsorption ratio, SAR 9.8 mmol L⁻¹; residual sodium carbonate, RSC, nil) available at the site, and two synthesized waters, saline (SW; ECw 9.4 dS m⁻¹, SAR 10.3 mmol L⁻¹; RSC nil) and alkali (AW; ECw 3.7 dS m⁻¹, SAR 15.1 mmol L⁻¹; RSC 9.6 meq. L⁻¹). The depths of applied SW, AW, and GW per irrigation ranged from 0.7 to 3.5 cm; the depths of applied mixtures of GW with either SW (MSW) or AW (MAW) ranged from 3.2 to 5 cm. Thereby, the water applied for post-plant irrigations using either of GW, SW or AW ranged between 15.2 and 34.6 cm and 17.1 and 48.1 cm during 2004-2005 and 2005-2006, respectively and the range was 32.1-37.0 and 53.1-60.0 cm for MSW or MAW. Grain yields, when averaged for two years, ranged between 3.08 and 4.36 Mg ha⁻¹, 2.57 and 3.70 Mg ha⁻¹ and 2.73 and 3.74 Mg ha⁻¹ with various quantities of water applied using GW, SW and AW, respectively, and between 3.47 and 3.75 Mg ha⁻¹ and 3.63 and 3.77 Mg ha⁻¹ for MSW and MAW, respectively. The water production functions developed for the two sets of water quality treatments could be represented as: RY = 0.528 + 0.843(WA/OPE) − 0.359(WA/OPE)² − 0.027ECw + 0.44 × 10⁻²(WA/OPE) × ECw for SW (R² = 0.63); RY = 0.446 + 0.816(OPE/WA) − 0.326(WA/OPE)² − 0.0124RSC − 0.55 × 10⁻⁴(WA/OPE) × RSC for AW (R² = 0.56). Here, RY, WA and OPE are the relative yields in reference to the maximum yield obtained with GW, water applied for pre- and post-plant irrigations (cm), and open pan evaporation, respectively. Crop yield increased with increasing amount of applied water for all of the irrigation waters but the maximum yields as obtained with GW, could not be attained even with increased quantities of SW and AW. Increased frequency of irrigation with sprinklers reduced the rate of yield decline with increasing salinity in irrigation water. The sodium contents of plants increased with salinity/alkalinity of sprinkled waters as also with their quantities. Simultaneous decrease in potassium contents resulted in remarkable increase in Na:K ratio.     

Cd胁迫对花花柴幼苗生长和生理特性的影响

[目的]研究Cd胁迫对花花柴幼苗生长和生理特性的影响。[方法]在实验室条件下,研究不同浓度Cd胁迫对花花柴幼苗生长的影响,检测不同浓度Cd胁迫对花花柴的相对电导率、叶绿素含量、MDA含量、CAT、SOD及POD活性的影响效应。[结果]Cd能够抑制花花柴幼苗的生长,随着Cd处理浓度的增加,苗的发芽率、发芽势、活力指数、鲜重、干重、根长、株长呈降低趋势。随着Cd浓度的增加,花花柴叶片相对电导率显著增加,MDA含量有增加趋势,CAT、POD和SOD活性相应增加并有波动情况,叶绿素含量显著下降。[结论]花花柴对Cd胁迫具有很强的耐受力,可作为Cd污染环境生物修复的候选植物。     

K+和Mg2+对盐胁迫下荞麦种子萌发及幼苗生长的影响

以耐盐荞麦品种川荞1号和盐敏感荞麦品种TQ-0808 为试验材料袁研究不同浓度K+和Mg2+对盐胁迫下荞麦种子萌 发及幼苗生长的影响。结果表明,不同浓度K+和Mg2+均对盐胁迫下荞麦种子萌发及幼苗生长有明显促进作用,10 mg/L K+和Mg2+对耐盐荞麦品种种子萌发及幼苗生长的促进效果最好,15 mg/L K+和Mg2+对盐敏感荞麦品种种子萌发及幼苗生长的促进效果最好,且最适浓度K+和Mg2+对盐敏感荞麦品种种子萌发及幼苗生长的促进效果优于耐盐荞麦品种。     

供Mg水平对烤烟累积N、K、Ca、Mg的影响

盆栽试验表明 :(1 )供 Mg促进烟株对 NO- 3-N的吸收和积累 ;(2 )供 Mg极显著提高烟叶中 Mg的含量 ,但也显著降低 K和 Ca的含量 ;(3 ) Mg与 K、Ca之间存在着拮抗作用 ;(4 )供 Mg提高烟叶的 K/(Ca+Mg)值 ,改善卷烟燃烧品质 .缺Mg,K/(Ca+Mg)比值较低 ,品质不良