Effect of salt stress on activity of superoxide dismutase （SOD） in Ulmus pumila L.

The injury tolerance of cell plasma membrane and the correlative enzymes activities of plasma-membrane protection system in the Ulmuspumila leaves treated by nine concentrations （0.3%, 0.6%, 0,9%, 1,2%, 1.5%, 1.8%, 2,1%, 2.4%, 3.0%） of Na2CO3 and NaHCO3 mixtures were studied in a greenhouse of Northeast Forestry University, Harbin, China. The rate of electrolyte leakage （REL） and SOD （Superoxide dismutase） activity in leaves of different samples were determined. Results showed that the REL in leaves of U. pumila presented a slowly increasing trend at the salt concentrations less than 1.5%, which indicated that cell plasma membrane of U. pumila leaves had rather strong resistance to the injury of salt ion, and had a significant increase at the salt concentrations more than 1.5%. The SOD activities in leaves of U, pumila presented an increased trend at salt concentrations less than 1.5%, the growth of seedlings did not decline, and tress and leaves had no symptom of injury, while the salt concentrations exceeded 1.5%, SOD activities sharply decreased and REL increased promptly.     

海南西瓜三叶枯病的病原鉴定及室内药剂筛选试验

西瓜三叶枯病是海南省西瓜栽培过程中出现的一种严重的病害。通过对该病菌原培养特性，形态特征和寄主范围的测定，鉴定出西瓜三叶枯病的病原为极孢属。采用含毒介质法，进行了８种药剂对该菌的毒力测定。结果表明：扑海因和代森锰锌抑菌效果最好。     

鱼在腌制过程中水份活度和有关参数的变化关系

本文研究了腌制鱼的水分活度(Aw值)变化及其与其他有关参数的关系。以鲳鱼作为试验原料,用混合腌渍法对鱼品进行不同时间的腌制,然后观察鱼体中水分活度、盐分含量和水分含量的变化情况,并进一步探索这些参数之间相互的变化关系。实验结果表明,鱼体中水分活度和水分含量的降低,盐分的增加均在开始腌制至18小时时为最快;18小时后变化缓慢;34小时后基本趋向平衡。实验表明,水分活度,盐分含量与水分含量之间存在简单的线性关系,因此在腌制过程中,测定出水分和盐分含量就可以计算出水分活度Aw值,从而达到控制鱼品质量的目的。此方法在提高鱼品的保藏效果上具有一定的实用价值。     

甲基汞对鲤鱼血浆渗透压及鳃丝Na＋－K＋－ATPase活性的影响

以水体甲基汞不同浓度（μｇ／Ｌ）分别染毒鲤鱼２４小时和１周。实验结果表明：在浓度高于５０μｇ／Ｌ染毒２４小时和浓度２０μｇ／Ｌ染毒１周时，多数染毒鱼的血浆Ｋ＋和Ｍｇ２＋浓度增高，Ｎａ＋和Ｃｌ－浓度下降，ＰＯ３－４值变化不明显。血浆Ｃａ２＋浓度仅在２００μｇ／Ｌ染毒２４小时和高于４０μｇ／Ｌ染毒１周时，染毒鱼的血浆Ｃａ２＋出现极显著下降。甲基汞量高于１００μｇ／Ｌ染毒２４小时和８０μｇ／Ｌ染毒１周，染毒鱼的血浆渗透压呈明显下降趋势。鳃线粒体Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ活性仅在染毒２４小时浓度为２５μｇ／Ｌ和５０μｇ／Ｌ剂量时受到抑制。甲基汞还引起了血糖含量的明显增高。     

离子浓度和一氧化氮供体对池塘养殖鳗鲡精子活力的影响

鳗鲡是世界性的优质养殖鱼类,20世纪80年代以来养鳗业迅速发展,已成为水产产业化程度最高的养殖品种之一,但养殖所需的苗种完全靠天然捕捞。早在1934年Boucher等[1]就用孕妇尿促使雄性欧洲鳗(A.anguilla)精巢成熟,Yamamoto和Yamauch于1974年对日本鳗鲡进行人工催熟获得精子[2],但多年来鳗鲡精子质量和数量一直在波动(数量JOURNALOFFISHERIESOFCHINA　　　　　　　　　　　Vol.27,No.4　为0.1～0.4g,运动精子为20%～50%)[3,4],因此,如何稳定和提高精子的质量和数量的研究是非常必要的。绝大多数鱼类的受精过程是在体外条件下进…     

Potassium antagonizes damage of coronary artery induced by high salt intake

AIM：To investigate the effect of potassium treatment on coronary arterial impairment induced by high salt intake. METHODS：Sprague-Dawley rats (4-week-old, n=10 in each group) received distilled water (NS), water containing 1.5% NaCl (HS), or 1.5% NaCl and 0.5% KCl (HS+HP) for 16 weeks. Systolic blood pressure (SBP) was determined by tail plethysmography every 2 weeks. After 16 weeks of treatment, vascular remodeling, superoxide production, malondialdehyde (MDA) content, and endothelial nitric oxide synthase (eNOS) and gp91 expression in the coronary arteries were detected. RESULTS：After 16 weeks of salt loading, the rats in HS group was divided into salt sensitive subgroup and salt resistance subgroup according to the tail-cuff blood pressure. In this experiment, the salt-sensitive rats were selected as HS group. In HS group, salt loading significantly increased SBP, serum MDA and gp91 expression, decreased serum NO and eNOS expression in the coronary arteries, and induced the coronary artery remodeling compared with NS group. In salt-loaded SD rats, 16-week potassium treatment abrogated the effects induced by salt loading. CONCLUSION：High salt may affect structural and functional changes in coronary arteries by activating oxidative stress. Potassium treatment antagonizes the effect of high salt intake.     

蔬菜盐害生理及其缓解措施的研究进展

综述了近年来蔬菜盐害生理的最新研究进展,包括盐胁迫下蔬菜种子萌发、幼苗生长、光合特性、抗氧化能力、离子分配、果实产量和品质等方面,以及一些缓解盐胁迫的农艺措施,同时分析了目前存在的问题及发展趋势。     

植物bZIP转录因子及其耐盐性调控研究进展

盐害影响植物的生长发育,碱性亮氨酸拉链类转录因子bZIP参与了植物的盐胁迫响应,因此就植物对高盐胁迫的理化反应、bZIP转录因子的功能及在植物高盐逆境下的作用的研究进展进行了综述,对今后利用bZIP基因改良植物耐盐性具有参考价值。     

Some proteolytic properties of hatching liquid in the sea trout,Salmo trutta m. trutta L.

Proteolytic activity of sea trout hatching liquid was examined towards casein and azocazein as a function of pH and temperature. The optimum pH for caseinolytic and azocaseinolytic activities were 9.4, and 9.0, respectively. At alkaline pH the enzyme was activated by low concentrations of Zn²⁺ ions (10⁻⁵ M). Maximum proteolytic activity of the hatching liquid was observed at 25°C. Temperatures exceeding 30°C caused a rapid reduction in enzyme activity. Proteolytic activity observed at 10°C was approximately 50% of that observed at 25°C. In general, a pseudo-Arrhenius plot indicated a Q₁₀ of 1.6 between 6 and 25°C.     

玉米自交系耐盐种质的筛选及耐盐性评价

在0+0、2.5+2.5、5+5和7.5+7.5 mmol/L（Na₂CO₃+NaHCO₃）盐浓度胁迫下,对118份玉米自交系芽期、苗期的耐盐性差异进行比较,以主要农艺性状综合表现为依据筛选耐盐种质。各指标受盐害影响程度大小顺序为株高>芽势>叶长>根长>地上含水量>地下含水量>叶宽>芽率>须根数>根冠比>茎粗>根粗;当盐胁迫溶液为7.5 mmol/LNa₂CO₃+7.5 mmol/L NaHCO₃时,对玉米自交系影响差异显著。综合各个指标的盐害率对118份玉米自交系进行评价和排序,5个耐盐性强的自交系品种为DL、A71、PHB1M、A92和WM33;对盐敏感的5个品种为06NY-25、Mo17、郑32、南引26和农M1。