硬骨鱼类渗透调控的研究进展

盐度是影响鱼类生长的重要水环境因子之一,盐度变化时鱼类会通过相应的生理调整来维持体内外渗透压的动态平衡。鱼类渗透调控的机制较为复杂,从细胞、酶、基因和激素等方面,对不同鱼类的盐度调节机理进行了分析和阐述。     

盐藻DNA对大豆幼苗耐盐性的影响

[目的]增强大豆幼苗的耐盐性。[方法]用0.1 mol/L氯化钙溶液浸泡大豆种子4 h后,将其浸入5 mg/L盐藻DNA水溶液中,蒸馏水浸泡作为对照组。选取长势一致的大豆幼苗,用蒸馏水冲洗干净幼苗的根部,栽于含3 g/L氯化钠的MS培养液中,处理与对照各60株。检测大豆幼苗耐盐适应性的变化。[结果]处理组的植株鲜重和株高分别较对照高出33.6和22.1个百分点,存活率高出46.7个百分点,根数减少了26.2个百分点,根长缩短了17.6个百分点。[结论]盐藻DNA提高了大豆幼苗的耐盐性。     

盐度胁迫对茳芏·短叶茳芏萌芽的影响

[目的]研究茳芏及短叶茳芏两种盐沼植物不同盐胁迫下对其萌芽的影响情况。[方法]以2种茳芏作为材料,采用盆栽实验研究盐胁迫下不同种茳芏的萌芽情况。[结果]低盐度对2种植物萌芽有促进作用,在盐度〉10‰的情况下,萌芽受到抑制,盐度越高抑制作用越大。[结果]2种植物适宜种植在低盐度地区。     

盐度对黄颡鱼幼鱼生长与饲料利用率的影响

[目的]为推广黄颡鱼养殖技术提供参考。[方法]用不同盐度水体养殖黄颡鱼幼鱼,研究其对水体盐度的适应性及盐度对其生长和饲料利用率的影响。[结果]在盐度为11.5‰的水体中养殖96h后黄颡鱼无死亡现象,而盐度为14.4‰的水体中黄颡鱼全部死亡,且水体盐度越大,黄颡鱼死亡速度越快;水温为（25±1）℃时,黄颡鱼的安全盐度为3.83‰,48、96h的半数致死盐度分别为13.38‰、12.93‰;在盐度为2‰～7‰的水体中养殖85d后,黄颡鱼的成活率达94%～100%,鱼体日增重0.24～0.25g/尾,不同盐度水体中鱼体重增加幅度无显著差异;黄颡鱼的饵料系数在1.6～3.0,随水体盐度增加饵料系数呈下降趋势。[结论]该研究明确了黄颡鱼幼鱼的耐盐性及其生长的适宜水体盐度范围。     

温度和盐度对球形棕囊藻细胞群体形成的影响

球形棕囊藻的生活史中表现为两种不同的生活形态：群体和自由单细胞。环境因子在球形棕囊藻细胞群体形成过程中有相当重要的作用。采用单因子试验研究温度和盐度对球形棕囊藻细胞群体形成的影响。结果表明,温度和盐度与球形棕囊藻细胞群体形成都有显著相关性。盐度28、温度25℃时形成的细胞群体平均值最大。     

基于叶绿素a浓度的珠江口感潮河段咸潮监测研究

依据实测资料研究了珠江口最主要的感潮河段沙湾-虎门水道和磨刀门水道水体的叶绿素浓度、盐度的高光谱特征及其空间变化趋势。结果表明：水体叶绿素a浓度和反射率波段比值有较好的相关关系,最佳关系在R704/R513处,r=0.92;在盐度大于2‰的情况下,随着盐度增加叶绿素a浓度逐渐降低,并且向伶仃洋方向随着盐度的增加叶绿素a浓度是递减的。在珠江沙湾-虎门以及磨刀门感潮河段,水体表面盐度与叶绿素a浓度之间表现为较好的负相关关系,表明可以用叶绿素a浓度来推定咸潮的入侵情况。因此,通过遥感图像反演出水体的叶绿素a浓度进而推断珠江口河网区的咸潮入侵空间变化是可能的。     

盐度对克氏双锯鱼仔鱼活力和仔稚鱼培育效果的影响

[目的]为提高克氏双锯鱼人工育苗技术提供科学依据。[方法]研究不同盐度梯度海水对克氏双锯鱼仔鱼盐度耐受力及仔稚鱼培育效果的影响。[结果]盐度为15 psu时,仔鱼的生存活力指数（SAI）最高,为（5.67±0.27）;盐度为5 psu和40 psu时,SAI较低,分别为（0.20±0.17）和（1.25±0.25）。培育结果表明,盐度对克氏双锯鱼仔稚鱼存活率存在显著影响,盐度在10~35 psu,存活率呈现中间高两边低的趋势;盐度为15 psu和20 psu时,存活率最高,分别为（50.37±3.35）%和（48.52±4.46）%;盐度10 psu时,存活率最低,为（12.04±2.31）%。各盐度组仔稚鱼全长和体重的增长呈现随盐度上升而下降的趋势,盐度15 psu时生长最快,全长增长12.46 mm,体重增长84.34 mg;盐度35 psu时生长最慢,全长增长9.20 mm,体重增长33.44 mg。[结论]克氏双锯鱼在盐度15~20 psu存活率最高,盐度10~15psu生长最快,因此,壳氏双锯鱼仔稚鱼培育的最佳盐度是15~20 psu。     

海蓬子抗盐性研究进展

对近年来海蓬子（Salicornia bigelovii）抗盐机理的研究进展作了概述,阐明了海蓬子对盐分的反应及盐分对植物的不同伤害;并对盐胁迫对海蓬子生长状况的影响和生理生化变化的研究进展作一综述,对海蓬子的开发前景进行了展望。     

The combined effects of salinity and excess boron on mineral ion relations in broccoli

Two plant stress factors, salinity and high levels of boron, often co-occur in natural and agricultural environments. Many investigations have been conducted to document the influence of the combined stresses on crop growth and yield. Only limited information, however, is available concerning the combined effects of the two stresses on mineral ion uptake and partitioning to shoot organs and tissues. Data for this study were obtained from an experiment conducted in greenhouse sand cultures with two water types: (1) a chloride-dominated system, and (2) sulfate-dominated waters characteristic of those present in the San Joaquin Valley of California. Each saline composition treatment was tested at three salinity levels (2, 12, 18 dS m⁻¹) and three B concentrations (0.046, 1.11, 2.22 mM; 0.5, 12, 24 mg L⁻¹). The gradient in B distribution in individual leaves sampled midseason was steep, with less boron accumulating in petioles than in the blades. The highest B concentrations (>100 mmol B kg⁻¹ dry weight) were found in leaf margins of plants grown in the low salinity-high boron treatments. These leaves were cupped upward, an unusual visual symptom characteristic of B toxicity. At final harvest, concentrations of B, Ca, Mg, Na, K, and Cl were highest in the oldest leaves on the broccoli shoots, decreasing acropetally to the heads. Total-P, however, was highest in broccoli heads, decreasing in the older tissues. Leaf-B accumulation was more closely related to salinity rather than to the concentration of Cl in the irrigation waters. Analysis of variance indicated that substrate B had little effect on Cl accumulation in salt-stressed broccoli leaves regardless of water type. No clear cut relationships were evident that would explain the reciprocal effects of B and Cl on crop yields.     

pH及盐分对大丽轮枝菌微菌核形成的影响

微菌核是棉花黄萎病原大丽轮枝菌(Verticillium dahliae Kleb.)在土壤中的主要存活形式及该病的侵染源,研究土壤pH及盐分对大丽轮枝菌微菌核形成的影响对明确黄萎病发生具有重要意义。采用菌丝生长速率法研究培养基pH及盐分质量浓度与种类对病原菌生长及微菌核形成的影响。供试大丽轮枝菌菌丝生长最适pH为7.0,偏酸或偏碱会抑制菌丝生长,但培养基偏碱可显著促进微菌核形成。当pH为8.0时,大丽轮枝菌菌丝生长受抑制较小,同时微菌核区面积较pH为7.0时增加22.6%。盐分质量浓度影响大丽轮枝菌菌丝生长及微菌核形成。随培养基NaCl质量浓度增加,供试大丽轮枝菌生长受到抑制,菌落面积和菌丝面积均逐渐减小,但微菌核形成量却显著增加;当NaCl质量浓度为10g·L~(-1)时,微菌核区面积较无NaCl时增加40.7%。盐分种类影响供试大丽轮枝菌生长。随盐分质量浓度增加,氯化物(NaCl和KCl)和硫酸盐(Na_2SO_4和MgSO_4)均可促进大丽轮枝菌微菌核形成,而CaCl_2则显著促进菌丝生长,并在质量浓度大于7g·L~(-1)时抑制微菌核形成。在培养环境偏碱性或氯化物和硫酸盐含盐量较高时,均可促进棉花黄萎病原大丽轮枝菌微菌核形成量增加。