草坪草耐盐性研究 Ⅰ.不同草种和品种在盐胁迫下的抗逆性

用 5个盐分浓度对 2 6个 4周龄草坪草品种进行盐胁迫处理 ,结果证明 ,同一种的不同品种间耐盐力无显著差异 ,而不同草种间差异明显。高浓度 (2 .0 % )下所有草坪草均不能存活 ,而低浓度(0 .5% )下存活时间最长的为高羊茅和匍匐剪股颖。     

NaCl对转P5 CS基因水稻种子萌发的影响

脯氨酸是植物体内非常重要的渗透调节化合物,它的积累可增加植物对干旱、盐碱的耐受能力。P5CS(Δ1-吡咯啉-5-羧基合成酶基因)在植物中催化脯氨酸生物合成的前两部反应,其活性受到脯氨酸含量的反馈抑制。本研究对转P5CS基因的水稻T4代种子与对照在不同浓度的NaCl胁迫下的萌发进行试验。结果表明,随着NaCl浓度的增高,种子萌发受到的抑制越大,但在100 mmol/L时转P5CS的种子萌发率、生理指标、ABA、脯氨酸和可溶性糖的含量显著高于对照,但可溶性蛋白低于对照。说明转P5CS基因的水稻有显著的耐NaCl胁迫作用。     

盐胁迫对雪菊种子萌发的影响

采用纸培法，用不同浓度NaCI单盐溶液（O％、0．5％、0．6％、0．9％、1．2％）处理雪菊种子，研究不同浓度盐胁迫对种子萌发的影响。结果表明：随着盐浓度的升高，雪菊种子的发芽率、发芽势、发芽指数、活力指数都有所降低，在O％～0．9％盐浓度范围内，各性状指标与对照差异不显著，1．2％盐浓度下与对照形成显著差异。低浓度（0．3％）盐胁迫对雪菊种子萌发有促进作用，发芽率为87％，高于对照3个百分点，盐浓度超过0．9％时，明显延迟种子发芽时间，发茅率为57％，低于对照27个百分点。雪菊种子萌发时的耐盐适宜范围为0％～1．5％，耐盐半致死浓度为2．25％，耐盐极限浓度为5．85％，可在河北滨海滩涂盐渍化土壤地区推广种植。     

Existence of salt glands on leaves of kallar grass (Leptochloa fusca L. Kunth.)

Light microscopic studies have established the existence of salt glands on “Kallar grass”; leaf blades. The salt glands resembled the two‐cell type structure described for some halophytic genera within the Gramineae. The secreted salts crystallized and formed whiskers when the plants were grown under continuously high saline conditions. The salt secretion appears to be selective. The secretion of Na exceeded that of K and considerable quantities of Cl were also extruded, preferentially in concomitance with Na. The significance of growth hormones and Ca in regulating the salt secretion process is discussed.     

Effects of Salinity and Soil–Drying on Radiation Use Efficiency,Water Productivity and Yield of Quinoa (Chenopodium quinoa Willd.)

Drought and salinity reduce crop productivity especially in arid and semi‐arid regions, and finding a crop which produces yield under these adverse conditions is therefore very important. Quinoa (Chenopodium quinoa Willd.) is such a crop. Hence, a study was conducted in field lysimeters to investigate the effect of salinity and soil–drying on radiation use efficiency, yield and water productivity of quinoa. Quinoa was exposed to five salinity levels (0, 10, 20, 30 and 40 dS m^?1) of irrigation water from flower initiation onwards. During the seed‐filling phase the five salinity levels were divided between two levels of irrigation, either full irrigation (FI; 95 % of field capacity) or non‐irrigated progressive drought (PD). The intercepted photosynthetically active radiation was hardly affected by salinity (8 % decrease at 40 dS m^?1) and did not differ significantly between FI and PD. Radiation use efficiency of dry matter was similar between salinity levels and between FI and PD. In line with this, no negative effect of severe salinity and soil–drying on total dry matter could be detected. Salinity levels between 20 and 40 dS m^?1 significantly reduced the seed yield by ca. 33 % compared with 0 dS m^?1 treatment owing to a 15–30 % reduction in seed number per m², whereas the seed yield of PD was 8 % less than FI. Consequently, nitrogen harvested in seed was decreased by salinity although the total N‐uptake was increased. Both salinity and drought increased the water productivity of dry matter. Increasing salinity from 20 to 40 dS m^?1 did not further decrease the seed number per m² and seed yield, which shows that quinoa (cv. Titicaca) acclimated to saline conditions when exposed to salinity levels between 20 and 40 dS m^?1.     

Salt‐Induced Regulation of Some Key Antioxidant Enzymes and Physio‐Biochemical Phenomena in Five Diverse Cultivars of Turnip (Brassica rapa L.)

A greenhouse experiment was carried out to examine the differential morpho‐physiological responses of five cultivars of turnip (Brassica rapa L.) to salt stress. Five diverse cultivars of turnip (shaljum desi surakh, shaljum purple top, shaljum golden bal, neela shaljum, and peela shaljum) were subjected for 6 weeks to varying levels of NaCl, i.e. 0, 80 and 160 mm in Hoagland’s nutrient solution in sand culture. Imposition of varying levels of salt substantially decreased shoot and root fresh and dry weights, chlorophyll contents, leaf osmotic potential, relative water contents, different gas exchange attributes, total phenolics, malondialdehyde, activities of superoxide dismutase, peroxidase catalase, and leaf and root K⁺ levels while enhanced the proline contents, membrane permeability, level of H₂O₂, leaf and root Na⁺ and Cl^? and leaf Ca²⁺ in all turnip cultivars under study. Of all cultivars, peela shaljum and neela shaljum were consistently higher in their growth than the other turnip cultivars at all salt concentrations of the growth medium. Photosynthetic capacity (A) and stomatal conductance (g_s) were higher in high biomass‐producing cultivars, i.e. peela shaljum and neela shaljum, which provide to be potential selection criteria of salt tolerance in turnip. However, the regulation of antioxidant system was cultivar‐specific under saline conditions.     

水稻耐盐分子机制研究进展

水稻是世界上重要的粮食作物之一，对盐胁迫比较敏感，土壤盐碱化对水稻的安全生产造成潜在风险。盐胁迫会引起水稻的渗透胁迫和离子毒害，还会在植株中引起氧化胁迫，导致水稻品质和产量下降。由于水稻根系能吸收盐分分泌有机酸，同时具有田间持水和排水晒田的生长特性，因此水稻也是一种改良盐渍土的优良作物。因此培育耐盐水稻新品种，提高水稻耐盐性，可有效提高盐渍化耕地的生产潜力，对保障我国乃至全球粮食安全具有重要意义。近年来，数量遗传学和分子标记技术不断发展，通过遗传、生化及分子生物学等手段，挖掘出大量耐盐相关 QTL 和基因，对于解析水稻耐盐分子机制，利用分子标记辅助选择、基因编辑等提高耐盐水稻育种效率，均具有非常重要的意义。但目前克隆的耐盐相关基因大多采用反向遗传学方法获得，且大多是在过表达条件下表现出耐盐性，或者耐盐基因为隐性，难以在耐盐水稻育种中应用。总结近年来水稻耐盐相关基因的鉴定和挖掘研究中所取得的进展，从有机物渗透调节、离子吸收转运调节、抗氧化系统清除活性氧调节、激素调节 4 个方面综述水稻耐盐分子机制的研究进展，并探讨未来水稻耐盐性研究面临的挑战，为开展水稻耐盐分子育种提供建议。     

麦草碱木质素三甲基季铵盐对酸性染料溶液的絮凝性能影响

以从造纸黑液中提取的麦草碱木质素为原料,通过曼尼希反应合成麦草碱木质素三甲基季铵盐,以脱色率为指标检测其对酸性黑ATT、酸性橙GG和酸性红B的絮凝性能。实验结果表明:对于0.1 g/l酸性黑ATT溶液,pH为2,麦草碱木质素三甲基季铵盐使用浓度在0～3 500 mg/l范围内时,脱色率随浓度增大而升高;麦草碱木质素三甲基季铵盐使用浓度为2 884 mg/l时,在pH为1～4范围内,脱色率随pH降低而增加。酸性橙GG和酸性红B也有类似的规律。由上述结论结合麦草碱木质素三甲基季铵盐和酸性染料的结构特点,认为絮凝过程先是麦草碱木质素三甲基季铵盐中的铵离子与酸性染料中的磺酸根之间氢键吸引,然后染料间产生"架桥"现象,具有三维网状结构的碱木质素分子继续网捕和卷扫脱除染料。     

复方柴胡散治疗鸡尿酸盐沉积效果初报

  鸡尿酸盐沉积病是由多种病因引起的肾脏机能障碍的总称【1】。发病时间长，死亡率高。主要表现为肾尿酸盐沉积,肿胀、充血、出血。轻者使雏鸡生长受阻、成鸡生长性能降低，重者导致大量死亡。尿酸盐沉积为一种慢性疾病。日粮中蛋白质含量过高、高钙日粮或高钙低磷日粮、维生素缺乏、药物慢性中毒、某些传染病及其它若干因素都可引发本病。目前临床上尚无特效的治疗方法，而且治愈率较低，治疗操作不便等因素，给养鸡业带来一定的经济损失。本实验以柴胡方剂为主要药物，以清热、通便、理气为治疗原则。本试验药物具有操作简便、治愈率高、经济实惠。通过人工复制病例和鸡场自然病例的试验，治愈率达到90％以上。     

奶牛阴离子日粮的配制与应用

目前防治奶牛产褥热效果较好的方法是给产犊前3—5周的经产怀孕母牛饲喂阴离子日粮。但高量阴离子盐类适口性差，对采食量产生不良影响，因此想要地通过添加阴离子盐类来防止产褥热并期望得到应有的效果，有时是不可能的。针对该问题，本文介绍了阴离子日粮的配制与应用的方法。