沼液配施钾肥对果园土壤理化特性和微生物及果实品质影响

【目的】研究沼液和钾肥配合施用对苹果园土壤理化特性和微生物数量及果实品质的影响,为沼液在陕西渭北旱塬合理使用提供理论依据。【方法】以10年生礼泉短枝富士为试材,研究施用沼液和沼液与钾肥配施对苹果园土壤理化特性、微生物数量、果实品质的影响,筛选单施沼液和沼液配施钾肥的施用剂量。【结果】追施沼液可使土壤容重降低、孔隙度增加、碱解氮和速效钾的含量升高。其中沼液100kg/株处理的土壤容重比对照降低了10.6%,土壤孔隙度增加了7.6%;沼液50kg/株+钾肥1kg/株配施处理的土壤速效钾含量比对照增加了20.5%。沼液配施钾肥均可增加土壤细菌、真菌、放线菌的数量,其中沼液100kg/株处理的细菌、真菌、放线菌数量分别比对照增加了132.7%、38.3%和58.2%。各施肥处理均能不同程度改善果实品质,沼液配施钾肥可使果实着色率、单果重、硬度、可溶性固形物以及花青苷含量均有不同程度的提高。其中50kg/株+钾肥0.5kg/株处理的花青苷比对照提高了48%;着色面积比对照提高了29.9%。【结论】沼液100kg/株和沼液50kg/株+钾肥0.5kg/株在果园应用效果较好,可在生产上推广。     

钾营养胁迫对棉花形态发育和生理特性的影响分析

本研究通过去除耕层营造土壤缺素环境的方法,探讨了钾素营养缺乏对于棉花形态发育和生理特性的影响。结果表明:钾素营养胁迫具有抑制棉株主茎伸长和加粗生长的效应,不利于棉花的营养生长;同时,钾素营养胁迫对棉花主茎功能叶片蛋白质含量、叶绿素含量及其有效光合速率具有明显的抑制作用,一定程度上改变了棉花生长进程中物质积累和消耗的动态,从而表明钾素营养对棉花生理发育具有一定的调节作用。     

穿琥宁注射液对大鼠的长期毒性试验

将SD大鼠随机分为4个组,3个剂量组分别按75.7、15.14、7.57mg/kg通过腹腔注射法对大鼠给药,对照组给予同体积生理盐水,连续观察28d,记录大鼠毒副反应情况。停药后继续观察2周,测试大鼠体重、血液学指标、血液生化学指标、脏器指数。结果表明,各剂量组大鼠与对照组比较,给药期与恢复期的体重增长、血液学指标、血清生化指标、脏器指数均无显著性差异(P0.05)。试验结果表明,穿琥宁注射液连续给药28d,大鼠无不良反应,停药14d后亦未出现迟发性不良反应。     

牛奶中抗生素残留规律研究

为了解新疆地区奶牛生产中常用抗生素类药物在牛奶中的残留情况,本试验按照新疆地区奶牛生产中抗生素类药物的使用方法及剂量进行投放,并采集牛奶样品进行检测。结果表明,青霉素钾在牛奶中的残留规律为：停药1d〉5d〉3d;头孢噻呋钠为：停药3d〉5d〉1d;链霉素为：停药1d〉3d〉5d;长效土霉素在牛奶中的残留量在停药1～11d一直维持在175μg／kg左右。本试验中除了长效土霉素外,其他药物的残留量均低于中国和欧共体（EEC）规定的标准残留限量。     

青海绵羊血钾型与血液指标间的相关性研究

[目的]揭示青海高原绵羊血钾型的多态性特征。[方法]以青海省8个品种836只绵羊为试验动物,采用火焰光度法研究其血钾型特征及其与血液指标之间的相关性。[结果]被检绵羊均有高血钾（HK）和低血钾（LK）2种表型,其中LK型为优势表型;绵羊的血钾型无性别差异;在被检测的15项血液指标中（PCV、RBC、HB、MCV、MCH、MCHC、WBC、pH值、STP、STCa、SCl、SK、BK、SNa、EK）,LK型绵羊的WBC极显著高于HK型绵羊,而BK值和EK值极显著低于HK型绵羊,其他血液指标均无型间差异。[结论]该研究为高原绵羊血钾型的区分及种质研究提供了依据。     

不同钾浓度对玉米幼苗生长的影响

为研究钾素营养对玉米幼苗生长的影响,进而为合理施用钾肥、提高玉米的产量和品质提供理论依据,通过水培实验,利用不同的钾浓度处理‘郑单958’、‘吉单419’、‘四密21’ 3个品种的玉米幼苗,结果表明,随着钾离子浓度的降低,此3个品种玉米的株高、地上部和地下部鲜重、植物含钾量、叶绿素含量都随之减少,脯氨酸含量、丙二醛含量、超氧化物歧化酶活性随之升高;在无钾处理下,3种玉米的生长状况最差。     

Evaluation of the therapeutic effect of potassium permanganate at early stages of an experimental acute infection of Flavobacterium columnare in channel catfish,Ictalurus punctatus (Rafinesque)

The efficacy of potassium permanganate (KMnO₄) against the early stages of an experimental acute infection of Flavobacterium columnare in channel catfish, Ictalurus punctatus, was evaluated. Fish were experimentally challenged by waterborne exposure for 2 h to F. columnare after cutaneous abrasion, and treated with KMnO₄ at 2.0 mg L^?1 above the KMnO₄ demand at 0, 1, 2 or 4 h postchallenge for 24 h. Challenged non‐treated fish acted as a positive control and non‐challenged non‐treated fish acted as a negative control. Fish challenged and treated with KMnO₄ at 0, 1, 2 or 4 h postchallenge had mortalities of 26%, 63%, 64% and 83% respectively. The mortality of challenged fish treated with KMnO₄ at 0 h postchallenge (26%) was significantly less than the positive control (77%). The mortalities of challenged fish treated at 1, 2 or 4 h postchallenge were not significantly different from the positive control fish. The results suggest that KMnO₄ has a clear therapeutic value in early stages of columnaris infection but limited therapeutic value once the infection has progressed.     

河西灌漠土施钾效应的定位试验研究

4年定位试验表明，小麦、玉米、甜菜单作条件下施K无明显效果。带状间作条件下小麦作物第3、4年出现施K显效效应，平均增产12.4%～14.9%；带田玉米当年出现施K效应，连续4年平均增产率为16%～27.9%。K肥对带田作物品质也有改善作用。     

Potassium leaching from cut grassland and from urine patches

In grassland farming, especially on coarse‐textured soils, K can be a critical element. On these soils, the actual K management as well as fertilizer history to a large extent determine the leaching of K. The effects of four fertilizer regimes on the nutrient balances and leaching of K from grassland grown on a sandy soil were investigated. The swards differed in the source and level of N input and K fertilizer: no fertilizer N + 166 kg K ha^?1 year^?1 (Control), 320 kg inorganic N ha^?1 + 300 kg K ha^?1 year^?1 (MIN 320), 320 kg N + 425 kg K ha^?1 year^?1 in form of cattle slurry (SLR 320) and a grass–clover sward + 166 kg K ha^?1 year^?1 (WCL 0) without any inorganic N input. In a second experimental phase, cores from these swards were used in a mini‐lysimeter study on the fate of K from urine patches. On cut grassland after 6 years K input minus removal in herbage resulted in average K surpluses per year of 47, 39, 56 and 159 kg K ha^?1 for the Control, MIN 320, WCL 0 and SLR 320, respectively. Related leaching losses per year averaged 7.5, 5, 15 and 25 kg K ha^?1. Losses of urinary‐K through leaching were 2.2–4.5 and 5.7–8.4% of the K supplied in summer and autumn applications, respectively. Plant and soil were the major sinks for K from fertilizer or urine. High levels of exchangeable K in the soil and/or large and late fertilizer or urine applications stimulated leaching of K.     

中华绒螯蟹眼柄端髓X器官神经分泌细胞钙激活钾通道研究

采用膜片钳的内面向外式记录了中华绒螯蟹眼柄端髓X器官(MTXO)神经内分泌细胞钙激活钾通道活动。结果表明,在对称性高钾溶液中(200mmol.L-1),钙激活钾通道的单通道活动为快速开放的矩形方波,时程长短不一,通道电导为(213.4±11.2)pS。在-80~ 80mV钳制电压下,通道电流幅度及开放概率呈现明显的电压依赖性;随浴液游离Ca2 浓度的增加,通道的开放概率和开放数目增加,表现出明显的钙敏感性。药物敏感试验结果显示,80mmol.L-1四乙胺(TEA)可完全阻断通道活动。表明中华绒螯蟹眼柄端髓X器官(MTXO)神经分泌细胞钙激活钾通道(BKCa)具有大电导、电压依赖性、Ca2 敏感性和四乙胺(TEA)敏感性等特征。