葡萄苗铝-旱交叉适应对水杨酸的生理响应

以‘玫瑰蜜’葡萄苗为试材,预先用氯化铝和水杨酸处理5周后,再用200g/L聚乙二醇(PEG-6000)模拟干旱处理10d,探讨铝诱导葡萄苗对干旱胁迫的交叉适应及铝-旱交叉适应对水杨酸的生理响应。结果表明,预先铝处理可使葡萄幼苗在干旱胁迫下叶绿素a、叶绿素b、叶绿素a+b、类胡萝卜素的质量分数和相对含水量的降低幅度明显减小,使MDA质量摩尔浓度、相对电导率、氧自由基产生速率和过氧化氢质量摩尔浓度的增加幅度明显减小,使SOD和POD活性、可溶性蛋白质和游离脯氨酸质量分数增加幅度明显增大。添加外源水杨酸后,使这种增减幅度进一步加大。其中,以添加50μmol/L水杨酸后效果最明显,使叶绿素a、叶绿素b、叶绿素a+b和类胡萝卜素的质量摩尔浓度及相对含水量的降低幅度进一步变小,使MDA质量摩尔浓度、相对电导率、氧自由基产生速率和过氧化氢质量摩尔浓度的增加幅度进一步变小,使SOD和POD活性、可溶性蛋白质和游离脯氨酸的质量分数增加幅度进一步变大。可见,预先铝处理可诱导葡萄苗对干旱胁迫的交叉适应性,水杨酸对其有明显的促进作用。     

池塘中亚硝酸盐对草鱼种的毒害及防治

亚硝酸盐对草鱼种有很高的毒性,特别是水温超过30℃以上时。它主要是诱导草鱼血液中的血红蛋白转变为高铁血红蛋白,高铁血红蛋白超过血红蛋白总量的23.0％时,容易诱发草鱼出血病。随着草鱼血液中高铁血红蛋白的增高,红细胞数量和血红蛋白含量逐渐减少。池中亚硝酸盐氮含量到0.099±0.03毫克/升时,草鱼会出现出血病。清除水中亚硝酸盐氮的方法是在池塘中施加次氯酸钠,亚硝酸盐氮超过0.15毫克/升时,最好在池塘中先施加熟石灰,然后施加次氯酸钠,且以分次施用,效果较好。     

Sodium alginate supplementation modulates gut microbiota,health parameters,growth performance and growth‐related gene expression in Malaysian Mahseer Tor tambroides

This study investigated the effects of sodium alginate supplementation on gut microbiota composition, health parameters, growth performances and growth‐related gene expression of Malaysian mahseer. Five test diets were formulated by supplementing 0%, 0.1%, 0.2%, 0.4% and 0.8% sodium alginate. Triplicate groups of juvenile Tor tambroides (2.19 ± 0.05 g) were stocked in 15 aquaria (20 individuals per aquarium) and fed at 3.0% body weight per day for 60 days. PCoA and UPGMA analysis showed that gut bacterial community were more convergence in higher sodium alginate‐supplemented diets. The percentage of Porphyromonadaceae, Bacteroides, Plesiomonas and Shewanella were substantially higher and Aeromonas, Entomoplasmatales and Prevotellaceae were drastically lower in higher sodium alginate (0.2%–0.8%) diets. Sodium alginate supplementation (≥0.2%) significantly improved the haematocrit value and respiratory burst activity of T. tambroides. Growth performances and feed utilization were significantly higher in 0.2%–0.4% sodium alginate‐supplemented diets. The increased growth rate of T. tambroides was governed by both hyperplastic and hypertrophic muscle growth. Real‐time PCR data demonstrated that most of the growth‐related genes were significantly upregulated in 0.2%–0.4% sodium alginate‐supplemented diet. Finally, it can be concluded that sodium alginate should be supplemented at 2 g/kg in practical fish feed formulation.     

Effects of dietary selenium on growth performance and oxidative stress in juvenile grass carp Ctenopharyngodon idellus

An 8‐week feeding trial was conducted to investigate the effect of dietary selenium (Se) on feed intake, weight gain and antioxidant activity in juvenile grass carp (11.2 ± 0.03 g). Six Se levels (0.13, 0.41, 0.56, 1.12, 2.18 and 4.31 mg/kg) of semi‐purified diets were assayed in triplicate. The maximum weight gain, specific growth rate and feed intake were obtained in fish fed with 1.12 mg Se/kg diet. Hepatic glutathione peroxidase activity was markedly increased when dietary Se ≤1.12 mg/kg diet and reached a plateau when dietary Se ≥1.12 mg/kg diet. Hepatic superoxide dismutase and serum catalase activities in juvenile grass carp fed with 0.56, 1.12 and 2.18 mg Se/kg diets were all significantly higher than those in the other groups. The malondialdehyde content in liver and serum was firstly decreased and then increased with increasing dietary Se content, and the lowest content was observed in fish fed with 1.12 mg Se/kg diet. With the increase in Se level, the activities of serum alanine aminotransferase and aspartate aminotransferase were reduced. In addition, serum alkaline phosphatase activity and albumin content were highest in fish fed with 1.12 mg Se/kg diet. This study indicated that both the Se deficiency and excess of Se caused negative effect on the oxidative stress in juvenile grass carp and suggested that the health‐giving concentration of dietary inorganic Se was 1.12 mg/kg diet. Moreover, based on the broken‐line regression analysis of weight gain, the optimal concentration of dietary inorganic Se was 0.83 mg/kg for juvenile grass carp.     

丁酸钠对脂多糖诱导的奶牛乳腺上皮细胞系炎性损伤的修复作用

本研究拟通过分析丁酸钠对脂多糖(LPS)诱导的奶牛乳腺上皮细胞系(MAC-T细胞)炎性损伤的修复作用,进一步从体外角度阐述丁酸钠对奶牛乳腺健康的调控机制。在MAC-T细胞中添加不同浓度(0、1、10、100、1 000、10 000 ng/mL)的LPS,检测细胞活力,以确定LPS的适宜浓度,建立细胞氧化损伤模型;并进一步在MAC-T细胞中添加不同浓度(0、2、4、8、16、32μmol/L)的丁酸钠,检测细胞凋亡率,以确定丁酸钠的适宜浓度。最终选用1 000 ng/mL LPS和16μmol/L丁酸钠用于本试验。试验分为3组,分别为对照组、LPS处理组和LPS+丁酸钠处理组,分别对其细胞形态、氧化应激指标及凋亡蛋白mRNA表达水平进行检测。结果表明：1)对照组MAC-T细胞呈扁平的无规则形态,贴壁状态良好;而LPS处理组MAC-T细胞核固缩、破裂,并出现大面积死亡脱落现象;LPS+丁酸钠处理组MAC-T细胞边缘清楚,胞内颗粒较少,死亡脱落现象明显减少。2)与对照组相比,LPS处理组MAC-T细胞中超氧化物歧化酶(SOD)活性和总抗氧化力(T-AOC)显著降低(P<0.05),丙...     

不同锌源及添加水平对肉仔鸡生长性能的影响及其生物学利用率评价

本试验旨在研究碱式氯化锌(BZC)和蛋白锌(PRZ)相对于一水合硫酸锌(ZSM)的生物学利用率以及对肉仔鸡生长性能的影响。采用双因素(3×3+1)完全随机试验设计,选取720只1日龄健康雄性爱拔益加(AA)肉仔鸡,随机分为10个组,每组6个重复,每个重复12只鸡。对照组饲喂玉米-豆粕型基础饲粮,3个ZSM组分别饲喂在基础饲粮基础上添加20、40和80 mg/kg ZSM的饲粮,3个BZC组分别饲喂在基础饲粮基础上添加20、40和80 mg/kg BZC的饲粮,3个PRZ组分别饲喂在基础饲粮基础上添加20、40和80 mg/kg PRZ的饲粮。各组不同锌源添加量均以锌计。试验期42 d,分为1～14日龄、15～28日龄和29～42日龄3个阶段。分别在14和28日龄时,从各重复中选取1只接近平均体重的鸡进行屠宰,测定血浆锌含量和抗氧化指标、组织锌含量以及胰脏锌相关蛋白基因表达水平。结果表明：1)1～14日龄,与对照组相比,饲粮添加不同锌源和添加不同水平锌显著提高肉仔鸡平均日增重(ADG)和14日龄体重(P<0.05),显著降低料重比(F/G)(P<0.05),且以添加40 mg...     

包膜含缩节胺氯化钾对棉花产量及土壤钾素的影响

棉花是具无限生长特性的喜钾作物,为解决其生育期内多次追施钾肥和叶面喷施缩节胺的用工问题,实现轻简化种植目标,研究包膜含缩节胺氯化钾对棉花产量、经济效益和土壤钾素变化特征的影响。试验设5个处理,分别为一次基施180 kg?hm-2包膜含缩节胺氯化钾（CRKMC）、减少30%钾素用量（126 kg?hm-2）的包膜含缩节胺氯化钾（70%CRKMC）、基施180 kg·hm^-2普通包膜氯化钾（CRK）、分次施用180 kg?hm-2普通氯化钾（KCl）和对照（CK,不施钾肥）,后三个处理叶面喷施三次缩节胺。结果表明：等量施钾条件下,CRKMC和CRK较KCl籽棉产量分别增加8.81%和9.36%,经济效益分别增加15.53%和12.86%,70%CRKMC较KCl增产6.53%,增加净收入13.64%。CRKMC抑制棉花盛花期前的株高,提高后期株高、茎粗和叶绿素含量,使生物量较KCl增加18.56%~24.98%,提高钾素吸收量,表观利用率增加25.06~38.83个百分点。CRKMC中的钾素和缩节胺在土壤中呈“先慢后快而后趋于平缓”的规律,释放高峰出现在盛花期至始絮期,显著提高蕾期以后土壤中的速效钾含量。因此,土壤基施包膜含缩节胺氯化钾,可合理协调棉花生长势指标,满足钾素吸收需求,减少30%用量仍有较高的经济效益和钾素利用率,实现了缩节胺和钾素在同一时空条件下的一体化调控,有助于棉花减肥、高产和轻简化种植。     

多效唑,缩节胺在秋番茄育苗上的应用

秋番茄育苗,于３片真叶施用５０～１００ｍｇ／Ｌ多效唑液或２５－５０ｍｇ／Ｌ缩节胺液,对防止幼苗徒长,培育壮苗有显著作用;增产效果极显著。     

盐藻运动特性及其影响因素

为了揭示盐藻的运动特性,在不同条件下观察了玻璃U形管两端盐藻的密度变化。结果表明,盐藻运动受光照、ATP、丙二酸钠和粘度的影响。盐藻具有向光源方向聚集的运动特性;供给ATP时盐藻运动加速,加入丙二酸钠时盐藻运动减慢,盐藻的运动是一个消耗能量的过程;增加介质粘稠度会使其运动速度减慢。     

胺鲜酯与氯化钙配施对烤烟育苗的影响

以云烟87为材料,研究8%胺鲜酯(DA–6)(质量浓度15.0、10.0、5.0μg/L)与10.0 mmol/L氯化钙配施对烤烟育苗的影响。结果表明：与清水对照相比,播种7d和15d后配施处理的烤烟出苗率分别提高4.50%～10.40%、2.74%～8.33%,成苗率提高3.19%～8.81%;成苗期的苗高、茎基宽、最大叶叶面积分别提高了5.99%～17.66%、1.29%～5.47%、21.1%～73.6%;根、茎、叶、全苗干物质积累量分别提高了25.0%～55.0%、16.7%～33.3%、14.1%～33.8%、16.5%～36.9%,根冠比提高了9.1%～17.0%;配施处理的叶片叶绿素(叶绿素a+叶绿素b)含量增加26.0%～64.9%;配施处理硝酸还原酶活性提高了52.1%～95.9%;过氧化氢酶(CAT)活性、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量分别降低了41.5%～59.3%、27.9%～62.9%、30.3%～81.1%和34.0%～63.7%,表明用10μg/L DA–6+10 mmol/L氯化钙配施浸种效果最佳。