Effect of dietary supplemental l‐carnitine on growth performance,body composition and antioxidant status in juvenile black sea bream,Sparus macrocephalus

Effects of dietary l ‐carnitine were studied in juvenile black sea bream (Sparus macrocephalus). The semipurified basal diet [crude protein 450 g kg^?1 dry matter (DM); crude lipid 126 g kg^?1 DM] was formulated to choose white fishmeal as the protein source and fish oil plus corn oil (1 : 1) as the lipid source. Six diets (control + diets 1–5) containing 0.1, 0.12, 0.16, 0.24, 0.39 and 1.1 g of l ‐carnitine kg^?1 diet were fed to triplicate groups of black sea bream (initial weight 13.10 ± 0.05 g) for 8 weeks. At the end of the feeding trial, growth performance, body composition and antioxidant status were determined. The results showed that relative growth rate (RGR) was significantly improved by the elevation of dietary l ‐carnitine level from 0.1 to 0.24 g kg^?1, but decreased with further increment (P < 0.05). Lipid content decreased significantly (P < 0.05) in the dorsal muscle whereas increased (P < 0.05) in the liver with the addition of dietary l ‐carnitine. Dietary l ‐carnitine supplements elevated enzymatic antioxidants (superoxide dismutase, SOD; catalase, CAT; glutathione‐S‐transferase, GST) activities (P < 0.05) yet decreased the content of non‐enzymatic factor, total sulphydryl groups (TSH) (P < 0.05). In summary, the optimum dietary l ‐carnitine level was 0.284 g kg^?1 diet by second‐polynomial regression analysis based on RGR (y = ?647.4x² +367.97x + 234.55; R² = 0.977, x = dietary l ‐carnitine levels, y = RGR), and dietary l ‐carnitine addition within the levels adopted in our study could depress lipid peroxidation in tissues of juvenile black sea bream.     

降水、灌溉和品种对玉米产量和水分利用效率的影响

8年田间试验结果表明,玉米产量明显受降水和灌溉的影响。玉米苗期灌溉最为关键,是保证高产的基础。在只灌溉苗水而没有其他灌溉条件下,夏玉米产量与7、8月份降水密切相关,而与生长季节的降水总量关系不明显。除了极干旱年份(季节降雨量小于200 mm)外,随着灌溉量增加,玉米水分利用效率(WUE)降低。玉米最优灌溉制度为:干旱年份,除了苗期的1次灌溉外,在拔节和扬花期分别实施2次灌溉;常年和湿润年份,除了出苗水外,在抽穗到扬花期的8月初实施1次灌溉。3年的田间试验结果表明,当地种植的不同玉米品种之间产量最大相差20%,水分利用效率差异在12%~19%。因此,将适宜的品种与优化的灌溉制度相结合,是提高华北平原夏玉米产量和水分利用效率的有效途径。     

Inhibition of ICAM-1 expression on endothelial cells in hypoxia/reoxygenation by antisense oligodeoxynucleotides

AIM: To investigate the effect of antisense oligodeoxynucleotides (AS-ODN) on the intercellsular adhesion molecule-1(ICAM-1) expression on endothelial cells in hypoxia/reoxygenation(H/R). METHODS: With cultured glomerular vascular endothelial cell in H/R, the positive percentage of ICAM-1 expression was measured by flow cytometry before and after giving AS-ODN. RESULTS: The ICAM-1 expression did not increase on glomerular vascular endothelial cell in 10 hours hypoxia compared to control group, it increased in 6 hours reoxygenation, and decreased by 40.6% after giving AS-OND. CONCLUSION: AS-ODN may decrease the expression of ICAM-1 on endothelial cells in H/R.     

Effect of ischemia or hypoxia on vascular endothelial growth factor production in rat myocardium and its significance

AIM:To determine the relationship between ischemia, hypoxia and the production of vascular endothelial growth factor in rat myocardium and its basic mechanism. METHODS:(1) 28 Wistar rats were randomly divided into 4 groups: group A, normal control;group B, 1 day's acute myocardial infarction;group C, 3 day's acute myocardial infarction;group D, 7 day's acute myocardial infarction. (2) Rat cardiac myocytes cultured were primarily divided into some groups, hypoxia incubated 24 hours; PMA groups, hypoxia incubated 24 hours with PKC activator (PMA), A 0 ng/mL; B 10 ng/mL; C 100 ng/mL; D 1 000 ng/mL; Chelerythrine groups, hypoxia incubated 24 hours with PKC inhibitor (chelerythrine), A 0 nmol/L; B 10 nmol/L. (3) By computer scanned and quantitated, vascular endothelial growth factor (VEGF) protein was detected with immunohistochemical technique. RESULTS:The longer time of ischemia and hypoxia was, the higher the VEGF production.The relat ionship was found between the time of ischemia or hypoxia and the production of VEGF.The product ion of VEGF protein was further promoted by PMA with different concentrat ion, decreased by chelerythrine.CONCLUSION: Ischemia or hypoxia strongly stimulated the production of VEGF in myocardium, which played an important role in autoprotecting of ischemic or hypoxic myocardium. Hypoxia-induced PKC activation is one kind of basic mechanisms in this course.     

利用CRISPR/CAS9技术编辑水稻香味基因Badh2

【目的】香稻作为一类特殊的水稻群体,以其清香可口的品质特性备受消费者的欢迎。到目前为止,水稻中的香味主要受第8染色体上编码甜菜碱醛脱氢酶基因Badh2控制。【方法】通过CRISPR/CAS9技术对中花11的香味基因Badh2进行编辑。【结果】获得转基因T_0代植株并对其所衍生的T_1代20个单株进行了鉴定分析,获得了一个剔除了载体骨架且第1外显子上插入一个碱基T的突变体材料。该材料中Badh2 RNA水平显著下调;利用GC-MS技术测定野生型及突变体材料籽粒2-乙酰-1-吡咯啉含量,结果表明突变体材料中的香味物质显著增加;此外,我们还对野生型及T_2代香型植株水稻产量及稻米蒸煮食味品质进行了考查及测定分析,发现除分蘖数及结实率呈现出显著差异外(P0.05),其余各项指标在两组材料间都无显著差异。【结论】通过CRISPR/CAS9技术成功地对水稻香味基因进行了编辑,可为香稻育种提供丰富的理论指导,加快香稻的育种进程。     

原位胚拯救技术获得花生属区组间杂种的研究

花生野生种尤其是不亲和野生种,具有高产、抗逆等优异基因,但长期以来得不到有效利用。为选育高油酸抗逆花生新品种,以高油酸品种花育963为母本、不亲和野生花生作父本杂交,采用原位胚拯救技术直接收获花生不亲和种间杂种F_1。利用MITE转座子分子标记对杂种进行真实性鉴定。结果表明萁中有35粒样品同时具有双亲条带,为真杂种,真杂种率为44.3%。近红外分析表明,真杂种油酸含量显著低于高油酸花生,为杂种真实性提供了旁证。     

基于雷达图分析法初步评价稻米食昧品质的研究

本研究建立了一种基于雷达图分析稻米食味评价的新方法.该方法选择胶稠度、碱消值、粒型、直链淀粉含量和蛋白质含量等5个对稻米食味品质影响较大的理化指标作为雷达图分析的评价指标.各个评价指标经无量纲化处理后用于绘制雷达图.为消除指标排列顺序不同引起的差异,本文采用雷达图的平均周长和平均面积作为特征向量构建评价参数,并对10个参试样品的食味品质进行综合评价.结果表明,采用本文建立的雷达图分析法得到的食味评价排序与常规感官评价法的排序基本一致,表明本文建立的雷达图分析法适用于稻米食昧品质的初步评价.     

夜间补光对小麦叶片激素含量及光合特性的影响

为探究夜间补光对小麦生育后期的调控作用,以冬小麦品种豫农186为材料,以自然光照时间为对照,在小麦抽穗后设置夜间人工补光2h、4h和6h三个处理,研究补光时间对小麦叶片内源激素含量、光合特性及产量的影响。结果表明,夜间补光可增加小麦叶面积及旗叶叶绿素含量和光合速率,以补光6h的效果最显著。与自然对照相比,夜间补光显著增加旗叶GA3、IAA、ZR含量,且激素含量的升高幅度随补光时间的延长而增加,但ABA含量受影响较小。夜间补光能显著提高灌浆前期和中期籽粒灌浆速率及千粒重和产量,其中补光6h处理的最大灌浆速率比自然对照增大16.21%,产量提高14.07%。说明小麦抽穗后适当延长光照时间有利于叶片的生长发育,可提高激素含量和光合效率,促进籽粒灌浆,增加产量。     

不同氮肥用量对番茄生长及植株养分含量的影响

利用盆栽试验,研究了不同氮素用量对番茄生长性状、果实品质及植株不同器官氮、磷、钾含量的影响。试验结果表明,N_2(N=2 g/盆)处理的单株结果数(21.5个/株)、平均单果质量(6.5 g/个)均达最高值,该处理所产果实鲜样VC含量(37.5 mg/100 g)和糖酸比(9.4)均为最高,显著高于其他处理(P0.05);植株中氮、磷含量均表现为果实叶茎,而钾含量则表现为果实茎叶。随着氮肥用量的增加,各器官中氮、钾含量均表现为先增加后下降,N_2处理显著高于N_1、CK和N_4(P0.05),该处理果实的VC含量和糖酸比也达最大值;综上,番茄盆栽中纯氮用量以2 g/盆为宜。     

福州地区露地越冬快菜品种比较试验

为筛选出适合福州地区露地越冬栽培的耐抽薹快菜品种,以万农5号为对照品种,对来自全国各地的20个快菜品种进行了农艺性状、耐抽薹性和产量比较的研究试验。结果表明,早熟和谐5号具有整齐度高、叶色绿、心叶色黄、耐抽薹性强等特点,每667 m~2产量为3 173.4 kg,比对照增产22.86%。说明早熟和谐5号适合在福州地区露地越冬茬口推广种植。