三肽囊素对鸡血浆蛋白组分及IL-2与IL-6含量的影响

144只1日龄黄羽肉鸡随机分为4组,第7日龄时第Ⅰ～Ⅳ组分别注射0、0.005、0.010、0.030mg/kg剂量的三肽囊素,在14、35及56日龄时每组各取一个重复,取血浆,醋酸纤维薄膜电泳检测血浆蛋白各组分的比率,放射免疫法检测血浆IL-2与IL-6的含量.结果显示不同剂量的三肽囊素可提高血浆γ球蛋白水平:对血浆...     

DTA-6对两种食用豆生理代谢及产量的影响

为探究2-N,N-二乙氨基乙基己酸酯（diethyl aminoethyl hexanoate,DTA-6）对食用豆叶片的生理代谢及产量的调控效应,选用芸豆（英国红）和小豆（龙垦2号）为试验材料,采用大田完全随机试验方法,于芸豆和小豆的初花期叶面喷施DTA-6,以喷施清水为对照（CK）,测定各生育时期叶片光合参数、碳代谢产物、干物质、产量及产量构成因素。结果表明：DTA-6提高了2种食用豆各生育期的SPAD值、盛花期和鼓粒期的净光合速率（P_n）、蒸腾速率（T_r）、气孔导度（G_s）和胞间CO₂浓度（C_i）,显著增加了叶片蔗糖和可溶性糖的含量,促进了叶片淀粉的积累;与CK相比,DTA-6提高了2种食用豆的地上部单株干物质积累量,并且显著提高了芸豆和小豆鼓粒期荚分配率;DTA-6可有效调控2种食用豆的单株荚数、单株粒数和百粒重,从而提高产量,DTA-6处理的芸豆和小豆产量分别较CK增加13.30%和12.91%,增产显著。     

Plant growth regulator and its interactions with environment and genotype affect maize optimal plant density and yield

Increasing planting density is important to raise maize yield, however, high density often leads to an increase risk of lodging due to dense canopy and weak stem. Maize yield and optimal plant density are increased by applying plant growth regulator compound of ethephon and DA-6, however, we do not know if this compound would interact with location and genotype. In this study, a novel plant growth regulator, as the synthesis of N, N- diethyl − 2 − hexanoyl oxygen radicals − ethyl amine (2-ethyl chloride) phosphonic acid salt (DHEAP), combining the effects of ethephon and DA-6 in one chemical, was developed and tested at three locations, five plant densities (6.75, 8.25, 9.75, 11.25 and 12.75 plants m⁻²) and three cultivars in 2014–2015. This study aimed to quantify the interactions between environment, genotype and management (Appling DHEAP and plant density) on lodging-related optimal plant density and yield. DHEAP significantly increased grain yield by 10.7% due to the increases of kernel weight by 3.2% and kernel number per ear by 4.4%. On average across genotypes and environments, applying DHEAP increased optimum plant density by 6%. The optimal plant density interacted with cultivar, DHEAP and environment. Applying DHEAP reduced lodging percentage by lowering ear height. The yield-lodging relationship was affected by genotype and location. We concluded that maize yield could be enhanced by optimizing plant density, applying DHEAP and cultivar selection, but climatic and environmental differences of locations should be considered.     

Simultaneous detection of multiple mycotoxins in broiler feeds using a liquid chromatography tandem-mass spectrometry

Mycotoxins are secondary fungal metabolites that are typically present in grain and feed ingredients used for animal feeds. An analytical method using LC-ESI-MS/MS was developed to quantify nine mycotoxins, consisting of aflatoxin B₁ (AFB₁), AFB₂, AFG₁, AFG₂, T-2 toxin, deoxynivalenol (DON), nivalenol (NIV), zearalenone (ZEA) and ochratoxin A (OTA) in broiler feeds. In total, 100 samples of broiler feeds were collected from poultry farms in Central Thailand. The survey found that AFB₁ and ZEA were the most prevalent mycotoxins in the feed samples at percentages of 93% and 63%, respectively. The limit of detections (LODs) of investigated mycotoxins was 0.20–0.78 ng/g. AFB₂, DON, AFG₁, NIV and T-2 toxin were also detectable at low contamination levels with percentages of 20%, 9%, 7%, 5% and 1%, respectively, whereas OTA and AFG₂ were not detected in any of the feed samples. These results suggest that there is a very low level of risk of the exposure to mycotoxins in feeds obtained from broiler farms in Central Thailand.     

三种融合标签对大熊猫轮状病毒结构蛋白VP6-VP7可溶性表达的影响

大熊猫轮状病毒(giant panda rotavirus,GPRV)是引起幼龄大熊猫腹泻的主要病原,对圈养大熊猫产生了较大的危害。轮状病毒结构蛋白VP6是一种载体蛋白,可介导黏膜免疫反应。VP7是轮状病毒结构蛋白中主要的中和抗原。因此,VP6-VP7的融合表达作为候选抗原对该病的防治具有重要的意义。传统大肠埃希菌原核表达存在表达量低、可溶性差以及纯度低等弊端。本研究使用醛缩酶(EDA)、谷胱甘肽S-转移酶(GST)、麦芽糖结合蛋白(MBP)3种融合标签,以实现获得表达量高和纯度高的GPRV-VP6-VP7重组表达蛋白。将扩增的VP6、VP7基因片段利用同源重组酶构建到含3种融合标签的表达载体pET21b上,将重组质粒转化至大肠埃希菌Rosetta(DE3)感受态细胞中进行低温诱导表达。用Ni-柱亲和层析法纯化目的蛋白,SDS-PAGE和Image J分析蛋白表达量和可溶性,Western blot分析得到表达的重组表达蛋白正确且具有蛋白活性。实验结果证明,EDA标签能显著促进VP6-VP7蛋白的原核可溶性表达,提高VP6-VP7蛋白表达量。     

基于GF-6卫星影像多特征优选的酿酒葡萄精准识别

多源遥感信息和特征优选是提高农作物识别精度的重要支撑，高分六号（GF-6）卫星作为首次引入红边波段的国产卫星，其丰富的光谱信息为作物识别提供了新的思路和解决途径。该研究基于宁夏回族自治区银川市永宁县2018年6月-2019年3月的GF-6数据，充分利用红边优势提取光谱特征、纹理特征和植被指数特征，构建多种特征组合方案，并根据随机森林算法对特征重要性进行度量，选取最优特征组合对酿酒葡萄进行精准识别。结果表明，与单一特征相比，多源遥感特征的增加显著改善了酿酒葡萄分类效果，其中，植被指数贡献程度最大，光谱特征次之；基于随机森林的优选特征组合分类效果最佳，其中，总体分类精度为94.15%，酿酒葡萄用户精度为94.23%，制图精度为92.59%；以实地调查的4个酒庄为验证区，将酿酒葡萄提取结果与统计数据进行对比，面积相对精度均在70%以上，其中优选特征结果相对精度在90%以上，研究结果将为国产卫星红边波段在植被分类和识别方面的应用提供数据参考。     

m6A甲基化在鸡肌肉生长发育中的表达研究

试验旨在研究RNA m6A修饰相关基因去甲基化酶Alk B同源蛋白5（Alk B homologue 5，ALKBH5）、去甲基化酶肥胖相关蛋白（fat mass and obesity-associated protein，FTO）、甲基转移酶样蛋白3（methyltransferase like 3，METTL3）、甲基转移酶样蛋白14（methyltransferase like 14，METTL14）和成肾细胞瘤1-结合蛋白（Wilms’tumor 1-associating protein，WTAP）在鸡骨骼肌发育过程中的表达，分析其与骨骼肌m6A甲基化水平的相关性。首先，利用实时荧光定量PCR技术检测m6A甲基化相关基因在金茅花鸡12（E12）、14（E14）、16（E16）、18（E18）胚龄和1日龄腿肌和胸肌组织中mRNA表达水平，以及其在鸡成肌细胞50%、100%增殖期和1、2、3、4、5 d分化期的mRNA表达水平；随后，利用m6A甲基化试剂盒检测金茅花鸡E12和1日龄腿肌和胸肌组织中m6A甲基化修饰水平，与m6A甲基化相关基因表达水平进行相关性分析。结果显示，m6A去甲基化基因ALKBH5和FTO mRNA表达水平在骨骼肌发育过程中显著上调（P<0.05），即在E12、E14低表达，E16、E18逐渐上调，1日龄达到最高。m6A甲基化写入基因METTL14、METTL3和WTAP mRNA表达水平在E12、E14、E16逐渐上升，E18下降，随后至1日龄表达量回升。在细胞增殖过程中，ALKBH5、FTO、METTL14、METTL3和WTAP基因表达均上调；在细胞分化过程中ALKBH5和FTO基因表达水平显著上调（P<0.05），在分化第5天达到最高。METTL14、METTL3和WTAP基因mRNA表达水平在细胞诱导分化的1、2、3、4 d表达量呈下降趋势，而在诱导分化的第5天有所回升。甲基化水平检测结果显示，腿肌和胸肌m6A甲基化水平变化趋势一致，均在胚胎发育过程中显著下降（P<0.05），至1日龄达到最低。相关性分析结果显示，鸡骨骼肌RNA m6A甲基化水平与m6A去甲基化修饰基因ALKBH5、FTO mRNA表达水平呈显著负相关（P<0.05）。综合以上试验结果，推测m6A甲基化修饰与鸡骨骼肌发育相关，而去甲基化基因ALKBH5、FTO可能通过调控RNA m6A甲基化水平，影响鸡骨骼肌发育。本研究结果为进一步研究m6A甲基化修饰调控鸡骨骼肌生长发育的功能和分子机制提供理论依据。     

不同混施钝化剂对水稻吸收累积Cd的影响

将石灰、赤泥和高岭土按不同比例混合(施用总量为4500kg hm-2)施加于Cd污染稻田土壤,根据混合比例不同设置CK(常规种植)、T1(1∶7∶4)、T2(3∶5∶4)、T3(4∶4∶4)和T4(6∶2∶4)共5个处理,探究不同混施钝化剂对水稻吸收累积Cd的影响。结果表明:4种混施处理能够显著降低土壤有效态Cd含量,较CK相比依次降低了28.0%、40.9%、43.4%和57.4%。4种混施处理能够不同程度地降低水稻各部位对Cd的吸收累积,籽粒的Cd含量依次降低47.1%、49.2%、55.5%和81.6%,T2、T3和T4处理水稻籽粒中Cd含量达到了食品安全国家标准(G B27622017,Cd≤0.2mg kg-1)。土壤有效态Cd含量与水稻根、茎、叶和籽粒中Cd含量的Pearson相关系数分别为0.826、0.709、0.778和0.532,均达到显著相关。不同处理根系富集系数依次为5.03、1.83、2.22、1.32和0.90,钝化处理显著降低了水稻根系对Cd的富集能力。各处理水稻产量以及籽粒K、Mg元素含量没有显著差异,T1到T4处理Ca元素含量依次增加。综合分析,T4处理对于降低土壤中有效态Cd含量以及水稻籽粒中Cd含量效果最佳,且没有降低水稻产量和与稻米品质密切相关的K、Mg和Ca元素含量。     

夏训对优秀皮划艇运动员铁调素等铁营养状况以及IL-6的影响

目的：探讨夏训对优秀运动员铁调素等铁营养状况以及IL-6的影响。方法：广东省优秀皮划艇运动员26人(男15人，女11人)参加测试，调查夏训前和夏训后血红蛋白、铁调素、可溶性转铁蛋白受体、血清铁蛋白、可溶性转铁蛋白受体/log铁蛋白、血清铁、总铁结合力、转铁蛋白饱和度以及白介素6变化情况。结果：夏训后，男运动员组铁调素和可溶性转铁蛋白受体极显著上升(P<0.01)、血清铁蛋白极显著下降(P<0.01)，可溶性转铁蛋白受体/log铁蛋白显著上升(P<0.05)，总铁结合力显著下降(P<0.05)，白介素6极显著上升(P<0.01)。女运动员组血红蛋白显著降低(P<0.05)，铁调素和可溶性转铁蛋白受体极显著上升(P<0.01)，血清铁蛋白极显著下降(P<0.01)，可溶性转铁蛋白受体/log铁蛋白极显著上升(P<0.01)，白介素6极显著上升(P<0.01)。结论：夏训可引起运动员炎症因子升高、铁调素升高，导致功能铁不足；铁调素介导的铁代谢紊乱可能是运动性低血色素发生的重要原因。     

Interactions between arbuscular mycorrhizal fungi and fungivorous nematodes on the growth and arsenic uptake of tobacco in arsenic-contaminated soils

The effects of inoculation with two AM fungi (M1, Glomus caledonium; M2, Glomus spp. and Acaulospora spp.) and a fungivorous nematode Aphelenchoides sp. on growth and arsenic (As) uptake of Nicotiana tabacum L. were investigated in soils contaminated with a range of As. The reproduction of Aphelenchoides sp. was triggered by the co-inoculation of AM fungi regardless of AM fungal isolates and As levels. Stimulative effects of Aphelenchoides sp. on the development of mycorrhiza, slightly different between two AM fungi, were found particularly at the lowest As level. Irrespective of mycorrhizal inoculi, increasing soil As level decreased plant growth, but increased plant As uptake. Co-inoculation of AM fungi and Aphelenchoides sp. led plants to achieving further growth and greater As accumulation at the lowest As level. Results showed that the interactions between AM fungi and fungivorous nematodes were important in plant As tolerance and phytoextraction at low level As-polluted soil.