Effect of chlorogenic acid on intestinal inflammation,antioxidant status,and microbial community of young hens challenged with acute heat stress

Heat stress in poultry is deleterious to productive performance. Chlorogenic acid (CGA) exerts antibacterial, anti-inflammatory, and antioxidant properties. This study was conducted to evaluate the effects of dietary supplemental CGA on the intestinal health and cecal microbiota composition of young hens challenged with acute heat stress. 100-day-old Hy-line brown pullets were randomly divided into four groups. The control group (C) and heat stress group (HS) received a basal diet. HS + CGA₃₀₀ group and HS + CGA₆₀₀ group received a basal diet supplemented with 300- and 600-mg/kg CGA, respectively, for 2 weeks before heat stress exposure. Pullets of HS, HS + CGA₃₀₀, and HS + CGA₆₀₀ group were exposed to 38°C for 4 h while the control group was maintained at 25°C. In this study, dietary CGA supplementation had effect on mitigate the decreased T-AOC and T-SOD activities and the increasing of IL-1β and TNFα induced by acute heat stress. Dietary supplementation with 600 mg/kg CGA had better effect on increasing the relative abundance of beneficial bacterial genera, such as Rikenellaceae RC9_gut_group, Ruminococcaceae UCG-005, and Christensenellaceae R-7_group, and deceasing bacteria genera involved in inflammation, such as Sutterella species. Therefore, CGA can ameliorate acute heat stress damage through suppressing inflammation and improved antioxidant capacity and cecal microbiota composition.     

不同氮肥运筹下玉米根系特征与产量的关系

明确玉米(Zea mays L.)根系性状对氮肥的响应特征及其与产量的关系,是揭示玉米氮营养机制、优化氮肥管理策略的基础。以供试玉米品种‘安农591’为试材,于2022年设置6种氮肥处理,即：不施氮(CK)、氮肥全部基施(N10)、基肥70%+拔节肥30% (N7∶3)、基肥50%+拔节肥50% (N5∶5)、基肥30%+拔节肥50%+大喇叭口肥20% (N3∶5∶2)、基肥20%+拔节肥40%+大喇叭口肥40% (N2:4:4),研究不同氮肥运筹下玉米根系性状的变化特征,并分析根系性状与产量的关系。结果表明,与CK相比,施氮提高吐丝期玉米根总长度、根表面积、根平均直径、根尖数、根体积、根组织质量密度和根系活力,降低比根长、根比表面积和根冠比。N7:3和N5:5处理的籽粒产量和全株生物量较高,其籽粒产量比N10处理提高6.6% ~ 7.3%。施氮降低成熟期玉米根干物质分配比例,提高籽粒干物质分配比例。适当氮肥后移有提高氮肥农学效率的趋势。玉米产量与吐丝期比根长和根冠比呈负相关,与根总长度、根表面积、根尖数、根系体积和根系活力呈正相关(P < 0.05)。在10种根系性状中,根总长度、根系活力、根表面积、根尖数和根冠比对产量影响较强,根平均直径、比根长、根表面积、根组织质量密度和根比表面积对氮肥农学效率影响较强。上述性状分别反映的是玉米产量潜力和氮肥利用率的重要根系性状。     

干旱胁迫对天彭牡丹生理生化和观赏特性的影响

研究干旱胁迫下天彭牡丹的生理生化响应及观赏特性变化,为天彭牡丹培育关键技术体系提供理论依据和技术支持.以盆栽天彭牡丹红丹兰为试材,采用称重控水法,设置对照、轻度胁迫、中度胁迫和量度胁迫4个水平,于破绽期、初花期、盛花期、谢花期、花后期Ⅰ、花后期Ⅱ6个时期进行各项生理生化及观赏特性指标测定.随着干旱胁迫强度的增加和时间的延长,天彭牡丹叶片脯氨酸含量、可溶性糖含量、可溶性蛋白含量均呈逐渐增大的趋势且花期变长;而叶片相对含水量逐渐降低,花朵大小逐渐变小;对天彭牡丹花瓣的花色素苷含量也有显著影响(LS＞CK＞MS＞HS).天彭牡丹抗旱能力较强,各指标对中度和重度胁迫均敏感,适当的水分管理可提高天彭牡丹的观赏价值.     

Chemical mutagenesis and soybean mutants potential for identification of novel genes conferring resistance to soybean cyst nematode

The resistance of soybean (Glycine max (L.) Merr.) to soybean cyst nematode (SCN, Heterodera glycines Ichinohe), which is a devastating pathogen in soybean production and causes a large quantity of annual yield loss worldwide, can shift during the long-term interaction and domestication. It is vital to identify more new resistance genetic sources for identification of novel genes underlying resistance to SCN for management of this pathogen. In the present study, first, two ethane methylsulfonate-mutagenesis soybean M2 populations of PI 437654, which shows a broad resistance to almost all of SCN races, and Zhonghuang 13, which is a soybean cultivar in China conferring strong resistance to lodging, were developed. Many types of morphological phenotypes such as four- and five-leaflet leaves were observed from these two soybean M2 populations. Second, 13 mutants were identified and confirmed to exhibit alteration of resistance to SCN race 4 through the forward genetic screening of 400 mutants of the PI 437654 M2 population, the rate of mutants with alteration of SCN-infection phenotype is 3.25%. Third, these identified mutants were further verified not to show any changes in the genomic sequences of the three known SCN-resistant genes, GmSHMT08, GmSNAP18 and GmSANP11, compared to the wild-type soybean; and all of them were still resistant to SCN race 3 similar to the wild-type soybean. Taken together, we can conclude that the 13 mutants identified in the present study carry the mutations of the new gene(s) which contribute(s) to the resistance to SCN race 4 in PI 437654 and can be potentially used as the genetic soybean sources to further identify the novel SCN-resistant gene(s).     

哈尔滨地区奶牛隐性乳房炎病原菌的分离鉴定

通过BMT法、乳汁pH检验法和体细胞直接计数法等方法相结合,对哈尔滨市3个大型奶牛场、10户奶牛养殖户选取的1 000头奶牛,4000个乳区进行隐性乳房炎的流行病学调查,以及致病菌的分离鉴定.结果表明,其中隐性乳房炎的发病率为47.7%(477/1 000);乳区发病率为27.3%(1092/4000),从477头的隐...     

山羊经济性状候选基因研究进展

通过对山羊经济性状候选基因和山羊经济性状的常用分子标记方法的研究,提出了小羊经济性状候选基因的研究意义,以亟利用这些信息选育产肉香、产毛好、产奶多的优良山羊新品种。     

Changes in growth and nitrogen assimilation in barley seedlings under cadmium stress

Barley (Hordeum vulgare L. cv. Martin) plants grown in solution culture, were exposed to increasing cadmium (Cd) concentration (0, 5, 10, 25, 50, and 100 μM) for a duration of 12 days. The sequence of important biochemical steps of nitrate (NO₃) assimilation were studied in roots and shoots as a function of external Cd concentration. Cadmium uptake in roots and shoots increased gradually with Cd concentration in the medium. This Cd accumulation lowered substantially root and shoot biomass. The nitrate reductase (NR, EC 1.6.6.1) and nitrite reductase (NiR, EC 1.6.6.4) activities declined under Cd stress. Concurrently, tissue NO₃ contents and xylem sap NO₃ concentration were also decreased in Cd‐treated plants. These results suggest that Cd could exert an inhibitory effect on the assimilatory NO₃ reducing system (NR and NiR) through a restriction of NO₃ availability in the tissues. We therefore examined, in short‐term experiments (12 h), the impact of Cd on NO₃ uptake and the two reductases in nitrogen (N)‐starved plants that were pretreated or not with Cd. It was found that Cd induced inhibition of both NO₃ uptake and activities of NR and NiR, during NO₃ induction period. The possible mechanisms of Cd action on NO₃ uptake are proposed. Further, in Cd‐grown plants, the glutamine synthetase (GS, EC 6.3.1.2) showed a decreasing activity both in shoots and roots. However, increasing external Cd concentration resulted in a marked enhancement of glutamate dehydrogenase (NADH‐GDH, EC 1.4.1.2) activity, coupled with elevated levels of ammonium (NH₄ in tissues. On the other hand, the total protein content in Cd‐treated plants declined with a progressive and substantial increase of protease activity in the tissues. These findings indicate that under Cd stress the usual pathway of NH₄ assimilation (glutamine synthetase/glutamate synthase) can switch to an alternative one (glutamate dehydrogenase). The changes in all parameters investigated were concentration‐dependent and more marked in roots than shoots. The regulation of N absorption and assimilation by Cd in relation to growth and adaptation to stress conditions are discussed.     

地锦与斑地锦的显微鉴别研究

为更好的鉴定区别地锦与斑地锦2种药用植物,利用光学显微镜和扫描电镜对2种植物的叶形态特征进行了显微观察和微形态研究.结果表明:地锦与斑地锦叶上表皮细胞形状及垂周壁式样不同、下表皮表皮毛的有无以及表皮细胞角质层加厚程度不同,认为可以以叶表皮作为这2种植物鉴定的依据.     

抗柱状黄杆菌多克隆抗体的制备及其免疫学特性鉴定

为制备抗柱状黄杆菌多克隆抗体,本研究利用颗粒性抗原免疫新西兰白兔,收集的抗血清通过辛酸-硫酸铵法纯化,采用间接ELISA法检测纯化后多克隆抗体的效价和交叉反应性。结果显示,制备的多克隆抗体蛋白质浓度为29.28 mg/mL,效价在1:6.4×10⁴以上,与迟钝爱德华氏菌、大肠杆菌、嗜水气单胞菌、鳗弧菌、溶藻弧菌、副溶血弧菌及哈维氏弧菌等水生动物致病菌均无交叉反应。本研究成功建立了抗柱状黄杆菌多克隆抗体的制备方法,可用于柱状黄杆菌的快速检测。