Comparison of immune responses and antioxidant status of different generations of growth‐selected Portunus trituberculatus families

The purpose of this study was to investigate the effects of inbreeding on the immune responses and antioxidant status of Portunus trituberculatus juveniles. Results showed that inbreeding affected the total haemocyte count, and phagocytic, pro‐phenoloxidase (propo), phenoloxidase and antibacterial activities decreased after the seventh generation. Antioxidant status showed a similar pattern: total antioxidant capacity, superoxide dismutase (SOD) activity and GSH/GSSG in the cell‐free haemolymph and hepatopancreas decreased, while catalase activity in the cell‐free haemolymph increased (P < 0.05). There were no significant differences in α₂‐macroglobulin and bacteriolytic activities in the cell‐free haemolymph and glutathione peroxidase activity in the cell‐free haemolymph and hepatopancreas among nine inbreeding generations. Gene expression levels of proPO and crustin in haemocytes and SOD in haemocytes and hepatopancreas also decreased significantly as the inbreeding generations increased. The results suggest that a high level of inbreeding could severely reduce the physiological health of P. trituberculatus. Our obtained data would be particularly useful for P. trituberculatus breeding programmes.     

转基因抗虫棉品种邯6203的选育及栽培技术

主要介绍棉花品种邯6203的选育过程、特征特性、产量、纤维品质、抗病虫性及栽培技术措施。     

The effect of dietary folic acid on biochemical parameters and gene expression of three heat shock proteins (HSPs) of blunt snout bream (<Emphasis Type="Italic">Megalobrama amblycephala)</Emphasis> fingerling under acute high temperature stress

The effects of dietary folic acid on biochemical parameters and gene expression of three heat shock proteins (HSPs) of blunt snout bream (Megalobrama amblycephala) fingerling under acute high temperature stress. Six dietary folic acid groups (0.0, 0.5, 1.0, 2.0, 5.0, and 10.0) mg/kg diets were designed and assigned into 18 tanks in three replicates each (300 l/tank) and were administered for 10 weeks in a re-circulated water system. The fingerlings with an initial weight of 27.0 ± 0.03 g were fed with their respective diets four times daily. At the end of the experiment, samples were collected before challenge, 0, 24, 72 h, and 7 days. Serum total protein (TP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), cortisol, glucose, complement C3 (C3), complement C4 (C4, immunoglobulin M (IgM) hepatic superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and the expression of heat shock protein 60 (HSP60), 70 (HSP70), and 90 (HSP90) were studied. The results showed that fish fed with dietary folic acid between 1.0, 2.0, and 5.0 mg/kg significantly (P < 0.05) increased serum TP, C3, C4 hepatic SOD, CAT, and the expression of HSP60, HSP70, and HSP90 before and after temperature challenge of 32 °C. Also, serum ALP, cortisol, glucose, and hepatic MDA were significantly (P < 0.05) reduced by supplementation of dietary folic acid level 1.0, 2.0, and 5.0 mg/kg before and after the same temperature challenge of 32 °C. Before stress, 0, 24, 72 h, and 7 days significantly (P < 0.05) affects serum biochemical parameters, immune and antioxidant capacities, and expression level of three HSPs. Furthermore, there was no statistical evidence to show that dietary folic acid inclusion level and temperature duration have significant interactive effect on serum biochemical parameters, antioxidant parameters, and gene expression level (P > 0.05) of the three HSPs. However, there were statistical significant interactive effect between dietary folic acid inclusion level and temperature duration on serum C3 and C4 (P < 0.05) except IgM (P > 0.05). The present results indicate that supplementation of basal diet from 1.0 mg/kg; 2.0 and 5.0 mg/kg can enhance acute high temperature resistance ability in M. amblycephala fingerling to some degree and improve physiological response, immune and antioxidant capacities, and expression level of three HSPs.     

昆山地区典型池塘虾蟹混养模式对水环境的影响

虾蟹混养是昆山地区主要的池塘养殖模式。为深入研究虾蟹混养式养殖尾水对水环境的影响,对典型养殖区锦溪镇南前村的600×667 m~2虾蟹养殖基地的水源、池水和尾水在2012—2014年养殖期间的水质指标pH、亚硝酸盐、氨氮、总氮、总磷、COD监测。结果表明:在不同季节水源、池水和尾水的pH变化较大,变动范围在7.08~9.26之间;亚硝酸盐和氨氮浓度均处于很低的水平,优于地表水环境标准Ⅲ类水质标准,养殖尾水的氨氮浓度通常较水源和池水更低;除总氮和COD在2014春季高于水源外,其余年份各季节总氮、总磷和COD均接近或低于水源水指标值。除COD外,各项水质指标均符合太湖流域池塘养殖水排放一级标准,且呈现为低于或接近养殖用水源水的水质指标,可以认为池塘虾蟹混养模式对外部水环境影响很小。尾水排放前应加强对COD的控制。     

Effects of stocking density on lipid deposition and expression of lipid-related genes in Amur sturgeon (<Emphasis Type="Italic">Acipenser schrenckii</Emphasis>)

To investigate the correlation between lipid deposition variation and stocking density in Amur sturgeon (Acipenser schrenckii) and the possible physiological mechanism, fish were conducted in different stocking densities (LSD 5.5 kg/m³, MSD 8.0 kg/m³, and HSD 11.0 kg/m³) for 70 days and then the growth index, lipid content, lipase activities, and the mRNA expressions of lipid-related genes were examined. Results showed that fish subjected to higher stocking density presented lower final body weights (FBW), specific growth ratio (SGR), and gonad adipose tissue index (GAI) (P < 0.05). Lower lipid content was observed in the liver, gonad adipose tissue and muscle in sturgeons held in HSD group (P < 0.05). The serum concentrations of triglyceride (TG), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C) decreased significantly with increasing stocking density, while no significant change was observed for low-density lipoprotein cholesterol (LDL-C). Furthermore, the cDNAs encoding lipoprotein lipase (LPL) and hepatic lipase (HL) were isolated in Amur sturgeon, respectively. The full-length LPL cDNA was composed of 1757 bp with an open reading frame of 501 amino acids, while the complete nucleotide sequences of HL covered 1747 bp encoding 499 amino acids. In the liver, the activities and mRNA levels of LPL were markedly lower in HSD group, which were consistent with the variation tendency of HL. Fish reared in HSD group also presented lower levels of activities and mRNA expression of LPL in the muscle and gonad. Moreover, the expressions of peroxisome proliferator-activated receptor α (PPARα) in both the liver and skeletal muscle were significantly upregulated in HSD group. Overall, the results indicated that high stocking density negatively affects growth performance and lipid deposition of Amur sturgeon to a certain extent. The downregulation of LPL and HL and the upregulation of PPARα may be responsible for the lower lipid distribution of Amur sturgeon in higher stocking density.     

3种龙胆科植物的资源分配对策

选择青藏高原东缘同一生境类型下具有不同交配系统特点和不同传粉者丰度的3种龙胆科植物湿生扁蕾(Gentianopsis paludosa)(自花授粉)、祁连獐牙菜(Swertia przewalskii)(高昆虫访问异花授粉)和线叶龙胆(Gentiana farreri)(低昆虫访问异花授粉)为对象,研究其资源分配特征。结果表明,1)3种植物的花粉胚珠比例(P/O)存在显著差异(P0.05),湿生扁蕾的P/O显著低于另外两种异花授粉植物的(P0.05),祁连獐牙菜的P/O显著低于线叶龙胆的(P0.05);2)3种植物的繁殖分配比例存在差异,湿生扁蕾的繁殖分配比例显著高于另外两种异花授粉植物的(P0.05),线叶龙胆的繁殖分配比例显著高于祁连獐牙菜的(P0.05);3)在繁殖分配比例与个体大小关系上,湿生扁蕾与其个体大小不存在显著相关关系(P0.05),而另外两种异花授粉植物则与其各自个体大小之间存在显著负相关关系(P0.05)。研究表明,交配系统类型和传粉者丰度与植物的资源分配模式有关,尽管3种植物的繁殖绝对投入量都与其个体大小显著正相关(P0.05),但自花授粉植物相对于异花授粉植物具有较高的繁殖分配比例,并且这种较高的繁殖分配比例不受个体大小影响,这种高繁殖投入的资源分配模式可能与自花授粉植物具有繁殖保障,从而降低其繁殖代价有关。     

昆明长水国际机场鳞翅目昆虫种群初探

对2018年1~12月昆明长水国际机场东西跑道外侧草坪的鳞翅目昆虫进行了调查,结果发现:该目昆虫具有明显季节差异,种类和数量均是夏季最多,秋季其次,冬、春季相对较少。生境分析表明,鳞翅目昆虫对生境依赖有一定差异,故提出了清除草坪内开花植物或种植不开花植物,从而减少昆虫多样性,降低鸟类到草坪觅食及鸟击概率的建议。     

安徽省花生产量与气象因素的关联度分析及预测模型研究

为分析气象因子对安徽花生产量的影响,构建适用于本地的花生单位产量预测模型,以期为探讨花生经济效益、应对气象灾害风险管理提供参考。对安徽各市2000—2017年花生气象产量和气象因子进行灰色关联度分析,筛选出关联度较大的气象因子,并采用逐步回归法建立产量预测模型。结果表明：安徽花生产量与生育期气象因子关联度5月份平均气温>7月份光照时数>5月份光照时数>6月份光照时数>7月份平均气温>8月份光照时数>8月份平均气温>6月份平均气温>8月份降水量>7月份降水量>5月份降水量>6月份降水量,应用建立的花生单位产量预测模型对历年产量进行回测,结果显示预测值与实际值均方根误差为815 kg/hm²、拟合指数为0.81,总体较好,具有一定的应用价值。     

晋中盆地典型耕地厚度、土壤养分空间变异

旨在探究旱作区耕地土壤耕层厚度及土壤养分空间格局与变异规律。以晋中盆地典型耕地土壤为研究对象,运用地统计学方法对耕地耕层厚度及土壤养分的空间变异进行分析,土壤养分选取有机质、pH、有效磷、缓效钾4个指标。结果表明：（1）各个指标的空间自相关性都是随着距离的增加而减小;（2）有效磷的半变异函数最优模型为高斯模型,其他指标的最优模型均为指数模型。各指标的块金系数由大到小依次为：有机质>有效磷>pH>耕层厚度>缓效钾;（3）耕层厚度、有效磷均为西北高东南低的空间格局,缓效钾为东北高西南低,有机质为西南高东北低,pH除北洸乡偏低外均偏高。地统计方法能良好地描述土壤性质的空间分布和变异特征,各土壤性质的空间变异过程中随机性与结构性并存,并且随机性均小于50%。