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31.
王云霞 《内蒙古林业调查设计》2019,(5):28-31
文章通过对内蒙古乌海龙游湾国家湿地公园野生动物资源2013年与2018年调查结果的比较,得出湿地公园经过5 a的建设管理,鱼类、两栖类和爬行类动物资源种类基本稳定不变,野生鸟类资源变化较大,对野生动物资源变化原因进行了分析。 相似文献
32.
花生黑腐病是花生的重要病害,对生产造成严重影响,被列为我国进境植物检疫性病害。为明确花生黑腐病的病原菌种类和筛选有效防治药剂,采用形态学特征与分子生物学技术相结合的方法,对花生黑腐病害进行了病原菌鉴定,同时采用菌丝生长速率法测定了8种杀菌剂对花生黑腐病菌的抑制作用。结果表明:花生黑腐病害的病原菌为冬青丽赤壳Calonectria iliciola。8种杀菌剂室内毒力测定结果显示,10%戊唑醇EC对花生黑腐病菌的毒力最强,EC50值为1.12 μg/mL;300 g/L苯甲·丙环唑EC、29%吡萘嘧菌酯SC、25%咯菌腈SC、15%吡唑嘧菌酯SC和22.5%啶氧菌酯SC对花生黑腐病菌也有较好的抑制作用,EC50均低于10 μg/mL;30%精甲恶霉灵的抑制作用最差,EC50值为76.71 μg/mL。以上研究结果可为花生黑腐病的防治提供理论依据。 相似文献
33.
为探究大气二氧化碳 (CO2) 浓度增高对杂交水稻光合和荧光特性的动态影响,利用开放式空气中CO2浓度增高(FACE)系统,研究高CO2浓度对大田水稻不同生育期叶片光合和荧光参数的动态影响及其种间差异。以高产杂交组合甬优2640和Y两优2号为试验材料,设置环境CO2和高CO2浓度2个水平,测定2个品种气体交换和荧光参数。结果表明,大气CO2浓度升高使2个品种平均叶片净光合速率(Pn)在移栽后30、59、76、91和108 d分别增加25%、16%、25%、18%和8%,除移栽后108 d外,均达极显著水平(P<0.01);甬优2640移栽后76和91 d叶片Pn对CO2的响应明显大于Y两优2号。除灌浆末期外,CO2浓度升高使2个品种叶片气孔导度(Gs)和蒸腾速率(Tr)均呈下降趋势,且Y两优2号的降幅多大于甬优2640。CO2熏蒸下叶片气孔部分关闭,但叶片胞间与周围空气中CO2浓度之比无显著变化,甚至明显增加。大气CO2浓度升高使2个品种灌浆末期PSⅡ最大光化学量子产量均下降4%,但对其他各期均无显著影响;除灌浆末期外,CO2浓度升高使PSⅡ实际光量子产量和光化学猝灭均显著增加。两杂交组合叶片光合参数对高CO2浓度的动态响应多存在种间差异,但荧光参数的响应品种间差异较小。本研究结果为增强气候假定情景下水稻响应的预测能力并制订应对策略提供了依据。 相似文献
34.
35.
通过正交试验设计可以大大减少试验次数,得到不同因素水平的最优组合,从而确定合理的试验方案及工艺条件等,因此在科学研究中应用非常广泛。为了更深入地理解正交试验设计方法,以表和图的形式对正交试验设计的特点进行了详细分析;对正交性的意义、体现从向量信息不相关及向量内积计算的角度进行详细的分析及解释,以期为广大师生的学习及应用提供一定的帮助。 相似文献
36.
Li Yang Gang Liu Xiaorui Liang Mengmeng Wang Xiaoqing Zhu Yan Luo Yunxia Shang Jing‐quan Yang Ping Zhou Xin‐Li Gu 《Animal Science Journal》2019,90(9):1229-1238
This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response‐related genes in lipopolysaccharide (LPS)‐challenged broilers. We assigned 120 one‐day‐old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T‐SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS‐induced decreases in the mRNA expression of nuclear factor‐kappa B (NF‐κB), TNF‐α, IL‐1β, inducible nitrite synthase and cyclooxygenase‐2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF‐κB signalling and the expression of inflammatory mediators. 相似文献
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38.
Hongyue Zhao Dong Han Shouqi Xie Xiaoming Zhu & Yunxia Yang 《Aquaculture Research》2009,40(16):1864-1872
The present study was carried out to investigate the influence of water temperature on the growth performance and digestive enzyme (pepsin, trypsin and lipase) activities of Chinese longsnout catfish. Triplicate groups of Chinese longsnout catfish (35.6±0.48 g, mean±SE) were reared at different water temperatures (20, 24, 28 and 32 °C). The feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) were significantly affected by water temperatures and regression relationships between water temperature and FI, SGR as well as FER were expressed as FR=−0.016 T 2 +0.91 T −10.88 ( n =12, R 2 =0.8752), SGR=−0.026 T 2 +1.39 T −17.29 ( n =12, R 2 =0.7599) and FER=−0.013 T 2 +0.70 T −8.43 ( n =12, R 2 =0.7272). Based on these, the optimum temperatures for FR, SGR and FER were 27.66, 26.69 and 26.44 °C respectively. The specific activities of digestive enzymes at 24 or 28 °C were significantly higher than that at 20 or 32 °C. In addition, there was a significant linear regression between FR or SGR and specific activities of pepsin and lipase, which indicated that pepsin and lipase played important roles in regulating growth through nutrient digestion in Chinese longsnout catfish. 相似文献
39.
Haokun Liu Quangen Yan Dong Han Junyan Jin Xiaoming Zhu Yunxia Yang Shouqi Xie 《Aquaculture Nutrition》2019,25(2):414-426
An 8‐week feeding trial was conducted to evaluate the effect of replacement of dietary fishmeal with cottonseed meal (CSM) on the growth performance and health status of juvenile grass carp, Ctenopharyngodon idellus (6.67 g). Six isonitrogenous and isoenergetic diets were formulated with different CSM levels (0, 121, 241, 362, 482 and 603 g/kg diet). The first limiting amino acid was methionine, which decreased with an increase in dietary CSM from 361 to 538 g/kg. When the dietary CSM content was lower than 241 g/kg, the limiting amino acid was histidine. Thermal growth coefficient (TGC) and feed efficiency first increased and then decreased (p < 0.05), which was consistent with the change in the limiting amino acid. The feeding rate increased with a rise in the dietary CSM level (p < 0.05). The activity of digestive enzymes except trypsin decreased significantly (p < 0.05), serum aminotransferase activity and triglycerides increased, serum cholesterol decreased (p < 0.05). When dietary CSM was raised to 362 g/kg, intestinal villi and hepatopancreas tissue were injured. When the dietary CSM was 603 g/kg, alternative complement pathway haemolytic activity was inhibited (p < 0.05). The gossypol level in dorsal muscles from each treatment was below the detection limit. Based on the quadratic regression analysis of the TGC, the optimal dietary CSM level was 175.9 g/kg, and the maximum could be up to 351.8 g/kg and still result in the same TGC as that of control group. 相似文献
40.
本试验从健康的鸡盲肠内容物中筛选出具有较高抑菌活性的病源拮抗菌JM-11菌株,经形态、生理生化及16S rDNA序列鉴定此菌为枯草芽孢杆菌(Bacillus subtilis subsp. subtilis)。经耐受胃肠道环境及胆盐试验,结果表明,JM-11菌株能耐受0.3%的胆盐环境,在pH为3.0的人工胃液中能够很好的存活。利用抗生素打乱雏鸡肠道菌群后,饲喂致病性大肠杆菌来制作腹泻模型。经益生菌JM-11对腹泻雏鸡的治疗试验结果显示,JM-11能显著降低腹泻雏鸡粪便中的大肠杆菌的数量(P<0.01),增加乳酸菌的数量(P<0.01),提高雏鸡免疫器官指数(P<0.05),对雏鸡具有安全无毒的作用。 相似文献