Optimizing the Proportions of Plant Protein Ingredients in the Diet of Juvenile Blunt Snout Bream,Megalobrama amblycephala

An 8‐wk feeding trial was conducted to evaluate the influence of different proportions of dietary plant ingredients on the growth of juvenile blunt snout bream, Megalobrama amblycephala. A 2 × 3 factorial arrangement was set for this trial with three ratios of cottonseed meal (CSM) and canola meal (CM) (2:1, 1:1, or 1:2) and three proportions of soybean meal (SBM) (2, 1, or 0). The results showed that the specific growth rate and protein efficiency ratio both significantly decreased with decreasing amounts of SBM in the diets of blunt snout bream (P < 0.05), while the feed efficiency ratio and feed intake increased significantly (P < 0.05). Meanwhile, the growth performance and feed utilization were shown to improve with increasing amounts of CSM, although the effects were not significant (P > 0.05). The interaction of these two factors had no effect on either growth or feed utilization (P > 0.05). Diet composition was not seen to affect body composition (P > 0.05). The ratio of CSM to CM significantly affected gut amylase activity, liver alanine aminotransferase content, and plasma cholesterol levels (P < 0.05). The interaction between the two main effects significantly influenced the plasma glucose level (P < 0.05). Therefore, the suitable proportion of plant feed for blunt snout bream should include high levels of SBM and CSM, with a SBM : CSM : CM ratio of 2:2:1.     

Integrated Evaluation and the Physiological and Biochemical Responses of Semi-Wild Cotton under Complex Salt-Alkali Stress

[Objective] The genetic diversity of semi-wild cotton was abundant, so more new elite resistant genes could be found and applied to improve the resistance of cotton. The aim of this study was to primarily study on the regulation of response to salt-alkali stress, explore the method of integrated evaluation and characterize the resistance of semi-wild cotton. [Method] Four semi-wild and two cultivated Gossypium hirsutum accessions were evaluated for phonotypical, physiological and biochemical traits under alkali-salt versus normal conditions in hydroponic solutions. The alkali-salt tolerance was determined based on principal component analysis, cluster analysis, correlation analysis, grey rational analysis and analysis of variance. [Result] On the basis of the overall results, the alkali-salt stress tolerance of the six accessions was ranked as: Marie-galante85 > Latifolium32 > CRI16 > CRI12 > Latifolium40 > Latifolium130. Roots were found to be the most important responsive systems to complex alkali-salt stress. At seedling growth stage, the active scavenging system played a crucial role in response to alkali-salt stress. In addition, the salt tolerant and salt sensitive accessions showed different response tends towards leaf peroxidase, root ascorbate peroxidase and root catalase within 48 h, suggesting the accessions have different levels of response to salt stress. [Conclusion]Our study identified the most alkali-salt tolerant accessions and provided basic concept of complex alkali-salt tolerance mechanism within cotton accessions. And, our study provided a simple and rapid, highly accurate and precise method for evaluating salt resistance of cotton, and proved that the balance of ROS system play an important role in response to salt-alkali stress. Hence, mining of salt tolerant genes from these accessions may facilitate the development of novel salt tolerant variety.     

A metabolic study in hepatopancreas of Litopenaeus vannamei response to white spot syndrome virus

International Aquatic Research - White spot syndrome virus (WSSV) cause great harm in shrimp aquaculture. To understand the impact of viral infection on the shrimp metabolism, we monitored the...     

Effects of adding sucrose on Penaeus monodon (Fabricius, 1798) growth performance and water quality in a biofloc system

A 60‐day indoor growth trial was conducted to study the effects of biofloc on the growth performance of a Penaeus monodon (Fabricius, 1798), water quality and biological indicators including biofloc volume, chlorophyll‐a, heterotrophic bacteria and Bacillus quantity. Two concentrations of sucrose (0 and 75%) were added daily to the P. monodon culture systems (2.94 ± 0.11 g), which were conducted indoors in fibre‐glass tanks (500 L). Results showed that the final body weight and weight gain of the adding 75% sucrose group were significantly higher (P < 0.05) than that of the control, as well as significantly (P < 0.05) improved specific growth rates and survival rates, and reduced feed coefficient. Adding 75% sucrose promoted heterotrophic bacteria, Bacillus and phytoplankton reproduction, and significantly (P < 0.05) reduced the concentration of ammonia‐N (NH₄‐N), nitrite‐N (NO₂‐N) and nitrate‐N (NO₃‐N). The changes of water quality indicators in the two groups showed the similar trend at the end of the experiment, and the ammonia‐N, nitrite‐N, nitrate‐N and phosphate‐P concentrations in the 75% sucrose group were significantly (P < 0.05) lower than those of the control group, Chlorophyll‐a concentrations peaked at 389.12 μg/L in the biofloc sucrose group at 18:00 h, and heterotrophic bacteria peaked 8 h after sucrose was added. The addition of sucrose also reduced the pH of the water. Our research showed that adding sucrose promoted biofloc formation and shortened the formation time; increased the number of heterotrophic bacteria and algae which might play a role in improving water quality by assimilating ammonia‐N and other harmful substances in the water; supplemented food for P monodon growth; and reduced the feed coefficient.     

加勒帕戈斯群岛野生棉第二次考察简报

在2015年考察的基础上，于2016年9月21日-10月2日再次赴厄瓜多尔的加勒帕戈斯群岛，重点对Santa Cruz、Isabela和San Cristobal三个岛上的达尔文氏棉和克劳茨基棉的自然分布进行调查。观察到28个野生棉自然居群，遗传多样性丰富；特别是发现了达尔文氏棉新类型，具有珍贵的保存和研究价值，充实和丰富了我国棉花种质资源基因库。同时分析了达尔文氏棉的地理分布、形态特征和生态适应性，并对其后续研究和利用方向进行讨论和展望。     

Molecular cloning and characterization of an inhibitor of apoptosis protein in the mud crab <Emphasis Type="Italic">Scylla paramamosain</Emphasis>: its potential anti-apoptosis role under air exposure stress

The mud crab Scylla paramamosain is a widely farmed commercial species in southeast coastal areas of China. The crabs are placed in water-free containers for transportation to inland markets, thus are exposed to dry conditions for more than 72 h after capture and may suffer from air exposure stress, triggering cell apoptosis leading to death. To evaluate whether an inhibitor of apoptosis protein (IAP) is involved in apoptosis resistance against air exposure stress in crustaceans, SpIAP was cloned and investigated for the first time. The full length of SpIAP was 3351 bp, encoding a polypeptide of 662 amino acids. The predicted SpIAP protein contained three baculoviral IAP repeat domains and one really interesting new gene (RING) finger domain. Protein basic local alignment search tool and phylogenetic analysis results showed that SpIAP was clustered together with other crustaceans IAPs. SpIAP was detected in all the examined tissues and predominantly expressed in the hepatopancreas. When crabs were challenged with air exposure for 12 h, the expression level of SpIAP in the hepatopancreas was significantly increased in the experimental group compared with the control group. A RNA interference assay and flow cytometry analysis showed that when SpIAP was silenced, the cell apoptotic rate significantly increased after 24 h air exposure. These results suggested that SpIAP was involved in an anti-apoptosis response induced by air exposure in S. paramamosain.     

Silymarin inhibits adipogenesis in the adipocytes in grass carp <Emphasis Type="Italic">Ctenopharyngodon idellus</Emphasis> in vitro and in vivo

In this study, two experiments were performed to explore the function of silymarin in adipogenesis in grass carp (Ctenopharyngodon idellus) using in vitro and in vivo models. In experiment 1, differentiated grass carp pre-adipocytes were treated with silymarin for 6 days. Treatment with 100 μg mL^?1silymarin (SM100 group) significantly reduced triglyceride accumulation at day 6. The adipogenic gene expression levels of PPARγ, C/EBPα, SREBP1c, FAS, SCD1, and LPL, and the protein expression level of PPARγ were significantly down-regulated in the SM100 group. Additionally, the SM100 group had significantly lower reactive oxygen species production and reduced glutathione contents compared with the control in vitro. In experiment 2, the juvenile grass carp (mean body weight= 27.4 ± 0.17 g) were fed six isonitrogenous and isocaloric diets in a factorial design containing 0, 100, or 200 mg kg^?1 silymarin (SM0, SM100, SM200) associated with either 4 or 8% lipid levels (low lipid, LL, and high lipid, HL, respectively) for 82 days. The results demonstrated that dietary silymarin supplementation significantly reduced the elevated intraperitoneal fat index in grass carp fed with high-lipid diets, and the gene expression of adipogenesis (PPARγ, FAS) when supplemented with dietary silymarin was notably lower than when no silymarin was supplemented under the high-lipid diets. Thus, our data suggest that silymarin suppressed lipid accumulation in grass carp both in vitro and in vivo, and the effect might be due to an influence on the expression of adipogenesis factors and ROS production partly associated with effects on antioxidant capability.     

森林土壤动物生态功能研究进展

森林土壤动物是森林土壤生态系统中不可分割的重要组成部分，对森林土壤生态系统的物质循环和能量流动起着重要作用。文中综述了近10年森林土壤动物生态功能的相关研究进展，包括森林土壤动物对土壤理化性质、微生物、植物的影响以及外来土壤动物入侵对土壤生态系统的影响等；展望了我国森林土壤动物的未来研究方向，未来研究应多关注森林土壤动物生态功能的作用机制、森林土壤动物对全球变化的响应、外来土壤动物入侵对森林生态系统的影响、森林土壤动物种类的研究范围以及新技术的应用，以期为我国森林土壤动物生态功能、土壤动物与生态系统、可持续利用土壤动物等领域研究提供科学参考。     

氟铃脲在韭菜中的残留分析及膳食风险评估

为评价氟铃脲在韭菜中使用的安全性,开展氟铃脲在韭菜中的残留量及残留降解研究。进行1年4地田间试验。消解动态试验按氟铃脲11250 g/ha(562.5 g a.i/ha,推荐最高剂量的1.5倍)施药;最终残留试验按氟铃脲11250 g/ha(562.5 g a.i/ha,推荐最高剂量的1.5倍)和7500 g/ha(375 g a.i/ha,推荐最高剂量)施药,施药1~2次,施药间隔7d,1次施药按照药后间隔10、14、21d采集韭菜样品;2次施药按照末次药后间隔7、10、14d采集韭菜样品。液相色谱串联质谱法对氟铃脲进行定量分析。田间消解动态试验表明:氟铃脲在韭菜中消解较快,在山东保护地和安徽露地半衰期分别为7.7和11.5d。膳食风险评估结果表明,氟铃脲在韭菜中的残留风险处于安全水平。建议使用5%氟铃脲乳油防治韭蛆,用药量7500~11250 g/ha,韭菜收割后2~3d,根部喷淋,最多施药2次,施药间隔7d,安全间隔期为14 d。