Partial replacement of fishmeal with Clostridium autoethanogenum single‐cell protein in the diet for juvenile black sea bream (Acanthopagrus schlegelii)

Clostridium autoethanogenum protein (CAP) is a single‐cell protein derived from ethanol production and may have potential to become a substitute for fishmeal in aquafeeds. A 70‐day feeding trial was conducted with black sea bream (Acanthopagrus schlegelii) (mean initial weight 6.03 ± 0.09 g) to evaluate partial replacement of fishmeal with CAP in diets. Seven isonitrogenous and isoenergetic diets were formulated with graded levels of CAP (0, 4.85, 9.70, 14.55, 19.40, 38.80 and 58.20%) to replace fishmeal. The inclusion of CAP at all dietary levels tested did not significantly affect the growth performance (p > .05). Fish fed the CAP58.20% diet showed a significantly lower feeding rate, with significantly higher protein efficiency ratio and feed efficiency ratio compared with fish fed the other diets (p < .05). No statistical differences were found in dorsal muscle and whole‐body compositions. Total superoxide dismutase in serum of fish fed CAP58.20% diet was significantly lower compared with that of the control. Malondialdehyde, catalase, total antioxidant capacity and digestive enzyme activities revealed no significant differences among dietary treatments. Phosphorus retention efficiency significantly increased, and phosphorus discharge showed a downward trend with increasing CAP inclusion levels. In conclusion, the results indicated that CAP is a safe and effective alternative protein source, which can replace fishmeal in the diet of black sea bream up to 58.20%, without adverse effects on growth performance, antioxidation and digestive enzyme activity. This study has shown the potential of converting industrial waste into a high protein feed ingredient for aquafeeds.     

Construction of high-density linkage map and identification of QTLs associated with resistance to black rot in radish (Raphanus sativus) by RAD sequencing

High-density marker-based QTL mapping can serve as an effective strategy to identify novel genomic information to facilitate crop improvement. In this study, we genotyped an F₂ population (KB12-1 × PP12-1) using a RAD-seq approach and constructed a high-density linkage map for radish. After a series of filtering procedures were performed, 17,124 SNPs and 3,336 indels with aa × bb genotyping were retained to obtain bin markers. Then, a linkage map comprising a total of 1,221 bin markers in nine linkage groups spanning 1,467.3 cM with an average marker interval of 1.2 cM was constructed. We evaluated the resistance of the F₂ mapping population to black rot using F₃ progeny, and two major QTLs related to black rot resistance were identified based on this map. Among these QTLs, qBRR2 on Chr.2 explained 26.97% of the phenotypic variation with a LOD score of 11.93, and qBRR7 on Chr.7 accounted for 27.06% of the phenotypic variation with a LOD score of 11.83. The additive effect of qBRR2 was positive (14.97); however, qBRR7 had the opposite effect (−11.99). The high-density linkage map and the major QTLs qBRR2 and qBRR7 provide new important information for disease resistance gene discovery and utilization in genetic improvement.     

周年耕作方式对砂姜黑土农田土壤养分及作物产量的影响

为探明适宜于砂姜黑土农田的周年耕作方式, 提升砂姜黑土农田地力及作物产量, 在冬小麦?夏玉米一年两熟种植制度下, 设置多年定位夏玉米季?冬小麦季免耕?旋耕(对照)、免耕?深耕、深松?旋耕、深松?免耕、免耕?免耕5种周年耕作方式田间试验, 在定位处理的第4个周年研究耕作方式对砂姜黑土农田土壤有机碳含量、土壤养分及其对作物产量的影响。结果表明, 在秸秆全量还田条件下, 与试验开始前相比, 各处理0~20 cm土层土壤有机碳、全氮、速效钾含量均有所增加。与对照相比, 其他处理均增加周年内0~20 cm土层土壤有机碳和全氮含量。免耕?深耕、深松?旋耕、免耕?免耕处理显著增加周年内0~20 cm土层土壤有效磷含量, 而深松?免耕处理显著增加冬小麦开花期和收获期0~20 cm土层土壤有效磷含量, 整个周年内对照在20~40 cm土层土壤的有效磷含量均最低。深松?免耕处理增加周年内0~20 cm土层土壤速效钾含量, 而深松?免耕、免耕?免耕处理20~40 cm土层土壤速效钾含量在夏玉米苗期、大口期、开花期和灌浆期显著高于对照处理。深松?旋耕和深松?免耕处理显著增加夏玉米?冬小麦周年籽粒产量, 增幅分别为7.67%和10.21%。综上所述, 在秸秆全量还田基础上, 深松?旋耕和深松?免耕能够改善土壤有机碳和养分状况, 显著提高周年作物产量, 可作为黄淮区砂姜黑土农田相对适宜的周年耕作方式。     

核桃坚果水浸液对4种植物种子萌发及生长的影响

为探究核桃果实不同部位水浸液对植物种子萌发及生长的影响,本试验以莴笋、萝卜、马蹄金、野牛草4种种子为试材,对其进行核桃种子、种仁及种皮的水浸液浸泡处理,进而研究核桃果实不同部位水浸液的化感作用,旨在探讨核桃水浸液对4种植物种子萌发及生长的影响。结果表明,在特定浓度下,核桃种子的水浸液对莴笋、萝卜、马蹄金、野牛草种子萌发均起到抑制作用,对萝卜幼苗生长的抑制作用大于莴笋幼苗的生长,对马蹄金和野牛草种子生长的抑制作用大于莴笋和萝卜。核桃种仁的水浸液对幼苗生长的抑制作用大于其余2个部位的影响,表现为:核桃种仁大于核桃种壳和核桃种子。本研究探索了核桃种子水浸液的化感作用及抑制植物种子萌发的物质,为农作物间作套种、化感抗害提供了依据和指导。     

金州黑色标准水貂对中国养貂行业的影响

介绍了金州黑色标准水貂这一品种的培育过程和优良特性 ,阐述了该水貂新品种对推动中国水貂养殖行业的发展将起到很大的作用     

Dispersal of black sea bass (Centropristis striata) larvae on the southeast U.S. continental shelf: results of a coupled vertical larval behavior – 3D circulation model

In the marine environment, pelagic dispersal is important for determining the distribution and abundance of populations, as well as providing connections among populations. Estimates of larval dispersal from spawning grounds are important to determining temporal and spatial patterns in recruitment that may have significant influences on the dynamics of the population. We present a case study of the dispersal of Centropristis striata (black sea bass) larvae on the southeast U.S. continental shelf. We use a coupled larval behavior – 3D circulation model to compare the effects of the timing and location of spawning against that of larval vertical migration on larval dispersal. Using the results of field data on larval vertical distributions, we compare the dispersal of virtual 'larvae' which have ontogenetic changes in vertical behavior with that of particles fixed near the surface and near the bottom. Larvae were released at potential spawning sites four times throughout the spawning season (February through May) for 3 yr (2002–04) and tracked for the assumed larval duration (from 27 to 37 days including the egg stage). Results indicate that adult behavior, in the form of spawning time and location, may be more important than larval vertical behavior in determining larval dispersal on the inner- and mid- continental shelves of this region.     

后现代主义“反侦探小说”——以《芒博琼博》为例

后现代“反侦探小说”是当代越来越受到评论家关注的一个亚文类。本文在简要梳理“反侦探小说”基本特征的基础上，结合非裔美国作家伊什梅尔·里德的代表作《芒博琼博》，从罪案之谜、侦探形象和叙事结构等方面进一步探讨后现代文本对传统侦探小说的解构。本文认为，对后现代“反侦探小说”政治性的认识，是一个值得商榷的问题。     

核桃腐烂病的发生与防治

略述了核桃腐烂病的危害症状、发病规律和适宜发病的生态环境 ,指出该病的防治方法     

海南黑山羊与萨能奶山羊杂交F1代的生理生化指标测定与分析

对海南黑山羊及其与萨能奶山羊F1 代的主要生理生化指标进行了测定与分析。结果表明，呼吸、体温、红细胞计数、白细胞计数、血清总蛋白、谷草转氨酶等指标都在正常范围，海南黑山羊公羊、海南黑山羊母羊、F1 黑色母羊、F1 白色母羊在海南适应性和生长发育表现良好。测定结果还能为海南黑山羊的饲养管理和疾病的诊断治疗提供血液学方面的参考。     

甘露青鱼肌肉营养分析和评价

取材太湖流域无锡甘露水产公司养殖的大青鱼,采用化学及仪器分析手段,对青鱼含肉率及肌肉营养成分进行了分析测定,含肉率为71 08%,肌肉中蛋白质含量为16 56%,脂肪含量为14 08%,其中70 73%为不饱和脂肪酸,18种氨基酸总量为14 91%,8种人体必需氨基酸的含量为6 07%,4种鲜味氨基酸的含量为5 62%,还含有多种微量元素,通过大量基础数据综合评价甘露青鱼的营养价值。