The isolation and characterization of myostatin gene in Japanese flounder (Paralichthys olivaceus): Ubiquitous tissue expression and developmental specific regulation     

Qiwang Zhong  Quanqi Zhang  Yanjie Chen  Yeying Sun  Jie Qi  Zhigang Wang  Shuo Li  Chunmei Li  Xun Lan 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):247-255

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The On-Farm Trials of the Rotational Prawn-Rice Farming in a Semi-Deep Water Area     

Lam My Lan  Jean-Claude Micha  Duong Nhut Long  Tran Thanh Hai 《Journal Of Applied Aquaculture》2013,25(3):168-183

ABSTRACT

The on-farm trials of rotational rice-prawn farming in a semi-deep water area in the Mekong Delta of Vietnam was carried out in six rice fields (0.7–1.0 ha) to evaluate the production and economic efficiency of using low and high cost feed on prawn culture in paddies at different densities. Two stocking densities of 4 and 5 PL/m² were investigated. Two treatments of feed types (pellets only or a combination of pellets, trash fish, and snail meat) were applied at stocking 4 PL/m². At the treatment of 5 PL/m², prawns were fed a combination of pellets, trash fish, and snail meat. Prawns were stocked in the mid-April and harvested in mid‐November before the next dry season rice crop. Rice farming was started 3 to 5 days after prawn harvesting. By cull harvesting during the culture period, final mean weights of prawn ranged from 47.2 to 57.2 g/prawn and the male:female ratio at harvesting was 2.5:1.0. The prawn yield of treatment 5 PL/m² was highest (630 ± 22 kg/ha). Net profits in treatments using the combination of pellets, trash fish, and snail meat were 861 ± 193 US$/ha to 1,019 ± 25 US$/ha for the prawn crop and 1,393 ± 71 US$/ha to 1,576 ± 180 US$/ha for the whole system (prawn crop + dry rice crop) and significantly higher than in treatment using pellet only (P < 0.05). Prawns fed on pellets or a combination of pellets and snail meat both offer similar results in terms of production and economics. The dry rice crop offered high cost benefit ratio (2.29–2.33) with low operating cost (414–434 USD/ha) and it made a better use in sustainable rice fields through the rotational rice-prawn system.  相似文献   

刺参血系统的超微结构观察与功能探讨   总被引：2，自引：0，他引：2  

刘晓云  陈西广  包振民  范瑞青  姜明  谭金山  高澜 《海洋水产研究》2004,25(6):69-72

在光学显微镜、扫描电镜和透射电镜下观察刺参血系统的组织细胞结构，探讨血系统的生理功能，结果显示：(1)刺参的血系统由复杂的管网构成，排列紧密的血管上皮细胞和上皮下连续成层的基膜，构成血系统中连续而封闭的管状结构，管腔中充满血液，血系统的管网承担了血管输送血液的功能，并通过与呼吸树的连接完成血液的气体交换。(2)血管上皮细胞游离面的细胞膜、微绒毛和吞饮小泡呈酸性磷酸酶阳性反应，表明细胞具有吸收功能。血管上皮细胞内的小泡在管壁内外的物质运输中起作用。由单层细胞和基膜构成的血管壁是血液与体腔液进行物质交换的场所。(3)血管上皮细胞富含内质网、脂滴、线粒体及分泌自噬体，具有类固醇激素分泌细胞的超微结构特点，可能与刺参体内的固醇合成有关。  相似文献   

岗更湖鲫的生长和生活史对策研究     

安晓萍  齐景伟  乌兰  孟和平  柳玉海  高玉奎 《水生态学杂志》2009,30(4):71-74

2008年5～9月于岗更湖取得803尾鲫标本,研究了其生长及生活史类型.用鳞片鉴定年龄,鳞径(R)和体长(L)的关系为L=3.667R-1.737;用特殊von Bertalanffy生长方程、一般von Bertalanffy生长方程、Gompertz生长方程和灰色动态生长模型共4种生长模型拟合了岗更湖鲫的生长,根据各模型拟合残差平方和的大小判断,特殊von Bertalanffy生长方程拟合效果最好;根据r-选择和k-选择的典型特征及7个生态学参数值,判断出岗更湖鲫偏向r-选择,应用平衡产量模式计算改变瞬时捕捞死亡率(F)和渔业补充年龄(tc)对应的产量变化,同样证实岗更湖鲫偏向r-选择.作为渔业管理对策,岗更湖鲫的捕捞年龄应在3龄以上,捕捞强度不应超过2.0.  相似文献   

猪-鱼复合养殖模式中气单胞菌I类整合子的流行情况及其耐药特征     

冯永永  姜兰  邓玉婷  谭爱萍  张瑞泉  罗理 《水产学报》2016,40(1):92-99

为了解广东地区猪-鱼复合养殖模式下气单胞菌整合子流行情况及其耐药特征,从广东省5个不同猪-鱼复合养殖场采集分离猪粪、鱼、池塘水及池塘底泥的气单胞菌共317株,通过微量二倍稀释法测定其对20种药物的敏感性;PCR扩增Ⅰ类整合子整合酶基因intI1,并分析其基因盒阵列结构。结果表明,317株气单胞菌对20种药物耐药程度不一,氨苄西林、磺胺间甲氧嘧啶、萘啶酸的耐药率相对较高。intI1的检出率为15.77%,鱼源和猪源的整合子检出率高于环境源。整合子阳性菌对测试的12种药物的耐药率显著高于阴性菌,且表现为多重耐药;50个Ⅰ类整合子共检测到16种耐药基因盒,包括了编码氨基糖苷类耐药基因aadA1、aadA2、aac6-Ⅱ、aacA4,甲氧苄啶耐药基因drfA1、dfrA12、dfrA15、dfrA17、dfrB4,β内酰胺类耐药基因bla_(OXA-10)、bla_(OXA-21),氯霉素耐药基因catB3、catB8,利福平耐药基因arr2、arr3以及质粒介导的喹诺酮类耐药基因aac(6')-Ib-cr。携带了不同类耐药基因盒的整合子阳性菌还表现出所对应的对甲氧苄啶、链霉素、氯霉素类等的耐药表型,由此推测整合子的存在与细菌的多重耐药密切相关。研究表明,I类整合子分布于广东地区猪-鱼复合养殖模式下不同来源气单胞菌,并介导细菌对多种抗菌药物耐药。有必要开展畜禽-鱼复合养殖模式下细菌耐药性的传播机制研究,为水产养殖合理用药提供依据。  相似文献   

Jagged1 knocking down in endothelial cells accelerates PDGF induced proliferation and migration of vascular smooth muscle cells in rats     

WU Xiao-jing  HUANG Lan  ZHOU Qi  CHEN Jian-fei  ZHOU Yin-pin  NIU Qin  ZOU Yun-zeng  GE Jun-bo 《园艺学报》2009,25(10):1873-1877

AIM: To investigate the effect of Jagged1 expression in endothelial cells (EC) on platelet derived growth factor (PDGF) induced proliferation and migration of vascular smooth muscle cells (VSMC) in rat.METHODS: Rat aorta EC was inoculated in the lower chamber and VSMC were in the upper chamber of the cell coculture system. Three groups were divided: control, sicontrol and siJagged1. The EC Jagged1 protein expression was assayed by Western blotting to evaluate small RNA interfering (RNAi) efficiency. After the cells were cocultured with PDGF for 24 h, the proliferation and migration of VSMC were respectively evaluated by ［3H］-TdR incorporation and migrating cells counting. Protein expression of α-SM-actin in VSMC was assayed by Western blotting. RESULTS: The Jagged1 protein expression in EC was significantly lower in siJagged1 group than that in control group (0.26±0.02 vs 0.67±0.02, P<0.05), and no statistic significance was observed between control and sicontrol groups. The VSMC ［3H］-TdR incorporation and migration were higher in PDGF +siJagged1 group than those in PDGF group {［3H］-TdR incorporation (23 074±2 702) counts·min-1·well-1 vs (16 442±1 803)counts·min-1·well-1, n=5, P<0.05; migration (27±4) cells/field vs (15±3)cells/field, n=5, P<0.05}. The α-SM-actin protein in VSMC was lower in PDGF + siJagged1 group than that in PDGF group (0.25±0.06 vs 0.49±0.04, n=3, P<0.05).CONCLUSION: Jagged1 knock down in rat EC accelerates PDGF induced proliferation and migration of VSMC. These results suggest that Jagged1 expression in EC plays an important role in maintaining VSMC contract phenotype and inhibiting VSMC overgrowth after arterial injury.  相似文献   

东西汊湖水资源合理配置研究   总被引：1，自引：0，他引：1  

甘衍军  李兰 《中国农村水利水电》2009,(2):9-11

以应城市东西汊湖为例,建立了以经济、生态和社会效益为目标的区域可持续发展水资源优化配置模型,对该区域的水资源合理配置进行了初步的研究。研究结果表明,模型能够准确、合理地反应该区域可持续发展的各项指标。从而可为东西汊湖流域的水资源配置提供技术支持。  相似文献   

玉米机械精量播种技术在彰武地区的应用研究     

刘宝祥  高兰 《农业科技与装备》2009,(3):116-117

介绍几年来彰武县玉米精量播种技术的推广应用情况,通过与传统播种方式田间对比试验,证明采用精量播种技术种植玉米具有节本增效、省时省工、增产增收的优势,并指出玉米机械精量播种技术实施过程中的关键环节。  相似文献   

灌溉模式对不同密度小麦群体质量和产量的影响   总被引：3，自引：0，他引：3  

刘丽平  欧阳竹  武兰芳  孙振中 《麦类作物学报》2011,31(6):1116-1122

为明确灌溉模式对不同密度小麦群体的调控效应,在大田条件下设置了不灌水（W0）、灌1水（W1j,拔节期灌水;W1b,孕穗期灌水）、灌2水（W2,拔节期和孕穗期灌水）、灌3水（W3,拔节期、孕穗期和灌浆期灌水）5种灌溉模式和基本苗180万.hm-2（D1）、300万.hm-2（D2）、450万.hm-2（D3）3种密度的二因素试验,研究了灌溉模式对不同密度小麦群体质量指标和产量的影响。结果表明,在灌溉拔节水的基础上增加灌溉显著提高了群体总茎数、叶面积指数和成穗率,三个指标基本上均表现为W3〉W2〉W1j〉W1b〉W0。花后干物质积累量高低表现为W2〉W1j〉W1b〉W3〉W0。产量则随着灌溉次数的增多呈低-高-低的变化趋势,表现为W2〉W3〉W1b〉W1j〉W0。密度从D1增加到D3,总茎数、叶面积指数和干物质积累量显著增加,籽粒产量则呈低-高-低的变化趋势。因此在春季降雨较少的条件下,灌溉模式W2即灌拔节水和孕穗水,就可以满足小麦正常生长发育、群体合理构建和高产的需要,其适宜密度为300万.hm-2基本苗。  相似文献   

施肥水平对抽穗期水稻穗部温度的影响及其原因分析   总被引：7，自引：0，他引：7  

张彬  郑建初  杨飞  田云录  彭兰  李明安  卞新民  张卫建 《中国水稻科学》2007,21(2):191-196

在田间环境下, 利用2个冠层结构差异显著的水稻品种（扬稻6号、 扬粳9538）, 设置高、 中、 低3个施肥水平, 研究水稻抽穗期穗部温度特征, 以探讨水稻抗热避热的生态学机制。 穗部与大气的温度变化趋势基本一致, 但扬稻6号和扬粳9538的穗部平均温度分别比气温低3.58℃和3.04℃。 施肥水平显著影响大气 穗部的温度差, 高肥和中肥处理下, 2个品种的平均值分别比低肥的高1.54℃和0.90℃。 品种间大气 穗部温度差也存在差异, 扬稻6号平均比扬粳9538高0.85℃。 相关分析发现, 不同施肥水平下大气 穗部温度差与总叶面积指数、 穗上叶面积指数、 生物量和有效分蘖数呈极显著正相关, 而与穗部透光率呈极显著负相关。 说明通过优化田间管理比如合理的施肥来建立良好的群体结构, 对降低穗部温度, 提高水稻抗热避热能力的效应显著。  相似文献