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1.
东海毛颚类数量分布与环境关系   总被引:1,自引:0,他引:1  
根据1997-2000年东海23°30′~33°N、118°30′~128°E海域4个季节海洋调查资料,对东海毛颚类的数量分布,优势种丰度对总丰度变化的回归贡献进行了研究。结果表明:毛颚类总丰度有明显的季节变化,4季平均丰度(不含台湾海峡水域)为秋季(540ind/102m3)>夏季(322ind/102m3)>冬季(235ind/102m3)>春季(33ind/102m3);毛颚类高丰度区的移动和变化与带鱼渔场的移动和变化基本一致;春、秋季毛颚类总丰度与表层水温线性相关关系非常显著;肥胖箭虫(Sagittaenflata)、海龙箭虫(Sagittanagae)和百陶箭虫(Sagittabedoti)是构成东海毛颚类总丰度变化的最主要种类,其中肥胖箭虫具有较广泛的空间与时间分布的适应性,海龙箭虫分布的水温偏低,是影响冬、春季总丰度变化的主要优势种,百陶箭虫分布的水温偏高,是影响夏、秋季总丰度变化的主要优势种。  相似文献   

2.
东海毛颚类种类组成和多样性   总被引:7,自引:3,他引:7  
根据1997~2000年东海23°30′~33°N、118°30′~128°E海域4个季节海洋调查资料,对东海毛颚类种类组成、多样性分布特征及与环境关系进行分析。结果表明:春、夏季毛颚类种类最丰富(25种),冬季次之(23种),秋季种数最低(21种);冬、春季毛颚类种数仅与表层温度相关,夏季与表层温度、表层盐度二元线性相关,秋季与表层盐度相关;冬、春季毛颚类多样性和丰富度指数值由北向南,由近海向外海逐渐增高,夏季近海和外海差异缩小,秋季多样性指数值为4季最低。  相似文献   

3.
渤海长岛海域浮游动物的种类组成与时空分布   总被引:2,自引:1,他引:1  
于2012年11月、2013年2月、5月和8月4个航次对渤海长岛海域的浮游动物种类组成和时空分布特征进行调查研究,对影响其群落结构时空变化的环境因子进行分析。本次调查共鉴定出浮游动物38种(属),其中,夏季最多,共26种,其次是秋季23种,春季和冬季最少,分别是14种和13种。浮游动物优势种具有显著的四季演替现象。春季,优势种是墨氏胸刺水蚤(Centropages mcmurrichi)和中华哲水蚤(Calanus sinicus);强壮箭虫(Sagitta crassa)、长腕幼虫(Ophiopluteus larva)和糠虾幼体(Mysidaeea larva)取代两种桡足类成为夏季的优势种;秋季优势种类仅为强壮箭虫1种;冬季除了强壮箭虫,墨式胸刺水蚤和中华哲水蚤又重新成为优势种。浮游动物丰度季节变化明显,春季平均1 952.74ind/m3,夏季平均352.51 ind/m3,秋季和冬季丰度最低,分别为87.38ind/m3和79.95 ind/m3。Shannon-Wiener多样性指数(H)变化范围是0.222~2.766,平均值1.190,均匀度指数(J)在0.121~0.940之间,平均值0.444。分析表明,海水温度、盐度、浮游植物丰度和水团等是影响渤海长岛海域浮游动物时空分布特征的关键因子。  相似文献   

4.
根据1997~2000年东海23°30′~33°N、118°30′~128°E海域4个季节海洋调查资料,对东海毛颚类种类组成、多样性分布特征及与环境关系进行分析。结果表明:春、夏季毛颚类种类最丰富(25种),冬季次之(23种),秋季种数最低(21种);冬、春季毛颚类种数仅与表层温度相关,夏季与表层温度、表层盐度二元线性相关,秋季与表层盐度相关;冬、春季毛颚类多样性和丰富度指数值由北向南,由近海向外海逐渐增高,夏季近海和外海差异缩小,秋季多样性指数值为4季最低。  相似文献   

5.
杭州湾北岸表层水域浮游动物种类组成及季节变化   总被引:2,自引:1,他引:1  
为了探讨杭州湾北岸表层水域浮游动物的群落结构季节性变化以及与环境因子的相关性,2014年8月(夏季)、11月(秋季)和2015年2月(冬季)、5月(春季),在杭州湾北岸水域(121°45'~122°09'E,30°45'~30°51'N)设置10个站点,每月大潮期间,以大型仔稚鱼网(口径130 cm,网目0.5 mm)进行表层拖网。结果表明,4航次采集到浮游动物12类42种,其中优势种共10种,秋季优势种最多(7种),夏季最少(4种)。四季共有优势种为真刺唇角水蚤(Labidocera euchaeta)、火腿伪镖水蚤(Pseudodiaptomus poplesia)、虫肢歪水蚤(Tortanus vermiculus)3种。平均生物量和丰度在夏季达到最大(120.17 mg/m3,1 290.53 ind./m3),冬季最小(14.21 mg/m3,67.03 ind./m3)。该水域浮游动物可分为4种生态类群:淡水类群、河口类群、近岸低盐类群和广盐类群。与环境因子的SPSS双变量相关性分析得出,浮游动物群落结构与温度、盐度、溶解氧和叶绿素a有明显关系,其中温度和盐度是影响浮游动物群落结构的关键因子。  相似文献   

6.
椒江口海域浮游动物群落季节变化特征   总被引:4,自引:1,他引:3  
依据2010年4月、7月和11月对浙江鱼山渔场-椒江口近海海域的海洋调查资料,分析该海域浮游动物生物量、丰度、优势种和多样性指数等生态特征的季节变化及其与浮游植物丰度之间的关系。结果表明:浮游动物生物量、丰度、优势种和多样性指数均存在明显的季节变化,其中春季浮游动物生物量和丰度均是3个季节最高,丰度的高值区位于调查海域的南部,中华哲水蚤(Calanus sinicus)占绝对优势;夏季浮游动物生物量和丰度次之,丰度的高值区在大陈岛西南海域,以中华哲水蚤、太平洋纺锤水蚤(Acartia pacifica)、精致真刺水蚤(Euchaeta concinna)和海龙箭虫(Sagitta nagae)占优势;秋季浮游动物生物量和丰度最低,丰度分布较为均匀,以肥胖箭虫(Sagitta enflata)和双生水母(Diphyes chamissonis)占优势。浮游动物丰度调查结果与同时期浮游植物丰度的调查结果相比,3个季节浮游植物与浮游动物丰度的高值区并不一致,这是因为影响浮游植物丰度的主要因素是营养盐和光照,而浮游动物的分布主要是受水团和海流的影响。上述生态特性的季节变化规律与椒江口海域的季节性水团变化密切相关,春季以低温低盐性质的沿岸流为主,夏季受高温高盐性质的台湾暖流水影响,水团的转换使调查水域的营养盐、温度、盐度和透明度等发生变化,从而进一步影响到浮游动物的生态特征。  相似文献   

7.
湛江港夏秋季浮游动物群落结构的分布与变化   总被引:3,自引:0,他引:3  
2010年8月(夏季)和11月(秋季)分别对湛江湾浮游动物进行调查,并对该海域夏季和秋季浮游动物群落结构的时空分布特征及优势种组成特点等进行分析。结果表明,夏、秋季共采集到9个生物类群共51种,两季均出现的优势种仅两种,为刺尾纺锤水蚤(Acartia spinicauda)、藤壶幼虫(Balanua larva),夏季优势种的种类数较秋季多。夏季浮游动物的丰度(7807.3 ind/m3)远大于秋季的(190.15 ind/m3),夏季浮游动物丰度基本呈现湾内高于湾外的特征。夏秋季各类群中桡足类和浮游幼虫类数量相对较大,是调查海域浮游动物的主要组成部分,成为主导本海域浮游动物数量的主要类群。夏季浮游动物多样性指数均值为1.91,均匀度均值为0.50;秋季浮游动物多样性指数均值为2.28,均匀度均值为0.77;夏季多样性指数和均匀度均值均小于秋季。  相似文献   

8.
长江口九段沙附近水域浮游动物生态特征   总被引:6,自引:1,他引:6  
根据1998-2000年长江口九段沙附近水域(30°~32°N,121°27′~122°30′E)丰水期枯水期6个航次的海洋调查资料,对长江口水域浅水Ⅲ型(网目孔径0.077 mm)和浅水Ⅰ型(网目孔径0.505mm)浮游动物生态特征的变动趋势进行了研究。结果表明:丰水期盐度与浮游动物总丰度有很显著的线性关系,总丰度随着盐度的增加而增加;枯水期盐度与总丰度的关系不明显。同一季节温度与总丰度之间的关系不明显,但从总丰度的季节变化可见,不同水温环境下总丰度的差异依然明显。各年多样性指数(H′)值均小于2;丰水期和枯水期大型浮游动物H′值无论涨潮还是落潮均要大于小型浮游动物。本调查水域浮游动物种类组成简单,种间分布不均匀,优势种突出,主要由淡水生态类型、河口半咸水生态类型、沿岸生态类型和外海生态类型的种类组成。  相似文献   

9.
依据2006年8月(夏)、2007年1月(冬)、5月(春)和11月(秋)在舟山渔场及邻近海域(29°30′~32°00′N,127°E以西)开展海洋生态系统综合调查中所获得的虾蛄类调查资料,用渔获率作为虾蛄类资源分布的数量指标,对舟山渔场及邻近海域的虾蛄类种类组成和数量分布作了分析。结果表明:舟山渔场及邻近海域共有虾蛄类种类11种,隶属3科、7属,其中优势种有口虾蛄Oratosquilla oratoria、脊条褶虾蛄Lophosquilla costata和无刺口虾蛄Oratosquilla inornata,它们在春、夏、秋、冬季的渔获量之和分别占该季节总渔获量的97.54%、98.75%、99.85%、99.35%。不同季节的渔获率变化明显,其变化规律是夏季>冬季>秋季>春季。生物量平面分布结果表明,春、秋季虾蛄类渔获率以长江口渔场和江外渔场相对较高,夏、冬季以舟山渔场为最高。总体来说,虾蛄类数量分布分散,没有十分明显的密集分布。  相似文献   

10.
广东省主要城市湖泊后生浮游动物采样调查中共检出轮虫94种,其中以臂尾轮科(17种)、异尾轮科(14种)和腔轮科(15种)出现种类最多,共占检出轮虫种类的49%;枝角类7科14属20种;桡足类4科12属15种,另外三大桡足类均有检出.后生浮游动物丰度处于51.20~1 450.00 ind/L间,平均丰度为(427.29±38.36) ind/L,其中,轮虫丰度占据后生浮游动物丰度的优势,平均丰度为(345.95±32.33) ind/L;枝角类平均丰度为(5.89±0.97) ind/L;桡足类平均丰度为(23.66±4.83) ind/L.后生浮游动物优势种主要为广生多肢轮虫(Polyarthra trigla)、裂足臂尾轮虫(Schizocerca diversicornis)、剪形臂尾轮虫(Brachionus forficula)、萼花臂尾轮虫(B. calyciflorus)、角突臂尾轮虫(B. angularis)、裂痕龟纹轮虫(Anuraeopsis fissa)、刺盖异尾轮虫(Trichocerca capucina)、长三肢轮虫(Filinia longiseta)、卜氏晶囊轮虫(Asplanchna brightwelli)等.  相似文献   

11.
Web2.0,以个人为中心的互联网时代的到来   总被引:15,自引:0,他引:15  
本文介绍了Web2.0的知识和背景,对Web2.0出现的基础以及典型技术和应用作了阐述,同时对其作出了前景展望。  相似文献   

12.
迟贵富  张昱  李亮  钟子琳 《安徽农业科学》2009,37(12):5585-5587
以抚顺地区3个国家基本站50余年气象资料为依托,采用Microsoft Excel工作表实现由气候和农业气候2部分构成的气象与农业综合信息处理系统的基本思路、方法、内容、用途和使用情况。为了实现气候分析及应用的科学化、客观化、系统化、规范化、程序化及连续化的业务目标,按业务流程设计与实现的,包括资料处理、气候趋势模拟、气候预测、气候鉴定、季节性信息化处理、农作物产量预报、气候生产潜力分析等一系列内容在内的系统建设。关键是解决了大量的计算问题,建立了区域性通用模式。  相似文献   

13.
Urban water consumption has some characteristics of grey because it is influenced by economy, population, standard of living and so on. The multi-variable grey model (MGM(1,n)), as the expansion and complement of GM(1,1) model, reveals the relationship between restriction and stimulation among variables, and the genetic algorithm has the whole optimal and parallel characteristics. In this paper, the parameter q of MGM(1,n) model was optimized, and a multi-variable grey model (MGM(1 ,n,q)) was built by using the genetic algorithm. The model was validated by examining the urban water consumption from 1990 to 2003 in Dalian City. The result indicated that the multi-variable grey model (MGM(1,n,q)) based on genetic algorithm was better than MGM(1,n) model, and the MGM(1,n) model was better than MGM(1,1) model.  相似文献   

14.
Campylobacter species are a major cause of foodborne bacterial infections in both developed and developing countries worldwide. Campylobacter jejuni is responsible for the majority of infections. This study was conducted to identify virulenceassociated genes in Campylobacter species isolated from livestock production systems in South Africa. A total of 250 fecal samples consisting of cattle(n=50), chickens(n=50), goats(n=50), sheep(n=50) and pigs(n=50) were randomly collected from livestock in Eastern Cape and KwaZulu-Natal provinces of South Africa between April and October 2018. The samples were analyzed for the presence of virulence genes in Campylobacter species using molecular PCR-based methods. It was found that 77 and 23% of Campylobacter jejuni and Campylobacter coli respectively were isolated from all the livestock samples. There were positive significant(P0.05) correlations amongst all the virulence genes that were investigated. Chisquare and Fisher's exact tests were implemented to test for the effect of livestock species on the presence or absence of virulence genes. The study demonstrated that most of livestock species can potentially cause zoonotic infections and food poisoning due to the high prevalence of Campylobacter. The high prevalence of virulence genes highlights the significance of Campylobacter in livestock production systems in South Africa. This requires the implementation of one-health approaches to reduce the impact of foodborne and zoonotic diseases for the welfare of human and animal health.  相似文献   

15.
不同施肥水平对木薯氮磷钾养分积累、分配及其产量的影响   总被引:13,自引:0,他引:13  
 【目的】通过比较不同施肥水平下木薯氮磷钾养分积累、分配和产量的差异,探讨粤北坡岗地优质高产木薯氮磷钾养分的最佳用量。【方法】以木薯品种南美119为材料,采用“3414”方案,在粤北翁源进行大田试验。试验共设14个处理。【结果】施肥处理的氮素主要分配到地上部,不施肥处理的氮素则主要分配到根部;不同施肥处理的磷素均主要分配到地上部;不施肥处理和不施钾处理的钾素主要分配到根部,不施氮处理的钾素在根、冠间分配较均衡。在木薯不同生长阶段,植株氮磷钾含量均呈下降趋势,但施氮、磷、钾化学肥料处理植株氮磷钾含量的下降速度小于不施氮、磷、钾化学肥料的处理。处理N2P2K2的氮、磷、钾含量和积累量在各生育期均为最大,不施肥处理(N0P0K0)的氮、磷、钾含量和积累量在各生育期均为最小(P<0.05)。产量最高的是N2P3K2处理,为22 694.06 kg·hm-2,其次是N2P2K2处理,为21 417.87 kg·hm-2。【结论】木薯产量、氮磷钾养分积累及其在根冠间的分配,对施肥水平高度敏感, 适当比例的氮磷钾肥配合施用既可以显著增加木薯植株的氮磷钾含量和积累量,又可以提高产量。在粤北坡岗地木薯生产中,氮素最重要,在氮素得到满足的条件下,磷素较钾素更重要。在本试验条件下,氮磷钾养分最佳用量为358.80 kgN·hm-2、89.10 kg P2O5·hm-2和187.50 kg K2O·hm-2。  相似文献   

16.
选体重约38公斤的长白(♂)×成华(♀)杂交猪20头,随机分为四组,饲予四种不同的饲粮,研究饲粮中添加铜和/或喹乙醇对猪生产性能和某些血液生化指标的影响。结果表明:基础组、加铜组、加喹乙醇组和两者同时加组全期日增重分别为674、761、796、678克,日采食量分别为2.50、2.65、2.74、2.40公斤,饲料利用率分别为3.73、3.49,3.44、3.54,添加铜和/或喹乙醇对试验第65天血清铜兰蛋白、尿素氨及屠宰率、背膘厚和眼肌面积无显著影响(p>0.05);添加铜使65天血清碱性碱酸酶活性极显著增高(p<0.01),添加喹乙醇有使之升高的趋势,两者同时添加时,碱性酸磷酶活性降低。  相似文献   

17.
Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.  相似文献   

18.
The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ (PCV-2). Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups: control group (n = 3), piglets inoculated with PCV-2 alone (PCV-2, n = 3), and PCV-2 inoculated and KLH immunostimulated group (PCV-2 + KLH, n = 3). Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling (TUNEL) and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 + KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 + KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 + KLH piglets were significantly higher than those for the control group (P〈0.05 and P〈0.01). The proliferation index (PI) was 0.17_+0.01, 0.12_+0.01 and 0.12_+0.04 in the control, PCV-2, and PCV-2 + KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o  相似文献   

19.
郁达  王立新  郁建锋  杨珍  杜兰芳 《安徽农业科学》2010,38(32):18300-18302
以豌豆为试验材料,采用水培方法研究了锌对镉、汞复合污染下的豌豆种子萌发与生长的影响。结果显示,锌浓度≤100.0 mg/L时促进豌豆种子的萌发,锌浓度为200.0和300.0 mg/L时抑制豌豆种子的萌发。当镉、汞的浓度为3.0 mg/L时,100.0 mg/L锌的解毒效应最明显,表现为能够促进镉、汞胁迫下豌豆种子萌发和幼苗生长,降低豌豆幼苗根尖细胞畸变率,提高豌豆幼苗的叶绿素含量及过氧化物酶活性;但当锌浓度≥200.0 mg/L时,与镉、汞协同迫害豌豆幼苗的生长。  相似文献   

20.
以仙人掌为试验材料,采用硫酸铵分级沉淀法得到超氧化物歧化酶(Superoxide Dismutase,SOD)粗酶液。然后用Sephadex(葡聚糖凝胶)G-75层析柱层析对粗酶液进行进一步纯化,最后用邻苯三酚法测定酶活力,并对酶活力主要影响因素(包括pH值、温度、抑制剂)进行了研究。结果显示仙人掌SOD酶比活力为751.56U.mg-1。pH值为7.5~8.5时酶活力最大,稳定性也好。温度维持在25~30℃时酶活力最高。由于过氧化氢和氰化钾均能使仙人掌SOD的酶活力显著下降,因而可以初步判断从仙人掌中提取到的SOD是Cu.Zn-SOD。  相似文献   

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