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1.
采用完全双列杂交法对刺参中国群体(C)和韩国群体(K)进行群体间杂交和群体内自繁,获得C(♀)×C(♂)、K(♀)×K(♂)、K(♀)×C(♂)和C(♀)×K(♂) 4个交配组合的子一代。分析了各交配组受精率、孵化率、附着变态率、浮游幼体和幼参阶段的生长和抗病能力以及杂交子代的杂种优势。结果显示,杂交组与自繁组在受精率和孵化率等方面不存在显著性差异,杂交组附着变态率高于自繁组。C(♀)×K(♂)组在幼参期体长平均值均大于其他3个组,并表现出显著性差异,其体长杂种优势率在9.43%–23.75%之间;其体重从150日龄后表现出杂种优势,在4.09%–34.96%之间。而K(♀)×C(♂)组在幼参期体长和体重除在150日龄时表现为杂种优势,其他时间均表现为杂种劣势。K(♀)×C(♂)组抗灿烂弧菌病能力最强,杂种优势率为26.21%。  相似文献   

2.
刺参(Apostichopus japonicus)中国群体(C)和刺参韩国群体(K)进行完全的双列杂交,得到4个交配组合C(♀)×C(♂)、K(♀)×K(♂)、K(♀)×C(♂)和C(♀)×K(♂).各交配组合的子一代刺参在16℃、盐度为31的海水中暂养7d,然后转移到温度或盐度按以下4种方式改变的实验海水中:1)实验海水温度以1℃/h的速率上升;2)刺参被转移到梯度的高温海水(27℃、28℃、29℃、30℃和31℃)中;3)实验海水的盐度以2 psu/h的速率上升或者下降;4)刺参被迅速转移到梯度的高盐度(36、38、40、42和44)或者低盐度(21、19、17、15、13和11)的海水中.统计单个实验中刺参的存活率.结果显示,温度渐升时,C(♀)×C(♂)和C(♀)×K(♂)组的最高存活温度(Survival temperature maximum,STMax)显著高于K(♀)×K(♂)组,C(♀)×C(♂)和C(♀)×K(♂)组刺参存活率为50％时的温度(50％ critical temperature maximum,50％CTMax)显著高于其他2组(P＜0.05).温度突升时,两杂交组的半数致死高温(Median lethal temperature,LT50)高于韩国自交组,但低于中国自交组.单因素方差分析显示,盐度渐升时,C(♀)×K(♂)组的半数致死高盐(50％ critical salinity maximum,50％CSMax)显著高于韩国自交组(P＜0.05).盐度渐降时,K(♀)×C(♂)组的半数致死低盐(50％ critical salinity minimum,50％CSMin)显著低于K(♀)×K(♂)组(P＜0.05).盐度突降时,K(♀)×C(♂)组的耐受盐度下限(Lower salinity tolerance limit,LSTL)显著低于K(♀)×K(♂)组(P＜0.05).研究表明,中韩杂交刺参在温度和盐度耐受性方面有一定的杂种优势,意味着通过杂交育种,刺参的抗逆性能得到有效改善.  相似文献   

3.
刺参(Apostichopus japonicus)中国群体(C)和刺参韩国群体(K)进行完全的双列杂交,得到4个交配组合C(♀)×C(♂)?K(♀)×K(♂)?K(♀)×C(♂)和C(♀)×K(♂)。各交配组合的子一代刺参在16℃、盐度为31的海水中暂养7 d,然后转移到温度或盐度按以下4种方式改变的实验海水中:1)实验海水温度以1℃/h的速率上升;2)刺参被转移到梯度的高温海水(27℃、28℃、29℃、30℃和31℃)中;3)实验海水的盐度以2 psu/h的速率上升或者下降;4)刺参被迅速转移到梯度的高盐度(36、38、40、42和44)或者低盐度(21、19、17、15、13和11)的海水中。统计单个实验中刺参的存活率。结果显示,温度渐升时,C(♀)×C(♂)和C(♀)×K(♂)组的最高存活温度(Survival temperature maximum,STMax)显著高于K(♀)×K(♂)组,C(♀)×C(♂)和C(♀)×K(♂)组刺参存活率为50%时的温度(50%critical temperature maximum,50%CTMax)显著高于其他2组(P0.05)。温度突升时,两杂交组的半数致死高温(Median lethal temperature,LT50)高于韩国自交组,但低于中国自交组。单因素方差分析显示,盐度渐升时,C(♀)×K(♂)组的半数致死高盐(50%critical salinity maximum,50%CSMax)显著高于韩国自交组(P0.05)。盐度渐降时,K(♀)×C(♂)组的半数致死低盐(50%critical salinity minimum,50%CSMin)显著低于K(♀)×K(♂)组(P0.05)。盐度突降时,K(♀)×C(♂)组的耐受盐度下限(Lower salinity tolerance limit,LSTL)显著低于K(♀)×K(♂)组(P0.05)。研究表明,中韩杂交刺参在温度和盐度耐受性方面有一定的杂种优势,意味着通过杂交育种,刺参的抗逆性能得到有效改善。  相似文献   

4.
双列杂交法分析2个大菱鲆养殖群体的杂交效果   总被引：3，自引：0，他引：3  
采用完全双列杂交法对2个大菱鲆(Scophthalmus maximus)养殖群体:西班牙群体(S)和英国群体(E)进行群体间杂交及群体内自繁,得到了S(♂)×S(♀)、E(♂)×E(♀)、S(♂)×E(♀)和E(♂)×S(♀)4个组合的子一代。对各交配组合的受精率、孵化率、畸形率、30日龄和70日龄稚鱼的体长、体质量等指标进行比较,结果表明,杂交组与自繁组在受精率、孵化率及畸形率等方面均不存在显著性差异;但杂交组30日龄稚鱼和70日龄稚鱼的体长、体质量与自繁组相比,表现出不同程度的杂种优势,其中S(♂)×E(♀)组30日龄稚鱼的体长杂种优势达到5.43%,E(♂)×S(♀)组70日龄稚鱼体质量杂种优势达到25.00%。实验初步显示,不同养殖群体间的杂交有可能是大菱鲆遗传改良的一条有效途径。  相似文献   

5.
相同室外网箱养殖条件下,比较白鲫自交F_1及其与散鳞镜鲤、黑龙江野鲤、禾花鲤和兴国红鲤四种鲤鱼杂交F_1鱼苗的形态特征与生长的差异。结果显示:全长/体长、体长/体高、体长/头长、头长/头高等可量性状参数比值差异显著,可作为几者之间形态区别主要参数。其中白鲫(♀)×黑龙江野鲤(♂)的全长为体长的1.64倍,体长为体高的3.00倍,为头长的3.50倍,为尾柄宽的7.68倍,尾柄长为尾柄宽的1.48倍。各方面指标显著优于其他组别。从数据可以看出白鲫(♀)×黑龙江野鲤(♂)体略高,头略短,尾柄略窄长,体型较修长,表明该杂交组合鲫鱼体长体重增长率方面都显著优于其他组合,体型合适。  相似文献   

6.
为改良威海地区仿刺参的生物性状,在水温20.0~22.0℃,盐度30.0~31.0,幼体密度0.2个/m L的条件下,以中国威海的仿刺参群体(W)和韩国东海岸浦项市的仿刺参群体(P)为亲本,采用群体内自交和群体间杂交的方法建立了WW(W♀×W♂)、WP(W♀×P♂)、PP(P♀×P♂)等3个试验组,并于幼体孵化选育后,先后进行了为期11 d的浮游幼体培育和近1年的苗种中间培育(水温3.0~30.0℃,盐度28.0~31.0),测算了各组浮游幼体、稚参、幼参的生长速度。结果表明,组间受精率、孵化率、变态附着率差异不显著(P0.05);在浮游阶段,各组在大耳幼体时期的体长差异极显著(P0.01),WW组的体长最大[(1 121.5±68.4)μm],在小耳幼体、中耳幼体、樽型幼体时期各组的体长差异不显著(P0.05);在中间培育阶段,WP组的苗种生长速度先慢后快,其330日龄苗种的平均体质量最大[(123.6±8.6)mg],且与其余两组差异极显著(P0.01)。试验表明,威海仿刺参群体与浦项仿刺参群体的杂交子代在90日龄以前表现为杂种劣势,在90~330日龄表现为杂种优势,杂种优势率为31.5%。试验还发现300~330日龄的PP组雄性幼参中出现了性早熟现象。  相似文献   

7.
建鲤自交及与黄河鲤正反杂交子代的生长比较和通径分析   总被引：6，自引：2，他引：4  
以建鲤、黄河鲤为亲本,建立了建鲤自交JL(建鲤♀×建鲤♂)、正交JH(建鲤♀×黄河鲤♂)、反交HJ(黄河鲤♀×建鲤♂)3个试验组合,PIT标记后在养殖157、398、598 d时测定生长参数.结果表明:(1)157、398 d时增重率均为HJ>JH>JL,HJ与JL差异显著(P<0.05);598 d时JL>JH>HJ,子代差异不显著(P>0.05).(2)体长、体重的变异系数在157、398 d 时HJ>JH>JL,598 d 时JL>HJ>JH.体长的变异系数小于体重的变异系数.(3)肥满度随养殖时间增加而增长,JL的肥满度最高并与JH、HJ差异显著;(4)雌、雄鱼生长差异显著,雌鱼生长始终快于JL;雄鱼仅在157 d时有优势,398、598 d时杂种优势衰退.(5)在对体重的决定系数上,398 d时子代均以体长的决定系数占主导;598 d时HJ(♀)、JL(♀)中体高的决定系数占主导,JL(♂)、HJ(♂)、JH(♀)中体长的决定系数占主导,JH(♂)中体长、体高对体重的决定系数差异很小.(6)养殖时间对体重的差异显著性、绝对增重率无显著影响(P>0.05),对体长、绝对增长率、特定生长率、体重变异系数、生长指标及肥满度有极显著影响(P<0.01);鱼的不同交配组合和不同性别对上述生长参数均有极显著影响.  相似文献   

8.
该研究利用斑节对虾(Penaeus monodon)“南海1号”群体(S)、非洲品系选育群体(A)和泰国群体(T),采用完全双列杂交交配设计,建立9个自繁和杂交组合F1代。利用混合线性模型估计不同组合体质量性状的一般配合力(GCA)和特殊配合力(SCA)。结果显示,“南海1号”群体的一般配合力最高,其次是非洲品系选育群体,泰国群体的最低,其效应值分别为0.4373、?0.0624和?0.3749。9个交配组合的体质量性状的特殊配合力效应值介于?0.7798~0.613,其中非洲品系选育群体(♂)ד南海1号”群体(♀)组合(AS)体质量性状的特殊配合力最高,效应值为0.613。杂种优势分析表明,6个杂交交配组合的体质量性状中亲和超亲优势范围分别是8.41%~13.80%和2.66%~7.97%,其中非洲品系选育群体(♂)ד南海1号”群体(♀)组合(AS)的中亲杂种优势(HM)和超亲杂种优势(HB)最大,分别为13.80%和7.97%。研究表明,“南海1号”群体为母本,非洲品系选育群体为父本的杂交组合特殊配合力和杂种优势最好,可以考虑加强该组合在体质量性状方面的选育。  相似文献   

9.
对室内养殖的1龄和2龄褐菖鲉的生长特性进行了初步研究和比较。1龄褐菖鲉的初始体长、体质量分别为(5.91±0.74)cm、(7.15±2.44)g,2龄褐菖鲉的初始体长、体质量分别为(11.18±0.54)cm、(41.56±6.23)g。经63 d培育,1龄褐菖鲉体长增至(8.64±0.54)cm,日均增长量0.043 cm/d,体长相对增长率为46.19%;体质量增至(19.95±3.39)g,日均增长量0.203 g/d,体质量相对增长率为179.02%。体质量(W)与体长(L)呈幂函数关系,关系式为:W=0.052 5L~(2.737 4)(R~2=0.922 1),b值接近于3,属于等速生长型。体长(L)与日龄(t)的相关关系式为:L=0.0389t+0.4734(R~2=0.937 3,P0.01)。体质量(W)与日龄(t)的相关关系式为:W=0.199 9t-22.487(R~2=0.986 3,P0.01)。2龄褐菖鲉经63 d培育,体长增至(12.32±0.61)cm,日均增长量0.018 cm/d,体长相对增长率为10.19%;体质量增至(56.56±7.68)g,日均增长量0.238 g/d,体质量相对增长率为36.09%。体质量(W)与体长(L)呈幂函数关系,关系式为:W=0.075 5L~(2.624 5)(R~2=0.801 7),b值接近于3,属于等速生长型。体长(L)与日龄(t)的相关关系式为:L=0.014 7t+3.607 5(R~2=0.897 4,P0.01),体质量(W)与日龄(t)的相关关系式为:W=0.226 1t-76.214(R~2=0.977 9,P0.01)。  相似文献   

10.
运用人工催产的方法进行了9种交配组合鳢的人工繁殖试验,9种组合来源于乌鳢(Channa argus)、斑鳢(C.maculate)和杂交鳢(Hybrid snakehead)彼此之间的交配繁殖.结果表明,无论采用何种孵化方式,9种交配组合所产卵的受精率和孵化率高低顺序基本一致,且各组合间都存在显著差异.交配组合斑鳢(♀)×斑鳢(♂)、斑鳢(♀)×杂交鳢(♂)、杂交鳢(♀)×斑鳢(♂)及杂交鳢(♀)×杂交鳢(♂)在繁殖过程中,其受精率和孵化率高于其他组合,具有较强的繁殖优势,但其子代的生产性能优势还有待进一步研究.孵化方式对受精卵的发育与孵化有重大影响,其中以微流水孵化方式时的受精率和孵化率最高、孵化效果最好.雄亲鱼的重复催产次数会影响受精率及孵化率,一般以重复利用2～3次为宜.  相似文献   

11.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

12.
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13.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

14.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

15.
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus.  相似文献   

16.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

17.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  相似文献   

18.
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19.
A 5 × 3 factorial growth trial was conducted to evaluate optimal dietary protein and lipid levels (dietary protein level, DP; dietary lipid level, DL) for juvenile Sillago sihama (S. sihama) (2.0 ± 0.02 g, initial weight). Fish were fed 15 diets containing 5 DPs (350, 400, 450, 500 and 550 g/kg) and 3 DLs (60, 90 and 120 g/kg) for 8 weeks. The interaction between proteins and lipids significantly influenced the feed conversion ratio, condition factor, body composition, antioxidant indices and lipase activity (p < .05). DP 450 g/kg showed the highest average final body weight. DPs 500 and 550 g/kg significantly decreased the protein efficiency ratio (p < .05). DL 120 g/kg showed the highest percentage weight gain. The low feed conversion ratio was found in diets P45L12, P55L9 and P55L12. Diet P45L12 showed high superoxide dismutase activities. DP 450 g/kg showed the lowest average malondialdehyde content. Lipase activity was increased by increasing DP (p < .05) with a fall at DP 550 g/kg. Under the present experimental conditions, the optimal DP for S. sihama was 450 g/kg under the DL 120 g/kg.  相似文献   

20.
Plasma estradiol-17 (E2), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E2 and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E2 and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.  相似文献   

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