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本研究旨在对国内虹鳟(Oncorhynchus mykiss)代表性养殖群体开展全基因组水平的遗传评估。利用57K单核苷酸多态性(single nucleotide polymorphism,SNP)芯片,检测了来自不同地域的6个虹鳟养殖群体样本共计48尾,包括黑龙江虹鳟、黑龙江金鳟、四川虹鳟、四川金鳟、北京虹鳟和北京金鳟,共获得有效SNP位点50201个,在中国虹鳟中的多态比例达到97.7%,表明该芯片虽然基于美国和挪威虹鳟群体设计,但对中国群体同样具有良好的适用性。各群体最小等位基因频率均值为0.240~0.267,与国外主流养殖群体相近,黑龙江虹鳟、四川虹鳟和北京虹鳟群体内遗传多样性丰富,多态位点比例为83.6%~84.9%,与国外主流养殖群体相近,而黑龙江金鳟、四川金鳟和北京金鳟,多态位点比例相对较低,在60.2%~76.9%范围内。应用6个中国虹鳟群体和2个美国虹鳟群体数据开展系统发育分析、主成分分析和群体遗传结构STRUCTURE分析,结果显示8个群体可分为3个祖源类群,其中3个金鳟群体为遗传联系较紧密的一个类群,黑龙江虹鳟和北京虹鳟为一个类群,而四川虹鳟与2个美国虹鳟群体为一个类群,部分中国养殖群体中有显著离群个体存在,表明群体遗传背景不均一。本研究表明,高密度SNP芯片在我国虹鳟养殖群体遗传分析中具有广泛的应用前景,能够为种质资源评估、本土化良种培育、制种和引种工作提供基因组水平的参考信息。 相似文献
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Ken Overturf Roger L. Vallejo Yniv Palti Fredrick T. Barrows James E. Parsons 《Aquaculture International》2012,20(2):213-232
Microarray analysis was conducted using liver samples from two families of rainbow trout that differed in their growth responses
when compared between individuals fed a fishmeal or plant protein-based diet. Differential expression relating to dietary
utilization between the two families found significant changes in expression of 33 expressed sequence tags (ESTs). Eight of
the differentially expressed ESTs had identified mammalian homologs that had been previously researched with identified cellular
interactions and functions. Utilizing pathway analysis software to analyze sequences annotated with known mammalian genes,
we were able to map gene pathways and process interactions. From this information, we were able to infer that the metabolic
changes associated with utilization of plant protein versus fishmeal were associated with differential regulation of genes
related to cell oxidative stress, proliferation, growth and survival. Furthermore, we inferred from the changes we observed
in immune response gene expression that ingestion of this plant-based diet upregulated the expression of genes involved in
immunoregulatory processes. 相似文献
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J. Palti 《Phytoparasitica》1974,2(2):109-115
Pseudoperonospora cubensis is common throughout the world onCucumis crops (cucumber, melon); less common onCucurbita crops (squash, pumpkin, marrow), from which it is absent in Europe and parts of Asia; and more restricted onCitrullus, Luffu andLagenaria spp. This divergence in distribution is due chiefly to different physiological races in various countries. This must be taken into account in quarantine and breeding work. Resistance of some local cultivars, and the differential effects of environment on infection, add to the uneven distribution. 相似文献
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Agricultural practices such as irrigation and year-round cultivation of crops, render semi-arid areas much more suitable for development of downy mildews and late blight than might be supposed by weather criteria alone. These diseases can develop even under not very favorable humidity conditions, owing to a favorable microclimate and to abundant pathogen reproduction. However, the complex interrelations and shifting significance to be attributed to factors affecting disease development, make their regional forecasting in semi-arid areas impracticable. This is due to the absence of a clear-cut “zero-time” for the beginning of the disease development, the limited significance of the temperature factor, the unpredictable occurrence of hot and dry spells, the characteristics of short, intense subtropical rainfall, and the dominance of microclimatic factors. On the other hand, timing of control operations can be aided by regional determination of disease-free periods in crops sown in different seasons and by prediction of the length of such periods in individual fields according to their age and density, irrigation regime, and proximity to sources of inoculum. 相似文献
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A survey of mycoflora was conducted in uncultivated desert-type soils in eight localities, in the Sedom and Be’er Sheva’ regions. The following species ofFusarium were found in six of these localities:F. avenaceum, F. equiseti, F. moniliforme, F. oxysporum, F. semitectum, andF. solani. 相似文献
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William R. Wolters Gary S. Burr Yniv Palti Roger L. Vallejo 《Journal of the World Aquaculture Society》2013,44(4):473-485
Arctic charr, Salvelinus alpinus, were obtained as eggs from two North American sources, an eastern (Fraser River, Canada) and a western (Bristol Bay, Alaska, USA) stock. Fish were pit tagged (eastern , western ) and stocked communally into three replicated 7‐m3 tanks at a density of 7.6 ± 1.2 kg/m3. Each tank was supplied with 2 ppt salinity water from a recirculating biological filtration system. Fish were fed a commercial diet (48%P, 20%F) from automatic feeders. Fish were harvested approximately 24 mo after hatching at a final tank density of 56.2 ± 1.3 kg/m3. Mean daily water temperature was 10.4 C with a range of 5.9–12.6 C and mean dissolved oxygen was 12.6 mg/L with a range of 9.7 (91% of saturation) to 17.8 mg/L (149% of saturation). Individual fish were evaluated for total, carcass, and fillet weight, sex, stage of sexual maturity, fillet fat, fillet color, and gonad weight. The western stock fish grew faster and were significantly larger ( ) (P < 0.0001) than the eastern stock ( ). Heritabilities were low for all traits and ranged from 0.08 ± 0.06 to 0.28 ± 0.09. Genetic correlations for body size traits were highly positive and significant (0.99–1.00). Genetic correlations of fillet color and body size traits were positive, but not significant. Genetic correlations of fillet fat with body size traits were negative, but not significant. Genetic correlation of fillet fat and fillet color was positive and significant (0.55 ± 0.27). Random genetic variation was assessed from microsatellite variability on 30 fish from each stock (eastern and western) and 32 fish from a third commercial source of unknown origin for comparison. The amount of variation detected in the western stock was higher than the eastern and commercial stocks. The eastern stock was composed of an admixture of two sources, the commercial stock was composed by three different sources, and the western stock was composed by three to four source populations. Data will be used to calculate breeding values on a separate group of captive sibling adult broodfish and a line selected for carcass weight and maturity at 3 yr will be developed. 相似文献
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Downy mildew of Cucurbits (Pseudoperonospora Cubensis): the Fungus and its hosts,distribution, epidemiology and control 总被引：1，自引：0，他引：1
Taxonomy of the genusPseudoperonospora, morphology ofPseudoperonospora cubensis (Berk, et Curt.) Rostow. and occurrence of its oospores, are described briefly. A list is presented of over 40 cucurbitaceous host species, representing about 20 genera, on whichP. cubensis has been recorded. Two or more races exist in Japan and the United States, but not in Europe or the Middle East. The distribution ofP. cubensis is widest on all continents on cucumbers (70 countries) and muskmelon (50 countries); onCucurbita and watermelons it extends to about 40 and 25 countries, respectively. P. cubensis may overwinter as oospores, though this seems rare, and on wild hosts or crops grown in the open or under cover. Airborne sporangia may also reach cooler countries from regions with mild winters. Apart from the leaf wetness essential for infection, the factors determining disease progress are: rate of foliage growth and physiological age of the host; amount of primary inoculum available, light, and the rate at which lesions necrotize. The interaction of these factors is described for early, mid-season, and late crops. Losses caused byP. cubensis depend on the growth stage at which the crop is attacked, and on the rate of foliage and pathogen development. Breeding has produced downy mildew resistant lines of cucumbers, used chiefly in the United States, and some resistant lines of melons and watermelons. The most important agricultural practices used to restrict downy mildew development are proper irrigation management and avoidance of sowing in proximity to infected crops. Success of control by protectant chemicals depends largely on proper timing of applications. Proximity of inoculum sources, hours of leaf wetness, age of crop, and irrigation practices are the principal factors that determine when to begin treatments. These factors and rate of leaf formation determine the frequency of applications. Application of systemic fungicides is much easier to time correctly. 相似文献