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Thinh Tuan Chu John W.M. Bastiaansen Elise Norberg Peer Berg 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2018,68(1):1-10
To improve genetic gain of breeding programs for village poultry production, breeding schemes with observations obtained in village production systems using individual (VIO) and group recording (VGO) were examined under different levels of genotype-by-environment-interactions (GxE). GxE was modeled by varying the correlation between traits measured in the breeding station and village environments for bodyweight (rg_BW) and egg production (rg_EP). Relative and absolute genetic gains obtained from VIO and VGO were used for comparison between the schemes. Results showed that village observations significantly improved genetic gains compared to the scheme without birds tested in the village. The improvement was only slightly larger with individual observations than with group observations. Higher rg_BW and rg_EP led to lower relative genetic gain, but a higher absolute gain of VIO and VGO. It is recommended to apply a breeding scheme using group recording of village performance when strong GxE in breeding for village poultry is expected. 相似文献
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Differences in uptake and killing of pathogenic and non‐pathogenic bacteria by haemocyte subpopulations of penaeid shrimp,Litopenaeus vannamei, (Boone) 下载免费PDF全文
V V Tuan J J Dantas‐Lima K V Thuong W Li K Grauwet P Bossier H J Nauwynck 《Journal of fish diseases》2016,39(2):163-174
Phagocytosis is an important function of both invertebrate and vertebrate blood cells. In this study, the phagocytic activity of haemocyte subpopulations of penaeid shrimp, Litopenaeus vannamei, (Boone), against pathogenic and non‐pathogenic particles was investigated in vitro. The haemocytes of penaeid shrimp were firstly separated by centrifugation on a continuous density gradient of iodixanol into four fractions with five subpopulations (sub), of which sub 1 (hyalinocytes) and sub 4 (semi‐granulocytes) have the main function in phagocytosis of both pathogenic and non‐pathogenic bacteria as well as fluorescent polystyrene beads. It was found that these haemocyte subpopulations engulfed virulent Vibrio campbellii and Vibrio harveyi at a higher rate than non‐virulent Escherichia coli and polystyrene beads. When these bacteria were mixed with shrimp haemocyte subpopulations and incubated for 180 min, the percentage of viable intracellular V. campbellii (25.5 ± 6.0%) recovered was significantly higher than the percentage recovered from V. harveyi (13.5 ± 1.1%). No viable intracellular E. coli was observed in this study. In contrast to V. harveyi and E. coli, V. campbellii containing endosomes did not acidify in time. Incubation of haemocyte subpopulations with the most virulent V. campbellii strain resulted in a significant drop in haemocyte viability (41.4 ± 6.3% in sub 1 and 30.2 ± 15.1% in sub 4) after 180 min post‐inoculation in comparison with the less virulent V. harveyi (84.1 ± 5.6% in sub 1 and 83.4 ± 4.1% in sub 4) and non‐virulent E. coli (92.7 ± 2.8% in sub 1 and 92.3 ± 5.6% in sub 4) and polystyrene beads (91.9 ± 1.6% in sub 1 and 84.4 ± 3.4% in sub 4). These findings may be a valuable tool for monitoring shrimp health and immunological studies. 相似文献
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利用60 Coγ射线对紫色马铃薯品种黑美人萌芽薯块进行诱变处理。诱变材料表型鉴定结果表明,辐照剂量与出苗率呈显著负相关,其半致死剂量为70Gy,致死剂量为80Gy。辐照处理能显著延缓出苗时间,导致叶片减少、茎杆变细、植株变矮。高剂量处理可提高分枝数。与CK相比,各处理结薯数差异不显著。单株产量随辐照剂量增加而降低,CK处理显著高于其他处理。在表型鉴定的基础上,利用SSR分子标记对辐射材料进行DNA检测。10对引物集团选择结果表明,6对具有多态性,共获得10条多态性条带,平均每对引物有1.7条。单株检测共获得扩增条带28条,其中8条有多态性,多态性比率为28.9%。说明,辐射可引起紫色马铃薯黑美人表型和DNA水平的变异。 相似文献
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以越南河内(Hanoi)、江西吉水(Jishui)、湖南资兴(Zixing)3个产地1年生越南安息香幼苗为试材,采用人工模拟低温处理技术进行低温处理,测定电解质外渗率,并配合Logistic方程对不同产地枝条的半致死温度(LT50)进行了拟合;测定低温处理下各产地越南安息香的MDA含量、根系活力,并观察不同产地越南安息香1年生幼苗的恢复情况.结果表明,3个产地越南安息香耐低温能力差异显著,半致死温度值LT50在-14.93~-9.48℃之间,抗寒性强弱排序依次为:Zixing> Jishui> Hanoi;幼苗叶片MDA含量、根系活力及抽条指数均反映出产地抗寒性强弱与半致死温度基本一致. 相似文献
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芦荟试管微克隆繁育中芽增殖体系的建立 总被引:1,自引:3,他引:1
研究了库拉索芦荟茎尖组织、叶盘组织和茎盘组织的离体培养特性,发现芦荟茎尖组织芽增殖效率较低,叶盘组织无再生能力,而茎盘组织是芦荟试管克隆芽增殖系建立的最佳外植体。利用茎盘组织建立微克隆增殖系与茎盘组织在茎段上的位置有关,库拉索短宿茎的中部茎段不定芽形成能力最强。细胞分裂素是诱导库拉索芦荟芽增殖的主要激素,但质量浓度过高,不定芽生长弱,玻璃化现象严重。1.0mg/L6-BA,1.5mg/LKT和0.5mg/LNAA组合的MB培养基(该培养基由MS培养基大量元素、微量元素、铁盐,B5培养基的有机物质构成)是库拉索芦荟试管苗增殖的最佳培养基。 相似文献
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Preparation of a dicyandiamide-contained novel insulation paper and an experiment on the thermal aging characteristics of relevant oil-paper insulations 总被引:1,自引:0,他引:1 下载免费PDF全文
In order to study the influence of dicyandiamide added into the insulation paper on the oil-paper insulation during the aging process.The insulation paper containing dicyandiamide and the insulation paper without any stabilizer are prepared. They are immersed in transformer oil separately and placed in the aging chamber with predefined temperature of 130℃ for 31 days to perform thermal aging experiment of oil-paper insulation. The specimens are periodically sampled and some parameters are measured like the degree of polymerization(DP), the breakdown voltage, the nitrogen content, the acidity of insulation oil, and UV-Vis spectrum. The results show that the insulation paper added with dicyandiamide has a distinct anti-aging and anti-breakdown effect and the DP is 58% higher than that of blank sample at the later stage of aging. In the aging process, decline of the nitrogen content of insulation paper is not serious. The oil-paper sample containing dicyandiamide has a far lower value of acidity than that of blank sample, besides the oil color is deeper. Dicyandiamide in the insulation paper improves not only the anti-aging and anti-breakdown properties, but also the performance of oil in the aging process. 相似文献