Population dynamics of Xylosandrus compactus (Coleoptera: Curculionidae: Scolytinae) on Coffea canephora in the Lake Victoria Crescent agroecological zone of Uganda

We studied the seasonal population dynamics of Xylosandrus compactus on Coffea canephora for 24 months from June 2013 to May 2015 at the National Coffee Research Institute, Mukono, Uganda. Every month, we randomly sampled 20 infested twigs from different coffee trees on each of three experimental blocks, and dissected them to count different stages of X. compactus per twig. We recorded monthly mean temperature and total rainfall. Seasonal fluctuations in numbers of different life stages of X. compactus inside C. canephora twigs over time were analysed with a general linear model. Ambient temperature and rainfall were used to predict changes in monthly mean counts by means of a multiple linear regression. The population of X. compactus varied significantly across months and its major peak occurred from May to August. This variability was poorly explained by prevailing weather conditions with only the number of dead females correlated negatively with mean monthly temperature. Therefore, it may be suitable to apply management interventions against X. compactus on C. canephora in Uganda prior to May–August of each year to prevent the pest from attaining damaging levels. Further research is necessary to better understand the effect of weather variables on population dynamics of this insect pest.     

花椰菜—黑芥体细胞杂种的性状演变和对黑腐病抗性的转育

以对黑腐病(Black rot)感病的花椰菜(Brassica oleracea L.var.botrytis L.,2n=18,CC)‘Korso’和抗病的黑芥(B.nigra,black mustard,2n=16,BB)‘G1/1’的体细胞杂种(简称PFCN,protoplast fusion of cauliflower and Brassica nigra)高代自交及回交后代为材料,根据表型特征将其分为4大类:性状介于花椰菜和黑芥之间的中间型材料(M)、向花椰菜过渡的过渡型(M-K)、偏花椰菜型(-K)和花椰菜型(K)。连续5年的黑腐病人工接种鉴定结果显示:‘Korso’的病情指数在44~57之间,表现为耐病到感病;‘G1/1’在12~32之间,表现为抗病,从M、M-K、-K至K型,杂种后代病情指数总体上呈逐渐升高的趋势,其中M型和M-K型材料表现为高抗至抗病,-K型材料表现为抗病至耐病,K型材料表现为耐病。对2014年的15份典型-K至K型材料进行了形态演变及黑腐病抗性变化追溯:总体上,偏花椰菜的形态转变发生在S1BC4、S5、S1BC3和BC3(S为自交,BC为回交)世代中,伴随着形态的转变,黑腐病病情指数急剧升高;同一年中来源相同或者相近的株系病情指数相差不多。2015年进一步对2014年25个单株的自交后代进行黑腐病抗病性跟踪鉴定:整体上病情指数呈下降趋势,仅少数株系表现上升;来源相同的衍生株系变化趋势几乎一致,且差异不大,说明这些材料系内对黑腐病抗病性逐年趋于稳定。目前获得了6份相对于受体亲本‘Korso’表现出了对黑腐病抗性显著提高的材料:PFCN14-15-4.1、PFCN14-15-5.1、PFCN14-29-1.1和PFCN14-29-1.2,连续3年病情指数呈下降趋势,并最终稳定在30左右;PFCN14-14-1.1和PFCN14-14-1.2则连续6年保持在20~38之间。     

Control of bean common mosaic by deployment of the dominant gene I

The deployment of the dominant gene I for the control of bean common mosaic predisposes a bean crop to the risk of death by black root if one or more recessive genes to prevent the hypersensitive plant reaction are lacking. However, during 3 years of observation in Kenya black root occurred only exceptionally to more than 10%, and in such cases the yields from crops having the dominant gene I exceeded significantly those from mosaic-susceptible crops. The use of the dominant resistance factor in Kenya is therefore recommended, but continued caution and monitoring of the disease situation are required. Broadening the resistance basis by adding recessive genes to control black root is advisable.Samenvatting Het gebruik van het dominante gen I voor de bestrijding van de virusziekte bonerolmozaïek stelt een bonengewas bloot aan het gevaar van systemische necrose, als niet een of meer recessieve genen aanwezig zijn om deze overgevoeligheidsreactie van de planten te voorkomen. Gedurende een periode van drie jaar werden waarnemingen verricht om na te gaan hoe vaak deze necrose optrad. Slechts bij uitzondering bleek meer dan 10% van de planten te worden aangetast. In die gevallen werd de opbrengst toch aanmerkelijk verhoogd door de aanwezigheid van het dominante gen I. Het gebruik van dit gen ter bestrijding van het bonerolmozaïek wordt daarom voor Kenya aanbevolen. Voortdurend moet echter worden nagegaan in welke mate necrose-inducerende stammen van het virus voorkomen. Een verbreding van de erfelijke basis van de resistentie ter voorkoming van de necrotische reactie door introductie van recessieve resistentiegenen is raadzaam.

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Résumé L'emploi du gène dominant I pour la lutte préventive contre la mosaïque commune du haricot, en I'absence d'un ou plusiers gènes récessifs pour éviter une réaction hypersensible de la plante, entraine un danger de mort de la plante par racines noires. Néanmoins, pendant les 3 ans d'observations au Kénya, les cas de racines noires ne sont apparus qu'exceptionnellement à un taux superieur à 10%, et, dans de tels cas, le rendement du végétal ayant le gène dominant I était, de façon significative, supérieur à celui des végétaux prédisposées à la mosaïque. L'utilisation au Kénya du facteur de résistance dominant est par conséquent recommendé mais une attention et une surveillance permanentes de I'évolution de la maladie sont nécessaires. On peut conseiller I'élargissement de la base de résistance par addition de gènes récessifs pour le contrôle de la maladie des racines noires.

     

鸭LXRα基因过表达对原代肝细胞及PC3细胞脂质代谢的效应研究

旨在探究鸭LXRα基因对脂肪代谢的表达调控机制,本试验以pEGFP-N3为载体,构建携带HIS标签的LXRα基因真核过表达载体,并将过表达载体分别转染鸭原代肝细胞及PC3细胞,使用鸭HIS标签试剂盒测定LXRα基因在肝细胞及PC3细胞中的过表达量,分析该基因分别在两种细胞中过表达与各脂质指标含量的相关性,进而探究其对鸭肝细胞及PC3细胞脂质代谢的调控作用。试验结果显示,LXRα基因在两种细胞中过表达与三酰甘油含量(triglyceride,TG)及高密度脂蛋白(high density lipoprotein,HDL)含量均呈极显著正相关关系(P<0.01),与总胆固醇(total cholesterol,TC)含量及低密度脂蛋白含量(low density lipoprotein,LDL)则均呈极显著负相关关系(P<0.01)。本研究揭示了LXRα基因过表达对TG和HDL的合成代谢有重要的正向调控作用,对TC和LDL具有反向调控作用,且在这两种类型的细胞中调控机制相似。这一研究结果将对今后深入研究LXRα基因在脂质代谢网络通路中的作用及解决鸭体脂肪过度沉积等问题奠定理论基础。     

Responses of growing rabbits to supplementing diet with a mixture of black and red pepper oils as a natural growth promoter

The current study was explored to examine the impacts of dietary inclusion of mixture of black (BPO) and red pepper (RPO) oils as growth promoters on growth, carcass, blood haematology, serum chemistry, immunity and antioxidative status of New Zealand White rabbits (NZW). A number total of 100 5‐week‐old NZW growing weaned rabbits were randomly allocated into four treatment groups in a complete randomized experiment. The dietary treatment groups were as follows: control: basal diet; BRP0.5: basal diet + 0.25 g BPO + 0.25 g RPO/kg diet; BRP1.0: basal diet + 0.50 g BPO + 0.50 g RPO/kg diet; and BRP1.5: basal diet + 0.75 g BPO + 0.75 g RPO/kg diet. Rabbits fed the highest level of BRP mixture were the heaviest, while the control rabbits were the lightest. During 5–9 weeks of age, a gradual improvement in feed conversion ratio (FCR) was noticed with increasing BRP level. The control group excelled all BRP groups regarding the majority of blood haematological parameters. Liver function was better in rabbits fed BRP enriched diets than the control. A gradual depression (p < 0.05 or 0.01) in serum lipids regardless high‐density lipoprotein (HDL) were recorded with elevating BRP level in the diet. The supplementation of BRP mixture enhanced the immune function and serum superoxide dismutase (SOD) activities and depressed serum malondialdehyde (MDA) in comparison with control. It could be concluded that dietary BRP mixture can affect some of growth traits, improve the immunity and antioxidant parameters, lower lipid profile and lipid peroxidation. Based on the study results, the recommended level of BRP mixture is 1.5 g/kg diet.     

北京鸭群体遗传多样性及遗传资源分析

为研究北京鸭群体的遗传结构及遗传多样性,实验分别采集北京鸭F_0(120只)、F_1(100只)和F_2世代(100只)的血液样本,采用荧光标记毛细管电泳方法对北京鸭11个微卫星座位进行分析。结果表明:11个微卫星座位在北京鸭F_0、F_1和F_2世代的平均等位基因/有效等位基因数量分别为4.6/2.5、3.5/1.9和4.5/2.2个;平均多态信息含量分别为0.441 3、0.303 8和0.415 0;平均期望杂合度分别为0.487 7、0.363 3和0.454 2;北京鸭3个世代间的遗传变异指标差异不显著。近交系数及基因流分析结果表明,北京鸭群体3个世代近交系数较低,群体内近交系数为0.086 9,微卫星位点的平均基因流为0.934 1。总体来看,北京鸭群体遗传分化程度低,保持了北京鸭群体遗传多样性。     

金定鸭在小群保种方式下不同世代生长及生产性能的比较研究

本试验以国家水禽种质资源基因库引进的金定鸭为素材,在小群保种条件下,对3个世代保种群生长、生产性能进行比较,通过分析世代间的差异来检测保种效果。结果表明:3个世代保种群公鸭体重分别在育雏期末、育成期末存在显著差异。公鸭皮脂重、腿肌率在不同世代间存在显著差异。公、母鸭胸肌熟肉率分别在不同世代间存在显著差异,母鸭胸肌pH在不同世代间存在显著差异。公、母鸭腿肌干物质、熟肉率和pH分别在不同世代间存在显著差异,公鸭腿肌肉色在不同世代间存在显著差异。公、母鸭其他指标分别在不同世代间均无显著差异。上述结果表明金定鸭采用小群保种方法是可行的。     

人工感染鸭源新城疫病毒对绍鸭β-防御素和细胞因子基因表达的影响

试验旨在探讨人工感染鸭源新城疫病毒(Newcastle disease virus,NDV)对绍鸭β-防御素(avianβ-defensins,AvBDs)和细胞因子基因表达的影响。选用45只20日龄SPF绍鸭,随机分为攻毒组(27只)和对照组(18只),攻毒组采用滴鼻点眼的途径(108.38 EID50)接种鸭源NDV强毒株(Md/CH/LGD/1/2005),对照组接种磷酸盐缓冲液。在攻毒后24和48h,从对照组及攻毒组各随机取6只鸭屠宰,分别采集肾脏、肺脏、气管、腺胃、骨髓、脾脏、盲肠扁桃体、哈德氏腺、法氏囊9个组织,运用实时荧光定量PCR法检测组织样品中9种AvBDs和细胞因子的表达量;剩余鸭每天持续观察,每隔4d采血1次,直至24d,检测血清抗体水平;于攻毒后24、48、72和120h采集咽喉及泄殖腔拭子,以确定排毒周期。结果表明,感染该NDV毒株后,鸭没有临床发病症状和死亡情况发生;感染后鸭排毒开始于攻毒后第1天,到第5天停止,在攻毒组咽喉及泄殖腔拭子中均检测到NDV。抗体水平检测结果显示,该NDV能够诱导鸭体内产生抗NDV特异抗体。实时荧光定量PCR结果发现,与对照组相比,感染后24h,部分鸭组织中AvBD1、AvBD2、AvBD5、AvBD6、AvBD9和AvBD16表达量均显著升高(P<0.05);感染后48h,AvBD1和AvBD6在部分鸭组织中表达量均显著上调(P<0.05);感染后48h法氏囊中白细胞介素6(IL-6)和脾脏中干扰素γ(IFN-γ)的表达量明显低于感染后24h的表达量。综上所述,该鸭源NDV毒株感染可诱导绍鸭体内在早期产生天然免疫反应,这些反应可能与病毒在机体内复制有关。     

皖南黑猪种质资源保护现状与开发利用对策分析

皖南黑猪是我国优良的地方猪种之一,系华北型黑猪向南过渡在皖南山区长期饲养选育而形成的肉脂兼用型猪种,目前主要分布在宣城市的宁国、绩溪等地。近些年,受外来品种大量引进、疫病威胁和部分保种企业经营困难影响,皖南黑猪种群数量逐年缩减,优良基因面临流失危险。就皖南黑猪种质资源保护现状进行概述,通过分析存在的问题,提出了对皖南黑猪保种和开发利用的对策,以供参考。     

营养水平和酵母硒对烟台黑猪屠宰性能及肉品质的影响

本试验旨在研究不同营养水平及酵母硒对胴体性状和肉质指标的影响。选取体况良好、体重为(70.30±1.30)kg的烟台黑猪48头,公、母各半,随机分成4个处理组,每个处理组4个重复,每个重复3头。Ⅰ组饲喂低营养水平日粮(消化能11.19 MJ/kg、粗蛋白质12.28%),Ⅱ组饲喂低营养水平+0.5 mg/kg酵母硒日粮,Ⅲ组饲喂高营养水平日粮(消化能13.11 MJ/kg、粗蛋白质14.73%),Ⅳ组饲喂高营养水平+0.5 mg/kg酵母硒日粮。试验预试期为7 d,正试期为105 d。结果表明:与低营养水平组相比,高营养水平能够极显著提高烟台黑猪的胴体重(P0.01),显著提高眼肌面积和瘦肉率(P0.05);营养水平和酵母硒对烟台黑猪的肉质性状影响均不显著(P0.05),其中高营养水平有提高其肌内脂肪及肌肉风味氨基酸含量的趋势(P0.05);与未添加酵母硒组相比,添加酵母硒能够显著提高肌肉中油酸含量(P0.05),有提高其肌肉中亚油酸含量的趋势(P0.05),能够极显著提高其肌肉中硒元素含量(P0.01);营养水平和酵母硒对屠宰性能、胴体性能、肉品质等无互作效应(P0.05)。由此可见,在本试验条件下,高营养水平能够提高烟台黑猪肌内脂肪及风味氨基酸的含量;酵母硒有利于提高烟台黑猪肌肉中油酸含量,有提高亚油酸含量的趋势。