天府肉羊新品系在川北地区的杂交改良效果

本研究对川北地区繁育推广的天府肉羊与本地山羊杂交改良羊（天改羊）的生长性能进行抽样测定,结果表明：用天府肉羊改良本地山羊具有明显的杂交优势,改良羊（天改羊）的生产性能显著高于本地山羊。与本地山羊相比,2月龄天改公羊体重提高了33.13%,母羊体重提高了51.25%;9月龄天改公羊体重提高了47.31%,母羊体重提高了59.18%;体尺方面,9月龄天改公羊的体高、体长和胸围分别比本地山羊提高了17.35%、18.24%和8.14%,天改母羊分别提高了22.76%、18.96%、14.30%。     

糯玉米新品种“银糯一号”的选育

“银糯一号”是北京农学院生物技术系于2000年是以XN-5自交系为母本,BN51自交系为父本杂交而成的糯玉米杂交种。该品种经2000～2001年的测交试验,2002～2003年的产比试验,2004-2005年的北京市区域试验,皆比对照“中糯一号”增产30.8%(鲜穗)和20.7%(鲜粒)以上,大面积生产鲜穗产量达10800kg/hm2以上。在2006年3月北京市农作物品种审定委员会审定通过(京审玉2006008)。     

野猪分子遗传学与杂交利用研究进程

野猪是具有重要经济价值的动物,是现代家猪的祖先,因而野猪是可用于改良家猪品种的宝贵遗传资源之一。本文从野猪的核内基因、野猪线粒体DNA与家猪的起源进化关系及家野猪杂交利用方面对野猪的遗传学研究概况进行了综述,以期为野猪进一步的遗传学研究和种质资源的保护与开发利用提供参考。     

Effect of replacement rate,crossbreeding and sexed semen on the efficiency of beef production from dairy herds in Finland

Abstract

In Finland, during the past 10 years, the number of dairy cows has declined considerably leading to decreased domestic beef production which is partly compensated by increased suckler beef production. However, production of meat originating from dairy herds has been shown to be economically more profitable and to produce less greenhouse gas emissions per unit of product than beef production from suckler cow systems. Therefore, when safeguarding beef self-sufficiency, the intensification of beef production from dairy herds is a more promising option to consider. In this study, the possibility of different options for increasing dairy beef production was assessed by using a deterministic simulation. Increasing the use of crossbreeding in dairy herds, especially when combined with the use of Y-sorted semen, appeared to be the most efficient strategy for increasing dairy beef production. The decrease in the replacement rate increased beef production through the potential for enhancing crossbreeding.     

娟姗牛改良牦牛效果浅析

本文测定了娟姗牛改良牦牛的效果,分析了牦牛改良繁活率低的原因,提出了牦牛乳用改良的措施。     

一串红若干观赏性状在F1的遗传表现

对影响一串红品质的几个性状F1中表现进行了分析,以期为一串红杂交选育提供指导。以4个自育品种红粉佳人、橙香公主、白马王子、彩铃红和一个国外品种展望紫为亲本,进行不包括正反交在内的双列杂交,配制成10个杂交组合,对F1子代植株性状、花部性状和开花期进行统计分析。结果表明,F1株高、茎粗、叶面积、花序粗、花序长、花序轮间距、花轮数、盛花期8个数量性状的平均值分别占中亲值的104．87%,126．01%,123.79%,111.09%,147.41%,134.32%,120.84%,94.51%,且有超亲个体大量出现,F1整体表现出明显的杂种优势,但不同组合杂种优势不同。杂交F1只有红色和紫红色2种花色,玫红色、橙色和白色植株未出现。各性状中,除叶面积和花轮间距外,其他性状遗传变异系数均在15%以内,变异较小。亲本选配环节最好选择花轮间距较小的品种;以矮株为F1代育种目标时,杂交亲本双方尽量都选矮株;亲本花序较短的杂交组合,其F1也会表现出强杂种优势,花序明显增长;要获得新颖花色的子代,应采用花色新颖复杂的亲本进行杂交或者做F2至多世代的选育。经过综合比较,红粉佳人×展望紫、彩铃红×红粉佳人、展望紫×橙香公主组合的F1表现较好。     

广西武鸣木薯开花结果现状调查分析

[目的]为广西等高纬度地区开展木薯杂交育种工作提供理论参考。[方法]对广西武鸣80个木薯品种（品系）的花序、分枝和结果数量进行了调查。[结果]结果发现,80个木薯品种（品系）中,有73．75％正常开花,95．00％自然分枝,47．50％正常结果;通过SAS软件对分枝数量与花序数量分析,发现二者存在正相关。[结论]通过诱导木薯多分支、多开花以及通过组织培养技术对未成熟种子进行幼胚培养和胚拯救,可望解决限制在我国广西等大陆地区开展木薯杂交育种的技术瓶颈,加速培育出高产抗寒的木薯新品种。     

皮埃蒙特牛、夏洛来牛杂交改良南阳牛效果比较分析

本文主要介绍了皮埃蒙特牛、夏洛来牛杂交改良南阳牛方面的最新研究成果。测定了大量的皮南杂交牛、夏南杂交牛、南阳牛的体尺体重数据，并对3月龄、6月龄、12月龄各年龄段的体尺体重数据进行比较分析，发现用皮埃蒙特牛改良南阳牛的效果比夏洛来牛的改良效果好。     

摩拉水牛改良云南本地水牛的效果研究

为了提高云南本地水牛的产奶和产肉性能,云南省1974年、1997年和2002年先后从广西水牛研究所引进摩拉水牛对云南本地水牛进行杂交改良.以杂交一代、杂交二代及摩拉水牛、本地水牛为研究对象,从杂交后代体形外貌、生长发育情况、产奶情况几方面对杂交改良效果进行了总结,结果发现引进的种公牛对云南高原的气候条件适应性良好,精液品质优良.杂交一代水牛初生重、1月龄、3月龄、12月龄体尺、体重均显著高于本地水牛(P＜0.05),杂交一代水牛和本地水牛12月龄体尺、体重均极显著低于同龄摩拉水牛(P＜0.01),杂交一代母水牛产奶量极显著高于本地母水牛(P＜0.01),但显著低于杂交二代母水牛产奶量(P＜0.05).表明本地水牛可望利用摩拉水牛进行改良培育成乳用型水牛.     

Effects of non-genetic and crossbreeding factors on daily milk yield of Ayrshire × (Sahiwal × Ankole) cows in Mahwa station (Burundi)

The study was carried out at the Mahwa station located in Bututsi natural region in South of Burundi at 1850 m of altitude. The objective of the study was to assess the effects of days in milk, cow's calving age, type of crossbreeding, year and month of lactation, parity on daily milk yield of crossbreds Ayrshire (AY) × Sahiwal (S) × Ankole (A) cows. Milk yields were obtained from 9 cows (S) that have been both milked and suckled during the entire lactation, on 8 cows (M) only milked during the entire lactation and on 150 cows (SM) suckled before and milked after weaning. Data were analyzed using the procedure GLM in SAS for S,M, and SM cows separately. All factors affected significantly daily milk yields (P < 0.001). Least-squares means (LSM) for daily milk yields were highest at the 8th (7.16 ± 0.07 l), 8th (7.63 ± 0.35 l), and 7th (7.34 ± 0.39 l) day in milk for SM, S and M lactations, respectively. The Wood model was able to detect 2 main groups of curve shape: standard for SM and S cows and atypical decreasing for M cows. An important decrease in milk production was observed around the 120th day in SM cows corresponding to the weaning period. Crossbreeding improved milk production and highest yields were observed with 50% to 75% of Ayrshire inheritance (LSM = 5 ± 0.05 to 5.51 ± 0.02 l/day). A significant increase was observed from 1977 to 1992 due to the improvement of genetic and management techniques. During this period, LSM raised from 1.26 ± 0.11 l to 4.74 ± 0.03 l per day for SM cows. Unfortunately, the 1993 civilian war destabilized the managerial techniques and consequently, the milk production decreased in Mahwa station. In all cows, milk production was significantly higher from December to May (LSM = 3.96 ± 0.03 l/day) during the rainy season than in September (LSM = 3.12 ± 0.03 l/day) at the end of the dry season.