施氮量对一年生黑麦草生长特性的影响

研究了不同施氮水平(0、100、200和300 kg/hm2,分别表示为N0、N100、N200和N300)对扬州地区一年生黑麦草产量、分蘖数、株高等生长特性及经济效益的影响.结果表明:施氮量为100,200和300kg/hm2时,黑麦草鲜草总产量分别比不施氮增产75%,146%和134%.当施氮量达到200 kg/h...     

旱作条件下刈割次数对三得利苜蓿主要经济性状的影响

为获得甘肃中部地区旱作种植条件下合理的苜蓿收割制度参数,在陇西县文峰镇典型黄土高原丘陵山地,以秋眠级5级的三得利苜蓿为例,研究不同刈割次数与苜蓿产草量、鲜干比、茎叶比、越冬性能以及营养物质含量等几个主要经济性状的关系.结果表明:在保证苜蓿正常越冬的条件下,每年刈割4次和3次处理组比每年刈割2次的处理组产草量提高7.13...     

MHC及其在动物遗传与育种方面的应用

主要组织相容性复合体(Major histocompatibility complex,MHC)不仅与移植排斥反应有关,而且还与动物的一些经济性状密切相关。文章主要阐述了MHC的结构、功能和遗传特性,并且介绍了MHC基因作为遗传标记在动物遗传与育种方面的应用。     

贺兰山野生有蹄类动物的经济价值及种群动态变化

记述了贺兰山的4种野生有蹄类动物——马麝、马鹿、岩羊、鹅喉羚的经济价值及目前的种群动态变化,对贺兰山野生有蹄类动物的种群致危原因进行了分析,并据此提出了相应的保护管理建议。     

2007-2010年转地蜂场养蜂规模经济效益分析——基于浙江省缙云县80家蜂场的调研

养蜂规模是影响蜂场经济效益的主要因素之一,转地蜂场何等养蜂规模经济效益最好,是业内人士关注的热点之一。2007-2010年,我们对浙江省缙云县80家以生产蜂蜜为主、生产蜂王浆、蜂花粉为辅的转地蜂场养蜂规模经济效益进行了跟踪调查。结果表明,在目前的转地养蜂生产方式和生产力水平下,蜂场规模以2-4人为主,其中,4人规模的家庭蜂场饲养185-195群西方蜜蜂,为最佳的适度规模;5人蜂场的经济效益最佳,但发展缓慢,值得关注与期待。     

扁穗雀麦种质资源形态和农艺性状变异的初步分析

检测种质资源的多样性对于利用和有效管理种质非常重要。本研究对87份世界来源的扁穗雀麦种质利用常用的9个形态-农艺性状进行了统一田间评价。结果表明,所有采用的性状变异系数均表现出高度的变异,尤其以单株干物质产量、分蘖数和叶宽的变异幅度最大。反映株型大小的各性状之间呈显著相关,茎粗和第一节间长与其余8个性状之间存在显著相关(P<0.01),旗叶宽与倒二叶宽的正相关性最强(r=0.912,P<0.01)。主成分分析(PCA)表明前2个主成分可以解释总变异的74%。反映株型大小的性状以及分蘖数可能是扁穗雀麦种质形态变异的主要来源。基于欧氏距离的UPGMA聚类分析将供试材料分成3个主要的类群,第一类群具有最大的株型表现,茎干粗壮,旗叶和倒二叶宽大,分蘖数中等;第二类群具有中等的株型;第三类群具有较小的株型,叶片短而窄,但分蘖数较多。聚类分析很好地支持了前2个主成分分值的二维散点图的结果。总之,本研究表明扁穗雀麦是一种在西南平原和丘陵地区适应性极强的禾草,其表型多样性对于品种选育和资源收集具有重要的参考价值。     

Genetic correlations for foal and studbook traits with racing traits and implications for selection strategies in the Finnhorse and Standardbred trotter

Genetic correlations for body measurements and conformation and functional traits in foals and studbook horses with racing traits were estimated in the Finnhorse and Standardbred. Genetic response and accuracy were estimated using records of animal, half‐sibs and parents in selection scenarios for racing traits, for foal and racing traits, for studbook and racing traits, and using records of animal, half‐sibs and parents for foal traits and racing traits of parents. Racing time and earnings were the breeding objective. Low‐to‐moderate genetic correlations for body measurements and racing traits indicated that selection favours bigger horses at all ages. Being mainly favourable for the breeding objective, genetic correlations for conformation and functional traits with racing traits were highest for the foal traits of type, trot and overall grade and for the studbook traits of character and movements. Genetic correlations for foal and studbook conformation with racing traits were low in the Finnhorse and moderate to high in the Standardbred. In foals, the highest genetic correlations were for trot with racing time (?0.54) and with earnings (0.52) in the Finnhorse, and for overall grade with racing time (?0.54) and with earnings (0.54) in the Standardbred. In studbook horses, genetic correlations were high for character with racing time and earnings in the Finnhorse (?0.68, 0.61) and in the Standardbred (?0.63, 0.70), and for movements with racing time and earnings in the Finnhorse (?0.70, 0.69) and in the Standardbred (?0.90, 0.88). To increase accuracy of conformation and functional traits, foal traits would be more useful in the index with racing traits, as being less preselected than studbook traits. The foal traits (type, trot, overall grade) having moderate heritability and genetic correlations with racing traits would be useful in multi‐trait index before a racing career, where the greatest gain is because of a shorter generation interval. It would be feasible to implement for AI stallions.     

优质肉鸡繁育体系的效益评估

近十多年来，我国优质肉鸡的生产方兴未艾，许多育种公司和科研院所不断推出新品系。为充分发挥新品系的遗传潜力，探求优质肉鸡最佳的繁育生产模式具有重要意义。由于不同的品系及其杂种后代在不同的性状上各有优缺点，很难用生产性能进行直接比较，而适合用育种规划的方法通过经济学指标进行评价。系统分析通过把生产系统抽象概念化并用数学手段模型化的方法，