家畜繁殖生物技术研究现状及趋势

牛胚胎移植技术已趋于成熟。我国新疆牧科院用一步细管法移植牛冻胚受胎率达41%;牛和羊鲜胚四分胚移植也产下1头犊牛和6只羔羊。家畜体外受精,因卵子体外成熟和受精卵体外培养尚不过关,目前仍停留在实验室阶段。胚胎性别鉴定,1990年Koopman发现单拷贝基因,该基因是Y染色体的性决定区,命名为SRY,可利用PCR技术制成雄性特异DNA探针盒,进行马、牛、羊、猪早期胚胎性别鉴定。北京农学院等单位用PCR扩增牛SRY序列进行奶牛胚胎性别鉴定准确率达100%。英、日、法等国已获得牛胚胎细胞核移植后代;我国也获得1只核移植兔。北农大和新疆牧科院合作以绵羊精子为载体导入牛生长激素基因rMTbGH DNA成功,外源基因整合率为3%。     

一次防治大豆灰斑病籽粒灰斑

通过室内及田间大豆不同生育期接种试验证明，籽粒感染灰斑病的关键时期是Ｒ３－Ｒ５期．Ｒ２期以前侵染不造成籽粒斑驳，据此提出一次防治大豆籽粒灰斑病的关键时期为Ｒ２－Ｒ４期．     

An Ecological Foodniche Concept as a Proxy for Fish-Pond Stocking Rates in Integrated Aquacultural Farming for Malaysia

The merits of integrated aquaculture farming (IAF) as a strategy for bolstering income for the rural poor have been recognized, but the economic efficiency and sustainability are yet to be determined. The effects of one species on another and the economic benefits, net of government support, have not been critically evaluated. The concept of a foodniche for alternative species in an aquatic environment has not been properly tested in an economic setting. Thus, this report reflects the results of applying the technique of mixed integer linear programming to determine the optimum combination of species within the context of a foodniche. The objective also included maximizing revenues, with minimal external input requirements, for a representative small Malaysian wet-rice farm. It was found that the foodniche concept permitted flexibility in stocking rates, and that farmers could actually stock species at the exact rate that was optimal for profit, instead of standard fixed rates. Also, government subsidies for pond construction were essential for IAF success. The net revenues from IAF were low without interest-free loans for pond construction.     

Experience with fireblight in the Czech Republic1

Erwinia amylovora has been spreading in the Czech Republic since 1986 regardless of emergency phytosanitary measures which have been taken. Its spread follows the predominant wind direction (west to east). The infested area now covers two thirds of the area of the country. Wild Crataegus spp. are the most important and widespread host plants. E. amylovora is still regulated as a quarantine pest, and areas free from fireblight are subject to special phytosanitary measures.     

辣椒主要病害抗性的配合力分析

本文用6个亲本,按(1/2)n(n-1)双列杂交法配制15个杂交组合,对辣椒TMV、CMV、疫病、疮痂病抗性进行了配合力分析。结果表明,不同亲本、不同病害抗性的一般配合力效应和不同杂交组合的特殊配合力效应差异较大,疫病抗性显性方差所占份量较大,加性方差所占的份量较小;CMV和疮痂病抗性是加性方差所占份量较大,显性方差所占份量相对较小;TMV抗性介于二者之间。不同病害抗性间所有一般配合力的相关系数均未达到显著水平;特殊配合力是CMV与疮痂病阃的相关达到了极显著水平,TMV与CMV间和疫病与疮痂病间的相关系数达到显著水平。     

火鹤花衰退病诊断与检疫

本文描述了火鹤衰退病病害症状和2种穿孔线虫(香蕉穿孔线虫Rodopholus sim-ilis和柑橘穿孔线虫R．citrophilus)的鉴定特征，提出了检疫检验和疫情处理方法。     

蛋雏鸡马立克氏病与沙门氏菌混合感染的诊治

2003年6月6日,五家渠市一私人养鸡户前来就诊,我们立即进行发病情况调查、病理剖检和实验室诊断,现将有关情况报告如下:     

二氢杨梅素在动物营养中的应用

藤茶是显齿蛇葡萄的嫩叶经过杀青、揉捻、烘干而成的茶饮料。显齿蛇葡萄(Ampelopsis grossedentata)是葡萄科蛇葡萄属的木质藤本植物,具有极高的营养、保健、医疗价值。现代医学药理研究和临床上都已证明,显齿蛇葡萄全株药用,其味甘淡、性凉,具有清热解毒、抗菌消炎、祛风湿、降血糖等功效。藤茶由多糖、氨基酸、蛋白质、多肽、甾类、萜类、有机酸、挥发油、油脂、生物碱、二氢杨梅素以及多种酶和无机离子等组成,其中二氢杨梅素(DMY)是藤茶的主要活性成分之一,具有多种生物学功能。DMY又名双氢杨梅树皮素、福建茶素、白蔽素、二氢杨梅黄…