Amylose synthesis capacity of the three Wx genes of wheat cv. Chinese Spring

The Wx locus controls amylose synthesis in the cereal endosperm. Hexaploid wheat (Triticum aestivum L.) has the three Wx loci on chromosomes 7A ( Wx-A1), 4A (Wx-B1) and 7D (Wx-D1). To verify the effects of null alleles on reducing amylose content and determine the amylose synthesis capacity of each Wx gene independently and accurately, we produced eight possible types of recombinant lines carrying different null alleles at the Wx loci under the ‘Chinese Spring’ genetic background. Amylose content varied from 0% of the waxy ‘Chinese Spring’ to 25% of the ‘Chinese Spring’ normal type. The reducing effect of the single null alleles was the largest in Wx-B1b, and there was no significant difference between Wx-A1b and Wx-D1b. More than 3% reductions in amylose content were detected in the double null types. The results of the double null lines further demonstrated that for the capacity of amylose synthesis, Wx-B1a predominates and produces 21–22% amylose, followed by Wx-D1a (20–21%) and Wx-A1a (15–18%). These significant differences were partly correlated with variation in the amounts of the Wx proteins produced by different Wx genes. However, comparisons of the double null lines with the single null or normal lines indicated that amylose content was not linearly proportional to the number of the Wx genes, suggesting that the Wx genes act in an epistatic manner. This revised version was published online in July 2006 with corrections to the Cover Date.     

完达山地区珍稀濒危植物及其保护对策

完达山地区国家重点保护植物有１７种,其中,国家一级保护植物１种,二级保护植物４种,三级保护植物１２种。并根据植物资源状况提出本区有２４种植物应列入保护植物,并对珍稀濒危植物的保护和利用提出了几点建议。     

Intraspecific differentiation and geographical distribution of Wx alleles for low amylose content in endosperm of foxtail millet, Setaria italica (L.) Beauv.

To clarify the genetic mechanism which controls the variation in amylose content among nonwaxy landraces of foxtail millet, the inheritance of different starch types in endosperm was examined by I₂-KI staining. The level of starch granule bound protein in foxtail millet endosperm was also analyzed using SDS-PAGE. The segregation for starch types in F₂ and F₃ seeds determined by I₂-KI staining showed that there are three different alleles at the waxy (wx) locus. A major protein bound to starch granules was detected in nonwaxy endosperm but it was absent in most of the waxy endosperm, suggesting that the protein is the Wx gene product which is responsible for the synthesis of amylose in endosperm. The level of Wx protein proportionally corresponded to the amylose content among nonwaxy landraces. This implies that two different Wx alleles regulate quantitative levels of Wx protein. Landraces with the allele for low amylose content are from Taiwan, the Philippines, Indonesia and Thailand. This revised version was published online in July 2006 with corrections to the Cover Date.     

藏獒血液蛋白多态性研究

1材料与方法 1．1材料共采集血样103份,其中,44份河曲藏獒（HTM）,42份青海藏獒（QTM）,5份青海藏狮犬（QTS）以及12份青海土种犬（NAD）。均采集后肢静脉肝素钠抗凝血5—10ml,24h内带回实验室,处理后置低温冰箱（-40℃）冻存备用。     

腐殖酸与粘土矿物混合体系对稀土镧、钕吸附特性的研究

为进一步研究土壤固相之间对稀土元素的竞争吸附趋势,将腐殖酸和7种粘土矿物(高岭石、蒙脱石、伊利石、蛭石、绿泥石、凹凸棒石、膨润土)组合成一个相对独立的复合吸附体系,采用振荡平衡法,对稀土镧、钕进行吸附研究,通过ICP检测,对数据进行拟合,结果显示:Langmuir能更好地描述稀土吸附过程,而且经过验证实验得到,在La3+体系中,腐殖酸的吸附量为粘土矿物的3倍,且2∶1型粘土矿物的吸附能力是1∶1型的3.68~5.44倍;在Nd3+体系中,腐殖酸吸附量约为粘土矿物的3.5倍,且2∶1型粘土矿物的吸附能力是1∶1型的3.49~4.74倍;腐殖酸与粘土矿物的吸附竞争趋势为:腐殖酸>蒙脱石>膨润土>蛭石>伊利石>凹凸土>绿泥石>高岭石。     

广东天井山4种珍稀濒危植物的恢复策略研究

通过描述广东省天井山国家森林公园刺桫椤、广东松、观光木和伯乐树4种野生珍稀濒危植物的生物学特性,分析其致濒因素,提出了恢复策略以及加强对珍稀濒危植物进行就地保育和繁育技术研究的建议。     

三峡库区珍稀濒危陆生脊椎动物现状及其保护对策

三峡库区曾经是我国生物多样性非常丰富的地区之一，三峡工程的修建对库区珍稀濒危陆生脊椎动物将产生一定的影响。三峡库区共有陆生脊椎动物523种，国家级保护动物有10目19科64种，其中I级保护物种8种，Ⅱ级保护物种55种，中国特有种9目18科47种，既是特有种又是珍稀濒危动物的物种有4目5科8种。本文在综述三峡库区珍稀濒危陆生脊椎动物多样性特点，即区系复杂与组成多样性、成分特有及分布不均匀性的基础上，分析了库区陆生脊椎动物致危原因和目前所采取的一系列保护措施中所存在的各种问题，并提出了相应的保护对策。     

二花脸猪obese基因3714位点多态性与产仔性状的相关性

利用Bi PASA技术检测了二花脸猪OB基因的多态性 ,并且分析了其与母猪产仔性能的相关性。结果显示 ,OB基因在第 371 4碱基处存在G/T替换 ,经Bi PASA检测后分别定义为等位基因G和T。在二花脸母猪群中 ,等位基因G和T的频率分别为 0 339和 0 6 6 1。方差分析发现 ,G/G基因型个体的头胎产仔数以及平均产仔数略低于G/T型和T/T型个体 ,但相互之间无显著差异 ;在最高产仔数性状上 ,G/G型个体显著低于G/T型和T/T型个体 (P <0 0 5 )。表明G/G型个体的产仔潜力显著偏低     

几种利用抑制剂分离稀有放线菌的方法

稀有放线菌是生物活性物质的重要来源。从抑制剂方面,介绍利用卡那霉素、交沙霉素和溶菌酶,利富平和新生霉素,白霉素、新生霉素和衣霉素等选择性分离稀有放线菌的有效方法。     

稀土在林业育苗上应用技术的研究

２年试验结果表明：施用稀土浸种可提高针叶树场圃发芽率５．８％～３４．２％，阔叶树３１％～５０％，每公顷节省种子３．４８～１０．２６ｋｇ；叶面喷洒适宜的试验组合有促进苗木生长作用可提高成苗率２．０％～５０．７％；而且方法简单、使用方便，成本低。