亚精胺对提高玉米幼苗抗旱机理的研究

以掖单４号玉米幼苗为材料，用０．５Ｍｐａ的ＰＥＧ—６００进行人工模拟水分胁迫，同时叶面喷施１ｍＭ亚精胺（ｓｐｄ），研究了在水分胁迫条件下亚精胺对玉米幼苗中保护酶系、光合强度以及气孔阻力的影响。结果表明，亚精胺处理大大提高玉米幼苗中ＳＯＤ、ＰＯＤ的活性以及光合强度，适当减小气孔阻力，故亚精胺可以提高玉米幼苗的抗旱性。     

Pb胁迫条件下旱柳扦插苗生长过程生理生化响应机制研究

为研究旱柳对铅的耐受机制,以2年生旱柳(Salix matsudana)扦插苗为材料,进行盆栽实验,分析研究生长6个月后的扦插苗在铅浓度为0、200、600、1000、1200 mg/kg时的生理生化响应机制。结果表明：随着土壤铅浓度的增加,植株长势、根茎叶中的SOD、POD、CAT活性、可溶性蛋白含量以及叶中的叶绿素含量均呈先升后降的变化趋势,MDA含量呈上升趋势。各项生理指标：根＞茎＞叶。该实验表明：旱柳根系为重金属铅的主要累积部位,只有少量的铅转移到地上部分且600 mg/kg铅胁迫下旱柳幼苗有最佳耐性机制。     

除草剂防治云杉矮槲寄生效果初报

选用5种不同的常见除草剂,在云杉天然林中对云杉矮槲寄生芽进行防除试验,筛选出效果理想且无药害发生的药剂,并确定其最佳使用浓度。结果表明在寄生芽上喷施浓度为1∶100的90%乙草胺乳油防效最好,施药后3 d寄生芽开始脱落,施药14 d后对寄生芽防除率达到100％,其他几种试验药剂虽然对寄生芽也有防除作用,但效果次之。     

红麻韧皮部束纤维抗拉强度的分布规律研究

为探讨红麻韧皮部束纤维抗拉强度的分布规律,将红麻大小植株不同高度、不同层次的韧皮部束纤维进行分离并测定抗拉强度。结果表明,红麻韧皮部束纤维抗拉强度随着植株大小、植株高度及束纤维不同层次的变化在横向和纵向分布上呈现一定的变化规律,推测与红麻纤维发育期间的外界环境条件有密切关系。     

分子标记技术在棉花遗传育种中的应用

介绍了分子标记的类型及原理，综述了该技术在棉花的种质进化及亲缘关系、遗传结构和多样性、遗传图谱的构建与目标基因的定位、品种指纹图谱的构建与品种（杂种）纯度鉴定及分子标记辅助育种等研究中的应用情况．同时对其应用前景也进行了展望。     

猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌复合PCR检测方法的建立

目的建立可以同时检测猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的快速而可靠的PCR检测方法。方法和结果根据胸膜肺炎放线杆菌的Apx-VIA基因序列、多杀性巴氏杆菌和副猪嗜血杆菌的16SrRNA基因序列设计5条引物。猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌模板的PCR扩增产物大小分别为342bp,485bp和1258bp。复合PCR对1～12型猪胸膜肺炎放线杆菌标准株,6株多杀性巴氏杆菌标准株,1～15型副猪嗜血杆菌以及25株经生化鉴定确认为上述三种细菌的分离株的基因组DNA作为模板进行检测,均获得预期大小的扩增产物。以猪放线杆菌、吲哚放线杆菌等14种常见细菌作为阴性对照进行PCR检测,结果仅有支气管败血波氏杆菌产生了可以和上述三个特异性条带明显区分的PCR产物。复合PCR针对胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的敏感性分别为14pg、34pg和37pg。结论本研究建立的复合PCR特异性好,敏感性高,可以用于猪胸膜肺炎放线杆菌、多杀性巴氏杆菌和副猪嗜血杆菌的快速检测。     

Two single nucleotide polymorphisms in the promoter of the ovine myostatin gene (MSTN) and their effect on growth and carcass muscle traits in New Zealand Romney sheep

Myostatin is a negative regulator of muscle growth and development in mammals, and variation in ovine myostatin gene (MSTN) has been demonstrated to be associated with variation in the muscularity of sheep. Polymerase chain reaction–single‐stranded conformational polymorphism (PCR–SSCP) was used to look for single nucleotide polymorphisms (SNPs) in a 304‐bp amplicon from the promoter region of ovine MSTN. Sequence analyses revealed two previously identified SNPs (c.?2449G/C and c. ?2379T/C) that resulted in three haplotypes (H₁ (c.[?2449G; ?2379C]), H₂ (c.[?2449C; ?2379C]) and H₃ (c.[?2449G; ?2379T]). The effect of these SNPs on growth and carcass traits was investigated in 357 NZ Romney lambs. General linear mixed‐effect models revealed that sheep with the genotype c.?2449GC had a higher loin meat yield (p = 0.032) and proportion loin yield (p = 0.028), than those with the genotype c.?2449GG. The genotype c.?2379CC was associated with an increase in three weight traits: birthweight (p = 0.003), tailing weight (p = 0.009) and weaning weight (p = 0.028), when compared with the genotype c.?2379TC, but it was not found to have an association with growth rate. This suggests that c.?2379T/C has an effect that originates at, or before birth. Haplotype H₃ was associated with a decrease in birthweight (p = 0.002), tailing weight (p = 0.003) and weaning weight (p = 0.011). Haplotype H₂ was associated with increased loin yield (p = 0.012) and proportion loin yield (p = 0.002). The SNPs may have value as genetic markers for improved Romney breeding.     

小麦新品种“绵阳26”主要性状与产量的关系

对87个试验点的资料分析，绵阳26的主要性状与产量的回归方程为：y=-1084．3321＋5．265x1 9.0142x2＋5.2486x3＋8.3796x4＋6．3627x5。经偏回归和偏相关分析，产量构成因素中，千粒重，有效穗对绵阳26的产量贡献和影响最大（b'4=1．2769．b'2=1．1272，R2y0=0．7287，R4y0=005689）；而千粒重、有效穗、穗粒数之间为负相关，存在着不同程度的制约关系。在本资料现有产量的基础上，稳定千粒重，主攻穗数和穗粒数的提高，是发挥绵阳26高产潜力的决定因素。