Meiosis and fertility in interspecific hybrids of Nicotiana tabacum L. ×N. glauca Grah. and their derivatives

Nicotiana glauca is of potential interest to breeders as it carries resistance to black root rot of tobacco. Cytological investigations of sexual interspecific hybrids of N. tabacum T′T′TT (2n = 4x = 48) cv. ‘Wiślica’ × N. glauca GG (2n = 2x = 24) were carried out. The analyses of chromosome association at diakinesis and metaphase I in the PMCs of amphihaploid F₁ T′TG (2n = 3x = 36) revealed low variable pairing with 0–5 bivalents. The sterile amphihaploids F₁ were converted into partial female fertile amphidiploids T′T′TTGG by chromosome doubling. Among 36 mature plants obtained, 15 were found to have chromosome numbers (2n = 6x = 72) and were verified as amphidiploids, 9 had (2n = 6x = 70 or 71) chromosomes while the remaining 12 were haploid. True amphidiploids, in spite of quite high chromosome pairing during meiosis, were very different in pollen fertility, ranging from 0% to 85%. Male fertility disturbances did not correlate with the degree of female fertility upon pollination with N. tabacum. Sesquidiploids T′TG (2n = 5x = 60) obtained from backcrossing the amphidiploids to parental tobacco showed more than 22 bivalents, 10–12 univalents and occasional multivalents that indicated the possibility of interchange events between N. tabacum and N. glauca genomes.     

有机花生开发初探

对我国，特别是在贫困边远地区开发有机花生的有利条件进行分析，从而阐述种植有机花生的一些主要技术措施，对指导我国有机花生的开发具有一定的参考价值。     

伊犁地区玉米制种的气候适应性与玉米制种产业的发展前景

比较国内几个玉米产区气候条件对玉米制种的适应性，以及伊犁年际气候条件对玉米制种的适应性表明，伊犁地区适合玉米制种，玉米制种具有较大的发展空间。     

Alpha-amylase/subtilisin Inhibitor Levels in Australian Barleys

An enzyme-linked immunosorbent assay (ELISA) was used to determine the bifunctional alpha-amylase/subtilisin inhibitor (BASI) content of barley grain from 11 cultivars grown in six diverse locations in Australia. The inhibitor ranged from 119 to 254 μg/g in 57 barley samples. Genotype had a significant (P<0·05) effect on BASI content but there was no effect due to environment. Total protein varied independently of BASI and was influenced by environment and genotype. BASI content was higher (P<0·05) in malting barley than in feed barley and was correlated positively (r=0·29;P<0·05) with alpha-amylase activity in corresponding malts. The ELISA used monoclonal and polyclonal antibodies raised against purified BASI. In immunoblot analysis the monoclonal antibody showed high specificity for the inhibitor in barley and also detected the inhibitor in wheat. Low levels of inhibitor (mean 3·2 μg/g) were found in 12 Australian wheat cultivars using the ELISA developed for barley. The assay had a linear working range of 5–50 ng/mL with a detection limit of 2 ng/mL. Reproducibility between assays was good (CV=4·9%) but mean recoveries were high, ranging from 116–129% when purified inhibitor was added to barley extracts. The ELISA may have useful applications in brewing research and barley breeding programmes.     

品种多点试验中最优地点数和重复次数的确定

本文给出几个确定品种多点试验中最优地点数和每一地点内各参试品种最优重复小区数的公式，还给出实例．     

镉暴露对钩虾磷酸葡萄糖异构酶基因型的致死性差异研究

采用水平淀粉凝胶电泳技术和等位酶分析方法,比较了氯化镉处理后钩虾种群多态基因座Gpi各基因型个体的死亡率差异。将268头钩虾暴露于50g·L-1氯化镉中96h后平均死亡率为56.5%,将存活个体和死亡个体分别进行等位酶分析以确定每个个体的基因型。结果表明,氯化镉对钩虾Gpi6种不同的基因型表现出不同的选择性致死效应,各种基因型个体的死亡率分别为:67%(Gpi-aa)、50%(Gpi-ab)、57%(Gpi-ac)、69%(Gpi-bb)、56%(Gpi-bc)和73%(Gpi-cc)。列联表!2检验表明:Gpi-ab个体与Gpi-cc个体之间的基因型与死亡率存在显著关联(P<0.05)。以上结果说明该钩虾种群Gpi-cc基因型很可能与钩虾对镉毒性的敏感性存在相关关系。     

冬性小黑麦花药培养的基因型和培养基效应的研究

为提高冬性小黑麦的花药培养效率,以5个冬性小黑麦杂交组合的F1为材料,分别接种到四种培养基上,研究了冬性小黑麦花药离体培养中不同基因型和不同培养基以及不同培养条件对花药培养效率的影响。结果表明,基因型差异和培养基差异对愈伤组织的诱导有显著影响,不同基因型对花药的愈伤组织的再分化频率也有显著影响。对冬H329转分化后的愈伤组织进行了4℃的低温处理,不同的处理时间对绿苗分化率也有一定的影响,处理96 h绿苗分化率最高达22.22%。     

诱导培养基对水稻胚愈伤组织形成和分化的影响

将10个籼稻品种(系)的胚分别接种于附加2,4-D(2mg/l)的4种诱导培养基上,研究其对盾片愈伤组织形成和绿苗再生的影响。结果表明:(1)10个品种(系)的盾片愈伤组织的开始形成时间,形成高峰和频率差异显著,但同一品种对不同培养基的反应差异不明显。(2)在绿苗再生率方面,各品种对4种培养基的反应不同,培养基相同,不同品种间愈伤组织再生绿苗频率存在显著差异。总之,不同基因型的水稻,其盾片愈伤组织的诱导与绿苗再生需要采用不同的培养基,才能获得理想的结果。     

不同磷效率水稻基因型根系形态和生理特性的研究

以磷高效水稻基因型连珍11和磷低效水稻基因型嘉948为材料,通过溶液培养试验研究了正常供磷(10 mg P·L-1)和低磷胁迫(0.5 mg P·L-1)条件下的根系形态,根系磷吸收动力学参数和根系分泌酸性磷酸酶特性.结果表明,在两种供磷条件下,连珍11的吸磷量均显著高于嘉948.与嘉948相比,连珍11具有较大的根干重,根长,根表面积和侧根数量.低磷胁迫下连珍11的根系磷吸收动力学参数Imax,Km和Cmin均显著低于嘉948;而在正常供磷条件下两个水稻基因型的Imax和 Km没有显著差异.低磷处理显著增加两个水稻基因型的Imax,却显著降低Km.正常供磷条件下两个基因型根系分泌酸性磷酸酶活性没有显著差异,而在低磷处理条件下连珍11的根系分泌酸性磷酸酶活性显著高于嘉948.研究表明连珍11的磷效率显著高于嘉948的原因是其具有较庞大的根系以及在磷缺乏条件下具有较高的根系分泌酸性磷酸酶活性和较低的Km和Cmin值.     

上海地区猪戊型肝炎病毒部分序列的克隆与分析

对上海地区几个猪场的戊型肝炎感染情况进行了调查,共采集粪便样品36份,通过RT-nPCR的方法应用通用引物对病毒基因组的ORF2部分片断进行扩增,36份样品中有5份RT-nPCR阳性,HEV RNA阳性率为13.9%,去除相同的序列,得到2株HEV的ORF2部分序列。序列分析表明,这两段序列与基因I、II、III、IV的遗传距离分别为0.183、0.207、0.230、0.102和0.177、0.226、0.240、0.108。系统进化分析显示,这两株病毒都属于基因Ⅳ型。