普通烟草与黄花烟草体细胞杂种选育出新品系

通过烟草原生质体融合获得普通烟草(N.tabacum)与黄花烟草(N.rustica)的种间体细胞杂种植株,用普通烟草回交后,在其后代中选择优良单株,经二年的产质和抗性鉴定,证明是一个遗传性状稳定、抗病的优良新品系,在烤烟生产上有一定的利用价值,使烟草体细胞杂交技术由实验阶段进入应用研究阶段。     

烟草种间体细胞杂交及其在育种上的应用

我国烟草种间体细胞杂交研究已取得了很大进展。现已获得了普通烟草与８个野生烟草种的种间体细胞杂种，这些种间体细胞杂种可以分为３个类型，即对称杂种、不对称杂种和胞质杂种。体细胞杂种后代遗传变异的方式与常规有性杂种有较大差异。烟草体细胞杂交在抗病性转移、高尼古丁含量转育及新胞质雄性不育系的创造等方面显示了较大潜力。本文还指出了烟草种间体细胞杂种存在的缺点，并提出了解决方法。     

烟草种间体细胞杂交育成新品系

1980年通过原生质体融合获得普通烟草与黄花烟草(N. tabacum+N. rustica),普通烟草和粉蓝烟草(N. tabacum+N. glauce)种间体细胞杂种植株,对其后代连续9年进行遗传性状观察和选育。结果表明:杂种一代呈典型的双亲中间型,杂种三代和回交二代开始分离,也有一直不分离的稳定株系和雄性不育株系,杂种后代育性差,回交能转育并逐步累积轮回亲本性状,染色体数目逐渐减少;在杂种后代选育中,获得了抗黑胫病、耐CMV并且具有天然优质香味的新品系和一些具有特殊利用价值的稳定株系。      

烟草种间体细胞杂种植株当代细胞学观察

近十多年来植物体细胞融合的研究取得一些进展,先后在烟草、矮牵牛、胡罗卜、蕃茄等几个属的植物上获得种间和属间体细胞杂种植株。在国内自1980年以来也获得烟草种间和属间体细胞杂种植株。但是无论国际、国内对体细胞杂种植株的观察多只停留在外形观察和体细胞染色体的计数上。对体细胞杂种植株的细胞学观察却极少报导。体细胞杂种与有性杂种有否异同?同育性有关的减数分裂情况如何等都不清楚。我们用本所80年获得     

普通烟草和粉蓝烟草体细胞杂种植株后代育性观察

普通烟草(N.tabacum)和粉蓝烟草(N.glauca)原生质体融合获得种间体细胞杂种植株,其当代育性很低,但株系间稍有差异。杂种植株自交系(SC)随着自交世代的增加,染色体数目变化不大,正常花粉粒的比率增加,育性提高。体细胞杂种植株的回交系(BC)随着回交世代的递增,染色体数减少,直至接近回交亲本的染色体数,育性趋向正常。高度雄性不育的植株,染色体数稳定,回交仍保持高度的不育,其育性低的原四是雄性器官退化。     

普通烟草与野生烟草体细胞杂种植株育成

普通烟草与黄花烟草叶肉原生质体,用体细胞杂交方法育成的种间体细胞杂种植株,前文已经报道。在原生质体融合试验过程中,我们曾经观察到融合体稳定性差,培养不久,融合体就逐渐解体,最后聚集成团,导致试验失败。当然,影响融合体稳定性的因子很多,诸如原生质体活力、各种溶液组分、渗透浓度、培养条件以及各个环节的操作技术等,都可能直接或间接地影响到融合体的稳定性,因此,如何保持融合体的稳定性,是体细胞杂交过程中的一个重要方面。     

烟草体细胞杂交获得杂种植株——鉴定会在益都召开

1980年9月2日至5日,中国农业科学院在山东益都主持召开烟草体细胞杂交技术成果鉴定会。出席会议的有山东省科委、山东省农业科学院、山东大学、山东农学院,中国农科院作物、蔬菜、棉花、甜菜、柑桔、烟草等专业所,以及有关省烟草研究单位的领导干部、教授、专家和科技人员,共二十二人。会议期间,听取了中国农科院烟草研究所体细胞杂交研究课题组关于“烟草种间体细胞     

半嵌套式PCR检测转几丁质酶基因烟草研究

用含卡那霉素的培养基首先对转几丁质酶基因烟草种子和烟苗进行初步筛选鉴定,再用Western Blot进一步证实抗卡那霉素的转基因烟苗中外源转几丁质酶基因的表达。然后研究半嵌套式PCR(Semi-nested PCR)检测转几丁质酶基因烟草植株及其烤后烟叶中的所转目的基因;利用限制性内切酶Hind Ⅲ对半嵌套式PCR产物进行酶切,从而验证半嵌套式PCR产物是否为真正的目的基因。研究结果表明,半嵌套式PCR是一种快速、灵敏的检测转几丁质酶基因烟草植株及烤后烟叶的方法。      

中国烟草育种研究进展

对我国烟草新品种选育、种质资源、种子技术,以及体细胞杂交、基因工程、分子标记辅助选择育种等方面的研究进行了概述,在此基础上提出了未来我国烟草育种的研究方向和重点。     

白肋烟两个DH群体的构建与染色体倍性的鉴定

分别采用气孔保卫细胞叶绿体计数和流式细胞仪两种方法,鉴定了白肋烟烟碱含量和抗黑胫病两个杂交组合的杂种F₁代经花药培养获得的再生植株的染色体倍性,结果发现叶绿体计数法可以简单经济地检测烟草花药培养再生植株的染色体倍性,但由于受混倍体植株的影响,鉴定结果的准确性较低。流式细胞仪则更加简便快速而且准确地鉴定出各种染色体倍性的再生植株,鉴定结果与开花结实情况完全一致。在此基础上构建了可用于白肋烟烟碱合成代谢和抗黑胫病遗传研究及基因定位的两个双单倍体(DH)遗传群体。      

异质性体细胞杂种雄性不育性遗传及其生物学性状研究

普通烟草(Nicotiana tabacum)和粉蓝烟草(N. glauca)的叶肉原生质体融合再生出的体细胞杂种植株,其形态偏普通烟草,雌蕊发育正常,雄蕊发育异常。将融合双亲部分细胞质和细胞核的杂种株与普通烟草栽培品种(Speight G-28♂)回交,回交一代(BC₁)、回交二代(BC₂)保持其雄性不育,回交三代(BC₃)、四代(BC₄)育性有一定的恢复,并出现育性分离。让恢复一定育性株系自交,获得有一定育性的稳定株系,继续与其它普通烟草品种回交(Speight G-80♂,Speight G-140♂,净叶黄♂等),雄性不育性又得到恢复,并稳定地遗传,用普通烟草品种(净叶黄♂)反交时,后代育性恢复正常。对各个世代生物学性状抗病力进行了研究分析。      

啤酒酵母和糖化酵母的杂交

本文进行了生产用啤酒酵母07和糖化酵母Saccharomyoes diastat(?)cus 1752的种间杂交,试图通过杂交的方法将糖化酵母的DEX基因重组入杂交子中并得以表达。实验表明,杂交子不仅能够水解和发酵糊精即获得并表达了DEX基因,而且在细胞形态、巨大菌落形态、DNA含量以及产孢能力等方面均不同于单倍体双亲株1303 a his dex和2002 a ade DEX。遗传分析表明,杂交种N3204的51个减数分裂产物其糊精发酵特性以及遗传标记均出现了双亲类型的分离或重组现象。这些结果都证明,通过传统的杂交方法可以获得啤酒酵母和糖化酵母的杂交种。与生产用啤酒酵母亲株07比较,杂交种N3204和N3216在IL啤酒发酵过程中显示酒精产生速率快,发酵度高等较优良的发酵特性。     

Detection and analysis of quantitative trait loci affecting production and secondary traits on chromosome 7 in Israeli Holsteins

A total of 5,459 Israeli Holstein cows, daughters of 11 sires, were genotyped for 29 microsatellites spanning chromosome 7 and analyzed by the daughter design for 9 economic traits: milk, fat, and protein yield, fat and protein percentage, somatic cell score, female fertility, herd life, and milk persistency. Quantitative trait loci at chromosome-wise 0.05 significance were obtained for fat and protein yield, fat percentage, somatic cell score, and female fertility. Peak F-values were obtained at 29 cM for fat and protein yield and fat percentage, at 60 cM for somatic cell score, at 74 cM for herd life, and at 11 cM for female fertility. The 0.95 confidence intervals for quantitative trait loci locations were 20 cM for kilograms of fat, 27 cM for fertility, and 51 cM for somatic cell score. Two loci affecting fertility at opposite ends of the chromosome are apparently segregating in the population. A quantitative trait locus for fertility near the centromere was confirmed by application of the modified granddaughter design to a single family. Estimated frequency of the economically favorable allele in the Israeli Holstein cattle was less than 0.5. Significant genetic gain for fertility seems possible by marker-assisted selection.     

Genetic improvement of Citrus fruits: The essential oil profiles in a Citrus limon backcross progeny derived from somatic hybridization

The peel essential oil profiles of an interspecific allotetraploid somatic hybrid, achieved by protoplast fusion of the ‘Valencia’ sweet orange (Citrus sinensis L. Osbeck) and ‘Femminello’ lemon (Citrus limon L. Burm), and three sexual hybrids obtained by back crosses between Femminello lemon and the allotetraploid somatic hybrid (Valencia + Femminello), have been studied by gas chromatography (GC) combined with a flame ionization detector (FID) and a mass spectrometry (MS). In total, 83 components were fully characterized and grouped in four classes (monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes, and others) for an easier comparison of all oils. A statistical treatment by linear discriminant analysis (LDA) of the compositional data from the allotetraploid hybrid and the three sexual hybrids show an intermediate essential oil profile with respect to those of both parents. The contribution of ‘Femminello’ lemon parent is in all cases predominant in the production of the volatile profiles of the new hybrids; however, a different behavior in the peel essential accumulation between the allotetrapolid hybrid and the three hybrids is observed.     

Bivariate animal model estimates of genetic, phenotypic, and environmental correlations for production, reproduction, and somatic cells in Jerseys

Correlations were obtained between 18 response variables of a Jersey herd (Florida Agricultural Experiment Station, Gainesville) for 374 first lactations. Estimates were from the use of multivariate, derivative-free, restricted maximum likelihood procedures with the simplex method of partial maximization. Estimates agreed closely with those obtained previously by other methods in this and other dairy populations. All correlations between yields were high and positive; those between yields and days from parturition to first service were negative and near zero. Correlations between yields and somatic cell scores were moderate and negative; those between yields and constituent percentages in general were negative, except for the yield and percentage of the same constituent. Genetic correlations between chloride content and somatic cells and between measures of somatic cells were 1.0. Results suggest that single-trait selection for milk yield should result in correlated increases in constituent yields with slight decreases in percentage composition of constituents and somatic cell counts.     

烟草新胞质雄性不育系86-6的创造及其利用

普通烟草（Ｎ．ｔａｂａｃｕｍ）与野生粉蓝烟草（Ｎ．ｇｌａｕｃａ）叶肉原生质体诱导融合获得体细胞杂种,其中编号为ＴＧ－８的植株除具有雄性不育特征外,其他生物学性状及体细胞染色体数目均与其普通烟草亲本相同,且遗传性状稳定,表现为典型的胞质杂种特征。用普通烟草做轮回亲本与其杂交至１２代,后代仍然保持雄性不育特征。用烤烟品种Ｇ－２８回交４代,选育出烟草新胞质雄性不育系８６－６。用８６－６与烤烟新品系８８－４及８６－１组配成一代杂交种９２－７、９２－８,杂种优势明显,抗病性也有提高。     

Contribution of proteolytic activity associated with somatic cells in milk to cheese ripening

The effect of proteolytic enzymes from somatic cells on cheese quality was studied. In preliminary experiments, milk and two sodium caseinate systems (pH 6.5 and pH 5.2, the latter in the presence of 5% NaCl) were used as substrates to investigate the proteolytic activity of somatic cells recovered from mastitic milk. Urea-polyacrylamide gel electrophoretograms of hydrolysates suggested that somatic cell extracts contributed directly to proteolysis both in buffer and in milk, but that such activity was reduced by batch pasteurisation (63 °C for 30 min). Sodium caseinate was readily hydrolysed by somatic cell extracts; hydrolysis of α_s1-casein was greater at pH 5.2 and increased with level of somatic cells, suggesting that somatic cells contain proteolytic enzymes which are more active at acidic pH values. Subsequently, miniature Cheddar-type cheeses were made from batches of milk to which somatic cells were added (at levels of levels of 3×10⁵ or 6×10⁵ cells mL⁻¹), either before or after pasteurisation. Proteolysis during ripening of cheese (as measured by levels of pH 4.6-soluble nitrogen) increased with somatic cell addition, although this effect was reduced by pasteurisation after cell addition. Somatic cells may also have directly influenced cheese moisture content, which has been established as a principal indicator of quality of Cheddar-type cheese. Proteolytic enzymes of somatic cells from milk were shown to contribute directly to proteolysis in milk and cheese.