新疆阿魏胚萌发研究

研究了新疆阿魏离体胚培养中,不同培养基、光照、温度、碳源、pH值及低温层积、赤霉素、6-苄氨基嘌呤处理等因素对胚萌发及生长的影响。结果表明：诱导胚萌发较理想的培养基为MS（pH值为5.5-6.0）＋1mg／L GA3＋0.1mg／L6-BA＋3％蔗糖;光照对胚的萌发势差异不明显（P=0.334）,但存在显著的温度差异（P=0.000）,其中20、25、30℃较适宜;离体胚的萌发率随种子低温层积时间的延长而有所下降,推测新疆阿魏种子产生休眠效应的部位可能在胚以外的种皮或胚乳。本研究能有效克服新疆阿魏种子抑制物或种皮本身限制,萌发率可达94％。不仅为新疆阿魏人工培育奠定了基础,也为研究种子低温层积打破休眠的机制提供了新的思路。     

新疆阿魏种子无菌苗制备研究

为获得供新疆阿魏组织培养无菌苗制备的方法。研究了不同的消毒方法、激素、层积温度和相对湿度等条件下,对新疆阿魏无菌苗制作的影响。结果表明:新疆阿魏种子最佳消毒方法为70%酒精30 s+12%H2O215 min;层积温度4℃,相对湿度50%,新疆阿魏种子萌发最好;新疆阿魏种子经GA3处理可打破休眠,但发芽率低于低温层积处理。     

新疆阿魏种子休眠特性及发芽条件研究

通过TTC染色法及白菜种子萌发试验研究了新疆阿魏种子的休眠特性及温度和GA3对其休眠的破除。结果表明,新疆阿魏种子具有较高活力(80.8%),但种子中含有抑制种子萌发的成分;低温和GA3均可一定程度地解除新疆阿魏种子的休眠,但二者协同作用效果明显,其中以4℃和500 mg/L GA3的处理组合为最佳,处理50天后发芽率达到了60.0%。     

野生泸定百合种子休眠和萌发习性的研究

野生泸定百合属于百合科百合属多年生草本植物,其药用和园艺观赏价值极高,自然条件下泸定百合种子的萌发率极低,主要依靠幼芽鳞茎的形式来繁殖后代.为研究和确定云南野生泸定百合种子休眠和萌发的习性,本研究设置了不同光照、不同温度条件下种子的萌发试验,具体为在有光照(光照12 h/d)和无光照的黑暗条件下,分别设置了恒温20℃、30℃和20～30℃变温时种子的萌发试验;设置了5℃低温层积处理后种子的发芽试验,层积时间分别为7、14、21、28d和60 d;以及100mg/L赤霉素处理后,种子于光照和黑暗条件下的发芽试验.结果表明:恒温20℃和20～30℃变温的黑暗条件,适宜野生泸定百合种子的萌发,表现为萌发时间最短、发芽率达到了最高(45%);100 mg/L的GA3处理对种子的萌发有明显促进作用,可加快和缩短种子萌发时间,提高种子发芽率;而5℃的低温层积对野生泸定百合种子的萌发在萌发时间和发芽率方面没有明显促进作用.     

赤霉素与低温处理对短柱铁线莲种子萌发的影响

以短柱铁线莲为试材,研究低温层积、低温干藏、层积前赤霉素处理对短柱铁线莲种子萌发的影响.结果表明:短柱铁线莲种子萌发适宜的平均气温为20～25℃,低温干藏在室内恒温沙床发芽率达74.3％,可以作为短柱铁线莲种子的有效保存方法.50 mg/L GA3浸种后层积效果最佳,室内恒温与室外营养袋播种发芽率分别达到84.3％、61.8％,且种子出苗整齐,种苗质量较好.     

大叶蚁塔种子萌发特性研究

研究了低温层积处理、光照、温度、pH等因素对大叶蚁塔种子萌发的影响。结果表明:低温层积40～50 d处理有利于打破大叶蚁塔种子休眠,促进种子萌发。最适光照强度为1 500 lx,最适光周期为16 h;最适萌发温度为25℃;pH值最适为7,萌发率最高达80.25%。     

黔产竹节参种子萌发试验研究

以黔产竹节参种子为材料,分别考察GA3浓度、浸种温度、浸种时间对竹节参种子萌发的影响.单因素试验表明:GA3最适浓度为150mg/L,最适浸种温度为25℃,最适浸种时间为24h.正交试验结果指出:竹节参种子萌发率的优化组合为150mg/LGA3,浸种24h,温度25℃；而萌发指数的优化组合则为150mg/LGA3,浸种24h,温度30℃.     

北枳椇种子萌发特性研究

通过研究北枳椇种子的吸水特性、光照、温度、硫酸、赤霉素、低温层积等条件处理对北枳椇种子萌发的影响;测定不同保藏时间北枳椇种子的活力及发芽率和不同覆土厚度对北枳椇种子萌发的作用,探讨了北枳椇种子的萌发特性及其贮藏特性.结果表明:刚采收的北枳犋种子不存在生理休眠,生活力高达86%;北枳椇种皮坚韧,对胚具有机械限制作用,发芽周期超过100d,且发芽不整齐;光照对胚发芽无显著影响;45 d低温砂藏促进其种子萌发;0.5～4 g/L.浓度GA,的处理对其种子萌发促进作用不显著;用浓硫酸处理12 min后,在25℃温度下北枳椇种子30 d发芽势由不处理的21.67%提高到75.4%;北枳椇种子活力在常温下可以保存数年,保藏1年后的种子可能由于老化的原因,萌发时需要改进处理方法以提高发芽率;北枳椇为子叶出土型种子,育苗覆土小于0.5 cm为好.     

风车草种子休眠及萌发特性研究

以风车草种子为材料,探讨了温度、光照、植物生长调节剂、水分、低温层积及人工老化处理对其休眠及萌发特性的影响.结果表明,风车草为萌发喜光性植物,适宜浅播,最佳萌发温度为20℃/35℃或25℃/35℃;风车草存在浅度生理休眠,赤霉素(GA3)、氟啶酮(FL)、褪黑素(MLT)和低温层积均可破除其休眠,显著提高种子萌发率(p...     

长自山区三种橐吾种子萌发特性研究

对产自长白山的复序橐吾、全缘橐吾、三角叶橐吾种子在不同催芽温度、不同层积条件及不同浓度赤霉素处理下,进行发芽试验,对其发芽率、发芽势、发芽指数进行统计,目的是找出3种橐吾种子的最佳发芽条件。结果表明：复序橐吾经过0℃层积15d后。在0／10℃变温条件下发芽。其发芽率最高,达到88％;全缘橐吾经150mg／L的赤霉素处理后,于10℃恒温下发芽。发芽率最高为68.3％;三角叶橐吾在0℃层积5d后,在5／15℃条件下发芽,发芽率最高为81.7％。层积和赤霉素处理均有助于3种橐吾种子的萌发。     

Main gene centres of cultivated plants and their wild relatives within the territory of the U.S.S.R.

An account is given of the specific and varietal diversity of the chief indigenous cultivated plants of the U.S.S.R. and their wild relatives. The author also mentions the economic value of this initial material and describes some of the principal achievements of plant breeders in recent times. The genera dealt with are as follows: Triticum, Secale, Hordeum, Helianthus, Linum, Malus, Pyrus, Cydonia, Mespilus, Prunus, Armeniaca, Amygdalus, Cerasus, Microcerasus, Ribes, Cornus, Vitis, Juglans, Pistacia, Corylus, Cucumis, and Medicago.Prepared as a contribution to the symposium on Origin and Evolution of Cultivated Plants, at the Tenth International Botanical Congress, 1964. Submitted by J. B. Hutchinson and J. G. Hawkes.     

甘蔗斑茅的杂交利用及其杂种后代鉴定系列研究Ⅲ.甘蔗斑茅远缘杂交后代细胞遗传分析

以甘蔗与斑茅杂交和回交后代为供试材料，进行染色体计数与核型分析，结果表明，在5个供试材料中，海南斑茅92-105的体细胞染色体数2n＝60=60m，属原始的1A型染色体，其他材料的核型均属2B型。以拔地拉（2n=80=70m+10sm）为母本、海南斑茅92-105为父本的杂交后代崖城96-66的体细胞染色体数目为2n=70=68m+2sm；以崖城96-66为母     

金铁锁总皂苷提取工艺研究

采用正交设计,以齐墩果酸为对照品,采用5%香草醛冰醋酸-高氯酸显色剂,以总皂苷提取率为指标来确定金铁锁的最佳提取工艺。结果表明,最佳提取工艺如下：提取温度为70℃、乙醇浓度为80%、提取时间90 min、料液比1:8,该方法成本低、结果稳定、重复性好。     

Labor and the Geographic Reorganization of Container Shipping in the U.S.

The globalization of production and the geographic dispersion of economic activity have elevated the importance of the transportation and logistics sectors of the economy. One sector in particular that has experienced significant expansion is maritime transport and container shipping. As the cargo has become increasingly “discretionary” such that it can conceivably be transported through any port that allows intermodal access to the hinterland, the industry has become much more foot‐loose vis‐à‐vis a particular port of entry. The enhanced mobility of the cargo results in more intense port competition. One particular place to observe and study this dynamic is in the port and terminal selection of shippers and shipping lines and the role of port authorities in attempting to attract these carriers to their facilities. In this paper, the focus is on the role of labor and labor relations in such decisions. These issues will be studied in the context of the potential container traffic rerouting from the West to the East Coast of the U.S. and, as an illustrative case study, how these developments have played out for the East Coast port of Jacksonville, Florida.     

The Changing Regional Structure of the U.S. Economy

This paper utilizes newly available industry-specific historical measures of Gross Regional Product to highlight the changing regional structure of the U.S. economy between 1963 and 1986. During this period, the percentage of U.S. output produced in the eight different regions changed significantly. The largest changes occurred in the Great Lakes (?3.65 percent), Mideast (?3.32 percent), and Southeast (+3.64 percent). Four major industry sectors (Agriculture, Mining, Construction, and Government) declined in relative importance in all eight regions. Five major industry sectors (TCPU, Retail Trade, Wholesale Trade, FIRE, and Services) expanded in relative importance. Somewhat surprisingly, Manufacturing output expanded for the U.S. as a whole and for six of the eight regions. The perception of decline in the relative importance of manufacturing in the U.S. is clearly based on the dramatic declines in the once dominant manufacturing base of the Mideast and Great Lakes regions.     

Breaking breeding barriers in Lycopersicon. 5. The inheritance of the unilateral incompatibility between L. peruvianum (L.) Mill. and L. esculentum Mill. and the genetics of its breakdown

Summary The validity of the current hypotheses on the inheritance of unilateral incompatibility is disputed and the importance of intrapopulational research on the inheritance of unilateral incompatibility is emphasized.Such research has been carried out on the unilateral incompatibility between L. peruvianum and L. esculentum with inbred material of L. peruvianum. The results indicate that in this species the inhibition of L. esculentum pollen tube growth, built up of distinct processes, is based on independent dominant genes, and that the breakdown of the phenomenon is a consequence of segregation of recessive alleles, the expressivity of at least some of these being influenced by environmental factors.Research demonstrating differences between self-incompatibility and interspecific pollen tube growth inhibition is reviewed and it is concluded from this and own research that the two phenomena are distinct.     

马蔺种子特性研究

本文对马蔺种子的颜色、形状、饱满度和含水量等一般特性进行了研究,旨在为鉴别马蔺种子质量,探讨出苗规律提供依据.     

Variation in the pathogenicity of Erysiphe graminis D.C. F. Sp. Avenae,and its relation to the development of mildew-resistant oat cultivars

Two new physiologic races of Erysiphe graminis avenae are described, capable of attacking hitherto resistant hexaploid genotypes of Avena in the seedling stage. Two diploid forms namely A. strigosa var. glabrota and A. strigosa s.sp. hirtula provide the only sources of resistance to the races of mildew isolated in this investigation. In two cultivars, relative degrees of resistance to mildew infection in field trials have been shown to be due to resistance developing in later formed leaves of maturing plants. The importance of developing cultivars with a high degree of adult plant resistance to disease attack in the field is discussed.