Influence of the Indoleacetic Acid-Lysine Synthetase Gene (iaaL) of Pseudomonas syringae subsp. savastanoi on Yield Attributes of Potatoes

The iaaL gene of Pseudomonas syringae subsp. savastanoi encodes an indoleacetic acid-lysine synthetase which conjugates free indoleacetic acid (IAA) with lysine. lAA-lys is biologically less active than free IAA. The iaaL coding region was expressed under the control of the cauliflower mosaic virus 35S promoter and transgenic potato plants were produced (Spena et al. 1991). 35S iaaL potato plants are characterized by increased internodal length and epinastic bending of older leaves. In three greenhouse experiments with plants grown in pots of different size and in two growth chamber experiments tuber number increased in iaaL transgenic plants compared to untransformed and vector-transformed controls of the same genotype. The increase in tuber numbers observed under controlled conditions was reflected in tuber yield which increased in the pot grown transgenics.     

Restoration of tuber production by exposure to unshaded daylight in Eleocharis kuroguwai Ohwi shaded during the early tuber formation period

The loss of final tuber weight of Eleocharis kuroguwai Ohwi by shading during the early tuber formation period (TFP) is overcome by exposure to unshaded daylight thereafter (late TFP). In the present study, the growth parameters that contribute to the dry matter increase (DMI) per day of tubers in the late TFP were examined. DMI of the tuber during the late TFP was determined by that of the whole plant and the ratio of the DMI of the tuber to that of the whole plant during this period. The ratio of the DMI of the tuber to that of the whole plant during the late TFP was significantly correlated with the DMI of the whole plant during the first 14 days of the late TFP. During the late TFP after the exposure to unshaded daylight, DMI of the whole plant correlated with the surface area of the stem (SAS) and net assimilation ratio (NAR), and the SAS correlated with the stem dry weight (DW) and specific stem-surface area (SSA). SSA negatively influenced NAR, but NAR was increased by unshading. During the late TFP after shading, the effect of the decrease of the stem DW due to shading on the DMI of the whole plant was mitigated by the large SAS and high NAR. These results indicate that the growth parameters that contribute to the DMI of tuber during the late TFP after exposure to unshaded daylight are SAS and NAR just after unshading, and SSA during this period.     

光盘型电子出版物编目方法探讨

书目记录规范化、标准化是实现信息资源共享的前提。本文通过作者多年的工作实践,讨论了日前光盘型电子出版物的分类中存在的问题,分析了其CNMARC格式著录方法和特点,提出了针时光盘型电子出版物规范化的对策。     

再议提要项著录

图书馆必须树立“以人为本”的服务理念,在贯彻“以人为本”的原则时必须注意服务细节。在为读者提供的书目数据中．一定要重视提要项的著录。提要是文献的精华,提要项著录是中国图书馆目录数据的特色,是目录数据的精华所在,在读者服务工作中起着很重要的作用。     

两种不同钾肥在马铃薯上应用效果的研究

盆栽试验结果表明，氯化钾和硫酸钾均能提高马铃薯叶绿素含量，块茎产量较对照增加显著。供试两种钾肥对马铃薯淀粉含量有增加作用，但对维生素C含量有降低趋势。田间试验结果表明，钾肥具有增加大、中薯，降低小薯比例的效果，从而提高商品率。在海伦黑土上，每公顷施氯化钾52．5～202．5kg，增产块茎6．8％～17．6％。在富锦黑粘土上，每公顷施等量的氯化钾，增产块茎6．5％～20．0％。     

脱毒马铃薯扩繁技术初探

本试验以早熟品种东农３０３、中熟品种系薯１号和晚熟品种晋薯７号为试验材料，采用Ｌ１２（４×３￣２）正交试验法，分室内和室外两组同时进行试验，结果表明，出芽天数随着温度的上升而减少；大薯块出芽数极显著高于中小薯块；出芽数则随着掰芽次数的增加而减少；系薯１号的出芽数明显高于晋薯７号，与东农３０３差异不显著．产量结果表明，主因素为品种；其次为薯块大小；掰芽次数间差异不显著；母薯则极显著高于掰芽次数．综合结果分析，脱毒马铃薯掰芽扩繁是一项节省种薯，提高繁殖系数的有效措施；以选择适宜当地种植的高产高效和大薯块掰芽为好；三次掰芽扩繁移栽和母薯直播是可行的马铃薯扩繁技术措施．     

钢球滚子弧面分度凸轮载荷分布

运用空间啮合原理和回转张量法,推导出凸轮滚道截形采用双圆弧结构时,钢球滚子弧面分度凸轮的廓面方程和啮合方程.应用赫兹接触理论和变形协调条件,推导出载荷在每个参与啮合钢球中的分配关系.通过实例计算,发现每个钢球上的载荷大小分配不同,在钢球的啮入、啮出点,钢球受力发生突变,参与啮合的钢球数目越多,每个钢球的受力越小.     

榨菜生长过程中硝酸盐分布规律初研

按照榨菜的正常播种时间和生长季节,连续3 a对榨菜移栽苗、返青苗、榨菜茎膨大初期、膨大期、成熟期及雨水节后期按GB/T 15401-94方法进行了硝酸盐含量的测定,从900多个检测数据中发现了硝酸盐蓄积量从移栽到成熟过程中的分布规律.     

马铃薯纺锤块茎类病毒山西分离物侵染性克隆的构建

马铃薯纺锤块茎类病毒(Potato spindle tuber viriod,PSTVd)侵染马铃薯会严重影响薯块的产量和品质。根据PSTVd的同源序列设计引物,以山西省马铃薯感病块茎中提取的总RNA为模板,经RT-PCR方法扩增出全长cDNA片段,将其克隆到质粒pBS-T载体上,进行序列分析。结果表明,该类病毒全长359 nt,能通过分子内序列互补形成致密的二级结构。以该序列作为种子序列进行Blast搜索,该序列与PSTVd荷兰分离物(GenBank登陆号:AY372400.1)的序列一致性为100%。将该序列与东北株系、河北株系及已公布的弱株系(GenBank登陆号:M14814.1)、强株系(GenBank登陆号:U23058.1)、中间株系(GenBank登陆号:AY937179.1)比对,有12个核苷酸具有多态性,其中有5个发生在致病区。将线性化的质粒pBS-PSTVd及其PSTVd的体外转录产物接种番茄矮红宝的无毒苗,20 d后接种株轻微显症,RT-PCR检测均呈阳性。将RT-PCR产物测序,其结果与接种的PSTVd原序列完全一致,证实构建的PSTVd山西分离物的克隆具有侵染性。     

魔芋种芋大规模室内架藏技术研究

宜昌市在发展规模化魔芋生产基地和魔芋种繁基地之初,都遇到了种芋大规模贮藏较为困难的突出问题。为此,该文对魔芋种芋室内架藏技术进行总结,以指导相关企业和基地进行大规模室内架藏。