Enzymatic saccharification and ethanol production of <Emphasis Type="Italic">Acacia mangium</Emphasis> and <Emphasis Type="Italic">Paraserianthes falcataria</Emphasis> wood,and <Emphasis Type="Italic">Elaeis guineensis</Emphasis> trunk

We examined the saccharification and fermentation of meals from Acacia mangium wood, Paraserianthes falcataria wood, and Elaeis guineensis trunk. The levels of enzymatic hydrolysis of cellulose and ethanol production were highest for P. falcataria wood and lowest for A. mangium wood. Ultrasonication pretreatment of meal further increased the rates of hydrolysis and ethanol production in meal from P. falcataria wood. Through this pretreatment, hemicelluloses (xylan and xyloglucan) and cellulose were released in the meal from P. falcataria wood. Loosening of hemicellulose associations can be expected to make P. falcataria wood more useful for bioethanol production.     

东海中北部小眼绿鳍鱼的食物组成及摄食习性的体长变化

应用聚类分析和单因素方差分析等方法.对2008年5月至2009年2月东海中北部小眼绿鳍鱼(Chelidonichthys spinosus)的食物组成及摄食习性的体长变化进行了研究.结果表明.小眼绿鳍鱼摄食的饵料种类有93种.优势饵料种类有太平洋磷虾(Euphausia pacifica)、细巧仿对虾(Parapenaeopsis tenella)、脊腹褐虾(Crangonafnis)和六丝矛尾虾虎鱼(Chaeturichths hexanema).摄食强度有明显的体长变化.同时主要饵料类群组成也有明显的体长差异.鱼类饵料的质量百分比随着体长的增大而增大.尤其当体长大于200 mm后.鱼类成为最重要的饵料类群.而糠虾类的比例则减少.另外.平均单个饵料的质量则随着体长的增大而增大.这符合"最佳摄食理论".聚类分析的结果表明.小眼绿鳍鱼在体长达到100 mm时.摄食范围由狭食性逐步向广食性转变.可以认为小眼绿鳍鱼食性的转变与其体长密切相关.     

Improvement of foreign gene expression in transgenic rice ( Oryza sativa L. ) by matrix attachment regions (MARs)

Matrix attachment regions or matrix associated regions (MARs) were special DNA sequences in chromatin of eukaryotic cells that tightly associated with the nuclear matrix or scaffold in vitro after a combination of nuclease digestion and extraction. They were also called scaffold attachment regions (SARs).     

1996～1998年杂交水稻主要品种的胞质类型分析

杂交水稻的生产应用为我国粮食生产作出了巨大贡献,其种植面积占水稻年播种面积的50%以上.本文采用九种不育胞质类型划分法,对我国1996～1998年杂交水稻主要品种的胞质类型进行了分析.生产上应用的三系杂交稻按其胞质类型所配组合的播种面积比重排序依次为野败型、冈·D型、印尼水田谷型、矮败型、两系、红莲型、K型和BT型;野败型的面积比重在逐年下降,冈·D型、印尼水田谷型和矮败型等的面积比重在逐年增加.两系杂交稻10余个组合通过了省级审定,培矮64S的广泛应用展示了两系杂交稻超三系的广阔前景.我国已育成超级杂交稻苗头组合,个别组合在部分连片示范点(6.7hm2)达到了日产稻谷100 kg/hm2的超级稻指标.     

用微卫星标记验证水稻4N×2N早世代体的稳定性

从水稻双胚苗群体中筛选出来的自然发生的四倍体和正常的二倍体进行杂交,在早世代获得了在田间表现稳定的群体,用微卫星分子标记验证了早世代群体在遗传上的稳定性,并对这种现象的机理进行了讨论,认为这一个特殊现象的发现对水稻的理论研究和育种实践都具有重大的意义.     

Re-integrating ecology into integrated landscape approaches

Landscape Ecology - Integrated landscape approaches (ILAs) that aim to balance conservation and development targets are increasingly promoted through science, policy, and the donor community....     

Enlargement of individual cellulose microfibrils in transgenic poplars overexpressing xyloglucanase

Holocellulose samples prepared from transgenic poplars overexpressing xyloglucanase had crystal widths of 3.2–3.5 nm as a result of the (2 0 0) plane, based on their X-ray diffraction patterns, and crystal widths were greater than those of the wild type (3.0 nm). Cellulose microfibril widths in the holocellulose samples were further determined from transmission electron microscopic (TEM) images of individualized fibrils prepared by 2,2,6,6-tetramethylpiperidine-1-oxy radical-mediated oxidation of the holocelluloses and the successive disintegration of the oxidized products in water. The TEM images also supported the finding that cellulose microfibril widths of transgenic poplars were larger than those of the wild type. The cellulose microfibril widths of transgenic poplars were approximately 6 nm, whereas those of the wild type were about 5 nm. However, such enlargement of cellulose microfibril widths could not be explained by the increased cellulose contents of the transgenic poplars alone.