西伯利亚白刺优良无性系嫩枝扦插技术试验

采用自动喷雾扦插育苗设备,对双岗01、双岗02、双岗03、双岗04四个白刺优良无性系用正交设计进行嫩枝扦插试验,结果表明:白刺无性系间生根率及生根数有极显著差异,对主根长没有影响;植物调节剂的种类及浓度和处理时间对生根率有显著影响,但对生根数及主根长没有影响。其中双岗04的生根效果最好,其最佳生根组合为250 mg.kg-1的生根粉处理2 h。     

沙冷杉结实特性的观测

以沙冷杉为材料,对其结实特性进行观测,结果表明:在城市人工栽培条件下,初次结实年龄为40～45 a,与野生植株基本相同,初次结实株率为31.3%;充足的光照可使结实植株和球果数量增加,温度对其无明显影响.球果着生于2 a或3 a生枝条基部,以2 a生枝条基部居多;多集中分布在树冠上部的枝条上.果鳞开裂至有种子与果鳞脱落...     

Immunohistochemical studies of cone photoreceptors and cells of the inner retina in feline rod-cone degeneration

Previous studies using electroretinography and immunohistochemistry have shown normal cone function and structure in early stages of hereditary rod‐cone degeneration of Abyssinian cats. To further investigate the cone photoreceptors and the inner retina of dystrophic cats, antibodies against green‐ and blue‐sensitive cones and specific cell types of inner retina were used in seven cats with the recessively inherited rod‐cone degeneration, and three normal European short‐haired cats. There was a reduction in number of both types of cones early in the disease. Changes at early stages of disease also occurred among horizontal cells in which there was an extension and a thickening of their lateral processes. The regular configuration of bipolar cells was changed in the more advanced stages of disease and their apical dendrites were lost. Abnormalities were not observed in the amacrine cells and in the ganglion cell layer in any of the present cases. This study shows that the cone system is morphologically abnormal in young cats at an earlier stage of disease than previously shown. The present findings also support the assumption that the inner retina is largely preserved throughout the disease process.     

播种深度对青藏铁路沙区植物白刺、油蒿、沙棘存活和生长的影响

研究了青藏铁路沙区植物白刺、油蒿、沙棘对不同播种深度的生长反应。结果表明:在播种2a和3a时,3种沙漠植物的成活率、植株高度和冠幅都随播种深度的增加而增加。油蒿在播种深度为6cm时的成活率最高,白刺在播种深度为2cm时植株高度最大,白刺的冠幅在播种深度为4cm时达到最大值。沙棘的植株高度和冠幅在播种深度为4cm时达到最大值。播种深度对白刺、沙棘和油蒿的存活和生长有显著的影响。研究结果对于青藏铁路沙区植被的人工恢复有一定的指导意义。     

Variation in Leaf Shapes of Nitraria Species and Effect on Leaf δ13C

Leaf shapes are not only the useful indicators in plant taxonomy,but also the important factors affecting energy and material exchange in leaves.In this paper,we collected and scanned the leaves of Nitraria tangutorum in Dengkou of Inner Mongolia Autonomous Region（the mean annual precipitation 145 mm） and Minqin of Gansu Province （the mean annual precipitation 115 mm） and N. sphaerocarpa in Dunhuang,and then analyzed leaf shape parameters with Image - Pro Plus6.0 image processing software and leafδ¹³C values in the isotope laboratory of the Chinese Academy of Forestry.The result showed that:1) as leaf area increased with increasing water availability the increases in the leaf length and width were asynchronously;2) with the same leaf width,the 1 eaves of N.tangutorum and N.sphaerocarpa were significantly longer in high water available conditions;and 3) although there were significantly differences in water availability between Dengkou and Minqin,as well as between the bottom and middle of the alluvial fan near the East Lake in Dunhuang,the leafδ¹³C values of N.tangutorum or N.sphaerocarpa were similar in different water conditions（P>0.05）.Our results suggested that the ratio of leaf perimeter to area would be an important factor which linked leaf shape to plant water physiology.During growing procedure of leaf area,leaf length increase was prior to its width to alleviate the reduction in ratio of perimeter to area and maintain water use efficiency of the plant.     

白刺枝叶生长对人工模拟降雨的响应

为揭示未来降水增加对荒漠地区植物生长的影响,以甘肃民勤的典型荒漠优势植物白刺为对象,研究白刺枝叶形态在2010年和2011年不同人工模拟降雨处理(增雨量分别为多年平均降水量的+0%、+25%、+50%、+75%、+100%)的变化规律。结果表明:100%增雨处理能够显著促进2010年和2011年白刺当年生枝叶生长;75%增雨处理显著促进2011年白刺当年生枝叶生长,75%增雨处理对6月花枝长度、基部直径、新生叶片和营养枝长度、新生叶片,以及9月花枝成熟叶片和营养枝基部直径、成熟叶片增长量的影响均显著,其值分别为(1.20±0.35)cm、(0.012±0.004)cm、(4.35±2.51)片、(1.65±0.69)cm、(3.20±1.45)片、(2.15±0.69)片、(0.013±0.006)cm、(2.20±1.10)片。2011年白刺当年生花枝和营养枝的长度、基部直径、新生叶片和成熟叶片增长量出现显著差异的阈值均低于2010年,这表明白刺能够通过改变其枝叶形态特性及其数量来适应降雨的变化。     

白刺光合生理特性对人工模拟增雨的响应

在乌兰布和沙漠东缘即内蒙古磴口县,利用Li-6400xt便携式光合测定系统分析仪测定不同增雨处理(4个增雨处理的增雨量分别是当地年降水量的25％、50％、75％和100％)条件下,典型荒漠植物白刺的光响应曲线,采用非直角双曲线模型对曲线进行拟合,计算最大净光合速率(Amax)、表观量子效率(AQY)、暗呼吸速率(Rd)、光补偿点(LCP)以及光饱和点(LSP)等生理参数,研究白刺光合生理特性对人工模拟增雨的响应.结果表明:对照的Amax、AQY、Rd、LCP和LSP分别为13.41 μmol·m-2·s-1、0.029 mol·mol-1、0.61 μmol·m-2·s-1、20.63 μmol·m-2·s-1和481.85 μmol· m-2·s-1.增雨使白刺的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、Amax、AQY和Rd升高,使水分利用效率(WUE)降低.增雨处理在一定程度上改变白刺的光合生理特性,提高白刺的光合生产能力.对胞间CO2浓度和气孔限制值的变化分析表明:气孔因素是限制光饱和阶段光合速率的主要因素.     

Variability of the seeds and cones and key taxonomic characters selection ofLarix in Northeast China

The paper presents the results of biometrical study of the seeds and cones of larch taxa from Northeast of China. Fourteen characters are considered and their analyses showed that the seeds and cones of the larch taxa were relative greatly variable. Cluster analysis and principal component analysis for all 6 larch taxa were made. The analysis results proved that the dominant larch population in Toudao Farm fell within the range of variation ofLarix olgensis. The key taxonomic characters are the length of seed wing, length of cone, length of seed, the length/width ratio of seed and number of scales. This research was supported by Natural Science Foundation of Heilongjiang Province.(C9515) Responsible Editor: Chai Ruihai     

不同类型白刺沙丘土壤理化性状与微生物相关性研究

利用民勤荒漠绿洲过渡带不同类型白刺沙丘的土壤微生物、土壤理化性状及二者之间的相关性进行研究,旨在探讨白刺沙丘的成土过程,为绿洲生态建设提供基础数据,结果表明,1)固定、半固定和流动沙丘粘粒、粉粒、细砂粒、粗砂粒含量差异较大;土壤养分含量与土壤粘粒、粉粒、细砂粒等细沙物质含量呈正相关性,与粗砂粒含量呈负相关性,表现为土壤养分含量随土壤颗粒的增大,相关性减弱。2)土壤微生物类群数量在半固定沙丘明显高于固定沙丘和流动沙丘。3)过渡带土壤均处于偏碱性状态,有机质、全氮、全磷、全钾、水解氮、速效钾、速效磷和CaCO₃含量随沙丘发育年代的增加逐渐增加。4)不同年代沙丘中土壤微生物和土壤理化因子均具较好的相关性,尤其是细菌和放线菌与pH值呈显著的负相关关系,土壤有机质含量与三大菌群数量都表现出显著的正相关关系。     

西伯利亚白刺肌动蛋白基因的分离与特性分析

利用兼并PCR及RACE技术克隆了西伯利亚白刺的肌动蛋白基因(Nitraria sibirica Actin, NsAct),并对其基因结构和表达特性进行了分析。所克隆的NsAct cDNA全长序列为1 831 bp,包含1 134 bp的开放阅读框,编码377个氨基酸;基因组DNA全长序列为2 913 bp,包含5个外显子和4个内含子。系统进化分析结果显示,NsAct与其他植物的肌动蛋白基因具有较高的同源性,与芒果(无患子目)亲缘关系最为接近。基因表达特性分析的结果显示,该基因在根、茎、叶中的表达量基本一致;在干旱、盐、低温及外源脱落酸胁迫下,表达量无明显变化,这些结果验证了该基因作为分子内标的可靠性。