林木遗传工程及木质素的生物合成调节(英文)

林木遗传工程有利于保存林木遗传资源，改善全球气候，减轻自然林的过度采伐和满足人类日益增长的林木产品需求。控制林木真菌、病毒病、虫害和杂草的遗传工程方法正被广泛地研究和应用。尽管转基因林木的历史不长，种类不多，但它有广泛的应用前景。目前，抗除草剂基因、抗虫基因以及和木材质量相关的基因已被分离并应用于林木遗传工程。植物分子生物学和基因组学中的新技术使得高效林木遗传改良成为可能并将促进这些技术的商业化应用。木质素的应用已有一百年的历史，但木质素生物合成的全过程并不完全清楚。有关松树自然突变体和转基因林木的最新研究结果表明，木质素的生物合成是一个可以调节的过程。这些发现对完善木质素的生物合成途径、加深对木质素前体生物合成途径的理解和通过遗传工程改善木材质量有促进作用。本文综述了林木遗传工程在这些领域中取得的一些进展。     

植物基因捕获系统及其应用研究进展

随着人类和其他一些重要动、植物序列数据的快速积累,我们面临着如何鉴定这些序列数据所代表的生物学功能的巨大挑战。基因捕获技术是一种产生大规模基因突变的便利手段,对于揭示大量基因序列所对应的基因功能具有重要应用价值。本文介绍了植物中的基因捕捉系统及其在植物分子生物学研究中的应用。     

工能基因组学:T-DNA介导的基因诱捕和植物基因鉴定(英文)

拟南芥菜、水稻、蕃茄、土豆、玉米、小麦和大豆的全基因组测序为植物细胞和发育生 物学研究提供了许多有用的信息。基因组学的中心任务是利用这些信息去探索蛋白质的功能 和鉴定与发育有关的重要基因。尽管依赖于毁坏基因和产生可识别的突变表型的经典遗传学 方法仍然是极为成功的基因鉴定方法，借助于报告基因结构，随机插入植物基因组的T-DNA 介导的基因诱捕正发展成为植物细胞和发育生物学研究的极强有力的技术。本文描述了基因 诱捕、启动子诱捕和增强子诱捕在植物生物学中的应用，并且希望这些基因鉴定方法有助于 植物分子生物学家和生物技术工作者的研究。     

Altitudinal and longitudinal variations in Pinus brutia (Ten.) of Crete Island,Greece: some needle,cone and seed traits under natural habitats

Four populations representing the entire natural distribution range of Pinus brutia (Ten.) in Crete (Greece) were sampled to determine: (1) Altitudinal variation within populations of Lassithi, Vorizia, Koustagerako, and Samaria, and; (2) Longitudinal variation among the four populations, based on morphological and anatomical differences in cone, needle and seed characteristics. Samples were collected from 10 trees per altitude, at three altitudes in each population. A total of 12 morphological and anatomical traits from needles, cones and seeds were analyzed to assess the altitudinal and longitudinal variations of the species in the island. The number of teeth per cm showed significant (P<0.01) differences between altitudes in Samaria, Vorizia and Lassithi, while needle length, width and the number of resin canals showed significant differences (P<0.01) between altitudes in Koustagerako. Cone width showed patterns of variation along the altitudinal gradient in Koustagerako, Samaria and Vorizia. Most traits had their highest means at the middle altitudes (650masl) in all the four populations. Overall, no clear altitudinal differentiation was detected, probably due to high rate of gene flow. Longitudinal variability showed a clear pattern of differentiation along the east–west climatic gradient. Needle length, width, sheath length, number of teeth per cm and the number of resin canals were the most useful traits for determining the climatic gradient clines.     

The feasibility of using variable rate water application under a central pivot irrigation system

The purpose of this paper was to assess the feasibility and significance of applying spatially variable irrigation under a central pivot system at the Federal German Agricultural Research Center, Braunschweig, Germany. The assessment was based on soil moisture holding capacity, soil depth variation and root development. Soil texture analysis was carried out by sampling on a 60 meter grid. The German Agro-Meteorological Model was applied to simulate the water balance in the crop-soil-atmosphere system for the growing season 2003/4. The research findings are presented in terms of six scenarios: 20, 30, 40 mm water application depths per irrigation under both variable rate application and uniform application. The comparison revealed that the loss of water was higher for the uniform application scenarios than that for the variable rate application (VRA) scenarios for the applications of 20 and 30 mm. The VRA scenario of 20 mm water application was found out to be the best option for water conservation.     

Enhancing the Simplified Surface Energy Balance (SSEB) approach for estimating landscape ET: Validation with the METRIC model

Evapotranspiration (ET) can be derived from satellite data using surface energy balance principles. METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is one of the most widely used models available in the literature to estimate ET from satellite imagery. The Simplified Surface Energy Balance (SSEB) model is much easier and less expensive to implement. The main purpose of this research was to present an enhanced version of the Simplified Surface Energy Balance (SSEB) model and to evaluate its performance using the established METRIC model. In this study, SSEB and METRIC ET fractions were compared using 7 Landsat images acquired for south central Idaho during the 2003 growing season. The enhanced SSEB model compared well with the METRIC model output exhibiting an r² improvement from 0.83 to 0.90 in less complex topography (elevation less than 2000 m) and with an improvement of r² from 0.27 to 0.38 in more complex (mountain) areas with elevation greater than 2000 m. Independent evaluation showed that both models exhibited higher variation in complex topographic regions, although more with SSEB than with METRIC. The higher ET fraction variation in the complex mountainous regions highlighted the difficulty of capturing the radiation and heat transfer physics on steep slopes having variable aspect with the simple index model, and the need to conduct more research. However, the temporal consistency of the results suggests that the SSEB model can be used on a wide range of elevation (more successfully up 2000 m) to detect anomalies in space and time for water resources management and monitoring such as for drought early warning systems in data scarce regions. SSEB has a potential for operational agro-hydrologic applications to estimate ET with inputs of surface temperature, NDVI, DEM and reference ET.     

Transplantation of bcl-2 gene-modified bone marrow mesenchymal stem cells improves cardiac function and angiogenesis in rabbit ischemic car-diac insufficiency model

AIM: To investigate the effects of transplantation of bone marrow mesenchymal stem cells (BMSCs) modified by bcl-2 gene on myocardial cell apoptosis, angiogenesis and cardiac function in the rabbit after acute myocardial infarction (MI).METHODS: The rabbit BMSCs were isolated, cultured and purified in vitro. The BMSCs were transfected with adenovirus or adenovirus-Bcl-2. The rabbit model of MI was established by ligation of left anterior descending branch. The rabbits were injected with Ad-Bcl-2-BMSCs (MI+Bcl-2-BMSCs group), Ad-BMSCs (MI+BMSCs group) and DMEM (MI group) in infarction marginal zone 2 weeks after ligation. The cardiac function was evaluated by echocardiography.The apoptosis of myocardial cells was measured by TUNEL. The mRNA expression of VEGF was detected by real-time PCR. The expression of CD31 was examined by immunohistochemical staining, and new blood capillaries were counted at 4 weeks after BMSCs transplantation. The correlation of the above values with cardiac function was analyzed.RESULTS: The cardiac function was better, the apoptotic rate was lower, the mRNA expression of VEGF and the capillary density were higher in both MI+Bcl-2-BMSCs group and the MI+BMSCs group than those in MI group, and those in MI+Bcl-2-BMSCs group increased more obviously.The left ventricular ejection fraction (LVEF) had a negative correlation with the myocardial cell apoptosis rate. A positive correlation with the mRNA expression level of VEGF and the capillary density was also observed.CONCLUSION: The transplantation of BMSCs modified by bcl-2 gene significantly reduces the myocardial cell apoptosis, promotes angiogenesis, improves heart function of the rabbits with MI.     

用于黄瓜白粉病抗性鉴定的InDel标记

根据黄瓜白粉病抗性主效基因/QTL的插入/缺失突变,将其设计成共显性的In Del分子标记。通过群体连锁分析,发现In Del-MLO1标记与黄瓜白粉病抗性主效基因共分离。应用该标记对24份来自世界各地且白粉病抗性已知的黄瓜材料进行抗性验证,21份材料的抗性表型与标记的带型一致,说明在黄瓜进化和驯化过程中,造成抗病表型的该插入/缺失突变发生普遍。因此,该In Del标记适合于大多数黄瓜材料的白粉病抗性鉴定和分子标记辅助育种,从而加快黄瓜白粉病抗病育种的进程。     

土壤微生物DNA木聚糖酶基因多样性的研究

采用国产硅胶Gk254（60型）代替进口Glass bead的改良方法抽提土壤微生物DNA，然后设计了一对扩增木聚糖酶基因片段的新简并引物，对抽提的土壤微生物DNA进行PCR扩增。扩增片段连接pMD18T载体，转化大肠杆菌，重组片段通过酶切进行RFLP分析后，测序分析得到10个木聚糖酶基因片段。对所得片段翻译的氨基酸序列进行BLAST分析表明有8个片段与来自放线菌的木聚糖酶具有较高的同源性，2个与假单胞菌的木聚糖酶具有较高的同源性。所得10个木聚糖酶片段的氨基酸序列同源性比较显示，第27个氨基酸均为天冬酰胺（N），暗示这些来自土壤微生物DNA的基因片段编码耐碱的木聚糖酶。通过构建系统进化树，发现扩增的木聚糖酶片段之间的相似性均在70％以上。     

鲍分子遗传学研究进展

阐述了近年来鲍分子遗传学方面的研究进展,总结了核型分析、等位酶、微卫星和小卫星、随机扩增多态性DNA、限制性片断长度多态性、线粒体DNA、表达序列标签研究和基因序列等技术在鲍种群遗传多样性、遗传分化、遗传结构及种质鉴定等方面的应用。并指出今后应加强鲍蛋白质组学、功能基因组学、遗传连锁图谱、数量性状基因座和标记辅助选择等方面研究。