基于景观图论和生物能学的景观演变分析方法

探讨将景观格局分析的结果应用于景观规划与管理实践,对维护区域生态安全有着重要的理论和实践意义。本文以苏州水岸带景观为例,尝试整合景观图论和生物能学理论,形成一种简单、直观且高效的景观演变分析方法,从生态视角评估土地利用变化的影响,为可持续的景观规划和管理提供决策依据。在ArcGIS支持下,以4期GoogleEarth图像为基础数据,绘制出景观图示;分析节点和连线数量、类型和空间形态的变化以追溯景观的变化历程,阐释图示的生态学含义。结果表明,苏州水岸带景观出现明显的破碎化、自然景观连通性显著降低、细小水系消失以及水岸缓冲带缺乏等问题,对关键生态节点和连线的识别,可以有针对性地保护自然景观元素,平衡保护与开发的矛盾。     

干旱胁迫和CO2浓度升高条件下白羊草的光合特征

采用盆栽控制试验,研究了黄土丘陵区乡土种白羊草在不同水分水平(80%FC和40%FC)和CO₂浓度(375和750 μmol·m^-2·s^-1) 处理下的光合生理变化特征.结果表明： 干旱胁迫使白羊草的最大净光合速率(P_nmax)、表观量子效率(AQE)、气孔导度(g_s)、蒸腾速率(T_r)、最大光化学效率(F_v/F_m)、潜在光化学效率(F_v/F_o)和光合色素含量降低,丙二醛(MDA)和脯氨酸(Pro)含量升高.水分充足条件下,与正常大气CO₂浓度相比,大气CO₂浓度倍增下白羊草的P_{n max}、MDA和Pro含量无显著差异.干旱胁迫下,CO₂浓度升高提高了白羊草的最大荧光(F_m)、F_v/F_m、F_v/F_o、叶绿素含量和AQE, P_nmax比正常CO₂浓度下高23.3%,差异达到显著水平,而MDA和Pro含量均显著降低.CO₂浓度升高对干旱胁迫引起的白羊草光合能力下降有一定的补偿作用,减轻了干旱胁迫对白羊草的伤害.     

K14和CMV启动子驱动裸鼠体内HPV16 E6/E7基因表达的差异

人乳头瘤病毒（human papillomavirus,HPV）是一种无包膜的环状闭合双链DNA病毒,具有严格的嗜人组织的特性．为探讨不同启动子驱动HPV E6/E7癌蛋白在裸鼠体内不同组织的表达效率,构建了带有角蛋白(K14)启动子和带有巨细胞病毒（CMV）启动子的E6/E7腺病毒载体（pAd-K14-E6/E7和pAd-CMV-E6/E7）,pAd-K14-E6/E7和pAd-CMV-6/E7、以及作为对照的重组腺病毒空载体pAdtrack- K14和pAd-CMV同源重组后,分别在293细胞中包装,收集重组病毒Ad-K14-E6/E7 、Ad-CMV-E6/E7、Adtrack-K14和Ad-CMV,通过尾缘静脉注射到随机分组的裸鼠体内,并每d向裸鼠腹腔注射0.05 mg雌激素．采用RT-PCR和Western 免疫印迹检测不同实验组E6/E7 mRNA 和蛋白表达水平,免疫组化法检测P53和Bcl-2蛋白表达．结果显示,注射病毒Ad-K14-E6/E7（实验组1）裸鼠子宫体中E6/E7 mRNA、E6蛋白质、P53和Bcl-2蛋白高表达,而其它组织中低表达;注射病毒Ad-CMV-E6/E7（实验组2）裸鼠各组织E6/E7　mRNA、E6蛋白质、P53和Bcl-2蛋白均低表达．研究表明,在裸鼠体内角蛋白K14启动子可以调控E6/E7在子宫体中表达,CMV启动子未能诱导E6/E7在子宫体中表达．     

人血小板生成素全长分子在酵母系统中的分泌表达及活性分析

外源基因可通过整合型载体被整合到毕赤酵母（Ｐｉｃｈｉａｐａｓｔｏｒｉｓ）染色体上,获得遗传性稳定分泌表达株．利用酵母信号肽ＭＦα,对该信号肽蛋白酶识别位点的相关序列进行重新设计,使天然人ＴＰＯ成熟肽在毕赤酵母系统中分泌表达成功．表达产物经Ｗｅｓｔｅｒｎ－ｂｌｏｔ进行分析,分子量约为６６ｋＤ处蛋白条带可被ＴＰＯ抗体识别;表达量约为０．１ｇ／Ｌ;Ｎ端氨基酸序列分析结果与设计的一致;表达产物对小鼠骨髓细胞形成巨核细胞集落形成单位（ｍｅｇａｋａｒｙ－ｏｃｙｔｅｃｏｌｏｎｙｆｏｒｍｉｎｇｕｎｉｔ,ＣＦＵ－Ｍｅｇ）具有明显的刺激作用．     

莎车巴旦姆物候期对气象条件的响应及花期预测模型

利用莎车县农业气象试验站2008—2013年巴旦姆物候期和同期气象观测资料,分析了巴旦姆物候期的变化特征以及气温、日照时数对物候期的影响.结果表明：巴旦姆花期之前的物候期始日之间均呈正相关,与花期之后的物候期始日的相关性大多较小,花芽膨大早迟与休眠期、生长期天数分别呈极显著的正相关和负相关.以果实成熟期为界,气温对之前、之后物候期间隔日数的影响分别为负相关和正相关,日照时数与物候期间隔日数大多为正相关.果实成熟 叶变色始期间隔日数对平均最高气温以及花序出现 开花末期、叶变色始期 落叶末期间隔日数对日照时数存在明显的响应.当巴旦姆休眠期符合日平均气温-3.0～-7.5 ℃的天数满30 d后,经过17～28 d将进入花芽萌动期.花芽萌动期、开花始期、叶变色始期和落叶末期的始日分别与首个候平均气温≥4 ℃且候平均最高气温≥12 ℃、春季侯平均气温≥14 ℃且侯平均最高气温≥22 ℃、秋季首个侯平均气温≤10 ℃且侯平均最高气温≤18 ℃和冬季首个侯平均气温≤1.9 ℃的候序一一对应.利用偏最小二乘法回归分析,建立巴旦姆盛花期始日预测模型,经过检验模型效果较好.     

Use of polymerase chain reaction to detect the soft rot pathogen,Pythium myriotylum,in infected ginger rhizomes

AIMS: The aims are to establish a polymerase chain reaction (PCR)-based method for detecting Pythium myriotylum in the rhizome of ginger and diagnosing ginger soft rot and screening health seed ginger. METHODS AND RESULTS: A booster PCR method was established for detection of P. myriotylum using a specific primer selected from rDNA ITS1 region coupled with universal primer ITS2. It successfully applied to the detection of P. myriotylum in naturally infected ginger rhizomes but not from DNA of ginger rhizomes collected from field without target fungus. CONCLUSIONS: A specific method for detecting P. myriotylum was achieved. SIGNIFICANCE AND IMPACT OF THE STUDY: The new PCR method has allowed us to monitor ginger for the presence of P. myriotylum as a way of disease diagnosis or healthy seed ginger examination.     

人肝金属硫蛋白-I_A基因在鱼腥藻中的克隆与表达

将人工合成的人肝金属硫蛋白（ｍｅｔａｌｏｔｈｉｏｎｅｉｎ,简称ＭＴ）－ＩＡ基因插入至中间载体ｐＲＬ－４３９上强启动子ｐｓｂＡ后,再将其与穿梭载体ｐＫＴ－２１０相连,得到大肠杆菌－蓝藻穿梭表达载体ｐＫＴ－ＭＴ,用三亲接合转移法将ｐＫＴ－ＭＴ转入丝状体蓝藻－鱼腥藻７１２０,经链霉素筛选,得到了稳定的转人肝ＭＴ－ＩＡ基因鱼腥藻．纯化单藻落,液体扩大培养．从鱼腥藻中提取的质粒经Ｓｏｕｔｈｅｒｎ印迹分析,确定人肝ＭＴ－ＩＡ基因已转入鱼腥藻７１２０中,Ｗｅｓｔｅｒｎ印迹分析表明,金属硫蛋白在转人肝ＭＴ－ＩＡ基因鱼腥藻中得到了表达．经原子吸收光谱法测定表达量约为７００μｇＭＴ／ｇ鲜藻,重金属耐受性实验表明,得到了能耐受重金属－镉的转人肝ＭＴ－ＩＡ基因鱼腥藻,它将在清除水域中重金属污染和医药研究方面发挥重要作用．     

Ultrastructural Study of Secondary Wall Formation in the Stem Fiber of Phyllostachys pubescens

Ultrastructural changes in secondary wall formation of Phyllostachys pubescens Mazel fiber were investigated with transmission electron microscopy. Fiber developed initially with the elongation of cells containing ribosomes, mitochondria and Golgi bodies in the dense cytoplasm. During the wall thickening, the number of rough endoplasmic reticulum and Golgi bodies increased apparently. There were two kinds of Golgi vesicles, together with the ones from endoplasmic reticulum formed transport vesicles. Many microtubules were arranged parallel to the long axis of the cell adjacent to the plasmalemma. Along with the further development of fiber, polylamellate structure of the secondary wall appeared, with concurrent agglutination of chromatin in the nucleus, swelling and disintegration of organelles, while cortical microtubules were still arranged neatly against the inner side of plasmalemma. Lomasomes could be observed between the wall and plasmalemma. The results indicated that the organelles, such as Golgi bodies together with small vesicles, rough endoplasmic reticulum and lomasomes, played the key role in the thickening and lignification of the secondary wall of bamboo fiber, though cortical microtubules were correlative with the process as well.