Effects of deficit irrigation on daily and seasonal variations of trunk sap flow and its growth in Calligonum arborescens

Water deficit in arid and semiarid regions affects whole-plant sap flow and leaf-level water relations. The objectives of this study were to clarify how sap flow of Calligonum arborescens responds to different drought stress conditions and to understand its acclimation mechanism to drought environments. A field experiment was conducted for C. arborescens during the growing season to evaluate the effects of deficit irrigation on the daily and seasonal variations of trunk sap flow in the shelterbelt along the Tarim Desert Highway, Xinjiang, China. Three different water regimes (2,380, 1,960 and 1,225 m3 /hm2 ) were applied at different stages of plant growth. From 1 May to 30 October 2007, a heat-balance stem flow gauge was used to monitor the sap flow dynamics of C. arborescens under different water regimes. Atmospheric evaporation demand and soil moisture conditions for differentially irrigated C. arborescens were also monitored. The result showed that sap flow exhibited a clear diurnal pattern regardless of treatments; the diurnal patterns of sap flow and vapour pressure deficit were very similar under different water regimes and growing seasons, while the slope of the linear regression of this correlation confirmed an increasing water regime. The sap flow decreased under reduced water regimes and there was nocturnal sap flow regardless of water regimes, which was mainly contributed to nocturnal transpiration and water recharge. The sap flow peaked before midnight and dropped afterwards with obviously higher values in summer than in other seasons. It is speculated that the water consumption of C. arborescens during the day can be supplemented through the sap flow at night, which increased with increasing irrigation amount. Net radiation was the most significant correlated factor that influenced sap flow velocity and transpiration under different water regimes (R2 >0.719). Compared with the commonly practiced water regime, the growth of C. arborescens was significantly slower in the stress deficit irrigation, but not significantly different from that in the moderate deficit irrigation. The moderate deficit irrigation would not affect the stability of the shelterbelt and was a more efficient use of water resources compared with the current watering amount.     

延河流域 1997—2006 年林草植被减洪减沙效应分析简

根据延河流域长系列水文资料,对1997-2006年林草植被减洪减沙效应进行重点分析.结果表明：1）与基准期的1956-1969年相比,延河流域1997-2006年汛期降水、径流、输沙量分别减少了15.1％、45.6％和67.2％.截至2006年底,延河流域（含未控区）水土保持措施保存面积37万1 751 hm2,其中林草措施保存面积30万7 412hm2,占82.7％;2）延河流域1997-2006年林草植被年均减少洪水量2 885万m 3,年均减沙量1 695万t,分别占水土保持措施年均减洪减沙总量的63.6％和58.2％,其中林地减洪减沙效应最为明显,其减洪减沙量分别是草地和封禁治理措施减洪减沙量之和的4.9和4.7倍;3）1997-2006年延河流域林草植被减洪减沙上升趋势明显,林草植被与工程措施减洪量之比约为64％∶36％,减沙量之比约为58％∶42％.     

关于《伤寒论》与《金匮要略》课程整合的思考

本文从历史背景、内容的完整性、辨证论治体系、教学效果等方面分析《伤寒论》和《金匮要略》整合的可行性。同时提出可参考桂林古本和白云阁藏本版《伤寒杂病论》编写,或按总论、外感篇、杂病篇三部分编写,或按六经辨证、脏腑辨证、特色病种篇三部分编写等整合的建议,整合后有望改善现中医院校的《伤寒论》和《金匮要略》分开教学的不足, 将张仲景的医学思想更全面、准确、真实地呈现出来,更好地传承和发扬中医经典。     

高效液相色谱-串联质谱法测定水稻中多杀霉素的残留及消解动态

采用高效液相色谱-串联质谱(HPLC-MS/MS)建立了水稻中多杀霉素的残留分析方法。样品经乙腈提取,乙二氨基-N-丙基硅烷(PSA)和石墨化碳黑(GCB)净化,HPLC-MS/MS检测。结果表明:多杀霉素A在0.006 ~1.2 mg/L范围内线性关系良好,相关系数(R2)为0.990 5;多杀霉素D在0.001~0.2 mg/L范围内线性关系良好, R2 为0.994 9。多杀霉素A和D的检出限(LOD)在田水中均为0.001 mg/L,在稻田土壤、水稻植株、糙米、稻壳和稻杆中均为0.005 mg/kg;多杀霉素A和D的定量限(LOQ)在田水中均为0.005 mg/L,在稻田土及各水稻基质中分别为0.06和0.01 mg/kg。在添加水平为0.005~6.0 mg/kg范围内,稻田土壤、田水及水稻各基质中多杀霉素A和D的平均回收率为72.9%~107.9%,相对标准偏差( RSD )为1.7%~13.5%。采用该方法对多杀霉素在田间水稻中的消解动态和最终残留进行了测定。结果表明,多杀霉素在稻田土壤、田水和水稻植株样品中的消解均符合一级动力学方程,半衰期分别约为7.5、1.2和 4.8 d,属于易降解农药。     

转接方法和青霉素处理对葡萄试管苗芽孢杆菌抑制效应的研究

研究了用不同节位材料转接处理和不同浓度青霉素处理挽救在继代中被芽孢杆菌污染的葡萄试管苗的效果。结果表明，培养基灭完茵后未凝固时每升培养基中加入50ml 32万单位／L的青霉素钠溶液，能显著抑制芽孢杆菌发生，且试管苗生长正常。灭菌前加入青霉素的处理方法，虽对芽孢杆菌的抑制作用很强，但对试管苗的生长有明显抑制作用。经各种方法处理后获得的无芽孢材料，转接到改良B5培养基上均能正常生长且无芽孢再发生。     

pBⅠ121载体酶切位点添加及拟南芥Na~+/H~+逆向转运蛋白基因表达载体的构建

对pBI121载体GUS基因后的终止子序列(SacⅠ-EcoRⅠ)通过PCR扩增法进行了酶切位点的添加,即在SacⅠ后添加了XhoⅠ、在EcoRⅠ前添加了KpnⅠ。序列分析发现,两个酶切位点的添加是成功的,但扩增的终止子序列与原序列的同源性间有差异,即有4个碱基发生了变异,特别是第17个碱基位点出现了缺失。利用绿色荧光蛋白(GFP)对添加酶切位点载体进行了终止子活性的检测,结果发现,它与携带GFP的pBI121载体一样,GFP基因能正常表达,说明pBI121载体终止子序列酶切位点的添加是成功的。利用改造后的载体(pBI121-GZ)构建了CaMV35S启动子驱动AtNHX1基因的植物表达载体。     

春小麦杂种优势利用研究中的几个问题

我国的小麦杂种优势利用研究,开始于1965年,当时蔡旭教授从匈牙利引进美国的 T型不育系,掀起了全国性小麦杂优热潮,但由于 T 型恢复源窄、籽粒不饱满等原因,研究进展缓慢。K、Ven 等一些新型不育系的育成,又把该项研究从低谷推上了高潮。目前全国不少单位加入了小麦杂优利用的行例,其中大多致力于冬小麦杂优利用研究,但春小麦上进行杂     

太行鸡CYP19A1基因克隆及生物信息学分析

试验旨在克隆蛋鸡CYP19A1基因,对其遗传结构进行生物信息学分析并探究其在太行鸡不同组织中及不同产蛋量个体中的表达情况。以河北省太行鸡为研究对象,通过设计引物对CYP19A1基因CDS区进行克隆测序,运用生物信息学软件对其功能结构进行预测。结果显示,CYP19A1基因含有一个1 509 bp的开放阅读框（ORF）,编码502个氨基酸。同源性比对和系统发生树分析结果表明,太行鸡CYP19A1基因与鸭的同源性较高（90.7%）,并且在不同物种间高度保守。对CYP19A1蛋白理化性质进行预测分析发现,该蛋白为亲水蛋白,蛋白分子式为C₂₆₀₂H₄₁₀₃N₆₇₅O₇₁₉S₃₆,分子质量为57.51 ku,理论等电点为5.99,其中含量最高的是亮氨酸（为14.0%）。蛋白质二级结构由α-螺旋、延伸链、β-折叠及无规则卷曲4种结构组成,所占比例分别为58.95%、2.18%、3.93%和34.93%。组织表达谱分析发现,CYP19A1基因在不同组织中均有表达,但其在卵巢中表达量最高。实时荧光定量PCR结果显示,CYP19A1基因在太行鸡高产组卵巢中的表达量显著高于低产组（P<0.05）。上述结果为研究太行鸡CYP19A1基因提供了重要的研究数据,为进一步挖掘太行鸡高产基因提供了参考。     

关于机械传动效率的研究

对广义传动比提出新的定义概念,并用π及π°表示。导出了机械传动效率的普遍式η_(ab)=(π°_(ab))/(π_(ab))。用此公式对齿轮啮合进行研究,得到输出功A的表示式 A=T_a integral from n=A to R[(1-(1/R_a±1/R_b)·sinμ/cos(α+μ)·1]dφ。     

国营条山鸡场蛋鸡舍冬季的环境分析与评定

本文通过对条山现代化鸡场蛋鸡舍冬季几项小气候指标的观测与分析,说明该鸡舍建筑结构较合理,环境控制较好。由于主要小气候指标在环境卫生规定的范围内,所以舍内各列各层笼架上鸡的产蛋率均无显著差异。