偃麦草属植物苗期耐盐性指标筛选及综合评价

对10份自国外引进的野生偃麦草属种质材料在不同梯度NaCl胁迫下,测定存活率、K /Na 、丙二醛含量、脯氨酸含量等12项指标,进行相关分析、主成分分析、隶属函数法和通径分析。结果表明,1)筛选出存活率、K /Na 、丙二醛含量、脯氨酸含量、生长胁迫指数、相对生长速度6个可以对偃麦草属植物耐盐性进行评价的指标;2)根据耐盐综合评价值(D)得出材料耐盐性排序为ZXY04P-6>ZXY04P-210>ZXY04P-29>ZXY04P-490>ZXY04P-176>ZXY04P-103>ZXY03P-271>ZXY04P-157>ZXY03P-444>ZXY03P-289;3)10个材料的耐盐性预测值(VP)与综合评价值(D)极显著相关。     

大熊猫肝脏分离病毒部分特性的研究

电镜观察磷钨酸负染的大熊猫肝脏分离病毒细胞培养物,发现冠状病毒样粒子.细胞培养物超薄切片上可见细胞浆内病毒包涵体.理化学和生物学特性研究结果表明,病毒对氯仿、乙醚敏感,可耐受1 %胰蛋白酶的作用,具有一定的耐酸性和耐热性;病毒对FCWF细胞敏感,对Vero细胞不敏感,无血凝性和血吸附特性.采用犬冠状病毒阳性血清,经中和试验确定该分离病毒是一株犬冠状病毒,命名为CCV DXMV.以犬冠状病毒特异性PCR引物,可以从大熊猫肝脏组织和不同代次的病毒细胞培养物中,扩增出目的核苷酸片断.序列分析结果表明,该株病毒部分纤突蛋白基因序列与分离自美国的CCV NVSL株相应基因序列的同源性高达100 %.     

几种寡糖类物质对菜薹矿质养分吸收的影响

采用溶液培养,研究了几种寡糖类物质(海藻酸钠及其寡糖、寡聚半乳糖醛酸和壳寡糖)不同施用浓度(0、10、20、50、100 mg·L^-1)对菜薹（心）矿质养分吸收的影响。结果表明：海藻酸钠及其寡糖和寡聚半乳糖醛酸低浓度处理可显著促进菜薹对氮、磷、钙、镁、硼、锰、锌的吸收,低浓度时寡聚半乳糖醛酸对菜薹钾吸收也有一定的促进作用;高浓度时,三者处理效果均不明显,且各浓度处理对菜薹铜吸收也无显著促进作用。壳寡糖低浓度时对菜薹氮、镁、硼、铜、锌的吸收有一定的促进作用;高浓度时引起铜的大量吸收,同时抑制菜薹氮、磷、钾、镁、锰的吸收及钙由地下部向地上部转运。     

Molding process influence on pull-off performance of composite stiffened panels

Two types of molding process of composite stiffened panels which are co-curing and secondary-bonding are investigated, and pull-off experiment was designed to obtain the load-carrying capability and failure modes. The results show that the main failure mode of the secondary-bonded composite stiffened panels is adhesive debonding between the skin and stiffener. The failure mode of co-cured stiffened panels is complex, which includes skin-stiffener debonding, fiber damage, delamination and so on. The performances of the co-cured stiffened panels are better than that of secondary-bonded stiffened panels. The debonding initiation and propagation were simulated by using the nonlinear finite element method. Using user subroutine and cohesive interface, Hashin and B-K failure criterion were applied to simulate co-cured stiffened panels and secondary-bonded stiffened panels respectively, and the simulation results agreed well with experimental results.     

犬瘟热病毒小熊猫株H、F和N基因的克隆及表达

根据GenBank中发表的犬瘟热病毒（CDV）的核苷酸序列，设计并合成了扩增CDVH、F和N基因的3对引物，经RT—PCR分别扩增获得了CDV小熊猫株（LP株）H、F和N基因，并对H、F及N基因进行了克隆和序列测定。序列分析表明，CDV LP株属于强毒谱系，与CDV流行株的亲缘关系近．H基因含有较多潜在的糖基化位点．F和N基因相对比较保守。将CDV LP株H、F和N基因克隆入真核表达栽体pVAX1的CMV启动子下游，构建了CDV基因疫苗表达载体pVAXLPH、pVAXLPF、pVAXLPN，体外转染BHK-21细胞．用间接ELISA方法检测到目的蛋白的表达。用构建的3个表达质粒免疫小鼠，从小鼠血清中检测到了抗CDV抗体．初步证实用CDVH、F和N基因作为核酸疫苗免疫动物，可以激活机体的免疫应答。     

十二卷属植物的生长环境与光照要求

百合科(Liliaceae),十二卷属(Haworthia)植物是一类形态优美、具有很高的观赏价值的植物,是多年来行业栽培者和众多的爱好者寻求的珍贵观赏种类.此类植物虽然属于多肉植物,但是由于原产地环境气候的特殊,再加上具有肥大的营养根,在长江流域栽培具有高温和低温休眠性的特性.现以工作积累为依据,以植物原产地的气候特征、生长习性、形态特点及其生物学特性阐述此类植物在我国部分地区的栽培和保存.     

California Simulation of Evapotranspiration of Applied Water and Agricultural Energy Use in California

The California Simulation of Evapotranspiration of Applied Water (Cal-SIMETAW) model is a new tool developed by the California Department of Water Resources and the University of California, Davis to perform daily soil water balance and determine crop evapotranspiration (ET c ), evapotranspiration of applied water (ET aw ), and applied water (AW) for use in California water resources planning. ET aw is a seasonal estimate of the water needed to irrigate a crop assuming 100% irrigation efficiency. The model accounts for soils, crop coefficients, rooting depths, seepage, etc. that influence crop water balance. It provides spatial soil and climate information and it uses historical crop and land-use category information to provide seasonal water balance estimates by combinations of detailed analysis unit and county (DAU/County) over California. The result is a large data base of ET c and ET aw that will be used to update information in the new California Water Plan (CWP). The application uses the daily climate data, i.e., maximum (T x ) and minimum (T n ) temperature and precipitation (P cp ), which were derived from monthly USDA-NRCS PRISM data (PRISM Group 2011) and daily US National Climate Data Center (NCDC) climate station data to cover California on a 4 km×4 km change grid spacing. The application uses daily weather data to determine reference evapotranspiration (ET o ), using the Hargreaves-Samani (HS) equation (Hargreaves and Samani 1982, 1985). Because the HS equation is based on temperature only, ET o from the HS equation were compared with CIMIS ET o at the same locations using available CIMIS data to determine correction factors to estimate CIMIS ET o from the HS ET o to account for spatial climate differences. Cal-SIMETAW also employs near real-time reference evapotranspiration (ET o ) information from Spatial CIMIS, which is a model that combines weather station data and remote sensing to provide a grid of ET o information. A second database containing the available soil water holding capacity and soil depth information for all of California was also developed from the USDA-NRCS SSURGO database. The Cal-SIMETAW program also has the ability to generate daily weather data from monthly mean values for use in studying climate change scenarios and their possible impacts on water demand in the state. The key objective of this project is to improve the accuracy of water use estimates for the California Water Plan (CWP), which provides a comprehensive report on water supply, demand, and management in California. In this paper, we will discuss the model and how it determines ET aw for use in water resources planning.     

白浆土微量元素含量及形态分布的研究

1992~2001年对三江平原白浆土部分微量元素进行了研究。长期定位试验表明,白浆土Fe、Mn、Cu、Zn全量处于中等或以下水平,而有效态含量均较高;形态分布上,Fe、Mn、Zn以残留态和铁锰结合态为主,Cu以残留态和有机态为主,其它形态均较低。长期种植下,形态间发生了不同程度的改变。     

不同调理剂对猪粪堆肥腐殖质特性及元素含量变化的影响

分别以木屑、泥炭及水葫芦作为猪粪堆肥的调理剂，制作有机堆肥，研究了3种堆肥体系在堆肥进程中腐殖酸（HA＋FA）及其组成、腐殖化指数（HI=HA／FA）、pH的变化过程，以及堆制前后1mol／L NH4Ac-0．05mol／L EDTA浸提态金属离子含量的变化。在此基础上讨论了HI、pH和阳离子交换量（CEC）之间的关系。结果表明，在整个堆肥制作中，HA＋FA和HA均呈现先下降后上升再稳中有降的趋现势，总体表现为增加；HI则上升明显，这些是堆肥腐熟和品质提高的重要表；pH变化因调理剂的不同而有较大的差异；除重金属Cr外，1mol／L NH4Ac-0．05mol／L EDTA浸提的绝大部分金属离子含量堆制后均有增加，3种堆肥增加幅度的顺序为：猪粪＋水葫芦〉猪粪＋木屑〉猪粪＋泥炭；堆制前后pH和HI的变化与堆制前后CEC变化分别呈较好的正相关和负相关，它们可以作为堆制前后交换态金属元素含量变化的指示指标。     

冬季覆盖作物秸秆还田对水稻植株养分积累与转运的影响

为明确双季稻区不同冬季覆盖作物秸秆还田对后茬水稻植株干物质和养分积累与分配的影响,选择不同冬季覆盖作物-双季稻种植模式为研究对象,采取田间小区定位试验,以冬闲-双季稻种植模式为对照(CK),开展了黑麦草-双季稻(Ry-R-R)、紫云英-双季稻(Mv-R-R)、油菜-双季稻(Ra-R-R)和马铃薯-双季稻(Po-R-R)种植模式下不同冬季覆盖作物秸秆还田后对后茬水稻各部位干物质和氮、磷、钾积累与分配影响的研究。结果表明：早稻成熟期,Po-R-R处理茎、叶物质贡献率均高于其他处理;晚稻成熟期,Ra-R-R处理的茎、叶物质转运率和物质贡献率均高于其他处理。早稻成熟期,Mv-R-R处理水稻植株穗和地上部分的氮素和磷素积累量均显著高于CK处理（P<0.05）;各秸秆还田处理水稻植株茎和地上部分的钾素积累量均显著高于CK处理（P<0.05）。晚稻成熟期,Po-R-R处理叶、穗和地上部分的氮素和磷素积累量均显著高于CK处理（P<0.05）。Mv-R-R处理穗和地上部分的钾素积累量均显著高于Ry-R-R、Ra-R-R和CK处理（P<0.05）。总的来说,各冬季覆盖作物秸秆还田措施均促进了水稻各部位干物质积累和转运;其中以紫云英秸秆还田处理有利于水稻群体养分的积累与转运。