糖在苹果果实中卸载机制的研究

在建立了活体研究苹果果实糖卸载体系－“卸载穴技术”的基础上，对金冠苹果果实糖迅速积累期糖卸载的生理机制进行了研究。１ｍｍｏｌ／Ｌ ＰＣＭＢＳ，１ｍｍｏｌ／Ｌ ＤＮＰ，１ｍｍｏｌ／Ｌ ＥＢ和８００ｍｍｏｌ／Ｌ Ｂｅｔａｉｎｅ明显抑制苹果果实糖的卸载，１０＾－５ｍｏｌ／Ｌ ＡＢＡ，５ｍｍｏｌ／Ｌ ＥＧＴＡ和５０／Ｌ ＮＯ＾－３明显促进苹果果实糖的卸载。     

饲喂不同日粮的山羊尿沉渣晶体的化学组成和显微形态

采集饲喂棉饼、玉米粉、麸皮、豆饼四种常见日粮的山羊尿样，应用化学定性分析、Ｘ－射线衍射物相分析、Ｘ－射线能谱分析和扫描电子显微镜观察等手段分别进行尿沉渣晶体的化学组成和显微形态的分析和观察。结果表明，饲喂棉饼日粮和麸皮日粮时山羊尿沉渣晶体的化学组成为磷酸钾镁，显微开矿为斜方柱状；饲喂玉米日粮时为碳酸镁，形态为长方柱状；饲喂豆饼日粮时为碳酸钙（方解石），形态为短方柱状。最后，还对几种尿沉渣晶体的生成     

QTLs and candidate genes for chlorate resistance in rice (Oryzasativa L.)

Chlorate resistance is one of the reliable characters in Indica/Japonica classification. To understand the genetic basis of chlorate resistance is very important for revealing the evolutionary mechanism of Indica/Japonica differentiation. In this study, a doubled haploid (DH) population derived from anther culture of ZYQ8/JX17, a typical Indica and Japonica hybrid, was used as the genetic material to investigate chlorate sensitivity of the parents and DH lines. The quantitative trait loci (QTLs) of chlorate resistance were analyzed based on the molecular linkage map of this population. Total of 3 QTLs (qCHR-2, qCHR-8 and qCHR-10) for chlorate resistance were detected on chromosomes 2, 8 and 10, respectively. A QTL × QTL epistatic interaction was detected between qCHR-2 and qCHR-10. Genes involved in nitrogen assimilation, such as nitrate reduction, molybdenum cofactor biosynthesis and nitrate transport were strong candidates of QTLs for chlorate resistance. A putative nitrate reductase gene (8611.t00011), and two putative nitrate reductase genes (9319.t00010 and 9319.t00012) were in the genomic region of qCHR-2, and qCHR-8, respectively, and a putative nitrate transporter gene (756.t00011) was in the region of qCHR-10. The expression of 8611.t00011, 9319.t00010 and 756.t00011 were confirmed by the corresponding cDNAs, and 2 in/del and 12 SNPs in the coding regions of these three genes were found between Indica (cv. 9311) and Japonica (cv. Nipponbare) in silico. These results indicated that these three genes were candidates of the chlorate resistance QTLs. An in/del in the coding region of 8611.t00011 was used to develop a new PCR marker. A polymorphism was detected between JX17/Nipponbare and ZYQ8/9311. This polymorphism corresponds to the chlorate sensitivity of Nipponbare and 9311. This marker was located between Y8007R and RM250 on chromosome 2 in the DH population, where qCHR-2 was also located.     

Numerical Simulation of Elastoplastic Multi-scales Model for Magnesium Alloy Under Tensile Load

In order to investigate the macroscopical mechanical performance of magnesium alloy material containing pore and the mechanism during distorting destructing, an accurate finite element model of magnesium alloy using the multiscales method was developed, and the macroscopic properties of material under the macroscopic tensile load using the developed constitutive model of multi-scales and finite element method was obtained. By analyzing the distortion results of meso-model through the multi-scales method, with macroscopical load increasing, the difference demonstrated on the macroscopic is very small, however, with the increase of the load step, the phenomenon that the ability of plasticity deformation of the meso-models which includes the cuboid pore decreased gradually remarkable and the phenomenon of stress centralized is more severity than the meso-models including cylindrical pore could be obviously observed during the process of deformation on the meso-models.     

缺镁胁迫对龙眼苗期氮代谢的影响

采用溶液培养方法研究了缺镁胁迫对龙眼苗期氮代谢的影响。结果表明 ,缺镁胁迫下 ,龙眼叶片硝酸还原酶 (NR)活性下降 ,游离氨基酸总量增加 ,水解氨基酸总量减少 ,蛋白质合成受阻而分解加剧 ;核酸酶 (RNase)活性提高 ,核糖核酸 (RNA)、脱氧核糖核酸 (DNA)含量降低 ,缺镁对RNA的影响比DNA大 ;活性氧 (O2-)净产生速率增加。统计分析表明 ,缺镁胁迫下 ,龙眼核酸和蛋白质含量下降是其合成受阻、分解加剧以及活性氧毒害综合作用的结果     

接种丛枝菌根真菌对小麦根内氮转运蛋白基因表达的影响

通过盆栽试验,研究了在低氮(不施氮)和高氮(施氮0.2 g·kg~(-1))水平下接种不同种类丛枝菌根(AM)真菌[Funneliformis mosseae(BGC-NM03D)、Claroideoglomus etunicatum(BGC-NM01B)和Rhizophagus intraradices(BJ09)]对小麦生长、氮吸收及根内4个硝态氮转运蛋白(NRT)基因、1个辅助蛋白(NAR)基因和2个铵态氮转运蛋白(AMT)基因表达的影响。结果表明,3种AM真菌均能够侵染小麦根系,以R.intraradices菌根的侵染率最高;接种R.intraradices或C.etunicatum能够显著提高小麦的生物量或地上部氮吸收量;无论是高氮还是低氮处理,接种AM真菌后均显著下调了小麦根内NRT、NAR和AMT基因的表达水平,且不同AM真菌调控小麦根内氮转运蛋白基因表达的能力具有明显差异。     

缺镁对龙眼光合产物生产和分配的影响

缺镁对龙眼 (DimocarpusLonganaLour.)光合产物的生产和分配有明显的影响。缺镁胁迫下 ,龙眼叶片单位面积和单位重量的叶绿素、类胡萝卜素含量均降低 ,光合速率下降 ,叶绿体亚显微结构发生明显的改变 ,叶绿体中可见有大量的淀粉粒。随着缺镁胁迫程度的加重 ,14 C -光合产物在标记叶中的滞留量增加 ,输出率降低。叶片非还原糖、淀粉含量增加 ,茎秆、根系的非还原糖尤其是淀粉含量降低。本文还就缺镁影响龙眼光合产物生产和分配的机理进行了讨论     

拟南芥蔗糖转运蛋白(SUTs)的功能研究进展

蔗糖是光合产物在植物体内贮藏、运输的主要形式.植物蔗糖转运蛋白对蔗糖的装载、运输、卸出与分配过程起着不可替代的作用.本文详细介绍了拟南芥9个蔗糖转运蛋白家族成员的功能、分类、表达定位以及动力学特性等方面的研究进展.     

不同钾镁施用水平下甘蔗花叶病对甘蔗产量的影响

在甘蔗伸长盛期,SCMV—A侵染的蔗株叶片中蔗糖含量明显低于健株,还原糖含量则相反;不同钾、镁肥施用水平下,SCMV—A侵染的蔗株均比对照健株显著矮化,蔗茎和蔗糖含量均显著降低.而蔗茎锤度、蔗糖和还原糖含量则因钾、镁肥施用量的不同或高或低于其相应健株;适量施钾可增加健株的蔗茎及蔗糖产量,又可部分减少由SCMV—A年致的产量损失.施镁肥也有部分减少由SCMV—A引致产量损失的效果.