STUDY ON D GENOME OF TRITICUMAESTIVUM SSP. YUNNANENSE KING

<正> Two accessions of Aegilops tauschii Cosson. one collected from the Middle East and the other from Henan Province of China. were crossed with Triticum aestivum ssp. yunnanense King. Chromosome pairings were analysed at metaphase Ⅰ. Meiotic configurations of the hybrids were 14.14Ⅰ+5.32 ring Ⅱ+1.52 rod Ⅱ for the Middle East Ae. tauschii x T. aestivum ssp. yunanense; 14.06Ⅰ+5.29 ring Ⅱ+1.69 rod Ⅱ for Henan Ae. tauschii x T. aestivum ssp. yunnanense. The frequencies of cells which had 7Ⅱ+14Ⅰconfiguration were 87.04％ and 97.05％ for the Middle East Ae. tanschii x T. aestivum ssp. yunnanense and Henan Ae. tauschii x T. asetivum ssp. yunnanense. respectively. The results indicated that D genome of T. aestivum ssp. yunnanense is unchanged compared with the D genome donor.     

Crossability percentages of bread wheat landraces from Shaanxi and Henan provinces,China with rye

Summary The crossability percentages of 118 landraces of wheat (Triticum aestivum L.) from Shaanxi and Henan provinces, China with rye (Secale cereale L.) have been tested. 14 landraces possess a higher crossability percentage than Chinese Spring, 30 landraces have a similar to and 74 landraces have a lower crossability percentage than Chinese Spring or are non-crossable with rye. Most landraces with high crossability percentage occur in south part of Shaanxi, and the west and southwest of Henan, their geographical distribution in these regions fits up with that in the Sichuan province.     

Crossability percentages of bread wheat collections from Tibet,China with rye

Summary The crossability percentages of 282 accessions of wheat (Triticum aestivum L.) collected in Tibet, China with rye (Secale cereale L.) have been tested. Five collections have a similar to and 277 accessions have a lower crossability percentage than Chinese Spring or are non-crossable with rye. The accessions with high crossability percentage occur along the highway near Lhasa. No landraces with higher crossability than Chinese Spring and rare landraces with similar crossability to Chinese Spring indicated that the landraces in Tibet region are different from those in Sichuan, Shaanxi and Henan provinces in the distribution frequency of high crossability, and there is no distribution of recessive kr4 alleles.     

Flavonoids with DNA strand-scission activity from Rhus javanica var. roxburghiana

The flavonoids isolated from the stems of Rhus javanica var. roxburghiana, taxifolin (1), fisetin (2), fustin (3), 3,7,4'-trihydroxyflavanone (4) and 3,7,4'-trihydroxyflavone (5) caused breakage of supercoiled plasmid pBR322 DNA in the presence of Cu(II). Cu(I) was shown to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine. The Cu(II)-mediated DNA scissions induced by 1, 2, 3 and 5 were inhibited by the addition of catalase and exhibited DNA strand break by the addition of KI and superoxide dimutase (SOD), while in the Cu(II)-mediated DNA scissions induced by 4 was inhibited by the addition of KI, SOD, and catalase. It is concluded that 1, 2, 3, and 5 can induce H(2)O(2) and superoxide anion, while 4 can induce OH() and H(2)O(2) and subsequent oxidative damage of DNA in the presence of Cu(II).     

A QTL on chromosome 2DS of ‘Sumai 3’ increases susceptibility to <Emphasis Type="Italic">Fusarium</Emphasis> head blight in wheat

Much effort has been invested in identifying molecular markers in wheat (Triticum aestivum L.) linked to quantitative trait loci (QTL) that confer resistance to Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein) Petch]. Even after several generations of crossing and selection by many wheat breeding programs, resistance of the Chinese spring wheat cultivar ‘Sumai 3’ (PI 481542) remains among the most effective. It therefore seems that undocumented resistance QTL present in Sumai 3 were not detected in various mapping studies. Using an extremely susceptible Tibetan landrace (‘Y1193-6’; unknown pedigree) in the creation of a mapping population with Sumai 3, the objective of this research was to identify undocumented resistance QTL in Sumai 3. This was accomplished through collecting disease index (DI) and Fusarium damaged kernel (FDK) phenotypic values along with 305 Diversity Array Technology (DArT) and 52 Simple Sequence Repeat (SSR) marker genotypes on 160 F_2:6 recombinant inbred lines (RILs). Disease response evaluations were based on four (two greenhouse and two field) experiments where spray inoculation methods were used. Three QTL were identified on chromosome arms 3BS, 6BL and 2DS explaining 26.1, 10.7 and 18.9% of the phenotypic variation for DI, respectively. The same QTL were also significantly associated with reduced FDK scores and explained 28.0, 11.0 and 23.0% of phenotypic variation. Lines within the mapping population were placed in eight categories with respect to their various QTL combinations. Lines with no QTL were the most susceptible, whereas those with the Sumai 3-derived 3BS and 6BL QTL combined with the 2DS QTL from Y1193-6 were the most resistant. Though the 3BS and 6BL QTL are well-documented, the 2DS resistance QTL, which was contributed by the susceptible parent, confers increased susceptibility when derived from Sumai 3. In this study no new FHB QTL from Sumai 3 was discovered, but results suggest that Sumai 3 contains a QTL for susceptibility on chromosome arm 2DS. Selection against this QTL may potentially increase resistance levels among Sumai 3-derived populations.     

神经网路模式在流量之预测

本文以倒传递神经网路模式,进行长期流量预测之应用研究,并以台湾中部德基水库上游松茂流量站历年观测资料进行探讨。初步得到预测结果与实测值比较尚有一倍以上的误差。但以神经网路之潜在应用潜力,寻找系统化网路参数值建立方法以得到更精确预测结果之经验,为寻人相当值得继续研究之课题。     

Induction of apoptosis by the Anthocyanidins through regulation of Bcl-2 gene and activation of c-Jun N-terminal kinase cascade in hepatoma cells

Anthocyanidins that are reddish pigments widely distributed in fruit and vegetables have been reported to possess antioxidant and anticancer activities. To understand the molecular basis of the putative anticancer activity of anthocyanidins, we investigated the antiproliferation effects of anthocyanidins in human hepatoma cell lines. Delphinidin, cyanidin, and malvidin exhibited strong growth inhibitory effects against human hepatoma HepG(2), but were less effective against Hep3B. According to the appearance of the caspase-3 fragments and stimulated proteolytic cleavage of poly (ADP-ribose) polymerase (PARP) in time-dependent studies, delphinidin induced apoptotic cell death characterized by internucleosomal DNA fragmentation and caused a rapid induction of caspase-3 activity. RT-PCR and Western blot data revealed that delphinidin stimulated an increase in the c-Jun and JNK phosphorylation expression at mRNA and protein levels, respectively. Moreover, delphinidin-induced apoptotic cell death was accompanied by up-regulation of Bax and down-regulation of Bcl-2 protein. Dephinidin-induced DNA fragmentation was blocked by N-acetyl-l-cysteine and catalase, suggesting that the death signaling was triggered by oxidative stress. Our experiments provide evidence that delphinidin is an effective apoptosis inducer in HepG(2) cells through regulation of Bcl-2 family moleculars and activation of c-Jun N-terminal kinase cascade. The results suggest that induction of apoptosis by anthocyanidins is a pivotal mechanism of their cancer chemopreventive functions.     

Determination of caffeine, theobromine, and theophylline in standard reference material 2384, baking chocolate, using reversed-phase liquid chromatography

A rapid and selective isocratic reversed-phase liquid chromatographic method has been developed at the National Institute of Standards and Technology to simultaneously measure caffeine, theobromine, and theophylline in a food-matrix standard reference material (SRM) 2384, Baking Chocolate. The method uses isocratic elution with a mobile phase composition (volume fractions) of 10% acetronitrile/90% water (pH adjusted to 2.5 using acetic acid) at a flow rate of 1.5 mL/min with ultraviolet absorbance detection (274 nm). Total elution time for these analytes is less than 15 min. Concentration levels of caffeine, theobromine, and theophylline were measured in single 1-g samples taken from each of eight bars of chocolate over an eight-day period. Samples were defatted with hexane, and beta-hydroxyethyltheophylline was added as the internal standard. The repeatability for the caffeine, theobromine, and theophylline measurements was 5.1, 2.3, and 1.9%, respectively. The limit of quantitation for all analytes was <100 ng/mL. The measurements from this method were used in the value-assignment of caffeine, theobromine, and theophylline in SRM 2384.