Variation in DNA-ploidy Levels of Reynoutria Taxa in the Czech Republic

The genus Reynoutria is represented by four taxa in the Czech Republic: Reynoutria japonica var. japonica, R. japonica var. compacta, R. sachalinensis and R. xbohemica. By using flow cytometry, cytological variability within the genus is described based on 257 Reynoutria samples. The varieties of R. japonica are cytologically uniform, var. japonica is exclusively octoploid (2n = 8x = 88) and var. compacta occurs only as a tetraploid (2n = 4x = 44), but R. sachalinensis and R. xbohemica exhibit some variation in chromosome numbers. Reynoutria sachalinensis is predominantly tetraploid (2n = 4 x = 44), but also occurs occasionally as hexaploid and octoploid cytotypes. The most common ploidy level in R. xbohemica is hexaploid (2n = 6x = 66), but tetraploid and octoploid clones were also found. The four taxa occurring in the Czech Republic are described briefly and the possible origins of the cytotypes discussed.     

Inter- and intra-specific variation among five Erythroxylum taxa assessed by AFLP

BACKGROUND: and Aims The four cultivated Erythroxylum taxa (E. coca var. coca, E. novogranatense var. novogranatense, E. coca var. ipadu and E. novogranatense var. truxillense) are indigenous to the Andean region of South America and have been cultivated for folk-medicine and, within the last century, for illicit cocaine production. The objective of this research was to assess the structure of genetic diversity within and among the four cultivated alkaloid-bearing taxa of Erythroxylum in the living collection at Beltsville Agricultural Research Center. METHODS: Amplified fragment length polymorphism (AFLP) fingerprinting was performed in 86 Erythroxylum accessions using a capillary genotyping system. Cluster analysis, multidimensional scaling (MDS) and analysis of molecular variance (AMOVA) were used to assess the pattern and level of genetic variation among and within the taxa. KEY RESULTS: A clear distinction was revealed between E. coca and E. novogranatense. At the intra-specific level, significant differentiation was observed between E. c. var. coca and E. c. var. ipadu, but the differentiation between E. n. var. novogranatense and E. n. var. truxillense was negligible. Erythroxylum c. var. ipadu had a significantly lower amount of diversity than the E. c. var. coca and is genetically different from the E. c. var. ipadu currently under cultivation in Colombia, South America. CONCLUSIONS: There is a heterogeneous genetic structure among the cultivated Erythroxylum taxa where E. coca and E. novogranatense are two independent species. Erythroxylum coca var. coca is most likely the ancestral taxon of E. c. var. ipadu and a founder effect may have occurred as E. c. var. ipadu moved from the eastern Andes in Peru and Bolivia into the lowland Amazonian basin. There is an indication of artificial hybridization in coca grown in Colombia.     

提高榨菜离体培养植株再生频率

采用榨菜“浙桐1号”品种为材料,以MS为基本培养基,通过对不同植物生长调节剂的组合和不同外植体等主要因素的筛选,大幅度提高了榨菜离体培养植株再生频率。结果表明,2mg／L6．BA 0．2mg／L2,4-D的组合较为适宜,其不定芽再生频率可达50％,且外植体以下胚轴为好：而CPPU和2,4-D的适宜组合为1．5mg／L 0．2mg／L,其不定芽再生频率高达66．67％,最适外植体为带柄子叶。同时,研究结果显示,添加0．25～1mg／L的GA,对榨菜已分化的不定芽的伸长有抑制作用;子叶柄和下胚轴外植体的分化具有极性现象。     

Antioxidant and anticancer activity of extract from Betula platyphylla var. japonica

The antioxidant and anticancer properties of a medicinal plant, Betula platyphylla var. japonica were investigated. The total methanol extract of B. platyphylla var. japonica had protective effects against hydrogen peroxide (H2O2) in the Chinese hamster lung fibroblast (V79-4) cell line and induced apoptotic cell death in human promyelocytic leukemia (HL-60) cells, a cancer cell line. B. platyphylla var. japonica extract significantly increased cell viability against H2O2. The extract also showed high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 2.4 microg/ml) and lipid peroxidation inhibitory activity (IC50 below 4.0 microg/ml). Furthermore, B. platyphylla var. japonica extract reduced the number of V79-4 cells arrested in G2/M in response to H2O2 treatment and increased the activities of several cellular antioxidant enzymes, including superoxide dismutase, catalase and glutathione peroxidase. Treatment with B. platyphylla var. japonica extract induced cytotoxicity and apoptosis in HL-60 cells, as shown by nucleosomal DNA fragmentation, increases in the subdiploid cell population, and fluorescence microscopy. B. platyphylla var. japonica extract gradually increased the expression of pro-apoptotic Bax and led to the activation of caspase-3 and cleavage of PARP. These findings suggest that B. platyphylla var. japonica exhibits potential antioxidant and anticancer properties.     

Studies on reproductive strategies of Vitex negundo L. var. heterophylla (Franch.) Rehder (Lamiaceae) based on morphological characteristics and SSR markers

Vitex negundo L. var. heterophylla (Franch.) Rehder (Lamiaceae) is an important tree species for soil and water conservation, yet the reproductive ecology of this species remains to be elucidated. To investigate the reproductive traits of V. negundo var. heterophylla, the phenology, morphological characteristics (a suite of characters was assessed: floral morphology, nectar production, pollen viability, and stigma receptivity) and mating system of this species were systematically revealed for the first time in this study. Phenological observations, morphological measurements, and nectar production analysis were conducted during anthesis. Pollen viability and stigma receptivity at different flowering stages were measured by biochemical methods. Finally, genetic analysis based on SSR markers was used to reveal the mating system; outcrossing index and pollen‐ovule ratio were also calculated to help analysis. V. negundo var. heterophylla showed several obvious characteristics of outcrossing, such as abundant and attractive flowers, secreting nectar, and emitting scent. In addition, mechanisms such as homogamy and a short anther‐stigma distance that can promote self‐fertilization were also identified in this species. The coexistence of selfing and outcrossing characteristics demonstrates a predominantly outcrossed mixed mating system (outcrossing rate, t = 95%). The scientific information provided by this study may contribute to conservation of V. negundo var. heterophylla from a reproductive perspective.     

蕨菜多酚氧化酶的酶学性质

研究了蕨菜[Pteridium aquilinum (L．) Kuhn var．latiusculum (Desv．) Underw．]多酚氧化酶的动力学性质,结果表明：以邻苯二酚为底物,该酶最适pH为7．4,最适温度为25℃,60℃以上使酶迅速失活,动力学方程v=619．08[S]/(0．031 [S]),Vc、异Vc钠、NaHSO3、L-Cys可完全抑制酶活性,饱和NaCl能显著抑制酶活性,蔗糖、SDS对酶有激活作用。该酶能催化邻苯二酚、焦性没食子酸氧化,但对焦性没食子酸亲和力更强。     

Comparison of RAPD and RFLP genetic markers in determining genetic similarity among Brassica oleracea L. genotypes

Genetic similarity among 45 Brassica Oleracea genotypes was compared using two molecular markers, random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphisms (RFLPs). The genotypes included 37 broccolis (var. italica), five cauliflowers (var. botrytis) and three cabbages (var. capitata) which represented a wide range of commercially-available germplasm, and included open-pollinated cultivars, commercial hybrids, and inbred parents of hybrid cultivars. Fifty-six polymorphic RFLP bands and 181 polymorphic RAPD bands were generated using 15 random cDNA probes and 62 10-mer primers, respectively. The objectives were to compare RFLP and RAPD markers with regard to their (1) sampling variance, (2) rank correlations of genetic distance among sub-samples, and (3) inheritance. A bootstrap procedure was used to generate 200 random samples of size n (n=2,3,5,... 55) independently from the RAPD and RFLP data sets. The coefficient of variance (CV) was estimated for each sample. Pooled regressions of the coefficient of variance on bootstrap sample size indicated that the rate of decrease in CV with increasing sample size was the same for RFLPs and RAPDs. The rank correlation between the Nei-Li genetic similarity values for all pairs of genotypes (990) based on RFLP and RAPD data was 0.745. Differences were observed between the RFLP and RAPD dendrograms of the 45 genotypes. Overlap in the distributions of rank correlations between independent sub-samples from the RAPD data set, compared to correlations between RFLP and RAPD sub-samples, suggest that observed differences in estimation of genetic similarity between RAPDs and RFLPs is largely due to sampling error rather than due to DNA-based differences in how RAPDs and RFLPs reveal polymorphisms. A crossing algorithm was used to generate hypothetical banding patterns of hybrids based on the genotypes of the parents. The results of this study indicate that RAPDs provide a level of resolution equivalent to RFLPs for detemination of the genetic relationships among genotypes.     

winged eye Induces Transdetermination of Drosophila Imaginal Disc by Acting in Concert with a Histone Methyltransferase,Su(var)3-9

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不同降水条件下科尔沁沙地南缘疏林草地樟子松针叶δ13C和叶性状特征

通过比较不同自然降水年份(极端干旱和极端湿润)19年生疏林草地樟子松的针叶δ¹³C、比叶面积和干物质含量,结合土壤含水量和地下水埋深,探讨了极端降水对樟子松水分利用的影响.结果表明: 干旱年份(2009)樟子松林土壤含水量显著低于湿润年份(2010),但樟子松当年生针叶的δ¹³C在两年间没有显著差异,且两年相同月份间亦无显著差异;干旱年份当年生针叶的比叶面积显著低于湿润年份,而不同年份间干物质含量的差异不显著.在两种极端降水条件下,樟子松的水分利用效率没有明显变化,主要通过改变当年生针叶的比叶面积来适应降水量的变化.对于地下水埋深高于3.0 m的疏林草地樟子松人工林生态系统,极端干旱不会严重影响樟子松的存活和生长.