Microsatellite markers for the common bean Phaseolus vulgaris

Efforts to develop molecular tools for genetic analysis and breeding of common bean in the tropics are still limited. The number of microsatellite markers available for the crop is small compared to other crops of similar social and economic importance. As part of a project to broaden the use of molecular tools in bean breeding, a genomic library enriched for AG/TC repeat sequences was constructed for Phaseolus vulgaris. Twenty microsatellite markers were initially developed and 10 were characterized using a panel of 85 representative accessions of the bean gene bank. The number of alleles per marker ranged from three to 10. The polymorphism information content (PIC) varied from 0.23 to 0.80. The results indicate that the new markers can be readily used in genetically analysis of common bean.     

Hydrogen evolution by co-immobilized Chlorella vulgaris and Clostridium butyricum cells

Whole cells of Chlorella vulgaris and Clostridium butyricum were co-immobilized in 2% agar gel. NADP was suitable as an electron carrier. The rate of hydrogen evolution increased with increasing NADP concentration. The optimum conditions for hydrogen evolution were pH 7.0 and 37°C. The immobilized C. vulgaris-NADP-immobilized Cl. butyricum system continuously evolved hydrogen at a rate of 0.29–1.34 μmol/h per mg Chl for 6 days. On the other hand, the system without NADP evolved only a trace amount of hydrogen.     

EFFECTS OF ARSENATE ON GROWTH OF NITROGEN-AND PHOSPHORUS-LIMITED CHLORELLA VULGARIS (CHLOROPHYCEAE) ISOLATES1

The effects of arsenate on the growth characteristics of five isolates of the freshwater alga, Chlorella vulgaris Beij., were examined. Two field isolates originated from arsenic-contaminated sites in Yukon, Canada and Kyushi, Japan; two reference isolates were obtained from the University of Texas Culture Collection. One isolate was selected for arsenic-tolerance in the laboratory. All five strains survived in culture solutions containing high arsenate concentrations. Arsenate (1–25 mM As) reduced photosynthesis and cell growth, as reflected by induced lag periods, slower growth rates, and lower stationary cell yields. Field isolates had shorter lag periods, higher growth rates, and enhanced cell yields compared to lab isolates when exposed to the same arsenic concentrations. Growth of the phosphorus-limited field strains was stimulated by the addition of arsenic. The cell yield of phosphorus-limited C. vulgaris Yukon, when treated with arsenic, was two times that of the phosphorus-limited control. This pattern was not evident when photosynthesis was used as a measure of cell response.     

Osmotic stress, endogenous abscisic acid and the control of leaf morphology in Hippuris vulgaris L

Abstract. Previous reports indicate that heterophyllous aquatic plants can be induced to form aerial-type leaves on submerged shoots when they are grown in exogenous abscisic acid (ABA). This study reports on the relationship between osmotic stress (e.g. the situation encountered by a shoot tip when it grows above the water surface), endogenous ABA (as measured by gas chromatography-electron capture detector) and leaf morphology in the heterophyllous aquatic plant, Hippuris vulgaris. Free ABA could not be detected in submerged shoots of H. vulgaris but in aerial shoots ABA occurred at ca. 40ng (g fr wt)⁻¹. When submerged shoots were osmotically stressed ABA appeared at levels of 26 to 40ng (g fr wt)⁻¹. These and other data support two main conclusions: (1) Osmotically stressing a submerged shoot causes the appearance of delectable levels of ABA. (2) The rise of ABA in osmotically stressed submerged shoots in turn induces a change in leaf morphology from the submerged to the aerial form. This corroborates the hypothesis that, in the natural environment, ABA levels rise in response to the osmotic stress encountered when a submerged shoot grows up through the water/air interface and that the increased ABA leads to the production of aerial-type leaves.     

Non-everted oxygenated rat intestinal segments as a measure of neutral detergent fiber effects on iron absorption

Iron absorption in the presence of varying amounts and sizes of dietary fiber was measured. A method using non-everted rat intestinal segments perfused in oxygen was refined. Neutral detergent fiber (NDF), a component of dietary fiber, was extracted from cooked pinto bean (Phaseolus vulgaris). The NDF did not affect iron absorption in intestinal segments from iron replete rats. However, 4 and 6 mg of NDF/ml significantly decreased iron absorption in the intestinal segments from anemic rats. NDF with a smaller particle size of 0.125 mm increased iron absorption relative to that absorbed with 0.180 mm particles. Histological examination validated using non-everted intestinal segments perfused with oxygen as a method for studying dietary effects on iron absorption. Segments which are not everted are less prone to damage. Perfusion with oxygen maintained metabolic activity in the tissue during the experiment.     

Effect of biologically active plants used as netst material and the derived benefit to starling nestlings

Summary The European starling Sturnus vulgaris preferentially incorporates fresh sprigs of particular plant species for use as nesting material. Chemicals found in these plants may act to reduce pathogen and ectoparasite populations normally found in nest environments. The present experiments were performed to test this Nest Protection Hypothesis. In the fild, we experimentally determined that wild carrot Daucus carota, a plant species preferred as nest material, effectively reduced the number of hematophagous mites found within nests relative to control nests without green vegetation. Chicks from nests containing wild carrot had higher levels of blood hemoglobin than chicks from control nests. However, there were no differences in weight or feather development. In the laboratory, we found that wild carrot and fleabane, Erigeron philadelphicus, (also preferred by starlings as nest material) substantially reduced the emergence of feeding instars of mites, while garlic mustard, Alliaria officinalis, (commonly available but not preferred) had little effect on the emergence of mites. We infer that preferred plant material may act to inhibit feeding or otherwise delay reproduction of mites, thereby reducing risk of anemia to developing nestlings.     

Circumnutation in Phaseolus vulgaris. I. Growth, osmotic potential and cell ultrastructure in the free-moving part of the shoot

Circumnutation of Phaseolus vulgaris L. cv. Blanc de Juillet twining shoots was examined at the cellular level. Cell growth was monitored inside the free-moving part of the shoot as a function of time and position with respect to the terminal bud. Complete elongation of epidermal cells required >7 days. A 60% increase in length of the cells in the bending zone was observed. Scanning and transmission electron microscopy studies showed the elasticity of cell walls, the extent of plasmodesmata and endoplasmic reticulum of epidermal cells. The osmotic potential in epidermal cells of the bending zone displayed significant differences only between the concave and convex sides. The pattern of cell growth in twining shoots is discussed. Circumnutation could be seen as a consequence of periodic turgor changes inducing periodic growth.     

A multivariate comparison between three NW. European populations ofArtemisia norvegica (Asteraceae) by means of chemometric and morphometric data

Specimens from Scotland, S. and C. Norway were grown in the botanical garden of Bergen, Norway. Some of the Scottish specimens came from a meristem tissue culture. The specimens were compared by a principal component analysis of lipids and related compounds, and of morphological characters from leaves and flowers. The populations differed from each other, but some overlap was found in leaf characters. The results are discussed in relation to distribution and immigration history, and it is argued that the differences among the populations may have evolved in postglacial time.     

Salicyloylaspartate as an endogenous component in the leaves of Phaseolus vulgaris

An amide conjugate of o-methoxybenzoic acid and aspartic acid has been isolated from bean leaves. After extraction and methylation of plant material, this compound was isolated as two isomeric monoethyl monomethyl esters. The ethylation of the aspartyl carboxyl groups was shown to be a likely result of an extraction procedure utilising acidified ethanol, the methylation of the aromatic hydroxy of the methoxy group to be due to the derivatisation procedure. Studies with pentafluorobenzylation confirmed that the endogenous compound is o-hydroxybenzoylaspartate.     

人工樟子松—差不嗄蒿植被及其固沙作用

植物固沙是整治沙漠和沙漠化土地的一种有效措施。人工植被的建立是植物固沙的必然结果。人工植被的演替、稳定性及其对环境的影响直接关系到流沙的固定程度。因此,本文旨在探讨人工樟子松(Pinus sylvestris var.