Search results for "botany"
showing 10 items of 4586 documents
Ultrafast excitation dynamics of low energy pigments in reconstituted peripheral light-harvesting complexes of photosystem I
2000
AbstractUltrafast dynamics of a reconstituted Lhca4 subunit from the peripheral LHCI-730 antenna of photosystem I of higher plants were probed by femtosecond absorption spectroscopy at 77 K. Intramonomeric energy transfer from chlorophyll (Chl) b to Chl a and energy equilibration between Chl a molecules observed on the subpicosecond time scale are largely similar to subpicosecond energy equilibration processes within LHCII monomers. However, a 5 ps equilibration process in Lhca4 involves unique low energy Chls in LHCI absorbing at 705 nm. These pigments localize the excitation both in the Lhca4 subunit and in LHCI-730 heterodimers. An additional 30–50 ps equilibration process involving red …
Regeneration of Sideritis angustifolia (Labiatae) Plants from Single Cell Cultures
1988
Summary Mechanically isolated cells from hypocotyl-derived calli of Sideritis angustifolia Lag. were inoculated on agar-solidified Murashige and Skoog (MS) nutrient medium containing CH and different concentrations and combinations of NAA and BA. Isolated cells underwent continued divisions giving rise to calli after 30 days of culture. Best results were obtained when medium was supplemented with 0.5 μM NAA and 4.4 or 8.8 μM BA or with 5 μM NAA and 4.4μM BA. Calli obtained in the presence of 0.5 μM NAA and 8.8 μM BA regenerated shoot-buds when transferred to MS medium without CH and supplemented or not with these growth regulators. Once shoots were excised, the calli maintained their morpho…
Occurrence of fumonisins B1 and B2 in broa, typical Portuguese maize bread
2007
Fumonisin B1 (FB1) and fumonisin B2 (FB2) are mycotoxins mainly produced by Fusarium verticillioides, and Fusarium proliferatum, fungi species most commonly isolated from maize. The natural occurrence of FB1 and FB2 in broa, typical Portuguese maize bread, was evaluated in 30 samples. Twenty five were found positive with levels ranging from 142 to 550 [mu]g kg- 1. The limit established by the European regulations was exceeded by 27% of the samples. The tolerable daily intake for fumonisin B1, and B2, alone or in combination, for all of the analysed samples, was lower than 2 [mu]g kg- 1 body weight per day established by the European Commission. http://www.sciencedirect.com/science/article/B…
Recombination profiles between Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus in laboratory and field conditions: evolution…
2012
Tomato yellow leaf curl Sardinia virus and Tomato yellow leaf curl virus have co-existed in Italian tomato crops since 2002 and have reached equilibrium, with plants hosting molecules of both species plus their recombinants being the most frequent case. Recombination events are studied in field samples, as well as in experimental co-infections, when recombinants were detected as early as 45 days following inoculation. In both conditions, recombination breakpoints were essentially absent in regions corresponding to ORFs V2, CP and C4, whereas density was highest in the 3′-terminal portion of ORF C3, next to the region where the two transcription units co-terminate. The vast majority of brea…
Comparison of neophyte communities of Robinia pseudoacacia L. and Acer negundo L. in the eastern Baltic Sea region cities of Riga and Kaunas
2015
Abstract In this study, we examined the species composition of neophyte communities of Robinia pseudoacacia and Acer negundo and compared the site conditions of the urban environment of two cities—Riga and Kaunas. Eighty-five plots of A. negundo and R. pseudoacacia communities were selected. Within each plot, all of the vascular plant species were recorded, and their abundance was estimated in 2014. Composite soil samples of the 0–10 cm mineral topsoil were collected for the estimation of the soil chemical properties at nine systematically distributed points in each sample plot. The soil pH KCL , exchangeable bases, total nitrogen, total organic matter, C/N ratio, and concentrations of the …
A new species of Hedya Hübner from Iran with proposed rearrangement of some species currently assigned to Metendothenia Diakonoff (Lepidoptera: Tortr…
2011
Hedya tritofa, new species, is described and illustrated based on eleven males and five females collected in northern Iran (Gilan, Mazandaran, and Golestan provinces). Morphology and diagnostic characters of Hedya Hubner, 1825, Metendothenia Diakonoff, 1973, the Olethreutes group of genera, and the Neopotamia group of genera are discussed. We propose the resurrection of the combinations Hedya atropunctana (Zetterstedt, 1840), revised status, and H. separatana (Kearfott, 1907), revised status, and the new combination H. inouei (Kawabe, 1987).
Effects of the ingestion ofSerratula tinctoria extracts, a plant containing phytoecdysteroids, on the development of the vineyard pestLobesia botrana…
1997
We describe here the effects of extracts from Serratula tinctoria, a plant producing phytoecdysteroids, on the growth and development of Lobesia botrana, an economically important pest in vineyards. Leaves, hairy roots, or semi-purified (by Sep-Pak procedure) methanolic extracts from this plant were incorporated into an artificial diet given to insects. Larval growth, mortality, weight, and sex-ratio were investigated, as well as sterol and ecdysteroid contents. Experimental diets induced an important mortality in the first, second, and third larval instars, but also in pupae. As males appeared more sensitive to extracts, sex ratio was significantly modified on experimental diets (particula…
Sensory adaptation of antennae and sex pheromone-mediated flight behavior in male oriental fruit moths (Leptidoptera: Tortricidae) after prolonged ex…
2013
Sensory adaptation has been measured in the antennae of male Grapholita molesta (Busck) after 15 min of exposure to its main pheromone compound (Z)-8-dodecen-1-yl acetate (Z8-12:OAc) at the aerial concentration of 1 ng/m(3) measured in orchards treated with pheromone for mating disruption. Exposing males to this aerial concentration of Z8-12:OAc for 15 min, however, had only a small effect on their ability to orientate by flight to virgin calling females in a flight tunnel. Experiments were undertaken to determine if exposure to the main pheromone compound in combination with the two biologically active minor compounds of this species, (E)-8-dodecen-1-yl acetate (E8-12:OAc) and (Z)-8-dodece…
Dichrorampha dinarica, new species, a century of confusion in European lepidopterology (Lepidoptera: Tortricidae) resolved by combining morphology an…
2012
Dichrorampha dinarica, new species, is described from the Dinaric mountains (Macedonia, Bosnia and Herzegovina). The newspecies was formerly confused with D. ligulana (Herrich-Schäffer, 1851) from the Alps and D. rilana Drenowsky, 1909 fromthe Rila mountains (Bulgaria). Therefore, a re-description of D. rilana is provided based on topotypical specimens. The diag-nostic morphological characters of the involved species, supported by significant divergence of the mtDNA barcode (COI fragment of 658 bp), are discussed in detail.
Description and Life History of an Unusual Fern-Feeding Tortricid Moth (Lepidoptera: Tortricidae) from Brazil
2004
Tortrimosaica polypodivora Brown & Baixeras, new genus and new species, is described and illustrated from Sao Paulo, Brazil. We also describe and illustrate the last instar and pupa and provide notes on the life history. Larvae of the new species are gall inducers on the stems of Microgramma squamulosa (Kauf.) Sota (Polypodiaceae), an unusual behavior and host for a tortricid. Although placed provisionally in Hilarographini, tribal and subfamilial assignment of the new genus is extremely problematic owing to a mosaic of morphological characters, suggesting placement in a variety of different higher taxa. The larvae have a bisetose L-group on the prothorax, and the pupa has multiple rows of …