A comparative study of Scalesia species (Asteraceae) by gas chromatographic analysis of the monoterpene hydrocarbons of their essential oils

ADSERSEN, A. & SVENDSEN, A. B., 1986. A comparative study of Scalesia species (Asteraceae) by gas chromatographic analysis of the monoterpene hydrocarbons of their essential oils. The monoterpene hydrocarbons of the essential oils of 13 species of Scalesia , Asteraceae, endemic to the Galapagos Islands, were analysed by gas chromatography to determine whether the composition of these compounds could show any characteristics for the various species. Marked differences in the monoterpene hydrocarbon patterns of the Scalesia species investigated were observed. Whereas a-pinene was usually found in amounts of 30–50%, Scalesia villosa contained only 12%. Sabinene usually occurred in amounts of 10-1.5%, but S. divisa and S. affinis contained about twice as much. The limonene content was usually less than 1%, but S. microcephala, S. baurii and S. affinis contained amounts varying from about 2% to 9.5%.     

The role of leaf and canopy-level gas exchange in the replacement of Quercus virginiana (Fagaceae) by Juniperus ashei (Cupressaceae) in semiarid savannas

Photosynthesis, transpiration, and leaf area distribution were sampled in mature Quercus virginiana and Juniperus ashei trees to determine the impact of leaf position on canopy-level gas exchange, and how gas exchange patterns may affect the successful invasion of Quercus communities by J. ashei. Sampling was conducted monthly over a 2-yr period in 12 canopy locations (three canopy layers and four cardinal directions). Photosynthetic and transpiration rates of both species were greatest in the upper canopy and decreased with canopy depth. Leaf photosynthetic and transpiration rates were significantly higher for Q. virginiana (4.1–6.7 μmol CO₂·m⁻²·s⁻¹ and 1.1–2.1 mmol H₂O·m⁻²·s⁻¹) than for J. ashei (2.1–2.8 μmol CO₂·m⁻²·s⁻¹ and 0.7–1.0 mmol H₂O·m⁻²·s⁻¹) in every canopy level and direction. Leaves on the south and east sides of both species had higher gas exchange rates than leaves on the north and west sides. Although Quercus had a greater mean canopy diameter than Juniperus (31.3 vs. 27.7 m²), J. ashei had significantly greater leaf area (142 vs. 58 m²/tree). A simple model combining leaf area and gas exchange rates for different leaf positions demonstrated a significantly greater total canopy carbon dioxide uptake for J. ashei compared to Q. virginiana (831 vs. 612 g CO₂·tree⁻¹·d⁻¹, respectively). Total daily water loss was also greater for Juniperus (125 vs. 73 Ltree⁻¹·d⁻¹). Differences in leaf gas exchange rates were poor predictors of the relationship between the invasive J. ashei and the codominant Q. virginiana. Leaf area and leaf area distribution coupled with leaf gas exchange rates were necessary to demonstrate the higher overall competitive potential of J. ashei.     

Nomenclatural transfer of Chamaecyparis obtusa (Siebold & Zucc.) Endl. 'Sanderi' (Cupressaceae) to Thuja orientalis L. 'Sanderi' on the basis of phytochemical data

The longstanding problem of the true identity of the juvenile conifer clone usually known as Chamaecyparis obtusa 'Sanderi' has been solved by comparing gas chromatograms of solvent extracts of foliage specimens. Forty-seven species of the northern Cupressaceae were compared with 'Sanderi' but close similarity was shown only by juvenile forms of Thuja orientalis. All other species studied showed significant, usually major, differences.     

Detection and identification of gibberellins in Sitka spruce (Picea sitchensis) of different ages and coning ability by bioassay, radioimmunoassay and gas chromatography – mass spectrometry

Gibberellins Al (GA₁), GA₃, GA₄, GA₉, and after enzymatic hydrolysis of GA-conjugate-like fractions, GA₉ and GA₁₅, were identified in shoots of Sitka spruce [ Picea sitchensis (Bong.) Carr.] of different ages by combined gas chromatography-mass spectrometry (GC-MS). The purification and separation of the GAs involved the use of reverse phase and normal phase high performance liquid chromatography (HPLC). The Tan-ginbozu dwarf rice bioassay and binding to antibodies raised against GA₁, GA₄ and GA₉ were used for detection of GA-like substances. The qualitative differences between the three ages of plant material were the presence of GA₃ and GA₁ in the 48-year-old material and the absence of detectable amounts of GA₄ in the same material. This indicates a difference in GA metabolism which may reflect the difference in ability to form reproductive buds.     

A comparative study of the soil zinc fractions determined by chemical methods and electro-ultrafiltration (EUF) and their relations to zinc nutrition in rice

Rice (IR 42) was grown on two soils differing in zinc status for 30 days with and without Zn under submerged conditions in pots. The fate of soil zinc was characterized by extraction of the soil successively with copper acetate and sodium hypochlorite and by EUF extraction. Most of the applied zinc was extracted by copper acetate and represented as complexed fraction. There exists a close and significnat relation between Cu(OAc)₂-extractable zinc and Zn extracted by EUF for 5 minutes at 50 volts (r=0.98). The EUF-extractable zinc and Cu(OAc)₂-extractable zinc were significantly correlated with the zinc content in the plant (r=0.82). The data from this investigation suggest the possibility of Zn fractionation with the EUF technique and the fractions obtained agree closely to those determined by chemical methods. The results obtained indicate that Zn in soil is held by weak organic bonding and that the extractions by Cu(OAc)₂ and/or EUF-5 minutes serve as a useful basis for extimating zinc availability in rice soils.     

A comparative genetic study of two groups of chukar partridges (<Emphasis Type="Italic">Alectoris chukar</Emphasis>) from Cyprus and Argentina,using microsatellite analysis

The aim of the present work is to estimate the usefulness of microsatellite genetic markers analysis to characterize and analyze the possible differences between a captive reared population and a wild one from the same species. The first sample consists of 27 chukar partridges (Alectoris chukar) bred in one farm in Argentina. The second one is composed of 31 chukar partridges coming from a wild Cyprus population (A. chukar cypriotes). We analyzed seven microsatellite loci: MCW135, MCW225, MCW276, MCW280, MCW295, LEI31, and ADL0142. The Argentina group showed higher genetic variation than the Cyprus did. Significant global F _IS value was found in the Argentina sample. Significant genetic differentiation exists between both groups (F _ST=0.394; p<0.01). The Argentina group did not show any signs of bottleneck. Results from Factorial Correspondence Analysis (FCA) suggest that the 58 partridges could be split into two distinct genetic clusters (Cyprus and Argentina). Nevertheless, in the light of PARTITION results, three Argentina individuals might be related to Cyprus. STRUCTURE is unable to assign these three animals to any of the two groups. This could be due to a single or repeated introduction of external individuals into the original Argentina group, so that these results would point to more than one origin for this population. This admixture of individuals could explain the high genetic variation observed in the Argentina farm. Global F _IS value would probably be higher without these immigrations; on the other hand, these admixtures could have prevented bottlenecks.     

A series of d transition metal coordination complexes: Structures and comparative study of surface electron behaviors (n = 9, 8, 7, 6, 5)

Ten transition metal coordination complexes [Cu₂(phen)(p-tpha)(μ-O)]_n1, [Cu(m-tpha)(imH)₂]_n2, [Ni(5-Haipa)₂(H₂O)₂]_n3, [Ni(phen)₂(H₂O)₂]·btc·[Ni(H₂O)₆]_0.5·9H₂O 4, [Co(2,5-pdc)(H₂O)₂]_n·nH₂O 5, [Co₂(2,5-pdc)₂(H₂O)₆]_n·2nH₂O 6, [Fe(2,5-Hpdc)₂(H₂O)₂]·H₂O 7, [Co(C₆H₄NO₂)₃]·H₂O 8, [Fe₂(μ₂-btec)(μ₂-H₂btec)(bipy)₂(H₂O)₂]_n9, [Mn(phen)(2,5-pdc)(H₂O)₂]·H₂O 10 (H₄btec = 1,2,4,5-benzenetetracarboxylic acid, phen = 1,10-phenanthroline, 2,5-H₂pdc = 2,5-pyridine-dicarboxylic acid, p-tpha = p-phthalic acid, m-tpha = m-phthalic acid, bipy = 2,2′-bipyridine, 5-H₂aipa = 5-aminoisophthalic acid, imH = imidazole, H₃btc = 1,3,5-benzenetricarboxylic acid) were synthesized through hydrothermal method. They were characterized by UV-Vis absorption spectra, single-crystal X-ray diffraction and surface photovoltage spectra (SPS). Structural analysis indicated that the complexes 1, 2, 3, 5, 6 and 9 were linked into infinite structures bridged by organic acid ligands. The other four complexes were molecular complexes and further connected to 2D or 3D structures by the hydrogen bonds. The SPS of complexes 1-10 indicate that there are positive response bands in the range of 300-800 nm showing different levels of photo-electric conversion properties. The intensity, position, shape and the number of the response bands in SPS are obviously different since the structure, species, valence, dⁿ electrons configuration and coordinated environment of the center metals are different. There are good relationships between SPS and UV-Vis spectra.