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Mg/Ca-temperature calibration for the benthic foraminifera Melonis barleeanum and Melonis pompilioides
Full text linkAn important tool for deep-sea temperature reconstruction is Mg/Ca paleothermometry applied to benthic foraminifera. Foraminifera of the genus Melonis appear to be promising candidates for temperature reconstructions due to their wide geographical and bathymetric distribution, and their infaunal habitat, which was suggested to reduce secondary effects from carbonate ion saturation (Δ[CO3 2−]). Here, we make substantial advances to previous calibration efforts and present new multi-lab Mg/Ca data for Melonis barleeanum and Melonis pompilioides from more than one hundred core top samples spanning in situ bottom temperatures from −1 to 16 °C, coupled with morphometric analyses of the foraminifer tests. Both species and their morphotypes seem to have a similar response of Mg/Ca to growth temperature. Compilation of new and previously published data reveals a linear dependence of temperature on Mg/Ca, with a best fit of Mg/Ca (mmol/mol) = 0.113 ± 0.005 ∗ BWT (°C) + 0.792 ± 0.036 (r2 = 0.81; n = 120; 1σ SD). Salinity, bottom water Δ[CO3 2−], and varying morphotypes have no apparent effect on the Mg/Ca-temperature relationship, but pore water Δ[CO3 2−] might have had an influence on some of the samples from the tropical Atlantic
Innovative Components on Thin Flexible PV Films Suited As Temporary and Fixed Covers for Lighting Archeological Sites
No full textMelonis affinis
No full textMelonis affinis (Reuss, 1851) Pl. 6, fig. 5 Nonionina affinis Reuss, 1851, p. 72, pl. 5, fig. 32. Noniona barleeana Williamson, 1858, p. 32, pl. 3, figs. 68–69. Nonionina crassula Parker & Jones, 1857, p. 14, pl. 11, figs. 5–7. Nonion barleeanum Cushman, 1930, p. 11, pl. 4, fig. 5. Melonis barleeanum Loeblich & Tappan, 1988, pl. 696, figs. 5–6; Hermelin, 1989, p. 88, pl. 17, fig. 12; Milker & Schmiedl, 2012, p. 115, fig. 26.11–26.12; Holbourn et al., 2013, p. 354. Melonis barleeanus Loeblich & Tappan, 1994, p. 159, pl. 347, figs. 1–5. Melonis affinis Milker et al., 2009, p. 218, pl. 3, fig. 20; Milker and Schmiedl, 2012, p. 115, fig. 26.9–10. Description: The test wall is calcareous and perforate. The test is planispiral and symmetrical in side view. The periphery of the test is rounded. Up to twelve chambers in the final whorl are separated by smooth, slightly curved sutures. The chamber walls are coarsely perforate and the sutures very finely perforate. The sutures radiate from the umbilical region, becoming thinner toward the test margin. The chambers gradually increase in size toward the apertural end. The aperture is an interio-marginal slit. Remarks: The relative abundances of Melonis affinis decrease toward the deeper cores, forming minor (<10%) to trace (<1%) components in the samples of all three cores. The tests are moderate in size, measuring up to 0.5 mm in diameter. Life strategy: This species lives unattached in mostly infaunal and muddy substrates (Murray, 1991). M. affinis is most abundant in oxic conditions, but is also tolerant of dysoxic and suboxic conditions (Kaiho, 1994; Murray, 2006). The species is also associated with the nitrate reduction zone (Fontanier et al., 2002) on the shelf to slope (Holbourn et al., 2013). Global stratigraphic range: This species occurs from the Oligocene to Recent (Holbourn et al., 2013). Regional occurrence: Melonis affinis is recorded to occur in middle Miocene sediments on the outer continental shelf of Namibia, south of the Kunene River mouth (this study) and in moderate abundances during the late Miocene to Pliocene along the slope of northern Namibia to the southwestern slope of South Africa (Wefer et al., 1998). Wefer et al. (1998) recorded the occurrence of M. affinis (= M. barleeanus) only in low to moderate (<2 to <20%) abundances along the slope off the Walvis Ridge during the Pleistocene.Published as part of Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, pp. 1-55 in Zootaxa 5091 (1) on pages 28-29, DOI: 10.11646/zootaxa.5091.1.1, http://zenodo.org/record/584043
Molecular characterization of Fusarium oxysporum f.sp. melonis.
No full textMolecular characterization of Fusarium oxysporum f.sp. melonis
Melonis pompilioides stable isotopic results of core LOM-1
No full textMelonis pompilioides stable isotopic results of core LOM-
Pathogenesis of Fusarium oxysporum f. sp. melonis: a transcriptomic approach.
No full textTranscriptomic analysis of different races of Fusarium oxysporum f. sp. melonis, grown on different melon genotypes or in vitro
Effect of Silicon Nutrition on Oxidative Stress Induced by <i>Phytophthora melonis</i> Infection in Cucumber
No full text The effect of silicon nutrition on root rot of cucumber caused by Phytophthora melonis was studied in a greenhouse experiment. Two cucumber cultivars (Cucumis sativus ‘Dominus’ and ‘Super Dominus’) fertilized with three concentrations of Si (0.0, 1.0, and 1.7 mM Si in the form of sodium silicate) were not inoculated or were inoculated with P. melonis. The P. melonis isolate significantly decreased root dry weights, although the magnitude of growth reduction varied with cultivar and Si concentration. Silicon nutrition at either concentration significantly reduced disease severity relative to the treatment that received no silicon. There was a significant negative correlation between the extent of root rot caused by P. melonis and the extent of electrolyte leakage of roots. Roots infected with P. melonis had greater root catalase (CAT) and ascorbate peroxidase (APX) activities. There was a positive correlation between silicon concentrations and CAT and APX activities in plants inoculated with P. melonis. Silicon improved activity of antioxidant enzymes, resulting in enhanced crop resistance to oxidative stress induced by P. melonis infection and improved cucumber growth. </jats:p
(Table 3) Stable carbon and oxygen isotope ratios of Melonis sp. from sediment core MD73-025
No full textNonion sp. = Melonis sp
Genetic relationships among 15 isolates of <i>Phytophthora melonis</i>.
No full text<p>The denrogram (UPGMA) shows the relationships among the isolates of <i>P. melonis</i> based on randomly amplified polymorphic DNA (RAPD) analysis with 16 decamer primers. Scale at the bottom depicts the genetic distance.</p
Phylogenetic relationships of Fusarium oxysporum f. sp. melonis in Iran
No full textFusarium wilt of melon caused by Fusarium oxysporum f. sp. melonis is a destructive fungal disease in melon growing regions. Isolates of F. oxysporum obtained from six major melon producing provinces in Iran, from melons and other hosts, were characteriz
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