Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design

[EN] Solanum torvum is a highly vigorous relative of eggplant that is resistant to a number of harmful soil-borne diseases and is compatible for grafting with eggplant. Being a potential rootstock, this plant frequently presents poor and erratic germination, which makes its practical use difficult. We used an L8 (2(7)) orthogonal array design to evaluate the primary effects of seven factors (soaking of seeds, scarification with sodium hypochlorite (NaClO), application of gibberellic acid (GA(3)), use of potassium mitrate (KNO3) as a moistening agent, cold stratification, application of a heatshock, and light irradiation during germination) at two levels (L0 and L1) using four germination parameters (early and final germination, germination rate and vigour index) in fresh S. torvum seeds. S. torvum seeds had a strong dormancy with no germination in the untreated seeds and high early and final germination (approximately 100%) in certain treatments. An evaluation of the main effects revealed highly positive effects on germination from seed soaking, and the use of GA(3), KNO3, and light irradiation, whereas NaClO scarification had a negative effect. The application of cold stratification and heat shock treatments also had a positive effect on seed germination but to a lesser extent than the other treatments. An improved proposed protocol that consisted of subjecting seeds to soaking, the application of GA(3) and KNO3, cold stratification, heat shock, and light irradiation was validated and demonstrated to be highly effective, with seed germination success greater than 60% being observed at 3 days and final germination reaching a plateau at 6 days. A second validation experiment using a commercial growing substrate also showed a high emergence (approximately 50%) at 7 days and a final germination of approximately 80% was recorded with application of the improved protocol. The seed germination protocol that we have developed will facilitate the use of S. torvum as a rootstock for eggplant and its use in breeding programmes. Our results also reveal that orthogonal array designs are a powerful tool for establishing improved protocols for seed germination. (C) 2015 Elsevier B.V. All rights reserved.This work was completed as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives", which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew and is implemented in partnership with national and international gene banks and plant breeding institutes. For further information see the project website: http://www.cwrdiversity.org/. Isabel Andujar and Pietro Gramazio are grateful to Universitat Politecnica de Valencia for their post-doctoral (PAID-10-14) and pre-doctoral (Programa FPI de la UPV-Subprograma 1) contracts, respectively.Ranil, RH.; Niran, HML.; Plazas Ávila, MDLO.; Fonseka, R.; Hemal Fonseka, H.; Vilanova Navarro, S.; Andújar Pérez, I.... (2015). Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design. Scientia Horticulturae. 193:174-181. https://doi.org/10.1016/j.scienta.2015.07.030S17418119

Magneto-optical properties of wurtzite-phase inp nanowires

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Magneto-Optical Properties of Wurtzite-Phase InP Nanowires

The possibility to grow in zincblende (ZB) and/or wurtzite (WZ) crystal phase widens the potential applications of semiconductor nanowires (NWs). This is particularly true in technologically relevant III-V compounds, such as GaAs, InAs, and InP, for which WZ is not available in bulk form. The WZ band structure of many III-V NWs has been widely studied. Yet, transport (that is, carrier effective mass) and spin (that is, carrier g-factor) properties are almost experimentally unknown. We address these issues in a well-characterized material: WZ indium phosphide. The value and anisotropy of the reduced mass (μexc) and g-factor (gexc) of the band gap exciton are determined by photoluminescence measurements under intense magnetic fields (B, up to 28 T) applied along different crystallographic directions. μexc is 14% greater in WZ NWs than in a ZB bulk reference and it is 6% greater in a plane containing the WZ ĉ axis than in a plane orthogonal to ĉ. The Zeeman splitting is markedly anisotropic with g exc = |ge| = 1.4 for Bĉ (where ge is the electron g-factor) and gexc = |ge - gh,//| = 3.5 for B//ĉ (where gh,// is the hole g-factor). A noticeable B-induced circular dichroism of the emitted photons is found only for B//ĉ, as expected in WZ-phase materials. © 2014 American Chemical Society