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Abstract

A method is proposed for the germination of fungal-free seeds of Magnolia grandiflora as a source of tissue for in vitro experiments. A combination sequence of a 16 hour water-soak at 25°C, hot water (52°C) for 1 hour, and then surface sterilization for 1 hour in 1:1000 aqueous mercuric chloride was the best treatment. Dips in 2.5% chlorox, 95% ethyl alcohol and concentrated sulfuric acid soak for 20 minutes were unsatisfactory. If seeds are selected carefully and treated as described, 60 to 90% of the seeds will germinate aseptically within 30 days.

Abstract

Southern Magnolia, Magnolia grandiflora (L.), cuttings are difficult or impossible to root without growth regulators. Age of parent plant, terminal or lateral source of wood and specific growth regulators are factors in rootability.

The best growth regulator and concn was 2.0% IBA followed in decreasing effectiveness by 0.8% IBA, 0.1% Chloromone, 10 ppm 2,4-D, and 20 ppm 2,4-D. Young tissue produced a higher percentage of rooted cuttings than old tissue at all growth regulator concn tried. Also in young tissue, terminal shoots produced a higher percentage rooted cuttings than lateral shoots, while in old tissue the opposite was true.

Abstract

When a 200 ppm N solution as (NH₄)₂SO₄ was percolated through a wet pine bark medium, 6 times the medium volume of the N solution was required to reach an equilibrium of N in the bark. Once equilibrium was reached, the water added, leaching of the ammonium ion was rapid. When twice the medium volume of water was passed through the medium, 85% of the ammonium ions were leached. After analysis of the leachate indicated no N being leached from the bark, 60 ppm of N remained in the bark.