Set de imágenes de microscopía óptica y electrónica de barrido de Astragalus garbancillo colonizaos por Alternaria

Abstract

Plants belonging to the genera Astragalus, Oxytropis, Ipomoea, Sida, and Swainsona often contain the toxin swainsonine (SW) produced by a symbiont fungus. Consumption of these SW-containing plants cause a serious neurological disorder in livestock, which can be fatal. The identity of the symbiont fungus in the plant species A. garbancillo was determined and its localization and distribution in different organs studied. Using PCR, we confirm that the fungus belongs to the genera Alternaria section Undifilum. Furthermore, we show by microscopic examination that the fungus mycelium grows in the (i) pith and cortex of petioles and stems, (ii) the external surface and inside the mesocarp of the fruit and (iii) in the mesotesta, and endotesta layers of the seed coat. Accordingly, SW could be detected in the corresponding tissues of petioles, stems, fruits and seeds. Our observations verify that the SW-producing fungus is vertically transmitted in the host plant A. garbancillo.