Possible dual roles of an allelopathic compound, cis-dehydromatricaria ester
The aqueous extract of the root ofSolidago altissima was lethal to nematodes. The major compound isolated from the toxic fraction wascis-dehydromatricaria ester (methyl 2-decene-4,6,8-triynoate), which is already known as an allelopathic compound of a composite showing growth-inhibition to a rice seedling. This compound showed high toxicity to plant-parasite nematodes. A composite exudes one defending substance against both competitive plants and plant-parasite nematodes.
DIE WIRKUNG VON EINIGEN PFLANZLICHEN SONDERSTOFFEN, INSBESONDERE VON ALKALOIDEN, AUF DIE ENTWICKLUNG DER LARVEN DES KARTOFFELKÄFERS (LEPTINOTARSA DECEMLINEATA SAY)
Die Wirkung von 83 Alkaloiden, Saponinen und einigen weiteren Naturstoffen bzw. ihren Derivaten wurde bei Zwangsfütterungen auf die Larven des Kartoffelkäfers getestet. Die ermittelten Befunde werden tabellarisch wiedergegeben und kurz diskutiert.
ÜBER EINIGE INHALTSSTOFFE DER SOLANACEEN UND IHRE BEDEUTUNG FÜR DIE KARTOFFELKÄFERRESISTENZ 1
A summary report is given of naturally occurring substances in plants which confer resistance to the Colorado potato beetle (Leptinotarsa decemlineata Say). Alkaloid‐glycosides occurring in many Solanum and Lycopersicon varieties' are discussed in some detail, and results are reported of some recent investigations of the alkaloids in Solanum dulcamara, S. nigrum, S. polyadenium and Acaulia. An attempt is made to explain the mechanism by which these substances affect insects. The harmful effects of alkaloid‐tetraosides of Solanum on the taste of fodder are attributed to biophysical processes, particularly to surface and interface phenomena. In addition it is assumed that the alkaloids in question induce a. blocking of the Steroide metabolism and affect the resorption of the phytosterines that are indispensable for the insects, thus explaining frequently observed disturbances in development and fertility.