Effects of jasmonic acid on mycorrhizal Allium sativum.

In experiments on spruce we have shown that jasmonic acid (JA), a cyclopentanone fatty acid, influences the ectomycorrhizal formation: we therefore also applied it to an endomycorrhizal symbiosis. Garlic (Allium sativum (L.)) bulbs were potted into substrates inoculated or not with arbuscular mycorrhizal fungi (AMF), and one half of the plants was foliar-treated with 5 μm JA. A synergistic effect of JA treatment and AMF inoculation on shoot length was found. Root growth of inoculated plants was accelerated especially when JA was applied. Either JA or AMF inoculation significantly enhanced bulb development. Mycorrhizal colonization was promoted and the development of arbuscules and vesicles was enhanced upon JA application.