Phaeoacremonium species and Phaeomoniella chlamydospora in vines showing "hoja de malvón" and young vine decline symptoms in Argentina

Abstract

Vines showing “hoja de malvon” and young vine decline symptoms in Argentina have been examined for the presence in the wood of Phaeomoniella chlamydospora, different species of Phaeoacremonium, and other fungi. In all the isolations from mature vines with hoja de malvon symptoms Phellinus sp. prevailed over Phaeoacremonium aleophilum, Pm. parasiticum, and Phaeomoniella chlamydospora. By contrast in young vines with decline symptoms the most prevalent fungi were species of Botryodiplodia. Pm. aleophilum was more frequently isolated than Pm. parasiticum either in mature or in young vines. This is the first time Pm. parasiticum was isolated from diseased grapevines. In mature vines Simple Correspondence Statistical Analysis showed that Pm. aleophilum was significantly associated with soft white rot and sectorial brown necrosis, and in terms of the portion affected, with the arms of the vine. Pa. chlamydospora was associated with necrosis of the brownish zone bordering the black line, with black spots, and with the base of the vine. Pm. parasiticum considered separately or together with Pm. aleophilum, was associated with black line necrosis, with the mid-trunk and with the primary vine branches. In young vines, Pa. chlamydospora was also associated with the base of the vine, Pm. aleophilum with the rootstock stem, and Pm. aleophilum and Pm. parasiticum with the grafting zone.