Long maintenance of phytoplasmas in grapevines Chardonnay and cabernet-sauvignonin vitro

Abstract

Long maintenance of phytoplasmas in grapevine in vitro was studied in cultivars Chardonnay (CHRD) and Cabernet-Sauvignon (CS). One-node segments from field grown asymptomatic and symptomatic vines were surface sterilized before planting in hormone-free medium containing activated charcoal. All the buds from asymptomatic vines sprouted within 10–12 days compared to 50–80% of the buds from symptomatic vines which sprouted within 20–40 days. The symptoms of yellows disease disappeared after several subcultures. Nevertheless, clones from symptomatic vines differed in various growth parameters from clones from asymptomatic vines. The weight of healthy shoots was 50% higher than infected shoots. After two and three years in culture, several clones were PCR positive for phytoplasma. The maintenance of phytoplasmas in grapevine shoots is discussed in relation to the medium components.