Improved detection of flavescence dorée and related phytoplasma in the elm yellows group in difficult material, with specific PCR primers that amplify a variable non ribosomal DNA fragment

Molecular-based methods are sometimes not sensitive enough to detect low-titre phytoplasmas in woody hosts. In order to enable the reliable routine diagnosis of Grapevine Yellows in dormant grapevine material, INRA-Dijon constructed new FD9 primers which, used in one step-PCR, proved very effective for the detection of phytoplasmas in symptomatic grapevine and elm. Used in nested-PCR assays, they provided an excellent signal from phloem chips or whole tissues taken from either canes or roots of dormant plants. Their restriction patterns were shown to be as informative as those from the original FD9 product. The new primers will help in the development of sanitary certification protocols and…