Flavescence dorée (FD) is one of the most destructive grapevine yellows (GY) diseases, and a
quarantine pest in Europe. It is caused by phytoplasmas, which are transmitted among plants by the
leafhopper Scaphoideus titanus Ball. Although grapevine varieties completely resistant to FD have
not been uncovered yet, some inter- and intra-specific differences in susceptibility have already
been observed as poor presence of infected vines in vineyard, no severe symptoms and recovery
ability of plants. The different behavior among grapevine varieties suggests the presence of putative
several loci, not yet disclosed, associated with high or low susceptibility to FD. In this context, the
development of a genetic map is the first crucial step to dissect the genetic basis that regulate FD
incidence. The aim of our study is to build a high-density genetic linkage map using F1 progeny
from a cross ‘Chardonnay x Tocai friulano’, characterized by high and low susceptibility to FD,
respectively. Two hundred and thirty F1 individuals were first checked with ten SSR (Simple
Sequence Repeats) markers to exclude self-fertilized individuals. A total of 184 individuals and
their parents were then subjected to Genotyping by Sequencing (GBS). A panel of 122,049 Single
Nucleotide Polymorphisms (SNPs) generated by GBS was filtered and used to construct a genetic
linkage map using the JoinMap 4 software. The genetic map resulted in 2,923 markers, distributed
among 19 linkage groups and covering 1336.05 cM, with an average distance of 2 cM between two
markers. At the same time, the F1 population is undergoing phenotyping. The information derived
from the genetic map will be combined with phenotypic data points to identify QTLs involved in
high or low FD susceptibility.
