Genetic diversity of chestnut tree in relation to susceptibility to leaf miner ( Cameraria ohridella Deschka & Dimič)

Key message Species of Aesculus genus are divided into five main sections according to their susceptibility and resistance to horse chestnut leaf miner using molecular markers. Abstract Some species of the genus Aesculus are yearly severely infested by horse chestnut leaf miner ( Cameraria ohridella ). The larvae mine the leaves and under appropriate conditions can damage up to 100% of the leaf area. In this study, we assessed the genetic diversity of eight species of horse chestnut and their genotypes which have varying susceptibility to the leaf miner. Analysis of eight microsatellite loci showed high polymorphic information content 0.45–0.77 (0.60 in average) and high genetic diversity. For each locus, we found on average 5.50 alleles. During three vegetation periods, the leaf area damage of these genotypes was evaluated using the statistical software Assess 2.0. Different pressure of leaf miner and different development at each locality was recorded, and in some cases less damage was found, in one case the lesser damage was permanent. From the data, a pathological scale was established and a dendogram of similarity was created. Based on SSR analysis, four groups of Aesculus trees were distinguished according to their resistance or susceptibility and five main section+ Hybrid were found. By cloning and analysing the inner transcribed spacers, the ITS1 and ITS2, inner and inter species variability was examined. For the sequence of hybrid species A. × carnea, no compliance was revealed in NBCI database. For this reason, the first sequence of this genotype was obtained.